Re-pulp able insulated paper products and methods of making and using the same
11806973 · 2023-11-07
Assignee
Inventors
- Andrew Howard Field (Chicago, IL, US)
- Nigel J. Flynn (Flowery Branch, GA, US)
- Taylor Kopacka Leigh (Alpharetta, GA, US)
- Jason Lye (Atlanta, GA)
- Lon E. Pschigoda, II (Gobles, MI, US)
Cpc classification
B65D65/403
PERFORMING OPERATIONS; TRANSPORTING
B32B29/06
PERFORMING OPERATIONS; TRANSPORTING
B65D81/3874
PERFORMING OPERATIONS; TRANSPORTING
D21H27/40
TEXTILES; PAPER
B32B2250/26
PERFORMING OPERATIONS; TRANSPORTING
B65D81/3823
PERFORMING OPERATIONS; TRANSPORTING
B32B29/005
PERFORMING OPERATIONS; TRANSPORTING
B32B5/18
PERFORMING OPERATIONS; TRANSPORTING
B32B7/12
PERFORMING OPERATIONS; TRANSPORTING
B32B29/02
PERFORMING OPERATIONS; TRANSPORTING
B65D81/3897
PERFORMING OPERATIONS; TRANSPORTING
B32B2307/718
PERFORMING OPERATIONS; TRANSPORTING
International classification
B32B29/00
PERFORMING OPERATIONS; TRANSPORTING
B32B29/06
PERFORMING OPERATIONS; TRANSPORTING
Abstract
Insulated paper products are disclosed. Methods of making and using insulated paper products are also disclosed.
Claims
1. An insulated paper product comprising: two or more paper layers and insulating material, said insulating material comprising particles having an average particle size of less than about 1000 microns (μm), said particles comprising perlite, expanded perlite, perlite hollow microspheres, perlite microspheres, milled expanded perlite, perlite flakes, an aerogel, vermiculite, hollow expanded vermiculite, or any combination thereof, the two or more paper layers being bonded to one another so as to form an integral paper product, wherein the integral paper product (i) has a non-uniform distribution of the insulating material therethrough and (ii) is repulpable, wherein the insulating material has a material bulk density of less than 0.6 gram per cubic centimeter (g/cm.sup.3), and wherein one or more paper layers within said two or more paper layers comprise the insulating material.
2. The insulated paper product of claim 1, wherein said insulated paper product comprises at least one layer in combination with said two or more paper layers with said at least one layer comprising said insulating material.
3. The insulated paper product of claim 1, wherein the non-uniform distribution of insulating material within said integral paper product comprises (i) at least two paper layers with the insulating material therein and (ii) at least one paper layer substantially free of the insulating material.
4. The insulated paper product of claim 1, wherein all paper layers within said integral paper product comprise the insulating material.
5. The insulated paper product of claim 1, wherein the integral paper product comprises (i) a first linerboard layer comprising one or more first paper layers, (ii) a second linerboard layer comprising one or more second paper layers, and (iii) a fluted paper layer comprising one or more fluted paper layers positioned between the first linerboard layer and the second linerboard layer, and one or more of (i) said first linerboard layer, (ii) said second linerboard layer, and (iii) said fluted paper layer independently comprises insulating material therein or thereon, and wherein said fluted paper layer provides pockets of air between said first linerboard layer and said second linerboard layer, and said pockets of air represent from about 20 to 80 volume percent of a total volume occupied by said fluted paper layer.
6. The insulated paper product of claim 1, wherein the insulating material comprises the aerogel.
7. The insulated paper product of claim 1, wherein the insulated paper product further comprises one or more non-paper layers, and the one or more non-paper layers comprise a gypsum layer, a clay-containing layer, a pigment-containing layer, a foam layer, a coating that provides a lower emissivity of the insulated paper product, bismuth oxychloride, mica, zinc oxide, sericite, gypsum, aluminum oxide, or any mixture or combination thereof.
8. The insulated paper product of claim 1, wherein each paper layer that contains insulating material comprises from 15.0 weight percent (wt %) to 80.0 wt % fibers, and from about 85.0 wt % to about 20.0 wt % of the insulating material, based on a total weight of a given paper layer within the two or more paper layers.
9. The insulated paper product of claim 1, wherein the insulated paper product is molded to form a three-dimensional object.
10. The insulated paper product of claim 1, wherein said insulated paper product comprises a storage container, said storage container comprising a box, a cup, a mug, a flask, a thermos, a clam shell type box packaging for hot food, a corrugated paper product, a salad container for chilled food, a padded envelope, or a shipping container.
11. The insulated paper product of claim 1, wherein said insulated paper product comprises a storage container, said storage container comprising a storage volume at least partially surrounded by one or more container walls, each of the one or more container walls comprising the two or more paper layers and the insulating material, and said insulated paper product further comprises a coating on (i) an inner surface, (ii) an outer surface, or (iii) both (i) and (ii) of the storage container, the coating having a thermal emissivity of less than 0.90 at 23° C., as measured using Thermal Emissivity Method #4.
12. A method of using the insulated paper product of claim 11, said method comprising: positioning an object within the storage volume of the storage container.
13. The insulated paper product of claim 1, wherein said insulated paper product comprises an ash content of at least 37.9 wt %, based on a total weight of said insulated paper product as determined by test method TAPPI T 211 om-16 Ash in wood, pulp, paper and paperboard: combustion at 525° C.
14. An insulated paper product comprising: two or more paper layers and insulating material, said insulating material comprising particles having an average particle size of less than about 1000 microns (μm), said particles comprising perlite, expanded perlite, perlite hollow microspheres, perlite microspheres, milled expanded perlite, perlite flakes, an aerogel, vermiculite, hollow expanded vermiculite, or any combination thereof, the two or more paper layers being bonded to one another so as to form an integral paper product, wherein the integral paper product (i) has a non-uniform distribution of the insulating material therethrough and (ii) is repulpable, and wherein said insulated paper product has an ash content of at least 37.9 wt %, based on a total weight of said insulated paper product as determined by test method TAPPI T 211 om-16 Ash in wood, pulp, paper and paperboard: combustion at 525° C.
15. The insulated paper product of claim 14, wherein the insulating material comprises the aerogel.
16. The insulated paper product of claim 14, wherein said insulated paper product comprises a storage container, said storage container comprising a box, a cup, a mug, a flask, a thermos, a clam shell type box packaging for hot food, a corrugated paper product, a salad container for chilled food, a padded envelope, or a shipping container.
Description
BRIEF DESCRIPTION OF THE FIGURES
(1) The present invention is further described with reference to the appended figure, wherein:
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DETAILED DESCRIPTION OF THE INVENTION
(47) The present invention is directed to insulated paper products comprising fibers 11 (e.g., wood pulp fibers 11) and insulating material 12. Although shown in all figures, each paper layer 10 comprises fibers 11 (e.g., wood pulp fibers 11) with or without other paper layer additives including, but not limited to, the insulating material 12. Some definitions of fibers, paper, and packaging, as well as product specification and fiber sources, are provided below.
(48) As used herein, the term “paper” is used to identify a type of non-woven material in which fibers are randomly oriented in all directions. Fibers principally made from cellulose are poured as a slurry on a mesh screen. As the paper is formed, the fibers come into contact with each other, and physically bond with neighboring fibers via a variety of interactions, including hydrogen bonding. The fibers originally come from plants including trees, although synthetic and mineral fibers, or other types of fibers, may optionally be included. Often, the paper also contains recycled fiber. Wood may be sourced from direct harvesting of trees from forest land, or from lumber industry byproducts (such as sawdust).
(49) Paper fibers may include the fibrous portions from many parts, including softwoods (such as those plants with needles instead of leaves, for example, loblolly pine) and hardwoods. Other plants that yield useful paper fibers include but are not limited to bamboo, sugar cane, wheat straw, reed grass, mischanthus grass, coconut fiber, hemp fiber, cotton fiber, jute, palm, reeds, and papyrus. Cellulose fibers in many plants are bound together with lignin.
(50) In the case of virgin (non-recycled) fiber, much of the lignin is removed during the pulping process. Recycled paper may include fibers from corrugated, fiber board, writing paper, pressboard, card, newspaper, tissue paper, specialty papers, linerboard, containerboard, boxboard, PE-lined paperboard, carton material, cup stock, or foodboard.
(51) When made from trees, the pulping process involves methods to separate the individual cellulosic fibers into a slurry, as well as remove some or all of the lignin. Pulping methods may include a) thermomechanical pulping, which involves the use of steam and sheer forces generated between a spinning and a stationary plate, b) chemical pulping, which uses strong chemicals to break down the pulp by dissolving the lignin, and/or c) the semi-chem process, which uses a combination of mechanical and chemical methods. Most often, fluted medium board (e.g., fluted medium board 23) is made using semi-chem process pulp and/or recycled paper fiber. Other types of pulp include solid bleached sulfate pulp, chipboard, and kraft.
(52) Paper (and paper layer 10), as used herein, may broadly include any material that includes 15% or more cellulose fibers (discussed further below). Other additives, including insulating material 12, other particles/additives/components that impart grease resistant and/or water resistant, as well as other particles/additives/components to impart strength. Non-paper (and non-paper layer 30) is anything containing less than 15% of cellulose fibers (discussed further below).
(53) As used herein, the term insulating material, such as insulating material 12, is used to describe inorganic or organic materials that provide some degree of insulation. The term insulating material, as in insulating material 12, does not include air alone or any other gas alone, although air and/or another gas could be trapped within one or more inorganic or organic insulating material 12.
(54) Paper products 10/100′/60, comprising fibers 11 (e.g., wood pulp fibers 11) and insulating material 12, can either be made flat (e.g., insulated paper products 100/100′) using a screen to make flat materials, or alternatively be molded, vacuum formed, or thermoformed from a pulp suspension to form essentially three-dimensional (non-flat) objects (e.g., molded or otherwise formed containers 60 shown in
(55) When forming a given paper layer 10, dried pulp sheets may be fragmented using a hammermill and the fibers 11 dispersed in air. This is often called fluff pulp. The solid-in-air suspension may then be vacuum formed into products 10/100′/60. Such products include air-laid pads, absorbent materials for use in other products such as diapers and feminine hygiene products, disposable pet waste pads, or fluff thermal insulation.
(56) Additives, including insulating material 12, may be added to the paper pulp prior to casting on the paper wire or otherwise molding the pulp into a product 10/100′/60. Alternatively, additives, including insulating material 12, may be added at the size press, or after the steam can dryers. Additives, including insulating material 12, can also be added to a clay coating (e.g., coating 30) often applied to liner board (e.g., liner board 21/22) to make clay coated kraftback, or clay coated newsback.
(57) Paper packaging (e.g., containers 60 shown in
(58) Medium board used in the insulated paper products 100/100′/100″ of the present invention may be fluted with flutes of different dimensions. See, for example, exemplary fluted medium board 23 shown in
(59) As discussed herein, the insulated paper products of the present invention may comprise a single paper layer with insulating material dispersed therein or thereon, or may comprise two or more paper layers in combination with insulating material, wherein the insulating material is within one or more of the paper layers of the insulated paper product and/or is present as a component within the insulated paper product (e.g., as a separate layer from the paper layers and/or as a filler within a layer or component of the insulated paper product). See, for example, exemplary insulated paper products 100/100′/100″ in
(60) The insulated paper products of the present invention may further comprise one or additional layers other than the one or more paper layers and possible layers of insulating material. Suitable additional layers may include, but are not limited to, a coating that provides enhanced emissivity of the insulated paper product, a coating that provides a desired color and/or surface texture for the insulated paper product, and a coating that provide enhanced water-repellency (e.g., waterproofing properties) to the insulated paper product. See, for example, exemplary insulated paper products 100/100′400″ in
(61) In exemplary insulated paper product 100/100′/100″ shown in
(62) In exemplary insulated paper product 100/100′/100″ shown in
(63) In exemplary insulated paper product 100/100′/100″ shown in
(64) In exemplary insulated paper product 100/100′/100″ shown in
(65) In addition, any of the insulated paper products of the present invention described herein may be configured into a variety of shapes. For example, in some embodiments, the insulated paper product is in the form of an insulated cup or mug that may be used to house a hot beverage such as coffee. Such insulated paper products may be used instead of STYROFOAM® cups, eliminating the disposal and environmental problems associated with STYROFOAM® cups. In other embodiments, the insulated paper product is in the form of insulated packaging for temporary storage and transport of items such as food, medicines, etc. Such insulated paper products may be in the form of an insulated box, corrugated or not corrugated, as well as many other packaging items discussed herein. See, for example, exemplary insulated paper products 100/100′/100″ in
(66) Regardless of configuration and/or shape, the insulated paper products 100/100′/100″ of the present invention provide a degree of insulation due to the construction of one or more paper layers 10 within a given insulated paper products 100/100′/100″. For example,
(67) In addition,
(68) The present invention is further directed to methods of making and using the herein-disclosed and described insulated paper products. The insulated paper products may be made using papermaking equipment and techniques so as to produce one or more paper layers. As discussed herein, the methods of making the insulated paper products of the present invention involve the strategic placement of one or more insulating materials within a given insulated paper product and/or the strategic placement of one or more optional coatings on the insulated paper product so as to provide superior insulating properties, as well as other properties to the insulated paper product. Exemplary method steps and procedures for forming insulated paper products of the present invention are shown/described in
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(70) As the layers of paper are formed and further processed, trimmings and rejected card (e.g., damaged, warped, etc.) is shredded and fed back into the pulping process. The card is washed in a wash clean device 203 to the extent possible to remove inks etc., then fed back into the beater 202.
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(85) Methods of making insulated paper products 100/100′/100″ of the present invention may further comprise forming one or more corrugated or fluted layers of material 10/100/100′/100″ as shown in
(86) In other embodiments shown in
(87) The method steps shown in
(88) Typically, in double-walled corrugated card (
(89) The methods of using the insulated paper products 10/100/100′/100″ of the present invention may comprise insulating food, medicines, etc. from hot or cold environments. In some embodiments, the method may simply comprise placing an item (e.g., food, medicines, etc.) within an insulated paper product 10/100/100′/100″ of the present invention (e.g., putting hot coffee in a cup of the present invention). In other embodiments, the method may comprise placing an item (e.g., food, medicines, etc.) within an insulated paper product 10/100/100′/100″ of the present invention (e.g., a box), and sealing the insulated paper product 10/100/100′/100″ for transport.
