Tape Closure System
20180282584 · 2018-10-04
Inventors
Cpc classification
B32B2405/00
PERFORMING OPERATIONS; TRANSPORTING
C09J2301/40
CHEMISTRY; METALLURGY
C09J2301/206
CHEMISTRY; METALLURGY
B32B29/005
PERFORMING OPERATIONS; TRANSPORTING
C09J2301/124
CHEMISTRY; METALLURGY
B32B7/00
PERFORMING OPERATIONS; TRANSPORTING
B32B7/12
PERFORMING OPERATIONS; TRANSPORTING
C09J2301/302
CHEMISTRY; METALLURGY
C09J2301/208
CHEMISTRY; METALLURGY
Y10T428/1476
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
B32B2307/54
PERFORMING OPERATIONS; TRANSPORTING
B32B2307/4026
PERFORMING OPERATIONS; TRANSPORTING
B32B29/02
PERFORMING OPERATIONS; TRANSPORTING
International classification
Abstract
A tape closure system is shown and described herein. The tape closure system includes a first tape component having a pressure sensitive adhesive and a second tape component having a pressure sensitive adhesive, where at least one of the pressure sensitive adhesives has a modified surface to reduce the tack of the surface such that when the first and second pressure adhesives are brought into contact with one another they may sufficiently adhere to one another to form a seal but are still separable from one another and able to be repeatedly opened and sealed.
Claims
1. An adhesive closure system comprising: a first pressure sensitive adhesive having an upper adhesive surface; and a second pressure sensitive adhesive having an upper adhesive surface, wherein the upper adhesive surfaces of the first and second pressure sensitive adhesives are releasably securable to one another to form a closure, and the upper adhesive surface of (i) the first pressure sensitive adhesive, (ii) the second pressure sensitive adhesive, or (iii) both the first pressure sensitive adhesive and the second pressure sensitive adhesive comprises a plurality of standoffs defining a modified surface topography, wherein the standoffs are provided by elongated lines, fibrils, or filaments of different lengths and/or thicknesses disposed in a random distribution and at least two of the plurality of standoffs on a given adhesive partially overlap with one another, and wherein the standoffs are formed by non-adhesive materials applied on the upper surfaces of the pressure sensitive adhesive layers.
2. The adhesive closure system of claim 1, wherein each of the first pressure sensitive adhesive and the second pressure sensitive adhesive has a modified surface topography.
3. (canceled)
4. (canceled)
5. (canceled)
6. (canceled)
7. (canceled)
8. (canceled)
9. The adhesive closure system of claim 1, wherein the standoffs cover from about 5% to about 60% of the surface area of the adhesive surface.
10. The adhesive closure system of claim 1, wherein the system has a T Peel value of from about 0.2 N/inch to about 20 N/inch.
11. The adhesive closure system of claim 1, wherein the first pressure sensitive adhesive and the second pressure sensitive adhesive are provided as a tape.
12. An article having a first surface and a second surface adapted to be releasably joined together, the article comprising an adhesive closure system comprising: a first pressure sensitive adhesive having an upper adhesive surface disposed on the first surface; and a second pressure sensitive adhesive having an upper adhesive surface disposed on the second surface, wherein the adhesive surfaces of the first and second pressure sensitive adhesives are releasably adherable to one another, and the adhesive surface of (i) the first pressure sensitive adhesive, (ii) the second pressure sensitive adhesive, or (iii) both the first pressure sensitive adhesive and the second pressure sensitive adhesive comprises a plurality of standoffs defining a modified surface topography, wherein the standoffs are provided by elongated lines, fibrils, or filaments of different lengths and/or thicknesses disposed in a random distribution and at least two of the plurality of standoffs on a given adhesive partially overlap with one another, and wherein the standoffs are formed by non-adhesive materials applied on the upper surfaces of the pressure sensitive adhesive layers.
13. The article of claim 12, wherein each of the first pressure sensitive adhesive and the second pressure sensitive adhesive have a modified surface topography.
14. (canceled)
15. The article of claim 12, wherein the standoffs are formed from an ink, an elastomeric material, a polymeric material or an inorganic material.
16. (canceled)
17. (canceled)
18. The article of claim 12, wherein the standoffs cover from about 5% to about 60% of the surface area of the adhesive surface.
19. The article of claim 12, wherein the system has a T Peel value of from about 0.2 N/inch to about 20 N/inch.
20. The article of claim 12, wherein the first pressure sensitive adhesive and the second pressure sensitive adhesive are each provided as a tape comprising a lower adhesive, an upper pressure sensitive adhesive defining the upper adhesive surface, and a facestock or carrier film disposed between the lower adhesive and the upper pressure sensitive adhesive, the lower adhesive of the first pressure sensitive adhesive adhering the first pressure sensitive adhesive to the first surface, and the lower adhesive of the second pressure sensitive adhesive adhering the second pressure sensitive adhesive to the second surface.
21. The article of claim 12, wherein the article is a package defining an opening between the first and second surface.
22. The article of claim 21, wherein the first and second surface each define an inner surface of the package.
23. The article of claim 12, wherein the article is formed form a polymeric material, a paper, a nonwoven material, or a foil material.
