METHOD AND COMPOSITION PROVIDING ENHANCED ALCOHOL BARRIER FOR PAPER PACKAGING APPLICATIONS
20260015798 ยท 2026-01-15
Inventors
Cpc classification
D21H23/64
TEXTILES; PAPER
D21H19/12
TEXTILES; PAPER
B65D65/42
PERFORMING OPERATIONS; TRANSPORTING
D21H23/66
TEXTILES; PAPER
D21H19/58
TEXTILES; PAPER
B65D65/40
PERFORMING OPERATIONS; TRANSPORTING
D21H19/826
TEXTILES; PAPER
International classification
B65D65/40
PERFORMING OPERATIONS; TRANSPORTING
B65D65/42
PERFORMING OPERATIONS; TRANSPORTING
D21H19/12
TEXTILES; PAPER
D21H19/58
TEXTILES; PAPER
D21H23/64
TEXTILES; PAPER
D21H23/66
TEXTILES; PAPER
Abstract
The methods and compositions of the present disclosure pertain to a package blank, having one or more fiber containing layers and having die cut edges. The methods and compositions provide multi-surface barrier protection for alcohol and liquid permeation along multiple axis of the packaging blank. The packaging blank can have many exposed surfaces depending upon how the blank is designed and cut from a sheet or roll. The methods and compositions provide permeation protection for the entire package, including the flat surfaces and the cut edge surfaces that make liquid contact, particularly alcohol, which are found enclosed or within the finished packaging structure. This is accomplished by both coating the blanks and structural methods of cutting, die cutting, and folding techniques.
Claims
1. A method for preparing coated packaging blanks comprising: a. providing a paper, wherein said paper comprises a plurality of cellulose fibers; b. applying a surface coating said paper on at least one of a planar top surface and a planar bottom surface with at least one layer of a polymer-containing coating; c. cutting said coated paper, such that a coated packaging blank is created that has a specific geometrical form and size and that has a plurality of side edges; d. applying at least one layer of a side coating on at least one of said plurality of side edges of said packaging blank; e. wherein each of said plurality of side edges has a smaller surface area as compared to a surface area of said planar top surface or said planar bottom surface.
2. The method of claim 1, further comprising, performing one or more curing or drying steps after said applying of said surface coating.
3. The method of claim 1, further comprising, performing one or more curing or drying steps after said applying of said side coating.
4. The method of claim 1, wherein said paper is selected from one or more of a paper sheet and a paper roll.
5. The method of claim 1, wherein said side coating is a dispersion coating or an emulsion coating.
6. The method of claim 1, wherein the applying of said side coating step is selected from the group consisting of: an extrusion coating; an extrusion lamination; a dispersion coating; and an emulsion coating.
7. The method of claim 5, wherein when said dispersion coating or emulsion coating is used, said dispersion coating or emulsion coating is selected from the group consisting of: a blade coating; an air knife coating; a roll coating; a size press coating; and a curtain coating.
8. The method of claim 1, wherein said polymer-containing coating comprises a polyolefin.
9. The method of claim 8, wherein said polyolefin is selected from the group consisting of: polyethylene; polypropylene; polyester; and vinyl alcohol.
10. The method of claim 5, wherein said side coating is an acrylic coating or an acrylic-latex coating, selected from the group of polymers consisting of: polyvinyl acetate; polyurethane; styrene butadiene; poly vinyl chloride; ethyl vinyl acetate; alkyd resins; polyethylene; polyvinyl pyrrolidone; polyethylene glycol; polyester; fluro-polymers; acrylic; acrylic-latex; ethyl acrylate; and methyl methacrylate co-polymer.
11. The method of claim 10, wherein all of said plurality of side edges are coated and both said planar top surface and said planar bottom surface are coated, such that said coated packaging blank is coated on all sides and surfaces.
12. The method of claim 2, further comprising: performing one or more curing or drying steps after the applying of said side coating.
13. The method of claim 12, wherein said one or more curing or drying steps of said polymer-containing coating is completed before the cutting step; and wherein said one or more curing or drying steps of said side coating is completed by applying heat and pressure.
14. The method of claim 1, wherein the step of cutting said coated paper is done at an angle between about 30 to 140 degrees with respect to one said planar top surface or said planar bottom surface.
15. The method of claim 14, wherein the step of cutting said coated paper is done at an angle between about 80 to 110 degrees with respect to one said planar top surface or said planar bottom surface.
16. The method of claim 1, wherein the step of cutting said coated paper provides a shape selected from the group of shapes consisting of: a circle; a straight; a radius edge, and combinations thereof.
17. The method of claim 13, wherein after completing the applying of said side coating by applying heat and pressure, said polymer-containing coating and said side coating are cross-linked.
18. The method of claim 1, wherein the cutting of one or more of said plurality of side edges exposes a plurality of fibers that are unprotected from alcohol permeation.
19. The method of claim 17, wherein the cross-linking of said polymer-containing coating and said side coating is between about 104 to 108 cross-links per nm3.
20. The method of claim 10, wherein the applying of said acrylic coating or said acrylic-latex coating is done during one or more of the following: stacking, moving, and transporting to a package forming and converting station.