(90) As discussed herein, methods of using the insulated paper products 10/100/100′/100″ of the present invention may involve insulating an item (e.g., food, medicines, etc.) from hot or cold environments, wherein the item (e.g., food, medicines, etc.) is placed or packaged within an insulated paper product 10/100/100′/100″ that has a conventional shape, such as a cup or box. In other words, the insulated paper products 10/100/100′/100″ of the present invention take the place or conventional items such as cups and boxes so as to provide one or more advantages as discussed above. As discussed herein, the insulated paper products 10/100/100′/100″ of the present invention may have a variety of shapes and configurations similar to many conventional items such as cups and boxes.
(91) During use, the insulated paper products 10/100/100′/100″/60 of the present invention desirably provide/have one or more of the following features/properties in addition to providing insulating properties:
(92) (1) Moisture Resistance: Desirably, the insulated paper products 10/100/100′/100″/60 of the present invention (e.g., a box 61) can be placed into a freezer and then taken out and stacked at room temperature. Such a process usually leads to the insulated paper product 10/100/100′/100″/60 (e.g., a box 61) “sweating” through condensation in the warm air condensing on the surface of the insulated paper product 10/100/100′/100″/60 (e.g., a box 61). In this regard, it is advantageous for the insulated paper product 10/100/100′/100″/60 (e.g., a box 61) to be resistant to moisture ingress. Multiple different additives can be used to reduce the propensity of the insulated paper product 10/100/100′/100″/60 (e.g., a box 61) to absorb moisture and weaken when moist. For example, perlite 12 is more hydrophobic than paper fibers 11, so the incorporation of perlite 12 into a paper layer 10 renders the paper layer 10 less absorbent. Further, the adhesive 40 that bonds flutes to liner board (see,
(93) While undesirable from an environmental and recycling perspective, a thin layer of low density polyethylene (PE) may also be coated onto paper layer 10, fiberboard 21/22/23, and card stock to impart oil and water resistance, as is common practice in the fast food and hot & cold beverage retail industry. In recent years, the paper industry has experienced increased pressure to seek alternatives to PE liners and linings for packaging, leading the chemical industry to innovate new coatings that impart grease and water resistance while being repulpable. US 2019/0077537 to Georgia Pacific Bleached Board LLC teaches the use of several different coatings to impart resistance to water and lipid fluids to paper without the use of PE film, including Epotal 5440 (BASF), Rhoplex P-376 (Dow), Diofan B204 (Solvay), Barrier-Grip 9471A (IGI), and Daran SL143 (Owensboro). These coatings were combined to impart heat seal-ability as well as water proofing to paper beverage cups.
(94) (2) Temperature History and Monitoring: In some embodiments, the consumer may wish to be reassured that the insulated paper product 10/100/100′/100″/60 (e.g., a box 61) contents have not been exposed to high temperatures. To this end, a temperature sensor may be included, such as: (a) a biodegradable and biocompatible temperature sensor may be included in the insulated paper product 10/100/100′/100″/60 (e.g., a box 61), for instance, the biodegradable microsensor for food monitoring as disclosed in NASA Tech Briefs Vol 42 No. 7, July 2018. The biosensor slowly dissolves in 1% saline solution; (b) a thermochromic material may be included in the insulated paper product 10/100/100′/100″/60 (e.g., a box 61), such that once the temperature rises above a certain temperature, the color changes, and the consumer is warned. The thermochromic material can be reversible or irreversible. The ink could also be reversible, however, with a large hysteresis loop, so that the color change is meta-stable. Such inks are used in Pilot® Frixion® ball pen inks, which change from black to colorless upon warming; (c) the formation of condensation and the production of moisture when frozen materials are thawed can be taken advantage of, if a highly visible food dye is included within the structure of the insulated paper product 10/100/100′/100″/60 (e.g., a box 61). When moisture hits the insulated paper product 10/100/100′/100″/60 (e.g., a box 61), the dye dissolves and stains the insulated paper product 10/100/100′/100″/60 (e.g., a box 61) as a warning.
(95) (3) Food Spoilage Sensors: In some embodiments, the insulated paper products 10/100/100′/100″/60 (e.g., a box 61) may further comprise: (a) a biodegradable microsensor for food monitoring as disclosed in NASA Tech Briefs Vol 42 No. 7, July 2018 can be configured to detect spoiling gasses, such as methane, hydrogen sulfide, methyl mercaptan, furfuryl mercaptan, indole, cadaverine, isovaleric acid, skatol, and other malodorous materials; and (b) certain colorants react with sulfides and amines, such as Michler's Hydrol Blue, which changes from blue to colorless when exposed to low levels of hydrogen sulfide and amines. Furthermore, Sensor Technology published within NASA Tech Briefs September 2018 describes a printable nanostructured conductive polymer wireless sensor that detects food spoilage by identifying odors emanating from bad meat, first described in American Chemical Society publication Nano Letters.
(96) (4) Freezer to Microwave: For smaller packages, an added feature may be that the insulated paper product 10/100/100′/100″/60 (e.g., a box 61) can be removed from a freezer and placed directly inside a microwave oven. In these embodiments, the insulated paper product 10/100/100′/100″/60 (e.g., a box 61) would need to be microwave transparent. Optionally, the insulated paper product 10/100/100′/100″/60 (e.g., a box 61) may contain a microwave susceptor.
(97) (5) Boxes with Reduced Edge Effects: 90° bends in cardboard pinches the cardboard at those points, leading to potential heat loss at the folded edges. Boxes 61 of the present invention (e.g., formed from insulated paper product 10/100/100′/100″) can be designed that replace 90° corners with two 45° corners, to help minimize the losses.
(98) (6) Transient Aluminized Layer for Low Emissivity: Addition of a thin aluminized coating 30 onto the paper (e.g., paper layer 10 and/or insulated paper product 100/100′ and/or corrugated paper product 100″ and/or storage container 60) and/or onto the perlite 12 to lower emissivity. Aluminum has a very low emissivity and may be applied to various materials through a process called sputtering, or by vapor deposition. In this process, aluminum atoms traverse a vacuum and condense onto the surface of another material (e.g., paper layer 10). Many thermal blankets are made via a process like this. Perlite particles 12, as well as other types of particles, may be coated partially or totally in aluminum via these types of process. Paper or paper fibers 11 may also be metallized by an aluminum coating by similar processes. Aluminum foil and metalized plastic films do not re-pulp and have to be removed from the OCC and later waste streams, so these materials are not preferred in some embodiments of the present invention.
(99) However, it is possible to incorporate a chelating agent in another layer of the packaging (e.g., box 61), or for instance in the adhesive, or in one of the coatings. Such a chelating agent would function to remove the aluminum during a pulping process. Chelating agents may include oxalic acid and oxalate salts, EDTA (ethylene diamine tetraacetic acid) and its various salts, salicylate, sodium hexametaphosphate and other materials. In this way, the aluminum could be removed. Soluble aluminum salts are already used in papermaking for instance as a flocculant for fines, as well as in combination with rosin soap to impart water resistance.
(100) (7) Odor Control and Taint of Foodstuffs: A concern with packaging and shipping of foodstuffs is taint and odor. This may arise from the inherent smell of virgin or recycled card, or it could arise when one package containing a strongly odorous material is placed in contact or adjacent to a package containing a food, beverage, drug, or tobacco product. There may be several ways to mitigate odor and taint of foodstuffs by incorporating materials into the paper structure. For instance, transition metal ion modified silica nanoparticles such as those described in U.S. Pat. No. 7,976,855 are able to efficiently capture malodorous chemicals such as mercaptans, carboxylic acids, amine and other odors. U.S. Pat. No. 8,168,563 teaches that silica nanoparticles may be modified by reaction with terminal aminoalkylthrimethoxysilanes and then with copper II ions to further enhance the odor capturing capabilities. Molecular sieves may also be included to sequester low molecular weight odor forming molecules such as hydrogen sulfide and zeolites to sequester ammonia and amine odors. Activated carbon was also found to impart thermal insulation, and would also be anticipated to absorb multiple odors. Activated carbon tends to be acidic in nature, and so may be especially good at taking up basic and weakly basic odors such as ammonia and amine odors. More complex odors also have an affinity for activated carbon, including mercaptan, thiol, and aromatic odors. Cyclodextrins, such as β-cyclodextrin or γ-cyclodextrin and their derivatives may also be incorporated for their odor absorbing properties. One or more of these materials/features could be incorporated into any of the here-in described paper layer 10 and/or insulated paper product 100/100′ and/or corrugated paper product 100″ and/or storage container 60 to modify and/or minimize any odors present.
(101) Odor transmission from one package to another, or from one good to another may also be mitigated through the use of barrier materials. As one object of the present invention is repulpability of packaging, aluminum foil, PE or PET film, and other synthetic materials would not be consistent with some embodiments of the present invention. However, some materials that provide thermal insulation have a microscopic flake morphology, such as mica and coated mica, and these materials may be useful for effectively blocking the transport of low and high MW malodor causing materials from ingress into packages (e.g., comprising or formed from insulated paper product 10/100/100′/100″) of the present invention.
(102) (8) Fiber Blend, Recycling, and Strength: Short length fibers tend to come from refined hardwood, while longer fibers come from softwood. A good ratio of 75% softwood 25% hardwood balances the properties of the two types of fiber, optimizing tensile strength. Recently, hemp fibers have come under increasing attention as a paper additive. Hemp fibers are far longer than other pulp fibers, help increase strength due to increasing contact points and bonding, and so may be subjected to multiple recycling steps—far more than regular wood fibers. Hemp fibers, being much longer than softwood may be recycled around 40 times vs. 6 for other types of fiber. One or more of these materials/features could be incorporated into any of the here-in described insulated paper layer 10 and/or insulated paper product 100/100′ and/or corrugated paper product 100″ and/or storage container 60.
(103) In order to increase the ability of wood fibers to bond more through surface interactions, additional processes may be used to further fibrillate the fibers. For instance, the fibers may be subjected to an extreme high-shear environment, such as a colloid mill, The high sheer environment of two plate spinning in contact fibrillates cellulose fiber aggregates, increasing bonding, as well as the propensity to retain filler solids. Other ways to fibrillate the fiber can include prolonged beating in a mechanical Hollander pulp beater such as disclosed in the U.S. Pat. No. 1,883,051 or by high-sheer mixing, high-speed mixing, or media milling. Fibrillated cellulose may increase porosity of the paper and paper strength due to enhanced bonding area between fibers. Other ways to increase strength is by including nanocellulose into the paper formulation. One or more of these materials/features could be incorporated into any of the here-in described paper layer 10 and/or insulated paper product 100/100′ and/or corrugated paper product 100″ and/or storage container 60.
(104) (9) Water Resistance Repulpability: Rosin is often used as part of a two-part system to impart moisture resistance in paper (e.g., paper layer 10 and/or insulated paper product 100/100′ and/or corrugated paper product 100″ and/or storage container 60). The second part is post addition of aluminum salt solutions—e.g. aluminum chloride or aluminum sulfate. The aluminum reacts with the rosin soap to make a hydrophobic coating, which may impact repulpability yield. However, including a chelating agent somewhere in another component of the paper product may remove the aluminum from the rosin, thereby increasing the repulpability yield. Other areas of the paper that could carry the chelating agent may include the starch adhesive, and internal layer—for instance, the fluted medium, or an inner layer of the composite. Vapor-Guard R5341B or Barrier Grip 9471A (The International Group Inc., Titusville Pa.) are also useful as barrier coatings that provide the paper with a degree of grease and water resistance, and are described along with other suitable materials in Georgia Pacific Patent Application Publication No. US2019/0077537.
(105) The present invention is further described by the following additional embodiments, examples, and claims. It should be understood that any feature and/or component described herein may be present alone or in combination with any other feature and/or component or combination of features and/or components described herein to form the here-in described paper layer 10 and/or insulated paper product 100/100′ and/or corrugated paper product 100″ and/or storage container 60 of the present invention. It should be further understood that the numbered embodiments provided below describe many embodiments of the present invention, some claimed and some unclaimed. Even though some of the features in the numbered embodiments provided below may not be claimed, the unclaimed feature(s) in the numbered embodiments provided below do form part of the present invention, and may optionally be incorporated into any claimed product.
ADDITIONAL EMBODIMENTS
(106) Insulated Paper Products 1. An insulated paper product 100 comprising: one or more paper layers 10 and insulating material 12, wherein (1) when two or more paper layers 10 are present, the two or more paper layers 10 form an integral paper product 100′, and (2)(a) at least one of: (i) one layer 20 in combination with said one or more paper layers 10 comprises said insulating material 12 and (ii) one paper layer 10 within said one or more paper layers 10 has a non-uniform distribution of insulating material 12 therein, or (2)(b) the integral paper product 100′ itself has a non-uniform distribution of insulating material 12 therethrough. Each paper layer 10 may further comprise one or more additives, other than insulating material 12, the one or more additives including, but are not limited to, flocculants and retention aids such as high molecular weight poly(acrylamide), poly(ethylene imine), cationic quar gum, and other cationic polymers; additives to provide water resistance (e.g., wax, synthetic latexes and resins); or any combination thereof. 2. The insulated paper product 100 of embodiment 1, wherein the one or more paper layers 10 comprises a single paper layer 10, and the single paper layer 10 has a non-uniform distribution of insulating material 12 therein. 3. The insulated paper product 100 of embodiment 2, wherein at least one outer surface 13/15 of the single paper layer 10 comprises a layer of insulating material 12. See,
(107) Methods of Using Insulated Paper Products 100. A method of using the insulated paper product 100 of any one of embodiments 1 to 47 or the storage container 60 of any one of embodiments 48 to 67, said method comprising: insulating an object via the insulated paper product 100 or the storage container 60. 101. The method of embodiment 100, wherein the object is a surface. 102. The method of embodiment 100, wherein the object is a food item, a medicine, or any other item that is desirably kept at a cool temperature (e.g., a temperature below room temperature or a refrigerating temperature) or at an elevated temperature (e.g., a temperature above room temperature or a hot-out-of-the-oven temperature). 103. The method of embodiment 100 or 102, wherein the object is a food item. 104. The method of any one of embodiments 100 to 103, wherein the method uses the storage container 60 of any one of embodiments 48 to 67. 105. The method of any one of embodiments 100 to 104, wherein the method uses the storage container 60 and the storage container 60 comprises a box 61, a container 62 for temporarily housing a liquid (not shown), a cup, a mug, a flask, or a thermos 62, a clam shell 60 for hot food 80 (See, for example,
(108) In addition, it should be understood that although the above-described insulated paper products and methods are described as “comprising” one or more components or steps, the above-described insulated paper products and methods may “comprise,” “consists of” or “consist essentially of” the above-described components or steps of the insulated paper products and methods. Consequently, where the present invention, or a portion thereof, has been described with an open-ended term such as “comprising,” it should be readily understood that (unless otherwise stated) the description of the present invention, or the portion thereof, should also be interpreted to describe the present invention, or a portion thereof, using the terms “consisting essentially of” or “consisting of” or variations thereof as discussed below.