24. The article of claim 12, wherein the article is in the form of a pillow pouch package, a stand up pouch, a flat bottom bag, a double seam consumer bag, a bar wrap package, a flexible overwrap package, a flexible lid on a rigid package, or a diaper.
25-30. (canceled)
31. The adhesive closure system of claim 2, wherein at least one of the standoffs on the first pressure sensitive adhesive overlaps with at least one standoff on the second pressure sensitive adhesive when the first and second pressure sensitive adhesives are brought into contact with one another.
32. The article of claim 13, wherein at least one of the standoffs on the first pressure sensitive adhesive overlaps with at least one standoff on the second pressure sensitive adhesive when the first and second pressure sensitive adhesives are brought into contact with one another.
33. The adhesive closure system of claim 1, wherein the non-adhesive material is an ink, an elastomeric material, a polymeric material, or an inorganic material, a hot melt elastomer, an emulsion polymer, an inorganic material, or a combination thereof.
34. The adhesive closure system of claim 33, wherein the standoffs are formed by printing, spraying, sprinkling, dusting, brushing, or combination thereof.
35. The adhesive closure system of claim 1, wherein the non-adhesive material comprising an elastomeric or a polymeric material has a modulus of about 0.510.sup.6 dyne/cm.sup.2 or greater.
36. The adhesive closure system of claim 1, wherein the non-adhesive material is a hot melt with a softening point of 67 C. or higher.
37. The adhesive closure system of claim 1, wherein the non-adhesive materials applied on the upper surfaces of the pressure sensitive adhesive layers comprise at least a hot melt with a softening point of 67 C. or higher, sprayed on the upper surfaces of the pressure sensitive adhesive layers.
38. The adhesive closure system of claim 1, wherein the standoffs have a height in the range of 2 to 500 and a width in the range of 20 to 120.
39. The adhesive closure system of claim 1, wherein when the upper adhesive surfaces of the first and the second pressure sensitive adhesives are releasably secured to one another, a first adhesive on the upper adhesive surface of the first pressure sensitive adhesive contacts a second adhesive on the upper adhesive surface of the second pressure sensitive adhesive or contacts a combination of the second adhesive and the standoffs on the upper adhesive surface of the second pressure sensitive adhesive.
40. The article of claim 12, wherein the non-adhesive material is an ink, an elastomeric material, a polymeric material, or an inorganic material, a hot melt elastomer, an emulsion polymer, an inorganic material, or a combination thereof.
41. The article of claim 40, wherein the standoffs are formed by printing, spraying, sprinkling, dusting, brushing, or combination thereof.
42. The article of claim 12, wherein the non-adhesive material comprising an elastomeric or a polymeric material has a modulus of about 0.510.sup.6 dyne/cm.sup.2 or greater.
43. The article of claim 12, wherein the non-adhesive materials applied on the upper surfaces of the pressure sensitive adhesive layers comprise at least a hot melt with a softening point of 67 C. or higher, sprayed on the upper surfaces of the pressure sensitive adhesive layers.
44. An adhesive closure system comprising: a first pressure sensitive adhesive having an upper adhesive surface and a lower adhesive surface; a second pressure sensitive adhesive having an upper adhesive surface and a lower adhesive surface; wherein the upper adhesive surfaces of the first and second pressure sensitive adhesives are releasably securable to one another to form a closure, and the upper adhesive surface of (i) the first pressure sensitive adhesive, (ii) the second pressure sensitive adhesive, or (iii) both the first pressure sensitive adhesive and the second pressure sensitive adhesive comprises a plurality of standoffs defining a modified surface topography; wherein the standoffs are provided by elongated lines, fibrils, or filaments of different lengths and/or thicknesses disposed in a random distribution and at least two of the plurality of standoffs on a given adhesive partially overlap with one another; wherein the standoffs are formed by non-adhesive materials comprising a hot melt with a softening point of 67 C. or higher, sprayed on the upper surfaces of the pressure sensitive adhesive layers; wherein the standoffs have a height in the range of 2 to 500 and a width in the range of 20 to 120; and wherein the upper surfaces of the pressure sensitive adhesive layers have a surface coverage by the standoffs in the range from about 10% to about 50%.
45. An article having a first surface and a second surface adapted to be releasably joined together, the article comprising an adhesive closure system comprising: a first pressure sensitive adhesive having an upper adhesive surface disposed on the first surface; a second pressure sensitive adhesive having an upper adhesive surface disposed on the second surface; wherein the upper adhesive surfaces of the first and second pressure sensitive adhesives are releasably securable to one another to form a closure, and the upper adhesive surface of (i) the first pressure sensitive adhesive, (ii) the second pressure sensitive adhesive, or (iii) both the first pressure sensitive adhesive and the second pressure sensitive adhesive comprises a plurality of standoffs defining a modified surface topography; wherein the standoffs are provided by elongated lines, fibrils, or filaments of different lengths and/or thicknesses disposed in a random distribution and at least two of the plurality of standoffs on a given adhesive partially overlap with one another; wherein the standoffs are formed by non-adhesive materials comprising a hot melt with a softening point of 67 C. or higher, sprayed on the upper surfaces of the pressure sensitive adhesive layers; wherein the standoffs have a height in the range of 2 to 500 and a width in the range of 20 to 120; and wherein the upper surfaces of the pressure sensitive adhesive layers have a surface coverage by the standoffs in the range from about 10% to about 50%.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0050] The accompanying drawings illustrate various systems, apparatuses, devices and related methods, in which like reference characters refer to like parts throughout, and in which:
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[0075] The following description and the drawings disclose various illustrative aspects. Some improvements and novel aspects may be expressly identified, while others may be apparent from the description and drawings.