21. The method of claim 1, wherein the applying of said polymer-containing coating is applied with weights between about 10 to 40 gsm.
22. The method of claim 1, wherein the applying of said polymer-containing coating is applied with weights between about 10 to 30 gsm.
23. The method of claim 1, wherein said polymer-containing coating comprises a mineral content.
24. The method of claim 1, wherein the applying of said side coating is applied with weights between about 3 to 20 gsm per coating layer.
25. The method of claim 1, wherein the applying of said side coating is applied with weights between about 3 to 20 gsm total for all layers.
26. The method of claim 1, wherein at least one of said polymer-containing coating and said side coating impregnate into one or more of said plurality of cellulose fibers of said paper at one or more positions to be present between about 3 to 80 microns from a nearest edge, such that an edge horizontal is created and there is vertical permeation resistance.
27. The method of claim 13, wherein curing temperatures are between 100 C. (212 F.) to 200 C. (392 F.).
28. The method of claim 27, wherein said one or more curing or drying steps are performed in one or more of: hot air ovens; drying sections; and drying tunnels.
29. The method of claim 23, wherein said polymer-containing coating has a mineral content between about 1 and 50 wt. % based on a total paper weight.
30. The method of claim 29, wherein said polymer-containing coating has a mineral content between about 1 and 30 wt. % based on said total paper weight.
31. The method of claim 1, wherein said plurality of cellulose fibers comprise fibers having a diameter/width between about 16-42 microns, as measured according to TAPPI T271 OM-15: Fiber Analysis of Paper and Paperboard or as measured according to TAPPI T233 OM-15: Fiber Length of Pulp and Paper by Automatic Image Analysis.
32. The method of claim 1, wherein one or more of said polymer-containing coating and said side coating comprises one or more components selected from the group of components consisting of: binders; pigments; dispersing agents; thickeners; rheology modifiers; coalescing agents; surfactants; crosslinkers; and combinations thereof.
33. The method of claim 1, wherein a thickness of said paper is between about 0.025 to 0.066 cm (0.010 to 0.026 inches).
34. The method of claim 1, wherein said paper weighs between about 129 to 273 lbs/msf.
35. The method of claim 34, wherein said paper weighs between about 129 to 173 lbs/msf.
36. The method of claim 1, wherein a thickness of said coated packaging blank corresponds to a length of a shorter side edge of said plurality of side edges if a 900 cut or no cut has been made to obtain said shorter edge; wherein said thickness of said coated packaging blank less than said length of said shorter side edge when a degree other than 90 is used for cutting.
37. The method of claim 1, wherein a plurality of coated packaging blanks are created.
38. The method of claim 37, wherein at least two of said plurality of coated packaging blanks are heat sealed together.
39. A method for preparing coated packaging blanks comprising: a. providing a paper, wherein said paper comprises a plurality of cellulose fibers; b. coating said paper on at least a planar top surface or a planar bottom surface with at least one layer of a polymer-containing coating; c. curing or drying said coated paper; d. cutting said coated paper, such that a coated packaging blank is created that has a specific geometrical form and size, and that has a plurality of side edges; e. applying at least one layer of a side coating on at least one of said plurality of side edges; and f. curing or drying said coated packaging blank.
40. The method of item 39, wherein the polymer-containing coating step is selected from the group consisting of: extrusion coating; extrusion lamination; dispersion coating; and emulsion coating.
41. The method of claim 40, wherein the side coating step is selected from the group consisting of: a blade coating; an air knife coating; a roll coating; a size press coating; a curtain coating, and combinations thereof.
42. The method of claim 41, wherein said polymer-containing coating comprises polyolefin and one or more biopolymers.
43. The method of claim 42, wherein said one or more biopolymers are selected from the group of biopolymers consisting of: polyethylene; polypropylene; polyester; vinyl alcohol; polylactic acid; bio-polybutylene succinate (PBS); and combinations thereof.
44. The method of claim 43, wherein at least one of said plurality of side edges is folded to prevent exposure of the plurality of cellulose fibers that are exposed by the cutting.
45. The method of claim 44, wherein said folding of said at least one of said plurality of side edges reduces permeation of a liquid contained by said coated and folded packaging blank into said at least one of said plurality of side edges.
46. The method of claim 45, wherein said coated and folded packaging blank forms a container for containing said liquid; and wherein all of said planar surfaces and said plurality of side edges that come into contact with said liquid are coated.
47. The method of claim 46, wherein said plurality of cellulose fibers have: a. lengths between about of 0.5 to 6 mm; b. diameters between about 10 to 40 microns; and c. densities between about 225 to 675 kg/m3.