(109) As used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having,” “contains”, “containing,” “characterized by” or any other variation thereof, are intended to encompass a non-exclusive inclusion, subject to any limitation explicitly indicated otherwise, of the recited components. For example, an insulated paper product and/or method that “comprises” a list of elements (e.g., components, layers or steps) is not necessarily limited to only those elements (or components or steps), but may include other elements (or components or steps) not expressly listed or inherent to the insulated paper product and/or method.
(110) As used herein, the transitional phrases “consists of” and “consisting of” exclude any element, step, or component not specified. For example, “consists of” or “consisting of” used in a claim would limit the claim to the components, materials or steps specifically recited in the claim except for impurities ordinarily associated therewith (i.e., impurities within a given component). When the phrase “consists of” or “consisting of” appears in a clause of the body of a claim, rather than immediately following the preamble, the phrase “consists of” or “consisting of” limits only the elements (or components or steps) set forth in that clause; other elements (or components) are not excluded from the claim as a whole.
(111) As used herein, the transitional phrases “consists essentially of” and “consisting essentially of” are used to define an insulated paper product and and/or a method that includes materials, steps, features, components, or elements, in addition to those literally disclosed, provided that these additional materials, steps, features, components, or elements do not materially affect the basic and novel characteristic(s) of the claimed invention. The term “consisting essentially of” occupies a middle ground between “comprising” and “consisting of”.
(112) Further, it should be understood that the herein-described insulated paper products and/or methods may comprise, consist essentially of, or consist of any of the herein-described components, layers and features, as shown in the figures with or without any feature(s) not shown in the figures. In other words, in some embodiments, the insulated paper products of the present invention do not have any additional features other than those shown in the figures, and such additional features, not shown in the figures, are specifically excluded from the insulated paper products. In other embodiments, the insulated paper products of the present invention do have one or more additional features that are not shown in the figures.
(113) The present invention is described above and further illustrated below by way of examples, which are not to be construed in any way as imposing limitations upon the scope of the invention. On the contrary, it is to be clearly understood that resort may be had to various other embodiments, modifications, and equivalents thereof which, after reading the description herein, may suggest themselves to those skilled in the art without departing from the spirit of the present invention and/or the scope of the appended claims.
EXAMPLES
(114) Insulated paper products similar to exemplary insulated paper products 100/100′/100″/60 shown and described in
Example 1. Paper Containing Insulating Materials
(115) Test Method:
(116) Swatches of paper containing perlite were prepared and found to be thermally insulating. The insulating properties of the resultant paper swatches were assessed using two thermocouples attached to either side of the sheet. The sheet was then placed on a hot plate and the rate of heating of the face not in contact with the hotplate was recorded as the rate of temperature rise (° C. per second per millimeter or Kelvin (K) per second per millimeter).
(117) When added to cellulosic pulp at 10 wt %, 20 wt %, and 25 wt % and made into a swatch of paper, the heat-resistive properties allowed the perlite-infused paper to outperform the paper control and the paper mixed with other compounds, and nearly as well as the polystyrene cups (0.0771 K/s.Math.mm average heating rate for the polystyrene cups, with a range of 0.0825 to 0.1346 K/s.Math.mm for the various perlite samples). Using a statistical analysis test known as the F-test, it was confirmed with 99.82% accuracy that the perlite-infused paper did indeed perform better than all other types of additives.
(118) Materials Used:
(119) TABLE-US-00001 Baking Soda-infused paper Chick-fil-A, McDonald's, and Sonic Expanded Polystyrene Cups Solo Cup #70 Wausau Crepe Paper(standard, with ridges, and double thickness) Additives: Polylactic Acid 1.3 denier fiber Polyethylene Fybrel Polypropylene 1.5 denier fiber Activated Carbon Sawdust Medium-Large Sized Perlite Medium-Small Sized Perlite Microspheres
Equipment Used:
(120) TABLE-US-00002 Blender Paper-press box Hot plate Computer Thermocouples
Procedure to Make Paper: 1. Weigh out 3.36 g of the #70 crepe paper and pour into the blender. 2. Add 400 ml of water to the paper and blend the two until the mixture becomes a pulp slurry. 3. Measure out the additives in the following quantities: 10% by weight (0.336 g), 20% by weight (0.672 g), and 25% by weight (0.840 g). These quantities are to prepare three different samples and would require the repetition of steps 1 and 2 for each amount. 4. Add the additive to the pulp slurry and mix the slurry with a stirring rod. 5. Set up the paper-press box as follows: a. Place the mesh screen over the white screen. b. Place the wooden paper-box form over the mesh screen and strap the box securely in place with the Velcro straps. c. Place the wood block shaper into the paper-box form such that it forms a 115 mm by 87 mm rectangle. It is shaped like a “T” and should fit snuggly into place. 6. Pour the paper slurry evenly into the rectangular mold that was created. 7. There is a wooden block that should just fit into the rectangular mold. Cover one side of the block with wax paper and press down on the paper slurry to remove the water. 8. Release the Velcro straps and remove the white screen, screen mesh, pressed pulp, wax paper, and wooden block as one unit. 9. Carefully remove the mesh screen from the pressed pulp. 10. Remove the pulp from wood block by carefully pulling the wax paper away from the block. 11. Lay the wax paper and pulp on a flat surface and remove as much water by patting it with paper towels. 12. Allow the pulp paper to air dry before conducting heat transfer testing. a. If time does not allow for the pulp paper to air-dry. Then a heat source may be used to dry the paper. The heat source should not exceed 65.6° C. b. Remove the paper from the heat source when the paper is only slightly damp.
Procedure to Test Rate of Warming of Surface Distant from the Hot Plate: 1. Plug the data logger into the computer and open Wavescan 2.0. 2. Go to “Settings” and go through the following steps: a. Click “Select Device” under “AI Selected Devices”. b. The data logger should be the only option to be in the menu. Click “OK”. c. Click “Set Range” under “AI Channel Setting”. d. Switch Channels 4 through 7 to “Thermo” on the top right of the window and close out the window. e. Set the “ChanStart” to 4 and “ChanCount” to 4 under “AI Channel Setting”. f. Change the “Interval” to 1000 ms. g. Click “OK” at the bottom of the window. 3. Turn on “AI” under “Signal” near the bottom right of the window. 4. Check the box “AI Save2Disk” under “Device” near the bottom left of the window. 5. Verify that the room temperature is 21.5° C.±2° C. 6. Heat the hot plate within the temperature range of 37° C.±2° C. 7. Tape two thermocouples to each side of the paper sample and place the test sample on the hot plate. 8. 9. Place a glass bowl on test sample such that the bowl is facing down. Make sure that the bottom thermocouple is in contact with the hot plate and the bowl does not cover the tip of the top thermocouple. 10. Click “Start” in WaveScan and allow the process to run for at least 120 seconds. 11. Record the ambient room temperature for each test. 12. After the test has run, “Stop” the test and remove the sample and bowl from the hot plate. 13. Place the bowl into water at room temperature bowl down. a. This helps to quickly cool the bowl to be reused for testing. b. Be sure to thoroughly dry the bowl to remove another variable heat sink from the experimentation. 14. Click “Save As” and save the file in the desired location. 15. Click on “History” and open “Project.wsp” in the file folder that was saved. 16. Click on “Convert” and save the file in the desired location. 17. Repeat steps 7 through 13 three times for each paper sample. 18. Testing each sample should take no more than 3 minutes.
Procedure to Process Data: 1. Open one of the data files with Excel. 2. Plot the data as Temperature versus Time for only the thermocouples on the top of the paper sample. These data points can be distinguished since they will have lower temperature readings than the bottom thermocouples. 3. Add a trend line to both graphs of the two thermocouples and record the slopes of the trend lines. These values are the heat transfer rates of the paper. 4. Do this for all three tests of each paper sample and take the average of the heat transfer rate values. 5. Divide by the thickness in mm to get the thickness-adjusted values. 6. Repeat steps 1 through 4 for all paper samples.
Data:
(121) The tables below categorize data for each sample containing 10% by weight of the different types of additives. Note: Thickness-adjusted values were obtained by dividing the average rate of heating by the thickness to eliminate the effect of variable sample thickness.
(122) TABLE-US-00003 Heat Transfer Rate Testing of Different Insulating Materials 10% By Weight Rate of Warming of Surface Furthest from the Hot Plate Average (Thickness Thickness Test 1 Test 2 Test 3 Adjusted) Sample mm (deg/s) (deg/s) (deg/s) (deg/s) (deg/s) (deg/s) (deg/s*mm) Cotton 1.65 0.2135 0.2134 0.2179 0.2179 0.2498 0.2498 0.1376 Activated Carbon 2.1 0.2299 0.2143 0.2016 0.1504 0.2051 0.2321 0.0979 Fybrel 1.52 0.2254 0.2193 0.3107 0.2919 0.1630 0.1764 0.1520 PLA 1.18 0.1787 0.1925 0.1531 0.1576 0.1726 0.1633 0.1437 Med-Sm Perlite 1.75 0.1934 0.1733 0.1152 0.1050 0.2803 0.2499 0.0941 Med-Lg Perlite 1.7 0.1872 0.1863 0.1207 0.1197 0.1202 0.1203 0.0837 Microspheres 1.18 0.1669 0.1690 0.1586 0.1606 0.2529 0.2430 0.1625 Polypropylene 2.6 0.1888 0.1883 0.2878 0.2773 0.3052 0.3062 0.1097 Sawdust 1.35 0.2218 0.2041 0.1878 0.1874 0.2304 0.2226 0.1548
The table below categorizes the data points for each sample containing 20% by weight of the different types of additives.
(123) TABLE-US-00004 Heat Transfer Rate Testing of Different Insulating Materials 20% By Weight Rate of Warming of Surface Furthest from the Hot Plate Thickness Test 1 Test 2 Test 3 Adjusted) Sample mm (deg/s) (deg/s) (deg/s) (deg/s) (deg/s) (deg/s) (deg/s*mm) Activated Carbon 2.3 0.2099 0.1941 0.1763 0.1711 0.2316 0.2316 0.1088 Fybrel 1.57 0.2893 0.2844 0.3004 0.2876 0.1877 0.2001 0.1645 PLA 1.68 0.2322 0.2258 0.2563 0.2563 0.2131 0.2131 0.1385 Med-Sm Perlite 2.03 0.3365 0.3365 0.2948 0.3093 0.2328 0.2525 0.1346 Med-Lg Perlite 1.99 0.2328 0.2525 0.2579 0.2579 0.1577 0.1577 0.1102 Microspheres 1.21 0.1987 0.1955 0.2569 0.2570 0.3377 0.3377 0.1834 Polypropylene 1.45 0.2132 0.2235 0.1925 0.1804 0.1651 0.1611 0.1305 Sawdust 1.35 0.3022 0.3192 0.2916 0.2715 0.1841 0.1841 0.1917
The table below categorizes the data points for each sample containing 25% by weight of the different types of additives.
(124) TABLE-US-00005 Heat Transfer Rate Testing of Different Insulating Materials 25% By Weight Rate of Warming of Surface Furthest from the Hot Plate Average Thickness Test 1 Test 2 Test 3 (Thickness Sample mm (deg/s) (deg/s) (deg/s) (deg/s) (deg/s) (deg/s) Adjusted) Activated 2.33 0.2155 0.2155 0.1970 0.1833 0.2334 0.2215 0.0905 Carbon Fybrel 1.31 0.1922 0.1806 0.2094 0.1974 0.2093 0.1960 0.1507 PLA 1.45 0.2404 0.2320 0.2027 0.2091 0.1965 0.1899 0.1451 Med-Sm 2.5 0.2086 0.2086 0.2339 0.2446 0.1712 0.1712 0.0825 Perlite Med-Lg Perlite 2.3 0.2055 0.2055 0.2698 0.2675 0.2062 0.2027 0.0983 Microspheres 1.25 0.3524 0.3303 0.308 0.2904 0.1969 0.1837 0.1455 Polypropylene 1.57 0.1823 0.1802 0.2354 0.2425 0.2478 0.2491 0.1417 Sawdust 2.33 0.2425 0.2272 0.2459 0.2459 0.1817 0.1718 0.1195
(125) The table below categorizes the data points for each sample not containing a mixed-in additive.
(126) TABLE-US-00006 Heat Transfer Rate Testing of Different Insulating Materials Other Materials Rate of Warming of Surface Furthest from the Hot Plate Average Thickness Test 1 Test 2 Test 3 (Thickness Sample mm (deg/s) (deg/s) (deg/s) (deg/s) (deg/s) (deg/s) Adjusted) Wausau #70 1.18 0.1640 0.2085 0.2681 0.2849 0.2317 0.2337 0.1964 Crepe Paper Wausau #70 3.48 0.2099 0.2000 0.1460 0.1460 0.2289 0.2289 0.0856 Crepe Paper w/ Ridges Wausau #70 2.96 0.1585 0.1585 0.1567 0.1505 0.1834 0.1834 0.1520 Crepe Paper Double Thickness Solo Cup 1.26 0.3434 0.3172 0.2734 0.2513 0.2577 0.2818 0.2281 McDonald's 2.79 0.1729 0.1481 0.1334 0.1116 0.1313 0.1051 0.0479 Fast-Food, Polystyrene Cup Sonic Fast-Food, 2.53 0.1833 0.1571 0.1549 0.1376 0.1498 0.1214 0.0595 Polystyrene Cup Chick Fil-A 2.08 0.2814 0.2814 0.2770 0.2867 0.2116 0.2114 0.1241 Fast-Food, Polystyrene Cup Prym Paper 0.35 0.3418 0.3418 0.3716 0.3716 0.3119 0.3119 0.1976
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(133)
(134) Within each weight-percentage bracket, comparing the paper samples with perlite to those without shows clearly that the perlite adds a noticeable improvement to heat insulation properties. The pair of perlite samples (one with a smaller particle size and one with the larger) were, in all three weight percentages, always among the top three most effective insulators. In comparison to the polystyrene cups sourced from various food vendors, the perlite samples generally performed on par with the polystyrene samples.