DETAILED DESCRIPTION
[0076] Reference will now be made to exemplary embodiments, examples of which are illustrated in the accompanying drawings. It is to be understood that other embodiments may be utilized and structural and functional changes may be made. Moreover, features of the various embodiments may be combined or altered. As such, the following description is presented by way of illustration only and should not limit in any way the various alternatives and modifications that may be made to the illustrated embodiments. In this disclosure, numerous specific details provide a thorough understanding of the subject disclosure. It should be understood that aspects of this disclosure may be practiced with other embodiments not necessarily including all aspects described herein, etc.
[0077] As used herein, the words example and exemplary means an instance, or illustration. The words example or exemplary do not indicate a key or preferred aspect or embodiment. The word or is intended to be inclusive rather than exclusive, unless context suggests otherwise. As an example, the phrase A employs B or C, includes any inclusive permutation (e.g., A employs B; A employs C; or A employs both B and C). As another matter, the articles a and an are generally intended to mean one or more unless context suggest otherwise.
[0078] Provided is an adhesive closure system. In embodiments, the closure system is a two-part tape based closure system comprising a first tape having a first pressure sensitive adhesive surface and a second tape having a second pressure sensitive adhesive surface, wherein the first pressure sensitive adhesive and/or the second pressure sensitive adhesive is modified to provide a surface having a reduced tack. The modified pressure sensitive adhesive surface is modified such that the surface has a relatively low tack or is non-tacky. The modified pressure sensitive adhesive surface has a tack such that an object, e.g., a finger, contents of a container, etc., can move over the modified pressure sensitive adhesive without sticking. The closure system with the modified pressure adhesive surface(s) allows for the pressure sensitive adhesive surfaces to be brought together and adhered to one another (to form a seal or closure), but the modified surface(s) allows for the surfaces to be separated from or pulled apart from one another. The sealing and unsealing may be repeated numerous times to operate as a resealable closure system.
[0079] Referring to
[0080] The respective components of the closure system comprise a pressure sensitive adhesive. The pressure sensitive adhesive may be provided as a transfer tape, a double-sided tape, or coated on a facestock such as, for example, a paper, a film, or a foil. Referring to
[0081] As described above, one or both parts of the closure system may be modified to provide the reduced tack surface. Referring back to
[0082] One or both of the pressure sensitive adhesives is modified to produce a pressure sensitive adhesive surface having a relatively low, or non-tacky surface. The modified surface having a low or non-tacky surface may also be referred to herein as a detack surface. The pressure sensitive adhesive is modified by an additive that is either (i) admixed with the pressure sensitive adhesive and coated to form the tape, or (ii) applied to a coated pressure sensitive adhesive surface. The additive employed to modify the surface may be referred to herein as a detack layer or detackified surface. Applying the additive to a coated pressure sensitive adhesive surface may be accomplished by any suitable method including, but not limited to, spraying, sprinkling, printing, brushing, dusting, etc.
[0083] The pressure sensitive adhesive employed as part of the tape system is not particularly limited and may be chosen as desired for a particular purpose or intended application. The PSA can be solvent, emulsion, or warm/hot melt based and can be removable or permanent. The PSA can be cured subsequent to coating using any of a number of crosslinking mechanisms such as ionic, hydrogen bonding, chemical, or mixtures thereof and using stimuli such as thermal, UV, IR, or EB radiation. Any of a number of PSAs from suppliers such as Dow, Henkel, BASF, and Avery Dennison can be used for making these two-part tape-based closure system. Some examples of hot melt PSAs that can be used are HL 8005X, Swiftmelt 82674PW, HL 2811-PW from HBFuller and FA 20, Hammerlock, R128 and Z3000 from Avery Dennison. Some examples of emulsion PSAs are AT20, AT20A, E898 from Avery Dennison. The choice of PSA is dictated by requirements such as adhesion under refrigerator or freezer conditions, adhesion under wet conditions, adhesion to wet surfaces, adhesion under oily and fatty conditions, adhesion to oily and fatty surfaces, adhesion after powdery and other particulate contaminants have been poured across the tape surface, FDA requirements for direct or indirect food contact, etc. The PSA may be provided in a coat weight of from about 10 gsm to about 100 gsm; from about 20 gsm to about 80 gsm; even from about 40 to about 60 gsm. In one embodiment, the coat weight is from about 20 to about 40 gsm.