48. The method of claim 45, wherein a pulp of said paper is selected from the group of pulp of: between about 75% to 100% of solid bleached sulphate pulp, with densities between about 0.3-0.9 g/cm.sup.3; between 75-100% unbleached chemical pulps, with densities between about 0.3-0.9 g/cm.sup.3; and combinations thereof, and wherein said coated and folded packaging blank having: a. an ISO 2493 MD Bending L & W, 15 degrees MD, mNm, in the range of 247 to 1320; b. an ISO 2493 CD Bending L &W 15 degrees MD, mN, in the range of 94 to 510; c. a Bending L & W, GM mN in the range of 152 to 811; d. a Taber Movement Bending 15 degrees MD, mNm in the range of 10 to 64 degrees; e. a Taber Moment Bending 15 degrees CD mNm in the range of 4.5 to 30 degrees; f. a Taber Moment Bending GM, mNm in the range of 6.0 to 44; and g. a T-541 ZDT kPa range from 310 to 259.
49. The method of claim 45, wherein, a knife and paper blade have: a. a feed rate between about 10 to 160 meters per minute; b. a line speed, including folding, between about 10 to 205 meters per minute; c. a cutting depth between about 0.3 to 0.9 mm; d. a blade length between about 25 to 70 mm; e. a blade width between about 4 to 30 mm; f. a handle length between about 90 to 160 mm; g. a total knife length between about 125 to 210 mm; and h. a blade thickness between about 0.4 to 1.2 mm.
50. The method of claim 45, wherein a pulp of said paper comprises: a. between about 15 to 70% of bleached sulphate having a density between about 0.3 to 0.9 g/cm.sup.3; and b. between about 20 to 60% of chemical thermomechanical pulp having a density between about 0.3 to 0.8 g/cm.sup.3.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The drawings are of illustrative embodiments. They do not illustrate all embodiments. Other embodiments may be used in addition or instead. Details which may be apparent or unnecessary may be omitted to save space or for more effective illustration. Some embodiments may be practiced with additional components or steps and/or without all of the components or steps which are illustrated. When the same numeral appears in different drawings, it refers to the same or like components or steps.
[0020]
[0021]
[0022]
[0023]
[0024]
[0025]
[0026]
[0027]
DETAILED DESCRIPTION
[0028] In the following detailed description of various embodiments of the present disclosure, numerous specific details are set forth in order to provide a thorough understanding of various aspects of one or more embodiments of the present disclosure. However, one or more embodiments of the present disclosure may be practiced without some or all of these specific details. In other instances, well-known methods, procedures, and/or components have not been described in detail so as not to unnecessarily obscure aspects of embodiments of the present disclosure.
[0029] While multiple embodiments are disclosed, still other embodiments of the devices, systems, and methods of the present disclosure will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the devices, systems, and methods of the present disclosure. As will be realized, the devices, systems, and methods of the present disclosure are capable of modifications in various obvious aspects, all without departing from the spirit and scope of the present disclosure. Accordingly, the screenshot figures, and the detailed descriptions thereof, are to be regarded as illustrative in nature and not restrictive. Also, the reference or non-reference to a particular embodiment of the devices, systems, and methods of the present disclosure shall not be interpreted to limit the scope of the present disclosure.
[0030] Before the present methods and systems are disclosed and described, it is to be understood that the methods and systems are not limited to specific methods, specific components, or to particular implementations. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting.
[0031] As used in the specification and the appended claims, the singular forms a, an, and the include plural referents unless the context clearly dictates otherwise. Ranges may be expressed herein as from about one particular value, and/or to about another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent about, it will be understood that the particular value forms another embodiment. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint.
[0032] Optional or optionally means that the subsequently described event or circumstance may or may not occur, and that the description includes instances where said event or circumstance occurs and instances where it does not.
[0033] Throughout the description and claims of this specification, the word comprise and variations of the word, such as comprising and comprises, means including but not limited to, and is not intended to exclude, for example, other components, integers or steps. Exemplary means an example of and is not intended to convey an indication of a preferred or ideal embodiment. Such as is not used in a restrictive sense, but for explanatory purposes.
[0034] Disclosed are components that may be used to perform the disclosed methods and systems. These and other components are disclosed herein, and it is understood that when combinations, subsets, interactions, groups, etc. of these components are disclosed that while specific reference of each various individual and collective combinations and permutation of these may not be explicitly disclosed, each is specifically contemplated and described herein, for all methods and systems. This applies to all embodiments of this application including, but not limited to, steps in disclosed methods. Thus, if there are a variety of additional steps that may be performed it is understood that each of these additional steps may be performed with any specific embodiment or combination of embodiments of the disclosed methods.
[0035] The present methods and systems may be understood more readily by reference to the following detailed description of preferred embodiments and the examples included therein and to the Figures and their previous and following description.
[0036] In the following description, certain terminology is used to describe certain features of one or more embodiments. For purposes of the specification, unless otherwise specified, the term substantially refers to the complete or nearly complete extent or degree of an action, characteristic, property, state, structure, item, or result. For example, in one embodiment, an object that is substantially located within a housing would mean that the object is either completely within a housing or nearly completely within a housing. The exact allowable degree of deviation from absolute completeness may in some cases depend on the specific context. However, generally speaking, the nearness of completion will be so as to have the same overall result as if absolute and total completion were obtained. The use of substantially is also equally applicable when used in a negative connotation to refer to the complete or near complete lack of an action, characteristic, property, state, structure, item, or result.