(135) Conclusion: When added to a paper mixture, perlite dramatically increases the paper's insulation properties (averaging a heat transfer rate of 0.100 deg/s*mm), making it comparable to the industry standard expanded polystyrene (averaging a heat transfer rate of 0.077 deg/s*mm).
(136) These results suggested that paper-based materials with insulating materials could be formulated to (i) provide highly thermally insulative characteristics, (ii) be able to be repulped, non-polluting, and (iii) be biodegradable and/or bio-destructable.
Example 2. Preparation of Insulated Paper Products
(137) Test Methods:
(138) % Solids Analysis:
(139) A polystyrene disposable weigh boat was accurately weighed to 4 decimal places (tare mass). Approximately 1-2 gram of liquid was placed in the weigh boat, and promptly weighed to four decimal places (gross-wet mass.) Subtracting the tare from the gross-wet mass gives the net-wet mass. The weigh boat was carefully tilted and rocked from side to side, allowing the liquid to coat the bottom of the weigh boat evenly, then it was placed in a cupboard for 24-48 hours to evaporate at room temperature. The dry weigh boat was re-weighed to four decimal places (gross-dry mass). Subtracting the tare from the gross-dry mass gives the net-dry mass.
% solids=100*net-dry/net-wet
pH:
(140) All pH measurements were made using universal indicator paper, as supplied by Micro Essential Laboratories Inc. The color of the paper and the chart were compared under indoor fluorescent strip lighting.
(141) Modified Lee's Disk Heat Transfer Rate Test Method
(142) Lee's disk method is a known way to measure thermal conductivity in thin sheets with low conductivity. A modified version of the Lee's disk was used to measure the heat transfer rate of samples generated, assembled using available laboratory equipment, to enable a large number of tests to be conducted in a short period of time. Instead of allowing the materials to reach thermal equilibrium, a digital hotplate was used to maintain a set temperature for one side of the sample. The apparatus is depicted in
(143) Materials/Equipment Used:
(144) Paperboard sample(s) Circular cutting device set to cut 113 mm diameter circles (100 cm.sup.2) Calipers Scientific Balance, accurate to 0.001 g Digital hot plate 70 that heats to at least 37° C. (98.6° F.) and with a heating surface 71 at least 113 mm in diameter 10×Aluminum disks 72, 113 mm in diameter (100 cm.sup.2) and painted matte black on one surface (McMaster 1610T37) Insulating hot plate guard 73, capable of withstanding temperatures greater than 37° C. (98.6° F.) and constructed to fit the hot plate 70 and the sample stack being used (McMaster 93475K65) IR Camera 74 & Image Analysis Software (the Flir E-40 Thermal Camera, available from Flir Systems Inc. Goleta Calif.) Timer
Assumptions:
(145) This test method assumes constant heat flow, and no edge losses or other effects from convection or radiation based heat transfer (all the heat flows through the disks and sample).
(146) Method:
(147) 1. Cut 102 mm diameter circular paper samples and label appropriately. Ideally at least three samples can be cut from a single sheet. Five samples are recommended for each datapoint. Measure and record the thickness and weight of each sample using Vernier calipers. 2. Turn on the hot plate 70 and set the temperature to 37° C. Place the Insulating Guard 73 around the hot plate 70. Set one Aluminum disk 72 on the hot plate 70, black side facing up. Once this disk 72 has reached 37° C., sample testing can begin. The temperature can be checked by using the IR camera 74. 3. While the hot plate 70 heats up, allow the other Aluminum disks 72 to sit out and come to room temperature. Measure the room temperature using the IR camera 74, and also use the IR camera 74 to confirm all the Aluminum disks 72 have reached room temperature. 4. When ready to test, in quick succession: Place the paper sample 10 on top of the hot plate aluminum disk 72 Place a room temperature aluminum disk 72 on top of the paper sample 10, black side up Start a timer for 1 and 2 minutes 5. At the end of one minute, record the temperature of the top black disc 72 registering in the Flir thermal camera 74. After two minutes, once again record the temperature and take an IR image of the top surface 75 of the aluminum disk 72. Remove the top aluminum disk 72 and paper sample 10. Set aside to cool. 6. Repeat steps 4 & 5 until all samples 10 have been tested. If running more than 9 tests, it must be ensured that the aluminum disks 72 cool all the way to room temperature before being reused.
(148) Representative warming curves are shown in
(149)
As the thickness of the sample also impacts the rate of heat transfer, the average thickness of the samples (d) was used to adjust the average temperature rise measurements over 3.5 mins. A “standard” thickness was chosen based upon a target material thickness (d.sub.std). The average temperature rise was adjusted using the formula:
Thickness Adjusted DeltaT TADT=T.sub.3.5 min−T.sub.0*d/d.sub.std.
The TADT is the heat transfer rate and is related to thermal conductivity in that the lower the TADT, then the lower the thermal conductivity of the sample.
Thermal Emissivity Comparison Method #1 (Via Conduction):
(150) A modified version of Leslie's cube was used to screen multiple materials rapidly. The equipment is depicted in
(151) One complication with this test is that it highly thermally insulating materials will skew the results, as the method relies upon conduction of heat from the back to reach the same temperature. So, if the flux of heat traveling through is reduced significantly, then the black painted area will be cooling faster (through radiation) than sample area, leading to a slightly misleading result. For this reason, we developed several other tests to screen materials for emissivity.
(152) Materials:
(153) Paperboard sample(s) 10 Rectangular corrugated strips, 1.5″×3″ Calipers Digital hot plate 70 that heats to at least 37° C. (98.6° F.) and with a heating surface 71 at least 113 mm in diameter IR Camera 74 & Image Analysis Software Timer Polished aluminum strip 76, 0.75 mm thick, 2″×3″ Matte black spray paint (Rust-oleum High Performance Wheel, matte black) 3M Spray Adhesive
Assumptions:
(154) This test method assumes constant heat flow, and no edge losses or other effects from convection or radiation based heat transfer (all the heat flows through the sample).
(155) Method:
(156) 1. Set the IR camera 74 to have an emissivity value of 0.95, or similar. 2. Turn on the hot plate 70 and set the temperature to 37° C. Once the hot plate 70 has reached 37° C., sample testing can begin. The temperature can be checked by using the IR camera 74. 3. Cut 1.5″×3″ cardboard strips. Spray them evenly with 3M aerosol adhesive. 4. Generously sprinkle the material 12 to be testing over the cardboard, then tap to remove the excess. 5. Mask one half of the cardboard with aluminum foil, then spray paint the unmasked half of the sample with the matte black paint. Allow to dry (˜45 minutes). 6. Turn on the hot plate 70 and set the temperature to 37° C. Once the hot plate 70 has reached 37° C., sample testing can begin. The temperature can be checked by using the IR camera 74. 7. When ready to test: Place the corrugated sample on top of the hot plate, painted side up Place the polished aluminum also on the hotplate as a control. Start a timer for 2 minutes 8. At the end of two minutes, take an IR image of the top surface 75 of the sample. Remove the cover plate and paper sample. 9. Repeat steps 6 & 7 until all samples have been tested.
Analysis:
(157) Use the thermal images to compare whether the sample is more or less emissive than the shiny or black painted portions.
(158) The portion of the sample painted black has a high emissivity (approx. 0.90), and thus shows up red and displays the correct temperature. The polished aluminum material has a low emissivity (approx. 0.03), and thus shows up blue and displays a lower temperature than the object actually is.
(159) So for this test, one should be able to say whether the emissivity of the test sample is higher, lower, or roughly equal to the emissivity of the black or silver samples.
(160) Thermal Emissivity Method #2 (by Illumination with an Incandescent Light Bulb):
(161)
(162) Materials with low emissivity were generally much darker in color, after illumination for a few seconds.
(163) Thermal Emissivity Method #3 Recommended by Flir Systems Inc.:
(164) The following procedure was found it the Flir E40 manual, to give an actual emissivity number. Method #3 is as follows: Step 1: Determine the reflected apparent temperature. This is needed to compensate for reflected ambient radiation sources, reflecting from your sample. Here are the steps: i) Scrunch up a sheet of aluminum foil into a ball, and then uncrumple it. ii) Attach this to a sheet of card of the same size. iii) Put the cardboard in front of the object to me measured, with the foil pointing towards the camera 74. iv) Set the internal camera emissivity setting to 1.0. v) Record the apparent temperature of the aluminum foil Step 2: Measuring the thermal emissivity: vi) Adhere a strip of black electrical tape to the sample. vii) Warm the sample up to at least 20° C. warmer than the ambient temperature. viii) With the camera 74 pointing to the tape, change the emissivity setting to 0.97 and use one of the on-screen temperature measurement selection tools to measure the temperature of the tape. ix) Move the temperature measurement tool to the sample surface without the tape. Now, change the internal emissivity setting until the measured temperature matches that of the insulating tape. x) Record the emissivity of the sample.
Thermal Emissivity Test Method #4:
(165) Thermal emissivity of certain samples was also tested by Thermophysical Properties Research Laboratory, Inc. of West Fayetteville Ind. using the following test methodology.
(166) The Table Top Emissimetry apparatus measures total normal emissivity over a broad wavelength band. Thin, square samples, 0.5″ on a side are mounted facing downward on an isothermal copper block heated by a resistance heater and surrounded by ceramic insulation. Five type-K thermocouples are mounted on the bottom face of the isothermal plate. Sample temperatures during emissivity measurements are inferred from the closest thermocouple. The samples are exposed to ambient air with convection losses minimized by the face-down orientation of the samples and the small gap to the detector head.
(167) The IR detector is a broadband thermopile with a 1 mm diameter sensitive area and flat spectral response from 1-40 micrometers. The detector and radiation shield are water cooled and view the sample through a 3.56 mm aperture 5 mm from the sample surface. The detector is sensitive to radiation from an approximately 4.57 mm diameter spot on the sample. Stray radiation on the detector is minimized by a flat optical black coating on the inner surface of the shield and both faces of the aperture plate and by cooling the shield and aperture plates. The shield temperature is monitored by two type-K thermocouples embedded in the shield walls. Thermocouple and detector voltages are fed to a A/D module and attached to a personal computer. The emissivity E is calculated by the equation:
(168)
and V is the detector voltage, T is the temperature measured in Kelvin. The subscripts are as follows: T.sub.shutter is the temperature of the shutter. T.sub.shieid is the temperature of the infrared detector when the shutter is in place. T.sub.sensor is the temperature of the infrared detector during measurements. T.sub.blackbody is the temperature of the standard blackbody used to calculate the unknown values. T.sub.sample is the temperature of the sample using the thermocouple nearest the sample. V.sub.shutter is the voltage from the infrared detector when the shutter is in place. V.sub.blackbody is the voltage from the two black body readings taken. V.sub.sensor is the voltage of the infrared detector from each sample. ∈.sub.shutter is the emissivity of the shutter at the temperature when read (∈=0.09) ∈.sub.blkbody is the emissivity of the blackbody standard (∈=0.95) ∈ is the emissivity of sample.
(169) In operation, power to the heater is adjusted by a computer controlled Eurotherm temperature controller to achieve a desired plate temperature and the system is allowed to stabilize. The detector is aligned with the sample to be viewed and its output voltage recorded. All samples on the isothermal plate are maintained in a constant radiation and convective heat transfer environment as the X-Y table is moved by the extended insulation block surrounding the detector head. Measurement of an oxidized copper reference standard with ∈=0.96±0.01 and a closed aperture measurement are made before and after each sample suite at each temperature. Total hemispherical emissivity is estimated from total normal/total hemispherical relationships developed for metals and insulators. The current temperature range covered is from room temperature to around 150° C.
(170) Expanded Polystyrene Cooler Window Test Method
(171) This test was devised to measure the amount of heat flowing through a given sample, as if it were placed in direct sunlight on a hot day. While a steady-state test would be ideal, the inventors sought methods to make rapid assessments of thermal properties for further research. While not wishing to be limited by theory, this test combines both emissivity (absorption of radiative heat) and conduction to give a measure of the amount of heat passing through a given sample.
(172) Approximately 5 US gallons of Atlanta city water was placed into a 6 gallon bucket and sealed with a lid to equilibrate to room temperature for at least 24 hours. Expanded polystyrene coolers 290 were purchased from Uline (Pleasant Prairie Wis.) (part number S21529), inside dimensions: 8″×6″×7″, wall thickness 1.5″, and outside dimensions 11″×9″×10″. A 100 mm diameter acrylic circular template was used to draw a circle 291 on one of the 11″×9″ faces 292 of the cooler 290. The circle 291 was positioned 60 mm from the top 293 of the cooler 290, and 88 mm from either side 294/294, as shown in
(173) Two part liquid silicone compound was mixed and used to seal the inside of the insulated cooler 290 by painting the inner surfaces 295. The silicone resin (for example, Diamond Driven Liquid Silicone Compound, available from Amazon.com, or Oomoo 30 Silicone Mold Making Rubber available from Amazon.com, or Smooth-On Ecoflex 00-35 fast platinum cure silicone rubber compound kit, available from Smooth-On through Amazon.com, or RTV Silicone Rubber for Mold Making available from Specialty Resin & Chemical LLC, Dowagiac Mich., or similar) was allowed to cure overnight. The following day, excess silicone resin was cut from the exterior of the cooler 290 in the vicinity of the cut circular hole 291, to ensure bondability between the expanded polystyrene and the sample. Although silicone resins were used, it was also found that epoxy resins could alternately be used to waterproof seal coolers 290 without destroying the expanded polystyrene structure.
(174) Sample preparation: Coatings were made onto 35 lb per 1000 sq ft (35 MSQ or 170 gsm) kraft board using meyer rods and dried. Example board is available from Juvo Plus Inc. (Irwindale Calif.) in the form of “200 pack kraft laser and ink jet printer post cards 2 up per page” SKU LJ-WACHG-031218-11-1. This paper was selected as it proved to be a more consistent source of kraft fiberboard than obtaining samples of 35 lb MSQ liner board from various corrugated board manufacturers. In some tests, the kraft fiberboard was substituted with a sheet of paper containing fillers, or thermal insulation elements or other materials that the inventors wished to assess, such as metallized bubble wrap.