[0084] The pressure sensitive adhesive is modified to provide a modified surface topography that will reduce the tack of the pressure sensitive adhesive.
[0085] The type, modulus, particle size, shape, height, amount, and coverage of the PSA surface with the additive controls the level of tack of the PSA surface and slidability of the finger along the surface. The amount of additive controls the contact made between the PSA of the two surfaces and the peel value when the two surfaces are brought together and bonded using applied pressure. Too little additive provides low surface coverage of the additive, and high contact area between the adjoining PSA surfaces leading to a strong bond, while too much additive leads to a weak bond.
[0086] It will be appreciated that
[0087] In one embodiment, the filler material is admixed with the pressure sensitive adhesive prior to coating. The additive is provided such that, upon formation of the pressure sensitive adhesive surface (e.g., via drying or curing or merely coating), the particles protrude or project from the surface of the adhesive. In another embodiment, the standoffs may be provided by applying an additive or material to a pressure sensitive adhesive. In such embodiments, the additive may be applied to the pressure sensitive adhesive surface by any suitable method including, but not limited to, printing, spraying, sprinkling, dusting, brushing, etc.
[0088] The standoffs may be provided in a random array or in a regular or uniform pattern. Methods such as printing may be required to provide the standoffs in a regular/uniform pattern. This allows a user to control the surface topography of the pressure sensitive adhesive. The standoffs may be provided as discrete dots or shapes or may be provided as a series of lines or filaments or fibrils of a uniform or varied (i.e. non-uniform) length or thickness. When provided as lines (including as filaments or fibrils) or shapes of a substantial length, the lines may be provided as uniform or random lines and may be straight, curved, undulating, zig-zag, stepped, etc.
[0089] Examples of suitable fillers include, but are not limited to, inorganic fillers, polymeric beads, etc. Some specific examples of suitable materials for providing the standoffs include, but are not limited to, hollow Expancel polymeric beads from Akzo Nobel, solid, elastic polymeric beads from any of a number of suppliers, or inorganic fillers such as CaCO.sub.3 from JM Huber Corporation. Inorganic fillers and polymer particles may be provided by admixing the inorganic filler or polymer particles into the pressure sensitive adhesive prior to coating. Alternatively, the inorganic filler or polymer particles may be applied to the surface of a pre-coated pressure sensitive adhesive by spraying, dusting, sprinkling, etc.
[0090] In other embodiments, the standoffs may be provided by inks, elastomeric materials, polymeric materials, etc. In embodiments, the standoffs may be provided by hot melt or emulsion polymers. In one embodiment, the standoffs are provided by an emulsion polymer. Such materials may be applied to the surface of a pressure sensitive adhesive by any suitable method including, but not limited to, printing and spraying. The modulus of the polymeric or elastomeric material should be in the range from just below Dahlquist criterion (10.sup.6 dyne/cm.sup.2) and higher. In embodiments, the elastomeric or polymeric material has a modulus of about 0.510.sup.6 dyne/cm.sup.2 or greater. Various hot melts can be used for spraying onto the PSA surface, such as Advantra PHC 9200 (softening point (SP) of 102 C.) from HB Fuller, 3H049B (SP of 82 C.), HL 7216 (SP of 74 C.), PHL 4157 (SP of 67 C.), HL-0842S (SP of 155C), Swifttherm 84659 (SP of 117 C.) etc.
[0091] In one embodiment, spraying with a hot melt polymer can be carried out using any suitable spray system. An example of a suitable spray system includes, but is not limited to, a Nordson Universal spray nozzle system. Any of a number of different nozzle types to control the filament size and pattern may be used to accomplish spraying. Some nozzle types include the Continuous signature nozzles, Intermittent signature nozzles, and Control coat nozzles made by Nordson.
[0092] Liquid based inks can also be used for modifying the PSA surface to provide the standoffs. The inks can be either printed or sprayed. In the lab, a multi-purpose Professional air brush kit such as from Apontus can be used for modifying the PSA surface to provide low to no tack, with good self-stick characteristics.
[0093] The adhesion (peel value) of the resulting modified PSA can be varied using a number of variables including, for example, the type of PSA and the coat weight, the height of the standoffs, the diameter or width of the standoffs, the modulus of the standoff, the coat weight of the additive, and the surface coverage. The peel value is also dependent on the flexural modulus and stiffness of the laminate controlled by a number of factors: modulus and stiffness of the facestock material such as PET, BOPP and such, the type of PSA (stiffness and coat weight, i.e. thickness) used to laminate the tape to the bag and the stiffness of the bag material. All these can be manipulated to control the level of detackiness and the adhesion.
[0094] The height of the standoffs may be selected as desired for a particular application or intended purpose. Smaller standoffs (i.e. lower height standoffs) will provide a higher level of adhesion between the tapes, which will provide a tighter seal and require a greater force to open the closure. The height of the standoffs may range from a few microns to several hundred microns. In one embodiment, the height of the standoff is from about 2 m to about 500 m; from about 10 m to about 300 m; from about 25 m to about 250 m; from about 50 m to about 150 m; even from about 75 m to about 100 m. Intermediate heights can be achieved using non-tacky or slightly tacky microspheres or fillers such as CaCO.sub.3 having diameters in the range of interest such as 10 to 100 m. Larger heights can be achieved using the Nordson spray unit.