[0037] As used herein, the terms approximately and about generally refer to a deviance of within 5% of the indicated number or range of numbers. In one embodiment, the term approximately and about, may refer to a deviance of between 0.001-10% from the indicated number or range of numbers.
[0038] Various embodiments are now described with reference to the drawings. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more embodiments. It may be evident, however, that the various embodiments may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form to facilitate describing these embodiments.
[0039] The methods and compositions of the present disclosure are designed to, and do, provide improved functional barrier performance along multiple cut blank surface axis and cut blank cut edge protection across and inside the score line perimeter, the method and composition comprised of the following steps: [0040] Step 1: Coat on one or two sides a paper sheet or roll with polymer containing coating(s), the coating(s) applied on the flat outer facing planar surfaces of the roll or sheet to include extrusion coating or extrusion lamination, dispersion, or emulsion coatings. The dispersion and emulsions coating methods include blade coating, air knife coating, roll coating, size press coating, curtain coating. [0041] Step 2: Apply acrylic or acrylic-latex dispersion or emulsion coatings and other coatings comprised of the chemicals described herein, on the cut score edge at approximately 90-degree angle. However, depending on die design, applied in the range of 30 to 140 degrees, from the flat planar surface of the blank. The coating is applied and cured at the cut blank edges, the edges having exposed fibers that are unprotected from alcohol permeation. This coating application is done during the process of blank stacking, moving, or transporting to the package forming and converting station. The acrylic or acrylic-latex barrier containing coatings are applied with weights from 3 gsm to 20 gsm. The coating then seeps into the fibers to about 3 to 80 microns from the cut edges, creating cut edge horizontal as well as vertical permeation resistance. The coating can be applied using spray, single and multiple rollers, pads, flexible plates, and cylinders among many other techniques know to the art. Depending upon the coating formulation a drying and curing station could be located after the coating material is applied to the fiber, curing temperatures between approximately 100 C. (212 F.) to 200 C. (392 F.) in hot air ovens, drying sections, or drying tunnels. Upon coating application, the packaging blank has 360-degree barrier protection along two axes, diminishing or preventing liquid permeation. After curing the first coatings have been completed, post curing heat and pressure is applied to the edge trim area into the interior fibers to up to about 0.5 from the outer edge of the blank, therefore, cross linking density improvements are achieved along a wide area including the exposed edge and the interior fibers of the blank including the interfacial surface.
[0042] During the above stated step, other chemicals and other ingredients can be mixed or used alone and applied to the package surface as part of the coatings. They include the chemical components of dispersion and emulsion coatings such as:
[0043] Binders. The binder is the primary film-forming component of the coating. It provides adhesion and cohesion to hold the coating together. Common binder types used in dispersion and emulsion coatings include pigments, acrylics, styrene-butadiene (SB) latex, polyvinyl acetate (PVA), and polyurethane. Pigments can be organic or inorganic, such as titanium dioxide, iron oxides, carbon black, phthalocyanines, and many others.
[0044] Dispersing Agents. Dispersing agents are chemicals added to the coating formulation to ensure proper dispersion and stabilization of the pigments or other solid particles. They help prevent settling or clumping of the particles, ensuring uniform distribution within the coating. Common dispersing agents include polymeric dispersants and surfactants.
[0045] Thickeners or rheology modifiers may be added to control the viscosity and flow characteristics of the coating. They help achieve the desired consistency and prevent sagging or running during application. Common thickening agents include cellulose derivatives, acrylic thickeners, and associative thickeners.
[0046] Coalescing agents. Coalescing agents may be added to aid in the film formation process of dispersion and emulsion coatings. They promote the fusion of polymer particles during drying, leading to the formation of a continuous film. Common coalescing agents include glycol ethers, such as ethylene glycol monobutyl ether (EGBE) or propylene glycol ethers.
[0047] Surfactants. Surfactants are surface-active agents that help to stabilize emulsions or dispersions by reducing surface tension and preventing coagulation or flocculation of particles. They assist in maintaining stability and ensure uniform coating properties. Non-ionic, anionic, or cationic surfactants can be used depending on the specific coating requirements.
[0048] Crosslinkers. In some cases, crosslinkers may be added to improve the durability and chemical resistance of the coating. Crosslinkers promote the formation of chemical bonds between polymer chains, enhancing the coating's performance characteristics. Examples of crosslinkers include melamine-formaldehyde resins, isocyanates, and epoxy resins. These are the main chemical components typically found in dispersion and emulsion coatings.
[0049] The specific formulation and composition may vary depending on the desired coating properties, application requirements, and industry standards. The viscosity of the coating is an important aspect when using dispersion or emulsion coatings for performance, processing, and application of the coating after die cutting is completed. The coatings used in the edge barrier viscosity can range from about few hundred to a few thousand centipoise (cP), medium-viscosity coatings typically have viscosities ranging from a few thousand to tens of thousands of centipoise (cP)T, and high-viscosity coatings having viscosities in the tens of thousands or even hundreds of thousands of centipoise (cP) range. These coatings offer a balance between flow and film build, making them suitable for various applications, including general industrial coatings, architectural paints, and certain specialty coatings.