(175) Aluminum foil (e.g. Glad® Heavy Duty Aluminum Foil, distributed by Phoenix Industries Inc Denver Colo., and available in grocery stores) was cut into sheets which were sprayed black on the dull side, using matt black spray paint (e.g. Rust-Oleum® Painter's Touch 2X Ultracover Paint+Primer, Rust-Oleum Corporation, Vernon Hills Ill.) and allowed to dry. The acrylic 100 mm diameter template was then used to mark and cut circular samples of coated kraft board. The back (kraft paper) sides of these were then sprayed with an adhesive such as 3M® Super 77™ Mulitpurpose Adhesive, made by 3M Company (Minneapolis Minn.) and sold in many craft, office, and hardware stores. The discs were carefully bonded to the shiny side of the painted foil, and placed between paper sheets under several books (about 1 kg pressure) until dry, to maintain flatness of the sample. The foil sheet was trimmed so that approximately 0.5″ to 1″ of shiny foil remained surround the each sample.
(176) 3M® Marine Adhesive Sealant Fast Cure 4000 UV (part #05280) was then used to carefully adhere the black surface of the foil-sample composite to the outside of the cooler 290, so that the sample was in line with the opening 291 into the cooler 290. Other sealants could be used provided that they bond to both painted foil and expanded polystyrene, do not destroy expanded polystyrene by partially dissolving it, and that they form a waterproof seal. This was then allowed to cure overnight.
(177) The cooler 290 with the sample window was placed on the test rig 296 built and illustrated in
(178) The water was stirred for several minutes until the temperature stabilized, at which time it was recorded. A timer was set for 15 minutes. The heat lamp 297 was switched on, and the timer (not shown) started simultaneously. The temperature of the water in the cooler 290 was recorded every 15 minutes for one hour.
(179) All tests were conducted in an air conditioned temperature controlled environment with an air temperature between 68° F. and 71° F. Positive control sample was a kraft disk that also had a layer of aluminum foil laminated to it before adhering it to the shiny side of black painted foil, and a negative control consisted of an uncoated kraft disk mounted onto a similar foil sheet. The temperature rise (DT) over one hour was used to determine the amount of energy (Joules) flowing through the coated kraft board 300 per unit time (Watts) using the equation:
(180)
where 4.2 is the specific heat capacity of water in J.Math.K.sup.−1.Math.g.sup.−1; and 4500 is the mass of the water present in the container. Rate of energy transfer into the water Watts (ER) through the window 291 is calculated by dividing by the number of seconds in one hour, viz.:
(181)
As the surface area of the disc 300 is known, then the energy flux Watts per square meter can also be calculated (W.Math.m.sup.−2)
(182) In some experiments, an infrared thermometer (Etekcity Lasergrip 1025D)(not shown) was also used to measure the outside temperature of the disk 300, to give an approximation of the temperature difference over the thickness of the sample.
(183) Cardboard Corrugated Box Performance Testing:
(184) The five specifications listed below for each of cool and frozen food are desired criteria for a successful product.
(185) Cool Food performance: Compliant with ISTA test TNPK-001 using “Heat” profile, which in summary is as follows:
(186) 23° C./73.4° F. Ambient temperature Box is 12″×10″×7″ Product: 900 g/2 lbs of Cooked Pork (or simulant)—packed at 2° C./35.6° F., 1800 g/4 lbs of Gel Paks: 1 lb each, conditioned to −20° C./−4° F. Temperature of the product remains below 8° C./46.4° F. after 10 hours at ambient.
Frozen Food performance: Compliant with a modified ISTA test TNPK-001 using “Heat” profile, which in summary is as follows: 23° C./73.4° F. Ambient temperature Box is 12″×10″×7″ Product: 900 g/2 lbs Frozen cooked pork (or simulant), conditioned to −20° C./−4° F. Gel Paks: 1800 g/4 lbs of gel packs (1 #each), conditioned to −20° C./−4° F. Temperature of the product remains below 0° C./32° F. after 10 hours at ambient.
% Ash Content:
(187) These tests were carried out by SGS Integrated Paper Services Inc., Appleton Wis. according to TAPPI T 211 om-16 Ash in wood, pulp, paper and paperboard: combustion at 525° C. Approximately 10.0 g of paper was accurately weighed, and then ashed in a muffle furnace at 525° C. The remaining ash was then re-weighed to determine ash content.
(188) % Moisture:
(189) These tests were carried out by SGS Integrated Paper Services Inc., Appleton Wis. according to TAPPI T 550 om-13 Determination of equilibrium moisture in pulp, paper and paperboard.
(190) Repulpability:
(191) Repulpability was tested by SGS Integrated Paper Services Inc., Appleton Wis. according to the “Voluntary Standard for Repulping and Recycling Corrugated Fiberboard treated to Improve It's Performance in the Presence of Water and Water Vapor Protocol of 2013”, generated by the Fiber Box Association, headquartered in Elk Grove Village, Ill., 60007. Repulpable means the test material that can undergo the operation of re-wetting and fiberizing for subsequent sheet formation, using the process defined in this standard. In the repulpability test, materials are weighed, pulped in a specific manner using laboratory equipment, run through a laboratory disintegrator, and then run through a screen. The amount of rejected material is compared to the material that could be reused as pulp to make board as a % by mass. Two figures are derived: The first is the acceptable recovery of the fiber based upon the mass of material first entered into the test, and the second is the percentage of the recovered fiber that is accepted, not rejected. These figures constitute the “% re-pulpability”, and the fiber box association has determined that a pass for both measures of repulpability is >85%. Other parameters recorded are: a) material fouling the equipment during pulping or forming b) material that does not disintegrate and has to be removed (becomes part of the rejects)
(192) Adhesive Bonding/Pin Adhesion and Ply Separation Test:
(193) This is an important test to ensure the strength of the bonds between the flutes and the liner board, which in turn relates to the integrity and strength of the box structure. A jig is used, with pins that fit between the corrugated flutes. The stress force needed to separate the layers of the corrugated card is measured. The Fiber Box Association has several tests for this bond strength.
(194) Pulp Preparation Method—from 35 #Unbleached Liner Board:
(195) Unbleached 35-lb liner board (available from International Paper) was cut into 8.5″×11″ sheets. These were then cut in half, making 8.5″×5.5″ sheets, weighing approximately 5.35 g. These were fed through an office cross-cut shredder and placed into a 1 quart mason jar (Ball). Boiling water was poured over the shredded paper (approximately 800 ml) and this was left to soak for at least 10 minutes. The paper wetted out, as evidenced by it changing to a darker brown and sinking to the bottom of the jar.
(196) The wetted out shredded paper was placed into a kitchen blender (Black+Decker, 10 speed, model number BL2010BPA) and blended at the highest speed. Blending took around 2-4 minutes, until the pulp appeared to me homogeneous, and poured without back into the jar without lumps.
(197) If other materials, such as insulating elements are to be added to the finished pulp, it is done so as follows. The mason jar of pulp was opened. A laboratory mixer blade was lowered into the jar and a variable frequency drive was used to run the stirrer motor to give a controlled stirring. Additives were added to the pulp jar. After the final material was added, the pulp was further stirred for an additional 5 minutes.
(198) Pulp Preparation Method—from Bleached Recycle Pulp:
(199) Grade 100 bleached pulp secondary fiber was supplied by Donco Recycling Solutions (with offices in Chicago Ill.) This pulp contained approximately 50% solids and 50% water. The fiber content was a blend of pre- and post-consumer fiber, sourced from PE-lined milk cartons, as well as pre-consumer paper scrap and pre-consumer PE-Lined paperboard carton material. The target specification for the pulp fiber was as follows: 9.050 g+/−0.050 g was placed into a 1 quart mason jar (Ball). City water was poured over the pulp (approximately 800 ml) and this was then poured into a kitchen blender (Black+Decker, 10 speed, model number BL2010BPA) and blended at the highest speed for 1 minute.
(200) If other materials, such as insulating elements are to be added to the finished pulp, it is done so as follows. The mason jar of pulp was opened. A laboratory mixer blade was lowered into the jar and a variable frequency drive was used to run the stirrer motor to give a controlled stirring. Additives were added to the pulp jar. After the final material was added, the pulp was further stirred for an additional 5 minutes.
(201) Handsheet Paper Formation Method:
(202) As shown in
(203) The fresh pulp formulation was poured into the center of the frame 96/98, and the furnish was “hogged”. Hogging is a process whereby the hand is lowered into the frame, while it is still filled with water and pulp, and agitated near the top of the screen. This helps ensure even distribution of fiber in the hand sheets.
(204) The frame 96/98 including the attached screen 95 was removed from the tub and held level to even allow drainage and distribution of the fibers. This process is known to paper crafters as “pulling”. Pulling is analogous to the wet end process shown in
(205) In a separate shallow tub (not shown), layers of thick non-woven PET felt were wetted and stacked. Additional wetted felt sheets were available to place on top of the newly formed sheet. The larger box frame 96/98 was removed from the screen holding the partially formed paper. In one smooth rolling motion, the screen frame was inverted, pressed onto the top layer of wet felt, and the screen lifted off, leaving the pulp behind on the felt. This process is known to paper crafters as couching. In a production environment, it is analogous to the felt press process of
(206) For two or more ply samples, the process was repeated, pulling and couching more layers of partially formed paper to build the paper sheet in layers. Once the desired sheet thickness was reached, after couching the last layer, a small paper label was placed in the corner, identifying the sheet sample ID, and a second sheet of moist felt was placed on top of the paper sheet. The next sheet for the next sample was then couched on top of the pile of nonwoven and paper, to form a stack.
(207) The stack of papers was placed in a press. A hydraulic jack was used to apply pressure, expressing water from the stack. This process is analogous to further felt presses on the production line (
(208) Coating Method:
(209) A clip attached to a ¾″ thick glass plate is used to hold a stack of photocopy paper and the sheet of paper to be coated. A strip of masking tape was placed along the top of the sheet to be coated, and a paper towel was left hanging off the end. A transfer pipette was used to make a line of coating on the masking tape. This prevented the coating from prematurely soaking into the paper board to be coated. Meyer rods (available from RD Specialties Inc.) were used to draw the coating down over the sheet. The coating was then dried under ambient conditions.
(210) Wetting Out and Stabilization:
(211) Before materials can be included in a coating or into the fibrous matrix of paper, materials first have to be wetted out and dispersed. Some materials such as glass have high enough surface free energy that the wet out spontaneously—whereas materials such as perlite and aerogel require surfactants to lower the surface free energy of the water enough to wet out the material.
(212) Surfactants may be non-ionic, cationic, or anionic. They may be high molecular weight polymers or copolymers, or they may be low molecular weight, and able to reach newly created interfaces rapidly. Surfactants for aqueous systems may be characterized by their HLB value. HLB stands for Hydrophilic-Lipophilic Balance, and is a measure of the capability of the particular surfactant to wet out various surfaces of differing surface free energy. Very hydrophobic materials have a low surface free energy, so a matching surfactant should also have a low HLB value. More hydrophilic surfaces—those with multiple polar groups perhaps, require surfactants with higher HLB values.
(213) Microspersion EZ manufactured by Micropowders Inc. of Tarrytown N.J. is a non-ionic low molecular weight surfactant with a low HLB. Dawn® liquid dish soap, manufactured by the Procter & Gamble Co (Cincinnati Ohio) is an example of a low molecular weight anionic surfactant. E-Sperse 100 (from Ethos, Greenville S.C.), Triton BG-10 (Dow) Glucopon 425 N (BASF) and Glucopon 215 UP (BASF) are additional materials that can wet out certain hydrophobic materials. The Surfynol® range available from Evonik are ethoxylated acetylenic diols of fairly low molecular weight. They are non-ionic, and low foaming due to the molecular interactions of the acetylenic moiety with the water surface. Surfynol 104, 440, 420 are representative examples.
(214) Higher molecular weight materials are useful for stabilizing dispersions of various materials in water. Polymers may be anionic, cationic, or non-ionic—or have a mixture of characteristics. Polymeric dispersants, also known as “grid aids” are often co-polymeric in nature, for instance some of the Joncryl resins from BASF are believed to be methacrylic acid-styrene-butylmethacrylate copolymers, containing anionic ionizable groups. Zetasperse 3100, Zetasperse 3800, TegoDispers 752W, and TegoDispers 755W are also higher molecular weight dispersing agents with a net negative formal charge when ionized available from Evonik. Disperbyk 190, as well as other Disperbyk products available from BYK Chemie (Wallingford Conn.) are also polymeric/copolymeric materials that help stabilize dispersions through a) increasing particle surface negative charge (electrokinetic stabilization), and b) by allowing steric stabilization by dint of segments of polymer dissolving into the continuous medium.
(215) Insulation Element Density:
(216) The insulating elements used to mitigate conductive heat transfer are very low in density. 1 g of Innova aerogel powder occupies around 7 cm.sup.3 of volume. The perlite microspheres and milled and classified perlite flake are of similarly low density, in the range of 100-200 kg.Math.m.sup.−3. If we assume that the density of paper fiber is approximately 1 g.Math.cm.sup.−3, then the following is approximately true regarding the % by volume:
(217) TABLE-US-00007 Approximate % Perlite % Perlite by mass: by volume: 66.7% 93% 50% 88% 30% 75% 25% 70% 20% 64% 15% 55% 10% 44% 5% 27%
Formulations Containing Starch Adhesive:
(218) Corn starch adhesive (approximately 25% solids) is applied to the top of the media board flutes in order to laminate with the linerboard, making corrugated cardboard. The corn starch is modified with the addition of a small quantity of sodium hydroxide and sodium borate (less than 1% of the solids.) These additions reduce the gel-point of the adhesive from around 185° F. to 145° F. Part of the starch contained in the adhesive is in true solution (referred to as “cooked starch”, while additional starch is added without cooking to form swollen starch gels. At the point of corrugation, the high temperature of the corrugator heats the gels, dissolving them, and boosting viscosity as the adhesive bonds with the paper fibers. If strength is needed under moist conditions, an additional resin may be added referred to as Moisture Resistant Additive (MRA), to impart moisture condensation resistance. For instance, if a box is stored in a freezer, then moved into a room temperature environment, then it's likely that the box will “sweat” as water vapor condenses on the surface of the cold box. Such MRA resins include Coragum SR available from Ingredion in WestChester Ill., and is typically added at 1%-1.5% to impart moisture resistance.
(219) The inventors realized that the physical contact between the corrugated flutes and the liner board presented opportunities for conductive heat transfer. For this reason, the inventors investigated increasing the thermal insulating properties of the starch adhesive.