[0095] In embodiments, the standoffs may have a diameter, circumference, or thickness of from about 5 m to about 500 m; from about 10 m to about 250 m; from about 25 m to about 150 m; even from about 50 m to about 100 m.
[0096] The dimensions of the standoffs and the space between the standoffs and/or surface coverage of the standoffs may be varied to control the bond strength of the reclosure system. For example, the larger the height of the standoff, the greater the distance may be between the standoffs to still achieve a relatively high adhesion. The adhesion is controlled, however, to allow for sufficient adhesion when the modified tape surfaces are brought together, but separated from one another on application of a suitable force.
[0097] The coat weight of the printed or sprayed standoffs may be in the range of from about 2 gsm to about 40 gsm; from about 5 gsm to about 30 gsm; even from about 2 to about 25 gsm.
[0098] The standoffs, whether premixed with the pressure sensitive adhesive or later applied to a pressure sensitive adhesive surface, may be provided at a concentration to provide a particular surface coverage. The standoff surface coverage will also contribute to the level of adhesion between the tape surfaces. In embodiments, the standoffs cover from about 5% to about 60% of the total surface area of the pressure sensitive adhesive; from about 10% to about 50%; from about 15% to about 45%; even from about 20% to about 30% of the total surface area of the pressure sensitive adhesive.
[0099] The peel value is also dependent on the flexural modulus and stiffness of the laminate controlled by a number of factors including, for example, the modulus and stiffness of the facestock material such as PET, BOPP, etc., and the type of PSA (stiffness and coat weight, i.e. thickness) used to laminate the tape and the container material.
[0100] The T peel value of the tape to tape laminate (attached to the bag material) can be tailored depending on the application, ease of opening and the number of reclosures needed, and can range from as low about 0.2 N/inch to about 20 N/inch; from about 0.5 N/inch to about 10 N/inch; from about 1 N/inch about 5 N/inch; even from about 2 N/inch to about 4 N/inch. In embodiments, the system has a T Peel value of at least 0.5 N/inch or higher after 10 reclosures. In embodiments, the system has a T Peel value of 0.5 N/inch to 15 N/inch; from 1 N/inch to 10 N/inch, or from 2 N/inch to 4 N/inch after 10 reclosures. Methods of evaluating T Peel are described herein.
[0101] The tape product can be further enhanced by using colored inks or other colored additives in the spray, ink, or additive such that one part of the tape has color A, and the other part of the tape has color B so that when the tapes are adhered to one another and arranged in a closed or sealed configuration it leads to a secondary color C indicating that complete closure has taken place. Other functionalities can be contemplated in the tape (either formulated in the adhesive or in the surface modifier) such as tamper evidence, proof of sterilization, anti-bacterial feature to prevent ingress of pathogens, oxygen absorption feature to prevent ingress of oxygen, a PSA that is water resistant to create a waterproof seal, and such.
[0102] The tape may be sized and dimensioned as desired for a particular purpose or application. In one aspect, the tape may be sized with a desired width and length to allow for attachment of the tape to a substrate at a desired or selected processing speed. In embodiments, the tape may have a width of from about 0.25 inches to about 3 inches; from about 0.5 inches to about 2 inches; or from about 1 inch to about 1.5 inches. The tape length may vary as desired. In embodiments, the tape has a length of from 0.5 inches to about 60 inches; from about 1 inch to about 45 inches; from about 2.5 to about 30 inches; from about 5 to about 25 inches; from about 10 to about 20 inches.
[0103] The tape closure system can be used for a wide range of closure applications and articles utilizing such enclosures. In embodiments, the tape is particularly suitable for use with a flexible package, or a flexible substrate that is attached to a rigid package structure (including, by way of exemplary embodiments, a film or foil lid attached to a plastic cup or holder). The tape closure system may be applied to a variety of materials that are employed to make such containers or packages. Flexible packages may be made from a variety of materials including, by way of exemplary embodiments, polymeric materials, paper, nonwoven materials, foils, and other such materials. Polymeric films are often used to make flexible packages. Suitable polymeric films include, by way of exemplary embodiments, polyolefins, polyesters, nylon materials, etc. Films are typically biaxially oriented polypropylene films, but may be polyester, nylon, cellophane and/or polylactic acid films. Polymeric films produced with a cast or blown process can be used, but their lower machine direction tensile strength and excessive extensibility under tension or under thermal exposure may prevent adequate lamination. These biaxially-oriented polymeric films are typically used as the outer film and the inner film in a composite laminated structure. The above-identified embodiments are exemplary and for the sake of brevity not all applicable package structures are included. The present teachings, however, can apply to any type or configuration of package structures.