[0050] These coatings are thixotropic and may require additional mixing or dilution before application. high-viscosity coatings are commonly used in applications when gap-filling properties are desired, such as barrier coatings applied to the inconsistent and damaged blank edge fiber surface. Additionally, coatings that have a pH from about between 2 and 11 are preferably used for this barrier coating application. Other important aspects of the coating application into the edge cut area of the blank include, but not limited to polymer particles, e.g., the mean particle size of polymer particles in dispersion and emulsion coatings used in this application, including particle size ranges from submicron (less than 1 m) to several micrometers. However, for certain specialized applications, smaller nanoparticles or larger microparticles may be utilized. Also, pigment particles can be used for cosmetic appearance and other reasons, such as inorganic pigments such as titanium dioxide having particle sizes ranging from a few hundred nanometers to micrometers. Organic pigments, on the other hand, can have smaller particle sizes, typically in the range of tens to hundreds of nanometers. Further, filler particles can have a wide range of particle sizes. Larger filler particles, such as calcium carbonate or talc, can have mean sizes ranging from several micrometers to tens of micrometers. Smaller fillers, like silica or nano-sized particles, can have mean sizes in the nanometer range. The polymer particles that can be used in the edge cut coating can include film-forming properties and contribute to the coating's adhesion, durability, and other desired characteristics. Examples of polymer particles used include acrylics, styrene-butadiene (SB) latex, polyvinyl acetate (PVA), and polyurethane, PP polypropylene, PE, polyethylene, HDPE, high density polyethylene, PVDC, PVA, acrylics, polyolefin, styrene-butadiene, polyvinyl acetate polystyrene, polyacrylates, carboxylated styrene butadiene, acrylics, polyester, or mixtures thereof in emulsion or powder form.
[0051] Additionally, alcohol permeation can be reduced or halted via mechanical means during and after the paper die cutting process, this is preferably done before forming and sealing the package. Prior to die cutting, the blank paper having a planar surface coating weight range from about 10 to 30 gsm can be coated on one or both flat sides of the blank using coatings and methods previously described in the patent specification. However, alternatively, rather than coating the blank cut edge to prevent permeation, the edge of blank wall can be crosscut, and the half thickness seam folded back over from the inside to the outside of the sidewall up to about 6.35 to 12.8 mm from the cut edge of the blank. The 90-degree crosscut removes material from the blank seam such that it can folded and hemmed inside the cup. In this case, after folding and sealing, the exposed cut edge is now on the exterior of the cup instead of the inside of the cup which had previously allowed for alcohol permeation. Instead of an exposed cut edge, the round folded hemmed edge makes contact with the inside liquid and the folding action removes exposure of the inner blank cut edge from the cup liquid contents, thus preventing permeation through the blank inner cut edge. However, because of alcohol permeability, the newly exposed bent edge must be properly coated to prevent permeation on the bent inner edge of the sidewall blank. Also, in addition to using an alcohol resistant coated surface sealable using adhesives or heat seal methods.
[0052] This mechanical process may be completed after a series of steps. First, during or after the die cutting process, the blank is cut with a skiving knife edge striking the blank outer surface from about a 25 degree to about at a 90-degree angle behind the liquid exposed cut edge of the sidewall blank. The knife can then crosscut at two angles and separate the inner paper walls along the seam into two overlapping pieces, of which the inner flap piece is reverse folded (see
[0053] However, both mechanical processes rely on specific paper mechanical processes and specific production parameters. For example, the blank paper vertical seam that is heat or adhesive sealed would be the range of about 5.00 mm to about 10.00 mm wide, the coatings or adhesives used may have weights from about 8 gsm to about 35 gsm and paper calipers from about 300 to 700 microns, with a basis weight from about 110 gsm to 360 gsm. The paper used can be comprised from about 15% to 70% of bleached sulphate having a density from about 0.3-0.9 g/cm.sup.3 and from about 20% to 60% chemical thermomechanical pulp having a density in the range of about 0.3-0.8 g/cm.sup.3. Also, the paper can comprise from about 75% to 100% solid bleached sulphate pulp, 75-100% unbleached chemical pulps, all pulp with densities used in the structure from about 0.3-0.9 g/cm.sup.3. Further, the paper used preferably may have the Table 3, 4, 5 characteristics, below. Tables 3-5 do not include paper fillers or paper coatings that can be applied after the paper making machine wet end manufacturing step has been completed.