(220) Modified starch mixed adhesive mixture was warmed, thoroughly mixed and the solids content measured at 29.7%. It was used to make the following coatings, 16-01 to 22-02. 22-02 had to be put into a blender for 8 minutes in order to make an acceptable coating.
(221) Paint base is sold in paint supply stores prior to adding pigment to make customized colors. Deep color paint base contains little in the way of pigments, and mostly only binder, viscosity control agents, and a mineral extender such as calcium carbonate. Behr Pro 23 Deep Base, available from The Home Depot retail store was tested for solids content: 53.6% solids. This paint base was used as a binder to make more coatings containing insulating elements, JL 30-01 to JL 39-01.
(222) TABLE-US-00008 Amount per Formulation Substance No. Formulation Contents (g) JL 16-01 Cornstarch Adhesive as supplied 150.00 Control JL 16-02 Microspersion EZ (neat) 0.15 Cornstarch Adhesive (warmed to 100.00 400° C.) Perlite 20 um 10.00 JL 19-01 Perlite 20 um 30.01 Microspersion EZ (neat) 0.37 Cornstarch Adhesive (warmed to 170.00 400° C.) JL 19-03 3M Glass Bubbles iM30k 18.00 Microspersion EZ (neat) 0.30 Cornstarch Adhesive 182.00 JL 20-02 3M Glass Bubbles iM30k 40.80 Microspersion EZ (neat) 0.30 Cornstarch Adhesive 163.20 JL 22-02 Aerogel IC 3120 18.00 Microspersion EZ (neat) 0.34 Starch Adhesive 182.00 Blended for 8 minutes Coating formulations based upon paint base. JL 30-01 Behr Deep Base 40.00 Water 40.00 3M Glass Bubbles 40.00 JL 30-02 Behr Deep Base 60.00 Control Water 60.00 JL 30-03 Behr Deep Base 50.00 Water 50.00 3M Glass Bubbles 8.83 JL 31-02 Behr Deep Base 50.00 Water 85.00 3M Glass Bubbles 80.40 JL 34-01 Behr Deep Base 100.00 Water 175.00 Aerogel Enova IC 3120 35.29 JL 35-01 Behr Deep Base 100.00 Water 100.00 Aerogel Enova IC 3120 19.78 JL 35-02 Behr Deep Base 100.00 Water 100.00 Aerogel Enova IC 3120 19.78 JL 39-01 Behr Deep Base 50.00 Water 50.00 Thermacell 25.00
Low Emissivity Insulative Clay Coatings:
(223) Many corrugated cardboard boxes and fiberboard packages are coated with a clay coating. This coating provides a smooth flat ink-receptive surface that allows high quality printing, it covers the brown color of unbleached pulp with white, and gives the packaging a higher quality feel. Often the coating is applied in two layers. The first layer is kaolin clay based, whitened by calcium carbonate. This layer helps smooth the surface by filling in low spots. The second layer also contains titanium dioxide and calcium carbonate. The formulations of clay coatings vary. Usually, they contain kaolin clay, along with a film forming binder, such as an acrylic latex, or sometimes a cornstarch. A polymeric dispersant is usually included to stabilize the clay coating, and a viscosity control agent is usually also included, such as carboxymethyl cellulose, or an hydrophobically associated alkali swellable polymer (HASE polymer.) Calcium carbonate is also usually included, along with titanium dioxide pigment for whitening. The clay coating offers another opportunity to incorporate insulative elements that reduce conduction and radiative heat transfer.
(224) Emissivity Screening Results of Materials—Conductivity Method:
(225) Powdered materials were sampled and tested to observe emissivity differences through a thermal camera. The emissivity of the powder surface and the powder surface sprayed with black paint were compared. NVD=no visible difference.
(226) TABLE-US-00009 Comment Material after 2 minutes of heating Aerogel IC 3120 powder Possible lower emissivity Perlite P-32 75 micron (cenosphere) NVD Thermacel powder Possible lower emissivity Hi Refractive Index glass beads 60μ Possible lower emissivity Hi Refr. Index glass beads NVD 35μ-45μ Hi Refr. Index glass beads NVD 180μ-600μ Titanium dioxide powder Lower Zinc oxide powder NVD Yellow oxide pigment (iron oxide) NVD Bismuth oxychloride powder Lower Party pink mica powder NVD Super pearly white mica powder NVD Snowflake sparkle mica powder Lower Queens purple mica powder NVD Diatomaceous Earth powder NVD Mica Sheet Lower Kaolin Clay powder NVD Silicon powder Lower Kaolin Coating - 42-02 Lower (slight) Diatomaceous earth coating 43-01 Lower (slight)
(227) These powder sample data gave us several ideas for follow up tests. Curiously, some of the materials gave different results if they are first formulated into a coating (e.g. kaolin and diatomaceous earth). In other cases, low thermal conductivity may have skewed some readings.
(228) Emissivity Screening Results of Materials—Illumination Method:
(229) Both powdered materials, as well as materials incorporated into coatings coated onto fiberboard were sampled and tested to observe emissivity differences through a thermal camera. The emissivity of the powder surface/coating surface and regular Cardboard were compared when illuminated by an incandescent tungsten spot light. NVD=no visible difference in emissivity vs. cardboard. Coating formulas follow below. NT=not tested
(230) TABLE-US-00010 Comment Material 4 seconds of illumination Aerogel IC 3120 powder NVD Silicon powder NVD Snowflake Sparkle Mica Lower Pewter Silver mica NVD Hi RI glass beads 60μ Al coated NVD Hi Refr. Index glass beads 35μ-45μ Slightly lower Thermacels NVD Titanium dioxide Lower Zinc oxide Lower Mica Sheet Much Lower Bismuth oxychloride powder Much Lower Perlite P-32 (75μ) NVD 30-03, Meyer #130 (25% glass bubbles) Slightly lower 22-02, Meyer#130, (24% Aerogel in starch) Lower 19-01, Meyer#130, (37% Perlite in starch) Much Lower 19-01, Meyer #40, (37% Perlite in starch) Lower Kaolin Powder Slightly Lower Kaolin Coating - 42-02 Meyer #40 Much Lower Diatomaceous Earth powder Lower Diatomaceous earth coating 43-01 NVD Aerogel Coating 38-02 (~50% aerogel) Much Lower Bismuth Vanadate Much Lower BiLite 20 Much Lower Gypsum Lower Sericite Pigment Lower Aluminum Oxide Powder Lower
(231) These data gave us additional ideas to pursue insulating against thermal radiative emission and absorption, in addition to insulating against thermal conduction.
(232) Additional Material Sources:
(233) Glass beads, including high refractive index glass, and retroreflective hemi-spherically mirrored glass beads—Cole Safety Products, Glass microbubbles—3M specialty materials, iM30K Bismuth oxychloride—Making Cosmetics Inc (Redmond Wash.). This is a pearlescent pigment, commonly used in cosmetics and packaging to impart a pearl effect. Other sources include BASF, as Biju Ultra UFC and Pearl Glo. BiLite 20 powder—BiOCl coated onto mica flakes (BASF) Bismuth Vanadate—Dominion Colour, Ontario Titanium Dioxide—Brambleberry (Bellingham, Wash.) Zinc Oxide—Brambleberry (Bellingham, Wash.), and Sky Organics Snowflake Sparkle Mica—Brambleberry (Bellingham, Wash.) Super Pearly White Mica—Brambleberry (Bellingham, Wash.) Pewter Mica—Brambleberry (Bellingham, Wash.) Party Pink Mica—Brambleberry (Bellingham, Wash.) Queens Purple Mica—Brambleberry (Bellingham, Wash.) Yellow iron oxide powder—Brambleberry (Bellingham, Wash.) Thermacels—HyTech Thermal Solutions, Melbourne Fla. This material is an additive that is advertised to be mixed into paint in order to increase the paint's insulating properties. Rhoplex VSR-50 is an acrylic low VOC film forming binder emulsion in water. Commonly used in architectural coatings. Originally sold by Rohm & Haas, now available from Dow Chemical. Sericite comprised sericite mica surface treated with magnesium myristate or Sericite White sparkle luxury mica colorant pigment powder by H&B Oils Center Co. Supertherm paint, from Eagle Specialty Coatings, British Columbia, Canada Coatings to test for Emissivity on Fiberboard or Card
(234) TABLE-US-00011 Formulation ID Materials Quantity/g JL 48-01 CaCO.sub.3 50.00 Water 50.00 10% Rhoplex VSR-50 in water 20.00 JL 48-02 Kaolin Clay 50.00 Water 70.00 10% Rhoplex VSR-50 20.00 JL 48-03 Bismuth Oxychloride 20.13 water 33.55 10% Rhoplex VSR-50 in water 8.05 HT 50-01 Eagle Specialized Coating
Low Emissivity Coatings on Fiberboard—Cooler Window Tests
(235) Based upon the rapid testing using tests 1 & 2, several materials were selected for further investigation. In preparation for printing, fiberboard is often coated with a clay coating, which smooths the surface and gives it a white color. A simple clay coat formulation was generated: Kaolin Clay Coating 127-01:
(236) TABLE-US-00012 Material Quantity (g) Water 130 Tego Dispers 755W 4.86 Evonik Rovene 6400 52.89 Mallard Creek Polymers Hydrite SB60 157.8 Imerys
Low Emissivity Coating Formulations by % Composition
(237) TABLE-US-00013 137- 137- 127- 137- 137- 136- % TS110 02 TS111 TS112 TS113 06 02 04 05 01 Water 62.5 68.15 64.28 65.51 65.51 65.51 65.51 17.5 30.48 65.55 T-755W 8.18 2.5 5.01 5.10 5.10 5.1 5.1 5.1 R-6400 2.75 R-4100 2.85 2.71 2.85 2.85 2.85 2.85 2.85 2.85 2.85 HPMC 1.96 BiOCl 26.56 BiLite 26.5 ZnO 26.04 ZnS 26.54 MgO 26.54 TiO.sub.2 26.5 Al-ZnO 26.54 TH1000 80 TH500EF 66.67 Ag-Glass bubbles 26.5 ZnO - Sky Organics HPMC - 3% aq solution of hydroxypropyl methyl cellulose. BiOCl - Bismuth oxychloride, sold as Pearl Glo (BASF) Al-ZnO - Aluminum-doped zinc oxide semiconductor, AZO 100, 20-40 nm particle size, available from Oocap Inc. Las Crusas NM. TH500 EF is Ropaque ™ TH500EF from Dow Chemicals hollow polymeric microsphere pigment of approximate size 0.4 micron diameter, and 30% solids. TH1000 is Ropaque ™ TH1000 from Dow Chemicals hollow polymeric microsphere pigment of approximate size 1 micron diameter, and 26.5% solids Silver (Ag) -coated glass bubbles, available from CoSpheric LLC. Conductive silver metal coated hollow glass microspheres 5-30 microns, density 0.75 g/cm.sup.3, product ID: M-18-Ag-0.75
(238) Kaolin clay coating 127-01 was coated onto 170 gsm (35 lbs/1000 sq ft) kraft laser & ink jet printer post cards, available from Juvo Plus Inc Irwinsdale Calif., using a #5 Meyer rod and dried in a hot air oven at 250° F. for 5 mins. Various coatings were selected and coated onto the board, drying the coatings between each application. A representative area was selected, and tested on the test rig illustrated in
(239) TABLE-US-00014 Exp: Al foil none 1 clay 2 clay 3 clay BiOC1 BiLite MgO Base: Kraft Kraft Kraft Kraft Kraft Kraft Kraft Kraft Coat 1 Al foil — 127-01 127-01 127-01 127-01 127-01 127-01 Coat 2 — — — 127-01 127-01 TS110 137-02 TS113 Coat 3 — — — — 127-01 — — — Temp Rise/° C. 1.3 4.1 3.7 3.5 3.5 3.4 3.1 3.5 W .Math. m.sup.−2 87 274 247 234 234 227 207 234
Al foil: Aluminum foil (Reynolds heavy duty kitchen foil) was mounted dull-face down to Juvo kraft paper using 3M spray adhesive.
(240) TABLE-US-00015 TH500 TiO2 Exp: ZnO ZnS TiO.sub.2 Al•ZnO AgGls* TH1000 EF on Foil Base: Kraft Kraft Kraft Kraft Kraft Kraft Kraft Kraft Coat 1 127-01 127-01 127-01 127-01 127-01 127-01 127-01 Foil Coat 2 TS111 TS112 137-06 127-02 136-01 137-05 137-04 137-06 Coat 3 — — — — — — — — Temp 3.2 3.3 3.5 5.1 3.1 3.7 3.3 2.9 Rise/° C. W .Math. m.sup.−2 214 221 234 341 207 247 221 194 *Ag-coated glass bubbles available from CoSpheric LLC. Conductive silver metal coated hollow glass microspheres 5-30 microns, density 0.75 g/cm.sup.3, product ID: M-18-Ag-0.75
(241) TABLE-US-00016 ZnO/ BiLite/ Exp: BiLite ZnO BiOCl BiLite ZnO Base: Kraft Kraft Kraft Kraft Kraft Coat 1 127-01 127-01 127-01 127-02 127-02 Coat 2 127-01 127-01 127-01 TS111 137-02 Coat 3 137-02 TS111 TS110 137-02 TS111 Temp Rise/° C. 3.2 3.1 3.3 3 3.1 W .Math. m.sup.−2 214 207 221 201 207
(242) These data suggest that we can reduce the amount of energy absorbed by a box, or emitted from the inside surfaces of a box using coatings, by around 30%. While aluminum foil, as well as aluminized bubble wrap are very effective, they can cause problems if introduced into the repulping stream, and in any case are challenging to recycle. Not only could many of these coatings be applied to the interior and or exterior of the box, but could also be used as separate sheets of packaging, as illustrated as the loose sheets in
(243) Results of Emissivity Testing by Test Method #4:
(244) TABLE-US-00017 Exp: Contrl 1 clay 2 clay 3 clay TiO2 ZnS AgGls* ZnO Base: Kraft Kraft Kraft Kraft Kraft Kraft Kraft Kraft Coat 1 — 127-01 127-01 127-01 127-01 127-01 127-01 127-01 Coat 2 — — 127-01 127-01 137-06 TS112 136-01 TS111 Coat 3 — — — 127-01 — — — — ∈ @ 23° C. 0.900 0.859 0.883 0.885 0.869 0.519 0.888 ∈ @ 30° C. 0.909 0.866 0.894 0.895 0.873 0.530 0.918 ∈ @ 40° C. 0.915 0.866 0.894 0.904 0.874 0.536 0.933 *Ag-coated glass bubbles, available from CoSpheric LLC. Conductive silver metal coated hollow glass microspheres 5-30 microns, density 0.75 g/cm.sup.3, product ID: M-18-Ag-0.75
(245) TABLE-US-00018 ZnO/ BiLite/ Exp: BiLite BiLite ZnO BiOCl BiLite ZnO Base: Kraft Kraft Kraft Kraft Kraft Kraft Coat 1 127-01 127-01 127-01 127-01 127-02 127-02 Coat 2 137-02 127-01 127-01 127-01 TS111 137-02 Coat 3 — 137-02 TS111 TS110 137-02 TS111 ∈ @ 23° C. 0.856 0.873 0.885 0.861 0.848 0.868 ∈ @ 30° C. 0.873 0.875 0.897 0.876 0.860 0.877 ∈ @ 40° C. 0.882 0.871 0.902 0.881 0.856 0.881
Discussion of Emissivity Vs. Heat Transfer Results
(246) The inventors were surprised by the results of their own emissivity tests methods 1 and 2, as well as the emissivity results provided by the outside laboratory (Thermal Emissivity Test Method #4). Several coatings have been discovered by the inventors that apparently reduce the transfer of radiant heat energy from an incandescent light bulb (as a proxy to the full-sun illumination of a delivered package) through sheets of paper. The inventors were surprised to find that the emissivity results from the third party laboratory did not correlate with the heat transfer through the materials measured by the cooler window tests. Clearly, the inventors may have discovered several coatings with non-obvious and unexpected thermal properties.