[0104] Examples of suitable flexible packages include, but are not limited to: [0105] Pillow pouch packages. These packages are sealed on the top and bottom of the package with a vertical seam. Such packages are used with cereal, potato chips, pretzels, etc. The packages may be formed from any suitable material, including, without limitation any type of food safe material. [0106] Stand up pouches, which are typically employed with candy, snacks, liquids, etc. The pouches may be formed from any suitable material, including, without limitation any type of food safe material. Moreover, the pouches may be of any configuration and are not limited to those shown. [0107] Flat bottom bags used for coffee, pet food, or to store large volumes of material. The flat bottom bags may be formed from any suitable material, including, without limitation any type of food safe material. [0108] Double seam consumer bags (e.g., bread bags). The double seam consumer bag may be formed from any suitable material, including, without limitation any type of food safe material. [0109] Bar wrap packages (e.g., for candy bars, snack bars, protein bars, etc.). The bar wrap packages may be formed from any suitable material, including, without limitation any type of food safe material. [0110] Flexible overwrap packages (e.g., for cookies). The flexible overwrap packages may be formed from any suitable material, including, without limitation any type of food safe material. [0111] Flexible lid on a rigid package. The flexible lid may be formed from any suitable material, including, without limitation any type of food safe material.
Persons skilled in the packaging art will understand and appreciate the types of packages described above and will understand that the present teachings apply to any applicable configuration of packaging.
[0112] The tape closure system can be employed in articles and packages used for a variety of applications and to store a wide range of materials. The tape may be used in articles as for packaged goods such as pet food bags; prepackaged foods such as cereal; snacks such as chips, cookies, crackers; pre-packaged cheese and meats; confectionary; coffee; nutritional foods; food storage bags; other applications such as in personal care (tissues, diaper tapes and such), or medical, industrial, and other business to business applications. These tapes can also be used for pre-made bags which are used to store all kinds of food and non food items.
[0113] In one embodiment, the tape may be attached to the flexible substrate. The tape employed may be a two-sided tape (e.g., as illustrated in
[0114] The two-part adhesive system is applied to the surfaces of the article that are to be joined together to selectively close or seal the article. By way of a non-limiting example, in a package (e.g., a food package) provided as a bag, the article (or more specifically the package) may comprise opposing sidewalls formed from a flexible material each having an inner surface with an opening at one end between the two sidewalls. Referring to
[0115] The tape may be applied to the flexible material in any suitable manner. The tape can be attached to the flexible material using automatic dispensing equipment in a continuous or intermittent manner. The tape can be attached through a manual process as well. The tape could be applied to the flexible material in the same direction as the package making process (i.e., in the machine direction (MD)), perpendicular to the package making process (i.e., in the transverse direction (TD)), or in any direction that is efficient to the applicable system. For example, the direction could be at a generally 45 degree angle relative to the direction of the package making process. The present teachings contemplated any variation of such angles. A tape dispensing mechanism may be incorporated into the unit to form the packaging. The tape dispensing mechanism may be of any appropriate configuration and type. The tape dispensing mechanism can allow for modifications to the location at which the tape is applied, can have a standard location that is not readily adjustable, or can comprise a combination of such. The tape dispensing mechanism may be manually controlled or controlled through a processor device, e.g., a computer or the like.
[0116] The tape can be applied to the flexible material off line and prior to filling the package, or the tape can be applied to the flexible material in situ as the bag is formed and filled with the desired contents. In embodiments, the tape is applied to the package in situ as the bag is filled with the desired contents. The tape can be applied in systems including vertical form fill and seal systems 300 and horizontal form fill and seal systems 400. It should be understood, however, that these are merely exemplary locations and that the tape can be applied in any appropriate direction relative to the applicable package. An example of a vertical film form and seal system 300 is illustrated in
[0117] Examples of horizontal form fill and seal systems 400 are shown in
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[0120] The following examples illustrate embodiments in accordance with aspects of the present teachings. Various pressure sensitive adhesives were modified with an additive material to provide a modified surface topography (also referred to as a detack layer or detack surface). The term PET and Mylar are used interchangeably in the examples and tables.
[0121] T Peel Measurements
[0122] The laminates were made by attaching the PSA layer 210 (such as S 246 from Avery Dennison at 18 gsm coat weight) from
[0123] In examples where food stuff such as cereal, chips, or other contents of a bag were used to test the adhesion of the adhesive after pouring the food stuff across the adhesive surface, the following method was used:
The tape with the adhesive surface was attached to the side of a cardboard jig having a 45 degree angle. The food stuff was poured across the tape, and the method described in the previous paragraph was employed to evaluate T Peel. T Peel was measured after 1, 5, and 10 closures.
[0124] Friction Test
[0125] A one inch sample of the laminate was laid down on a stationary stainless steel panel with the detack layer touching the stainless steel panel. A 200 gram weight was placed on top of the tape, and the end of the tape was attached to a Fish Scale AdiyZ portable electronic scale. The digital scale was pulled at a constant speed of 3.85 feet/min. with the tape moving across the stainless steel panel with the 200 gram weight on top of the tape. The frictional force of the detack/pressure sensitive adhesive layer moving across the stainless steel panel with the 200 gram weight on the tape is recorded in pounds (lb). Swifttherm 84659 and Advantra PHC 9200 yielded values of 0.18 and 0.3 lb. respectively.