TABLE-US-00003 TABLE 3 Paper Characteristic Ranges Fiber Fiber Strength Moisture % length diameter Density (Tappi 569) (ISO 287) 0.5-6 mm 10-40 225-675 175-285 3.5-12.0 microns kg/m3 J/m2 MD Bending (ISO 2493) CD Bending (ISO 2493) Bending L&W 15 degrees MD, mN L&W 15 degrees MD, mN L&W GM, mN 247 to 1320 94 to 510 152 to 811 Taber Moment Taber Moment Taber Moment Bending Bending Bending ZDT T-541 15 degrees MD, 15 degrees CD GM, mNm kPa mNm mNm 10 to 64 4.5 to 30 6.0 to 44 310-259
TABLE-US-00004 TABLE 4 Process Parameters, Knife Cutting, Folding, Sealing Paper Blanks Paper Feed Line speed Rate (including folding) Cutting Depth Blade Length 10-160 m/m 10-20 5 m/m 0.3 mm to 0.9 mm 25-70 mm Blade Width Handle Length Total Knife Length Blade Thickness 4-30 mm 90-160 mm 125-210 mm 0.4 to 1.2 mm
TABLE-US-00005 TABLE 5 Fiber Characteristics, Tear, Roughness, Burst Strength Surface Tear Resistance Roughness Burst Strength Fiber Weight g/m2 (Mn) mls/min (kPa) 115 180-190 1400-1900 100-2500 175-475 130 205-215 1600-2200 100-2500 250-675 200 315-330 1900-3200 100-2500 500-950 300 460-595 500-4000 100-2500 700-1850
[0054] Other chemicals that could be present for the purpose of coating the exposed cut edge that is acting as seam adhesive or heat seal layer include polymers of monoolefins and diolefins, e.g., polypropylene, polyisobutylene, polybut-1-ene, poly-4-methyl pent-1-ene, polyvinyl cyclohexane, polyisoprene or polybutadiene, homogeneous mettallocene copolymers, and polymers of cycloolefins, e.g., cyclopentene or norbornene, polyethylene, cross-linked polyethylene, ethylene oxide and high density polyethylene, medium molecular weight high density polyethylene, ultra heavy weight high density polyethylene, low density polyethylene, very low density polyethylene, ultra-low density polytheylene; copolymers of monoolefins and diolefins with one another vinyl monomers, e.g., ethylene/propylene copolymers, linear low density polyethylene, and blends thereof with low density polyethylene, propylene but-1-ene, copolymers ethylene, propylene/isobutylene copolymers, ethylene/but-1-ene copolymers, ethylene/hexene copolymers, ethylene/octene copolymers, ethylene/methylepentene copolymers, ethylene/octene copolymers, ethylene/vinyelcyclohexane copolymers, ethylene/cycloolefin copolymers, COC, ethylene/I-olefin copolymers, the 1-olefin being produced in situ; propylene/butadiene copolymers, isobutylene/isoprene copolymers, ethylene/vinylcyclohexene copolymers, ethylene vinyl acetate copolymers, ethylene/alkyl methacrylate copolymers, ethylene/acrylic acid copolymers or ethylene/acrylic acid copolymers and salts thereof (ionomers) and terapolymers of ethylene with propylene and diene, such as, for example, hexadiene, polytetrafluoroethylene (PTFE) or fluorinated ethylene propylene dicyclopentadiene or ethylidenenorbomene, pvdc, homopolymers and copolymers that may have any desired three dimensional structure (stereo-structure), such as, for example, syndiotactic, isotactic, bioPBS, hemiisotactic or atactic stereoblock polymers are also possible; polystyrene, poly methylstyrene, poly alph-methystyrene, aromatic homopolymers and copolymers derived from vinylaromatic monomers, including styrene, alpha-methylstyrene, all isomers of vinyltoluene, in particular p-vinyletoluene, all isomers of ethylstyrene, propylstyrene, vinylbiphenyl, vinylnaphthalene and blends thereof, homopolymers and copolymers of may have any desired three dimensional structure, including syndiotactic, isotatic, hemiisotactic or atactic, stereoblock polymers; copolymer, including the above mentioned vinylaromatic monomers and commoners selected from ethylene, propylene, dienes, nitriles, acids, maleic anhydrides, vinyl acetates and vinyl chlorides or acryloyl derivatives and mixtures thereof, for example styren/butadiene, styrene/acrylonitrile, styrene/ethylene (interpolymers) styrene/alkymethacrylate, styrene/butadiene/alkyl acrylate, styrene/butadiene/alkyl methacrylate, styrene/maleic anhydride, styrene copolymers; hydrogen saturated aromatic polymers derived from by saturation of said polymers, including polycyclohexylethylene; polymers derived from alpha, beta-unsaturated acids and derivatives; unsaturated monomers such as acrylonitrile/butadiene copolymers acrylate copolymers, halide copolymers and amines from acyl derivatives or acetals; copolymers with olefins, fluoropolymers, homopolymers and copolymers of cyclic ethers; polyamides and copolyamides derived from diamines and dicarboxylic acids and or from aminocarboxylicacides and corresponding lactams; polyesters and polyesters derived from dicarboxylic acids and diols and from hydroxycarboxylic acids or the corresponding lactones; blocked copolyetheresters derived from hydroxyl terminated polyethers; polyketones, polysulfones, polyethersufones, and polyetherketones; cross-linked polymers derived from aldehydes on the one hand phenols, ureas, and melamines such as phenol/formaldehyde resins and cross-linked acrylic resnes derived from substantial acrylates, e.g., epoxyacrylates, urethaneacrylates or polyesteracrylates and starch; polymers and copolymers of such materials as poly lactic acids and its copolymers, cellulose, polyhdyroxy alcanoates, polycaprolactone, polybutylene succinate, polymers and copolymers of N-vinylpyrroolidone such as polyvinylpyrrrolidone, and corsslinked polyvinylpyrrolidone, ethyl vinyl alcohol. More examples of thermoplastic polymers suitable for the mineral-containing composite include polypropylene, high density polyethylene combined with MS0825 Nanoreinforced POSS polypropylene, thermoplastic elastomers, thermoplastic vulcinates, polyvinylchloride, polylactic acid, virgin and recycled polyesters, cellulosics, polyamides, polycarbonate, polybutylene tereaphthylate, polyester elastomers, thermoplastic polyurethane, cyclic olefin copolymer; biodegradable polymers such as Cereplast-Polylactic acid, Purac-Lactide PLA, Nee Corp PLA, Mitsubishi Chemical Corp GS PLS resins, Natureworks LLC PLA, Cereplast-Biopropropylene, Spartech PLA Rejuven 8, resins made from starch, cellulose, polyhydroxy alcanoates, polycaprolactone, polybutylene succinate or combinations thereof, such as Ecoflex FBX 7011 and Ecovio L Resins from BASF, polyvinylchloride and recycled and reclaimed polyester such as Nodax biodegradable polyester by P & G.