(247) TABLE-US-00019 Thermal Conduction/ Sample Emissivity at 23° C. W .Math. m.sup.−2 Clay + ZnO + BiLite 0.848 201 Ag-coated glass 0.519 207 Clay + BiLite + ZnO 0.868 207 Clay + Clay + ZnO 0.885 207 Clay + BiLite NT 207 Clay + Clay + BiLite 0.861 214 Clay + ZnO 0.888 214 Clay + ZnS 0.869 221 Clay + Clay + BiOCl 0.861 221 Clay + TiO.sub.2 0.885 234 Clay + Clay 0.883 234 Clay 0.859 237 Kraft 0.900 274
Example 3. Sheets Containing Insulating Elements
(248) Approximately 5.35 g portions of 35 lb liner board (International Paper) was shredded and re-pulped. Additional materials were added, along with surfactants if necessary for wetting. While not yet optimum formulations, we had found that we could make paper sheets containing insulating elements by adding surfactant, along with a cationic polysaccharide, such as cationic Guar Gum, available from Making Cosmetics Inc., or a cationic starch sizing, or a synthetic retention aid, such as Polymin P (BASF), also known as poly(ethylene imine), or a high molecular weight poly(acrylamide) available from various sources. Hydrophobically associating polymers may also be incorporated, such as N-alkyl poly(acrylamides.) We wished to understand the amount of retained insulation in the paper following drying.
(249) The following formulations were made up and cast as paper, dried at room temperature and then sent for ash content and moisture content analysis:
(250) TABLE-US-00020 Formulation Target % % Moisture % Ash ID Materials Mass/g By mass paper Paper JL 24-02 Water 800.00 0% 8.4% 0.84% Control Pulp 5.35 JL 23-01 Water 800.00 25% 6.2% 15.9% Pulp 5.35 Microspersion EZ 2.00 (neat) Perlite P-50 (20 micron) 1.78 Cationic Guar 0.80 Gum JL 23-02 Water 800.00 50% 7.2% 28.5% Pulp 5.35 Microspersion EZ 2.00 (neat) Perlite P-50 (20 micron) 5.35 Cationic Guar 0.80 Gum JL 24-01 Water 800.00 50% 6.7% 22.9% Pulp 5.35 Microspersion EZ 2.00 (neat) Perlite P-50 (20 micron) 5.35 Cationic Guar 2.00 Gum JL 25-02 800.00 25% 8.0% 8.8% pH = 8-9 Pulp 5.35 Microspersion EZ 2.50 (neat) Perlite P-50 (20 micron) 1.78 Polymin P 0.80 JL 26-01 Water 800.00 50% 7.3% 16.8% pH = 6.0 Pulp 5.35 Microspersion EZ 2.00 (neat) Perlite P-50 (20 micron) 5.35 JL 32-01 Water 800.00 25% 7.5% 14.7% Pulp 5.35 3M Glass Bubbles 1.78 0.5% a.q. Cationic 10.00 Guar Gum JL 32-02 Water 800.00 50% 6.8% 28.5% Pulp 5.35 3M Glass Bubbles 5.35 iM30K 0.5% a.q. Cationic 10.00 Guar Gum
(251) A mass balance was performed to confirm that a portion of the perlite and a portion of the finer was lost during the drawing and pressing process.
(252) Repulpability Tests: Insulated Paper Vs. Uline Insulated Cardboard Box
(253) 90 lb fiberboard was fed through a paper shredder. 5.35 g was weighed and pulped in hot water as usual. The pulp was more dense and more difficult to disperse than the pulp from the 35 lb paper. Paper sheets were made using the following formulations:
(254) TABLE-US-00021 JL 41-01 water 800.00 Pulp - 90# shredded paper 12.50 iM30K glass bubbles 12.50 0.5% cationic guar gum 25.00 solution JL 41-02 water 800.00 Pulp - 90# shredded paper 12.50 Microspersion EZ (neat) 1.60 Perlite P-50 12.50 0.5% cationic guar gum 25.00 solution
(255) As a control (JL 44-01), the existing method of shipping cold objects was also tested for repulpability. Corrugated cardboard from a BS121007 single walled 12″×10″×17″ box sections were laminated to an insulated box liner, made from 3/16″ cool-shield bubble & metallized film, available from Uline as model number S-15223. The materials were laminated using 3M aerosol spray adhesive.
(256) TABLE-US-00022 Yield based upon Yield based upon total fiber original charge to the Operational collected. (% pulper (% accepts) impact Designation Summary accepts) Av. of 2 Av. of 2 (Pass/Fail) 44-01 Control 64.7% 56.4% Fail 41-01 50% iM30K 98% 70% Pass 41-02 50% perlite P-50 93% 66.9% Pass
(257) These data illustrate the validity that the approach of incorporating insulating elements into the paper structure has the potential to produce a repulpable thermally insulating material for packaging.
Example 4. Additional Sheets Made for Moisture, Ash Content, and Repulpability
(258) 35 lbs per 1000 sq. ft. single-ply sheets containing additives were made for additional repulpability tests, consistent with the Fiberboard Association voluntary standard for repulpability. Sheets FA, FD, FE, FF, FG were made using Grade 100 bleached pulp secondary fiber (supplied by Donco Recycling Solutions with offices in Chicago Ill.) The target basis weight for each sheet was 35 lbs per 1000 square feet (MSQ). Taking sample FD as an example, to make 35 MSQ board with 50% additive, 17.5 lbs of dry pulp is mixed with 17.5 lbs of additive for every 1,000 square feet of paper. Once ash content and moisture were measured, the sheets were then run through the repulping test in duplicate:
(259) Sample Details, Moisture, and Ash Content:
(260) TABLE-US-00023 Test Results Sample Details Measured Based upon Dried Material % % Moisture % additive ID Additive Additive Content % Fiber % Ash retention FA (control) 0 8.4 98.7 1.4 N/A FD 20μ spherical perlite 50 5.4 56.9 43.1 86.1 FE iM30k glass bubbles 50 5.1 54.5 45.5 90.9 FF Dicalite LD 1006 50 5.0 52.6 47.4 94.7 FG 75μ spherical perlite 50 6.2 62.1 37.9 75.7
(261) Repulpability Test Data:
(262) TABLE-US-00024 Initial Repulped Total Repulped Total Repulped Total ID Charge/g Mass/g mass accepted/g mass Rejected/g Fines/g FA 25.20 21.06 21.06 0.000 4.14 FA 21.60 17.62 17.62 0.000 3.98 FD 25.20 14.21 13.87 0.251 11.08 FD 25.10 14.81 14.80 0.008 10.29 FE 25.70 12.09 12.09 0.000 13.61 FE 25.40 12.74 12.74 0.000 12.66 FF 25.10 14.64 14.64 0.004 10.46 FF 25.60 15.98 15.24 0.036 10.32
Repulpability Test Results Analysis—Taking Ash Content Into Account:
(263) TABLE-US-00025 % accepts based on the amount of fiber present in Deposition % Accepts based % Accepts the initial charge on upon total fiber based upon (additive equipment ID collected initial charge ash excluded) noted: FA 100.0 83.6 84.0 No FA 100.0 81.6 82.1 No FD 98.2 55.0 85.8 No FD 99.9 59.0 89.6 No FE 100.0 47.0 75.2 No FE 100.0 50.2 80.0 No FF 100.0 58.3 84.3 No FF 99.8 59.5 91.9 No
Surface Modification of Insulating Fillers:
(264) Some fillers are quite hydrophobic, meaning that they are difficult to wet out. Aerogels fall into this class, as do silicone-coated micro-spherical perlite, such as CenoStar P grades, from Cenostar Corp. Newbury MAor from American Stone Pioneers, Rolling Hills Estates, Calif. To wet these materials out, mid to low HLB surfactants are useful, such as Microspersion EZ. Judicious selection of polymeric surfactants can also be added to increase the negative surface charge of the wetted particle. Such surfactants include Zetasperse 3800 (Evonik GmbH), which is a comb co-polymeric anionic dispersant, and Disperbyk 190, available from Byk, a division of Altana group. Even with surfactants, mechanical high sheer mixing may be necessary to fully disperse these materials. High sheer mixing may be achieved using for instance a sawblade mixer, or a Silverson mixer. A regular kitchen blender may also be used to mix in short bursts of for instance 2-3 minutes, followed by a cooling time to prevent the drive seals from overheating.
(265) In formulations that contain surfactants, defoamers may also be needed to prevent troublesome foam build up. Defoamers are widely known, and may be as simple as 1-octanol. They are usually low HLB surfactants, such as silicone containing surfactants, or surfactants such as Surfynol 440, Surfynol 420, Surfynol 104e from Evonik GmbH. Particulate dispersions, such as hydrophobic silica dispersions may also be used as de-foamers.
(266) Surface Modified Insulating Fillers
(267) TABLE-US-00026 g JL 97-01 Water 125 Disperbyk 190 25 Microspersion EZ 0.134 Mix, then add with stirring: (add in Cenostar P-32 (75 micron portions.) spherical perlite) 40.00 JL 91-01 Water 143.1 Microspersion EZ 0.6 Disperbyk 190 40.42 Mix and addi with stirring: Innova IC 3110 Aerogel 30.00 High Sheer Mix, with Cooling 12 minutes. JL 60-01 Water 97.5 Zetasperse 3100 4 Surfynol 420 0.4 Microspersion EZ 0.4 Mix, then add with stirring: Aerogel Innova IC 3110 High-sheer mix with cooling 15 (add in mins. portions.) 20.00
Example 5. Paper Incorporating Thermal Insulation
(268) The following formulations were made up and drawn into paper. Bleached recycled fiber, supplied by Donco Recycling Solutions. The pulp was measured at 50% solids 50% moisture, and so 9 grams (9.05+/−0.05 g) was weighed out in lieu of shredded fiber board.
(269) TABLE-US-00027 Formulation ID Materials Mass/g JL 46-01 Water 800.00 CONTROL Pulp 4.5 Microspersion EZ (neat) 1.60 (add last.) 0.5% a.q. Cationic Guar Gum 10.00 JL 46-02 Water 800.00 Pulp 4.5 Microspersion EZ (neat) 1.60 Perlite P-50 1.78 (add last.) 0.5% a.q. Cationic Guar Gum 10.00 JL 46-03 Water 800.00 Pulp 4.5 Glass microbubbles (3M) 1.78 (add last.) 0.5% a.q. Cationic Guar Gum 10.00 JL 33-01 Water 800.00 Pulp 4.5 Perlite P-50 5.35 Microspersion EZ (neat) 1.70 0.5% a.q. Cationic Guar Gum 10.00 JL 32-02 Water 800.00 Pulp 4.5 3M Glass Bubbles iM30K 5.35 0.5% a.q. Cationic Guar Gum 10.00 JL 49-01 Water 800.00 Pulp 4.5 Glass microbubbles (3M) 10.70 Kroger Household Ammonia 4.00 (add last.) 0.5% a.q. Cationic Guar Gum 10.00 JL 49-02 Water 800.00 Pulp 4.5 Perlite P-50 (20 micron) 10.70 Microspersion EZ (neat) 1.60 Kroger Household Ammonia 4.00 (add last.) 0.5% a.q. Cationic Guar Gum 10.00 JL 99-01 Water 800.00 Pulp 4.5 JL 97-01 42.9 Mix, then add: 0.5% a.q. Cationic Guar Gum 10.00 JL 49-01 Water 800.00 Pulp 4.5 Glass microbubbles (3M) 10.70 Kroger Household Ammonia 4.00 (add last.) 0.5% a.q. Cationic Guar Gum 10.00 JL 49-02 Water 800.00 Pulp 4.5 Perlite P-50 (20 micron) 10.70 Microspersion EZ (neat) 1.60 Kroger Household Ammonia 4.00 (add last.) 0.5% a.q. Cationic Guar Gum 10.00 JL 70-01 Water 800.00 Pulp 4.5 Microspersion EZ 1.6 Perlite P-35 75 micron 1.78 Household ammonia solution 2 Mix, then add: 0.5% a.q. Cationic Guar Gum 10.00 JL 110-01 Water 800.00 Pulp 4.5 Microspersion EZ 1.6 Perlite P-35 75 micron 4.5 Household Ammonia 4.00 (add last.) 0.5% a.q. Cationic Guar Gum 10.00 JL 63-01 Water 800.00 Pulp 4.5 JL 60-01 8.25 (add last.) 0.5% a.q. Cationic Guar Gum 10.00 JL 67-01 Water 800.00 Pulp 4.5 JL 60-01 16.5 (add last.) 0.5% a.q. Cationic Guar Gum 10.00
Single Ply Samples:
(270) TABLE-US-00028 Average Average Formula- Thick- TADT/ tion Explanation ness/in ° C. JL 46-01 Control 0.0092 22.7 JL 46-02 28.3% 20 micron perlite spheres 0.0140 13.1 JL 46-03 28.3% Glass microbubbles (iM30K) 0.0149 12.2 JL 33-01 54.3% 20 micron Perlite spheres 0.0226 6.9 JL 33-02 54.3% Glass microbubbles (iM30K) 0.0231 6.9 JL 49-01 70.4% Glass microbubbles (iM30K) 0.0257 5.4 JL 70-01 25% 75 micron perlite spheres 0.0177 9.1 JL 110-01 50% 75 micron perlite spheres 0.0221 6.5 JL 99-01 66.7% 75 micron perlite spheres 0.0317 2.8 JL 63-01 25% Innova Aerogel 0.0179 8.2 JL 67-01 50% Innova Aerogel 0.0254 4.3 JL 143-01 67% Innova Aerogel 0.0353 1.8 JL 68-01 25% Flaked Perlite (Dicalite LD 1006) 0.0169 9.7 JL 102-01 50% Flaked Perlite (Dicalite LD 1006) 0.0178 7.4 JL 100-01 67% Flaked Perlite (Dicalite LD 1006) 0.0282 3.8 JL 126-01 71.4% Flaked Perlite (Dicalite LD 1006) 0.0388 2.8 Thickness: This is the average over five disks with an average of three measurements for each disc of the paper (15 caliper measurements) Average TADT: This is the average for 5 sheets tested separately Thermal data TADT was adjusted to a thickness of 0.009 inches for single ply sheets.