[0126] Detack Surface Coverage Measurement
[0127] A digital photo of the detackified pressure sensitive adhesive surface was taken using an Ablegrid 2 Megapixel USB digital microscope. The image was analyzed using an ImageJ analyzer, which is an NIH free-ware. The surface coverage was recorded as a percentage of the total area covered by the detack layer.
[0128] Detack Coat Weight Measurement
[0129] The coat weight of the detack layer on the pressure sensitive adhesive was measured gravimetrically by first measuring the weight of a 2 inch by 2 inch area of the pressure sensitive adhesive with the film and subtracting it from the total weight of the detack layer/pressure sensitive adhesive/film.
[0130] Width of the Filament
[0131] A digital photo of the detackified pressure sensitive adhesive was taken using an Ablegrid 2 Megapixel USB digital microscope. The particle size and distribution of the spray coated samples was determined using ImageJ software. The filament width (with hot melt sprayed detack layer) was measured directly from the image and averaged.
Example 1
[0132] A hot melt adhesive HL 8005 X from HB Fuller was printed using nylon mesh screens (Component Supply Company) with the following Food Grade inks from Colorcon: FGN 5427 Black No Tox Direct contact printing ink, FGN 5474 Blue No Tox Direct contact printing ink, and FGN 5424 Yellow No Tox Direct contact printing ink. The following nylon mesh screens were used: 52 microns (32% open area), 64 microns (47% open area), and 25 microns (15% open area).
TABLE-US-00001 TABLE 1 PSA T coat Mesh T Peel, Peel, T Peel, wt size Ink coat Colorcon 30 min 24 hr 7 days Example gsm m wt, gsm Ink Type N/in N/in N/in Control 25 2.3 3 3.3 1.1.1 25 25 10.9 FGN 2 2.3 2.9 5427 1.1.2 25 25 15.8 FGN 1.1 1 1.5 5427 1.1.3 25 52 6.2 FGN 1.3 1.8 5427 1.1.4 25 52 11 FGN 1.6 1.7 1.4 5427 1.1.5 25 64 15.5 FGN 1.1 1.1 2.2 5427 1.1.6 25 64 21.9 FGN 0.5 0.2 0.5 5427 1.1.7 45 25 12.9 FGN 1.9 1.9 1.8 5424 1.1.8 45 64 12.1 FGN 1.1 1.2 1.8 5424 1.1.9 25 64 18.9 FGN 0.9 0.6 0.6 5424 1.2 45 25 11 FGN 1.9 1.6 1.8 5474 1.2.1 45 64 24.8 FGN 0.35 0.5 0.6 5474 1.2.2 45 64 19 FGN 0.6 0.3 0.4 5474 1.2.3 45 64 26 FGN 0.2 0.2 0.2 5474
Example 2
[0133] The hot melt adhesive HL 8005X coated on 2 mil Mylar was sprayed with a hot melt elastomer, PHC 9200 from HB Fuller. The spraying was carried out with a Nordson Universal spray nozzle system using low flow continuous signature, intermittent signature, and control coat nozzles using the VB12 unit and using low flow gear pump pR6m1 (flow rate of 0.83 g/cc per rev). The T Peel data of modified adhesive to adhesive on Mylar is shown in Table 2. The surface coverage is the percentage of PSA surface covered by the additive. The finger slide rating in Table 2 is rated from 5 being non-tacky to touch to 1 being tacky to touch. Several of the sprayed surfaces are shown in
TABLE-US-00002 TABLE 2 PSA T coat Pattern Air Pattern Line Gun Pump Finger Peel wt Nozzle pressure Air speed height speed Surface slide 30 min Example gsm Type (psi) Temp F. (fpm) inch (rpm) coverage % Rating N/in 2.1 15 Low Flow 8 275 200 3 3 16.3 4 0.15 Cont. Sig. 2.1.1 15 Low Flow 8 275 150 3 3 20.2 4 0.4 Cont. Sig. 2.1.2 30 Low Flow 8 275 175 3 3 15.4 4 0.7 Cont. Sig. 2.1.3 30 Low Flow 8 275 150 3 3 21 4 0.4 Cont. Sig. 2.1.4 45 Low Flow 8 275 200 3 3 19 4 0.8 Cont. Sig. 2.1.5 45 Low Flow 8 275 175 3 3 22.1 4 0.26 Cont. Sig. 2.1.6 45 Low Flow 8 275 150 3 3 29 3 0.14 Cont. Sig. 2.2 15 Intermittent 20 275 150 2.5 3 12.1 3 0.4 Sig. 2.2.1 15 Intermittent 8 275 175 3 3.25 19.2 4 0.25 Sig. 2.2.2 30 Intermittent 8 275 150 3 3.25 21.5 4 0.36 Sig. 2.2.3 30 Intermittent 8 275 100 3 3.25 24 5 0.3 Sig. 2.2.4 30 Intermittent 8 275 125 3 3.25 26.1 5 0.12 Sig. 2.2.5 45 Intermittent 8 275 200 3 3.25 25.2 4 0.2 Sig. 2.2.6 45 Intermittent 8 275 180 3 3.25 29.1 4 0.3 Sig. 2.2.7 45 Intermittent 8 275 150 3 3.25 32.8 5 0.2 Sig. 2.3 30 Control 20 275 100 2.5 3 19.1 0.4 coat 2.3.1 30 Control 20 275 120 2.5 3 22.5 0.3 coat 2.3.2 30 Control 20 275 150 2.5 3 28.7 0.6 coat 2.3.3 45 Control 20 275 85 2.5 3 23.9 1 coat 2.3.4 45 Control 20 275 60 2.5 3 27 0.8 coat 2.3.5 45 Control 20 275 45 2.5 3 30.8 0.6 coat