[0055] Alcohol and alcohol mixed with other liquids can be rapidly absorbed by fibers and therefore the permeation quickly discolors and degrades the appearance and cosmetics of the packaging structure and negatively effects the structural integrity of the package. The type of alcohol, such as methanol, ethanol, isopropanol, or higher alcohols, may have different permeation rates due to variations in their molecular size, polarity, and interactions with paper fibers. The composition of the paper, including the type of fibers and any additives or coatings present, can influence alcohol permeation rates. Papers with more porous structures or higher cellulose content tend to have higher permeation rates. Paper thickness, thicker papers typically have a higher permeation capacity, allowing for a greater amount of alcohol to be absorbed. However, the rate of permeation may still be influenced by factors such as the porosity and surface area of the paper. Temperature, humidity, and air circulation can affect the rate of alcohol permeation into paper. Higher temperatures and lower humidity levels generally enhance the permeation process due to increased molecular mobility and evaporation of solvents. One purpose of the invention is to reduce permeation of alcohols in the density range of about 0.77 g/cm3 to about 0.82 g/cm3. The invention is designed to reduce alcohol permeation when coating the inner blank wall cut edge into packaging structures containing fibers having the attributes illustrated in Table 6, below.
TABLE-US-00006 TABLE 6 fiber characteristics Filled Fiber Content 1% to 30% Fiber Density 0.3-0.7 g/cmL Fiber Diameter 16-42 microns Fiber Coarseness 16-42 mg/100 ml Fiber Pulp Types Mechanical, Thermo-Mechanical, (Single- to Triple-Layered) Chemi-Thermo-Mechanical, and Chemical Permeability 0.1-110 m(2) 10(15) Hydrogen Ion Concentration 4.5-10 Tear Strength (Tappi 496, 402) 56-250 Tear Resistance (Tappi 414) 49-250 Moisture Content 2%-18% by Weight
[0056] When applying the multi axial coatings, which include the flat planar surfaced and the cut edges of the blank, the package cut blanks can comprise multiple paper layers and have cut edges for each layer, each layer possibly exposed to liquids and therefore requiring multi axial protective coatings on the preformed packaging blanks, e.g., on the cut edges and also the flat. The coatings applied to the planar surfaces of the blank facing approximately 90 degrees from the cut edge with actual knife cut angle from about 30 degrees to 140 degrees. The package blanks can weigh from about 129 lbs/msf to about 173 lbs/3 msf and have a thickness from about 0.010 to about 0.026. The package blank surface having a TAPPI Brightness (TAPPI T 452) of a range of 75-100, and for bagasse papers a Tappi Brightness from about 25 to 75. Also, the paper cut blanks having a consistent brightness and strength with no discoloration or reduced tear strengths due to alcohol permeation wetness.
EXAMPLE
[0057] In this example, a customer requested a more environmental alternative to 100% thermoformed plastic cups. Therefore, paper packaging was preferred. However, due to alcohol permeation, previously available paper cups failed to provide an acceptable barrier solution. Therefore, seeking a paper cup having alcohol and liquid barrier, a representative sampling of various cup packaging blanks were prepared. The paper fibers in the cup samplings had properties found within Table 3. Also, the paper blanks with a Tappi Brightness of from 79 to 95, a CIE whiteness of from 65 to 95, a fiber density of between 0.3 to 0.7 g/cml, and Elmendorf tear strength of from 5-25 mN, the blank paper weights from 129 lbs/msf to about 273 lbs/msf with calipers from 0.010 to 0.026 and fiber moisture content from 2% to 8%. Prior to cutting the blanks, the parent paper roll was polyolefin extrusion coated. The extrusion coatings applied to one or two sides of the planar surfaces of the blanks in the coat weight range of about 10 gsm to about 28 gsm. The extrusion coatings included some having by weight up to 45% diatomaceous filler content. The blank samples edges were cut to shape at 90 degrees from the outer facing sides of the blank planar surfaces. The cut blank edges comprising circular, straight, straight with radius sections, and combinations thereof. Next, an acrylic containing dispersion coating was prepared having a PH within a range of about 2 to 11, a viscosity from about 150 to 250 cps, a coating particle molecular weight greater than 100,000, a TG in the range of 55 to 75 C, and post application density at 25 C from about 0.95 to about 1.15 g/cm3. The dispersion coating was then applied to the exposed cut blank edges in weight ranges from about 3 to 20 gsm, with the coating seeping into the cut edge fibers from 10 to 80 microns for the outer edge of the cut blank, thus providing permeation protection inside the fiber structure of the blank. Upon completion of the coating process, the blanks have a multi axial coating coverage. For example, axis one being the outer facing flat planar surface, axis two being the outer facing exposed edge of the cut blank, and the third axis having coating coverage along the varying cut edge angles formed through circular, straight, and radius edges of the blank cuts, or combination thereof. Adhesion and curing of the above coatings is preferably completed prior to the next step.