(271) The inventors noted that the pulp treated as described readily floated, whereas untreated pulp tends to settle toward the bottom of a jar of water if left for 30 minutes. Without wishing to be bound by theory, the inventors speculate that they have bound the assumed negatively surface charged particles to the negatively surface charged fibers through the use of a positively charged polymer (cationic guar gum).
(272) Clearly, the Average Thickness Adjusted Delta-T (see,
(273) As much of the pulp 11 floated, the inventors realized that gravitation may be classifying the insulating particles 12.
(274) Double Ply Samples:
(275) The inventors hypothesized that the uneven distribution of insulating particles 12 within paper sheets 10 may be helping provide insulation. The following experiment was designed to investigate the thermal insulative effect of having all of the insulation in one of two layers 10 vs. more evenly distributed through two layers 10.
(276) TABLE-US-00029 grams DP1 DP2 DP3 No filler 5% perlite (20 micron 10% perlite (20 micron hollow spheres) hollow spheres) Water/g 800 800 800 Pulp/g 4.5 4.5 4.5 Surfactant/g — 1.6 1.6 Perlite (20 — 0.25 0.50 micron)/g Mix Mix Mix 0.5% Cationic 10 10 10 Guar Gum aq/g Surfactant = Microspersion EZ
Several sheets were made from these pulp formulations, dried, tested, and thermally analyzed.
(277) TABLE-US-00030 Sheet: 1.sup.st ply 2.sup.nd ply Thickness/in TADT/° C. DL1 (control) DP1 DP1 0.0177 9.6 DL2 DP2 (5% P) DP2 (5% P) 0.0158 8.2 DL3 DP3 (10% P) DP1 0.0190 7.2
(278) Clearly, these data demonstrate the advantage of a non-uniform distribution of insulating particles 12 within the cross section of the paper sheet 10.
(279)
(280) Three Ply Sheets:
(281) Sheets with three plies were conceived in which the two outer sheets are pulp and the inner layer of the sandwich contains a high concentration of insulating materials. A flaked grade of perlite was also included in these experiments, Dicapearl LD1006 supplied by Dicalite Management Group. This material was mixed into pulp without the addition of other assistants. After mixing,
(282) TABLE-US-00031 DP1 TP2 TP3 TP4 TP5 TP6 50% perlite 66.7%: 50 um 66.7% (75 micron 50% 66.7% flaked iM30K hollow flaked flaked 50% 20 u glass No filler spheres) perlite perlite spherical bubbles Water/g 800 800 800 800 800 800 Pulp/g 4.5 4.5 4.5 4.5 4.5 4.5 Surfactant/g 1.6 1.6 Perlite (75 micron)/g 4.5 Perlite (20 micron)/g 4.5 Dicapearl LD1006 4.5 9.0 4.5 iM30K 9.0 Household ammonia/ 2-4 2-4 2-4 g Mix Mix Mix Mix Mix Mix 0.5% Cationic 10 10 10 10 10 10 Guar Gum aq/g
Results Thickness Adjusted Temperature Change (Delta-T)—adjusting for a thickness of 0.045 inches caliper.
(283) TABLE-US-00032 Thickness/ TADT*/ Sheet: 1.sup.st ply 2.sup.nd ply 3.sup.rd ply in ° C. TL1 (control) DP1 DP1 DP1 0.0228 28.8 TL2 DP1 TP2 (50% 75 u DP1 0.0415 13.4 Perlite) TL3 DP1 TP3 (50% flaked) DP1 0.0398 14 TL4 DP1 TP4 (66.7% flaked) DP1 0.0535 8.3 TL5 DP1 TP5 combination DP1 0.0527 8.6 TL6 DP1 TP6 (66.7% glass DP1 NT NT bubbles) *Thickness adjusted to 0.045 inches caliper.
Results Thickness Adjusted Temperature Change (Delta-T)—adjusting for a thickness of 0.009 inches caliper allows comparison to single ply samples.
(284) TABLE-US-00033 Thickness/ TADT**/ Sheet: 1.sup.st ply 2.sup.nd ply 3.sup.rd ply in ° C. TL1 (control) DP1 DP1 DP1 0.0228 5.8 TL2 DP1 TP2 (50% 75 u DP1 0.0415 2.7 Perlite) TL3 DP1 TP3 (50% flaked) DP1 0.0398 2.8 TL4 DP1 TP4 (66.7% flaked) DP1 0.0535 1.7 TL5 DP1 TP5 combination DP1 0.0527 1.7 **Thickness adjusted to 0.009 inches caliper.
(285) These data show that we are able to incorporate low density insulating materials into a paper structure to increase the thermal insulative properties by a factor of at least 3-4.
(286) Sheets TL1 through TL 5 contain a mixture of pulp and additive in the 2.sup.nd (middle) ply. It is also possible to make insulating paper by creating a 2.sup.nd ply (middle layer) that does not contain pulp. As shown in
(287) The middle layer could comprise a concentrate such as formulation JL 97-01. The middle layer may optionally include a binder, such as a latex Rovene 6400, or poly(vinyl acetate), or a modified starch, or a mixture of cooked and uncooked starch, or a water soluble synthetic polymer such as poly(vinyl alcohol). If necessary, a defoamer may be added to control foam. Surface active agents may also be included in the middle layer slurry to help wet-out and stabilize the insulating elements, such as Disperbyk 190, Zetasperse 3100, Surfynol 440, or numerous other resinous and non-resinous surfactants.
(288) The bottom and top plies may contain a retention aid, a flocculant, or a binder. Such materials may be cationic, such as poly(ethylene imine), poly(acrylamide), or quaternary ammonium functionalized natural polymers, such as cationic guar gum. In this way, migration of the additive as water drains from the top ply through the underlying middle and bottom ply is limited and fines are trapped.
(289) Concentrates for 2.sup.nd Ply (Middle Layer):
(290) TABLE-US-00034 Mass/g Formula JL 97-01: 75 u spherical perlite concentrate Water 125 Microspersion EZ 0.134 Disperbyk 190 25.0 Mix, then add in portions while mixing: Cenostar P-32 (75 micron spherical perlite) 40.0 Formula JL 147-01: glass bubbles concentrate Water 80 Rovene 4100 (binder of ~50% solids) 20 iM30K glass bubbles (3M) 90 Formula glass bubbles concentrate, binder free Water 85 iM30K glass bubbles (3M) 90
(291) These coatings may be applied to the paper forming line shortly after a layer of pulp exits the headbox. The concentrate coatings may be applied using a spray nozzle, or a blade coater, or a curtain coater, or a slot-die coater. A coagulant or flocculant may be then be applied on top of the middle ply via spraying, or slot-die coating as non-limiting examples. The coagulant flocculant may also be incorporated in additional layers of pulp below and above the middle insulating layer.
(292) It stands to reason that while a three-ply system has been explored, many more plies may be similarly formed, resulting in 5 ply, 7 ply, or higher-ply systems via similar processes.
Example 6. Corrugated Samples of 3-Ply Paper Sheets
(293) An antique desk-top hand cranked corrugator was purchased. The corrugator indicated U.S. Reexam Patent No. RE009,127 “Fluting-Machine”, re-issued Mar. 23, 1880 to H. Albrecht.
(294) A sheet of TL1 was hung from inside an inverted 5 gallon pail and held over a boiling tea kettle to steam the sheet. The cast iron hand-cranked corrugator was warmed with a hair dryer, and the warm steamed sheet was promptly rippled. This was promptly bonded between two non-corrugated sheets of TL1 to make a rudimentary corrugated structure.
(295) Single Ply Filled Sheets were Hand Pressed in the Lab and Dried:
(296) TABLE-US-00035 Sheet Composition ID EJ EK Water/g 800 800 Pulp/g 4.5 4.5 Flaked Perlite LD1006/g 9.0 iM30K glass bubbles/g 9.0 Household ammonia/g 2-4
(297) A sheet of EJ was hung from inside an inverted 5 gallon pail and held over a boiling tea kettle to steam the sheet. The cast iron hand-cranked corrugator was warmed with a hair dryer, and the warm steamed sheet was promptly fluted. This was promptly bonded between two non-corrugated sheets of EJ to make a rudimentary corrugated structure. This procedure was repeated using EK sheets for all three layers.
(298) A sheet of TL1, EJ, and EK were each coated with Kaolin clay formulation 127-01, then dried, and then coated with 137-02 (BiLite (BASF)—bismuth oxychloride coated mica flakes) and dried. More uncoated sheets were steamed and fluted, and similar corrugated structures were produced incorporating one of the coated sheets with the coating side facing out as depicted in
(299) 10 cm diameter disks were cut of each sample, and mounted into a cooler window for thermal testing. Prior to sealing with marine adhesive, the samples were gently pushed into the front of the cooler window so that the face of the composite was flush with the front of the cooler. 10 cm discs of the following were also cut as controls: Aluminized bubble wrap, corrugated C-flute (35 lbs.MSQ kraft liners with 23 lb medium, Corrugated Supplies Inc.), corrugated B-flute (35 lbs.Math.MSQ kraft liners with 23 lb medium, Corrugated Supplies Inc.), triple wall corrugated B-C flute (35 lbs.Math.MSQ kraft liners with 23 lb medium, Corrugated Supplies Inc.).
(300) Because these samples had significant thickness, temperature rise was monitored over a an initial period of time until three consecutive 15 minute temperature readings showed an increase in temperature within +/−0.1° C. of each other. Upon attaining consistent temperature increase readings over 15 minutes, this was designated as pseudo-steady state. The temperature of the outside lamp-facing surface was also measured using a hand-held pyrometric infra-red thermometer, taking care to try not to allow reflections of the hot lamp from interfering. Usually, a pseudo-steady state situation of incremental temperature increases was established within 15 minutes of run time.
(301) Results of Controls
(302) TABLE-US-00036 Paper corrugate corrugate Corrugate Bubblewrap C-Flute B-Flute BC Flute Aluminized Ave. Thickness/mm 4 3.175 6.35 3.175 Coating 1 — — — — Coating 2 (lamp — — — — facing) 1 hr Water T Rise/ 3.04 3.2 2.8 1.4 ° C. Ave temp difference 96.4 91.1 133.8 Very outer face of noisy data. window vs. water/ 74 +/− 25° C. ° C. W .Math. m.sup.−2 203 214 187 94
(303) TABLE-US-00037 Paper corrugate corrugate corrugate corrugate corrugate corrugate Control Flake Perl. Gls Bubls Coated Flk Perl. Gls Bubls TL1 EJ EK TL1 EJ EK Av. Thkns/mm 3.87 5.51 5.68 4.11 5.44 6.36 Coating 1 — — — 127-01 127-01 127-01 Coat. 2 (lamp) — — — 137-02 137-02 137-02 1 hr T Rise/° C. 2.4 2.13 NT* 2 1.73 1.8 Av. Delta T outer 78.5 87.1 NT* 74.2 86.2 77.5 face of window vs. water/° C. w .Math. m.sup.−2 154 143 134 116 120 *Structure failed during testing - delaminated
(304) These data demonstrate the additive combination of addressing both radiative heat transfer as well as conductive heat transfer.
Example 7. Coffee Cup Insulated Sleeve Demonstration
(305)
(306) Juvo kraft board 35 lbs/1,000 sq ft (170 gsm) postcards were also corrugated. 3 flat sheets were laminated and then one corrugated sheet was attached to the composite. When this net was cut out and formed into a sleeve, it also had a mass of 10 g. This composite device was designated “control” as it did not include insulating materials.
(307) Both the Juvo kraft control, the TL4 test device, were placed over two “tall” sized PE-lined paper cups 360 obtained from a Starbucks® store. In addition, an expanded poly(styrene) cup 360 was also placed close by for comparison. A kettle of water was boiled. As quickly as safely possible, all three cups 360 were filled with boiling water, and a timer started. Every 30 seconds from filling, an infra-red pyrometer thermometer was used to measure the temperature of the outside of the two sleeves made, as well as the apparent temperature of the EPS cup.
(308) TABLE-US-00038 Time from filling/s Expanded PS Control (kraft) TL4 30 61.0° C. 54.2° C. 48.7° C. 60 63.0° C. 57.3° C. 53.3° C. 120 60.2° C. 57.6° C. 52.5° C. 180 58.8° C. 58.6° C. 54.3° C. 240 56.7° C. 58.2° C. 55.0° C. 300 55.6° C. 55.0° C. 51.4° C.
(309) As can be clearly seen, the external temperature of the TL4 sleeve 320 was consistently lower in temperature than both the control sleeve and the expanded poly(styrene) cup 360.
(310) The present invention is described above and further illustrated below by way of claims, which are not to be construed in any way as imposing limitations upon the scope of the invention. On the contrary, it is to be clearly understood that resort may be had to various other embodiments, modifications, and equivalents thereof which, after reading the description herein, may suggest themselves to those skilled in the art without departing from the spirit of the present invention and/or the scope of the appended claims.