[0058] Next, to enhance cross linking density and therefore improve permeation barrier to alcohol, the coating was cured a second time along the outer blank edge areas. This second curing step applied heat and pressure to the cut edge surface area up to 410 F, with pressures up to 2.5 mPA up to 0.5 from the outer exposed cut edges. The heat and pressure applied simultaneously in time durations up to 4.25 seconds. The secondary heat and pressure compressing and rapid curing the edge of the blank, improving cross-linking density across the linear outer edge and three dimensionally across the entire surface of the blank edge. The minimum finished cross linking densities found in the edge cut area were from about 10{circumflex over ()}4 to 10{circumflex over ()}6 cross-links per nm3 to approximately 10{circumflex over ()}6 to 10{circumflex over ()}8 cross-links per nm3. Upon completion of the secondary curing process, at room temperature, the packages were then exposed to a range of 88 mL liquid solutions containing from 15% to 55% by volume of alcohol, the alcohol having a density in the range of 0.77 to 0.82 g/ml. The paper with a Tappi Brightness of from 70 to 95, a CIE whiteness of from 65 to 95, a fiber density of between 0.3 to 0.7 g/cml, and Elmendorf tear strength of from 5-25 mN, and a fiber moisture content from 2% to 18%. The liquid permeation in the cup was observed at 15 minutes, 30 minutes, 1 hour, 2 hours, and 12-hour time frames. Observations included the exterior and interior of the package on both the outermost coated areas and the outer facing fiber surface adhesion to the coating. The permeation rate of degradation and failure criteria was determined upon the total overall average surface area on the inner side of the planar surface and along the perimeter of the cut edges of the tested samples. Terminal failure identified at 5% overall average discoloration of the inner package surface, a 5% overall reduction in surface brightness, a 5% or more reduction in whiteness, and a 5% tear strength reduction. Example 1 sampling results and averages across the surface area of the samples are illustrated in Table 7, below.
TABLE-US-00007 TABLE 7 Example 1, ranges of permeation degradation rates, inner surface area Tear Time Brightness Whiteness Strength Discoloration 15 minutes 99-100% 99-100%.sup. .sup.100% >1% 30 minutes 98-100% 97-100%.sup. .sup.100% >3% 1 hour 96-100% 96-99% 98-100% >6% 2 hours fail-100% fail-99% 95-100% >11% 12 hours .sup.fail-98% fail-99% fail-100% >16%
TABLE-US-00008 TABLE 8 Alcohol permeation ranges by volume (100% start @ 88 mL) Time % Permeation Permeation mL 15 minutes 0-4 0-3.52 30 minutes 0-09 0-7.92 1 hour 013 0.88-11.44 4 hours 2-21 0.176-18.48 12 hours 5.3 4.66-22.88 Note on Table 8: The % permeation and volume is calculated from an original volume of 88 mL of liquid placed into the container.
[0059] Regarding the Figures,
[0060]
[0061]
[0062]
[0063]
[0064]
[0065]
[0066]
[0067] Unless otherwise stated, all measurements, values, ratings, positions, magnitudes, sizes, locations, and other specifications that are set forth in this specification, including in the claims that follow, are approximate, not exact. They are intended to have a reasonable range that is consistent with the functions to which they relate and with what is customary in the art to which they pertain.
[0068] The foregoing description of the preferred embodiment has been presented for the purposes of illustration and description. While multiple embodiments are disclosed, still other embodiments will become apparent to those skilled in the art from the above detailed description. These embodiments are capable of modifications in various obvious aspects, all without departing from the spirit and scope of protection. Accordingly, the detailed description is to be regarded as illustrative in nature and not restrictive. Also, although not explicitly recited, one or more embodiments may be practiced in combination or conjunction with one another. Furthermore, the reference or non-reference to a particular embodiment shall not be interpreted to limit the scope of protection. It is intended that the scope of protection not be limited by this detailed description, but by the claims and the equivalents to the claims that are appended hereto.
[0069] Except as stated immediately above, nothing that has been stated or illustrated is intended or should be interpreted to cause a dedication of any component, step, feature, object, benefit, advantage, or equivalent, to the public, regardless of whether it is or is not recited in the claims.