Example 3
[0134] A hot melt PSA HL 8005X from HB Fuller was coated on a paper liner (from Chemsultants) at 40 gsm coat weight and laminated to 2 mil Mylar from Chemsultants. The liner was removed and CaCO.sub.3 (Hubercal 150FG) from Huber Engineered Materials was sprinkled evenly onto the surface at various coat weights. This PSA surface was non-tacky to the touch and a finger could easily slide over it. Strips of this surface modified PSA brought together and pressed with fingers formed a good seal and could be repeatedly opened and closed. The coat weight of CaCO.sub.3 was 12.1 gsm, average particle diameter on surface was 42 m and 30 min T Peel was 3.75 N/inch.
Example 4
[0135] The hot melt adhesive HL 8005X coated on 2 mil Mylar was sprayed using an air brush with the following Food Grade ink from Colorcon: FGN 5427 Black No Tox Direct contact printing ink. Half inch strips of the sprayed PSA surfaces were brought together and rolled with a 2 kilogram (kg) roller, allowed to dwell for 30 minutes, 24 hours, and 8 days, and the T Peel value was measured. Data is shown in Table 4.
TABLE-US-00003 TABLE 4 Av T T T PSA Ink coat particle Peel, peel, peel, 8 PSA coat wt wt Colorcon Ink diameter 30 min 24 hr days Example type gsm gsm Ink Type coverage % (m) N/in N/in N/in 4.1 HL 25 7.3 FGN 10.60 36 3 4.2 4 8005X 5427 4.2 HL 25 10 FGN 12.4 38 2.4 4 4.6 8005X 5427 4.3 HL 25 11.6 FGN 16.4 40 2.2 2 8005X 5427 4.4 HL 25 12.4 FGN 32.5 56 1.6 2.4 8005X 5427
Example 5
[0136] Three hot melt PSAs from Avery Dennison, FA20, R128, Z3000 coated on 1 mil PET facestock were sprayed with Colorcon FGN 5427 Black ink at various coverages. The other side of PET was laminated to a transfer tape of Avery Dennison Hammerlock adhesive coated at around 30 gsm. The free side of the Hammerlock adhesive was laminated to 2 mil HDPE film. Half inch strips of the sprayed PSA surfaces were brought together and rolled with a 2 kg roller, allowed to dwell for 1 hour and tested in a T Peel configuration using the Labthink XLB(B) tester at 300 mm/min. Data is shown in Table 5.
TABLE-US-00004 TABLE 5 Av PSA particle T Peel, PSA coat wt, Ink coat Colorcon Ink diameter 1 hr, Example type gsm wt, gsm Ink Type coverage % (m) N/in 5.1 AD 30 0 3 FA20 5.1.1 AD 30 7.7 FGN 12.2 3.3 FA20 5427 5.1.2 AD 30 9.3 FGN 19.4 3.3 FA20 5427 5.1.3 AD 30 10 FGN 21.3 2.7 FA20 5427 5.2 AD R- 30 0 6.7 128 5.2.1 AD R- 30 7.8 FGN 14.6 39 4.2 128 5427 5.2.2 AD R- 30 9 FGN 19.3 3.8 128 5427 5.2.3 AD R- 30 9.8 FGN 24.6 2.6 128 5427 5.3 AD Z- 30 0 10.5 3000 5.3.1 AD Z- 30 7.6 FGN 11.2 6.2 3000 5427 5.3.2 AD Z- 30 8.9 FGN 17.6 6.2 3000 5427 5.3.3 AD Z- 30 9.9 FGN 24.3 3.6 3000 5427
Example 6
[0137] The hot melt adhesives of the examples coated on 1 mil Mylar at 30 gsm coat weight were sprayed with detack layer on a Nordson VB12 table top unit. The nozzle type was Continuous Signature Low flow, the pattern air temperature was 275 F., the line speed was 275 feet per minute, the gun height was 2.5 inches, and the pump type was PR6M1 with a feed rate of 0.93 g/revolution. The PSA types used were ADZ3000 (A), AD FA 20 (B), AD R128 (C), and Fuller8005 (D). The detack materials used were Fuller PHC 9200 (E) and PHL 4157 (F). This laminate was used for T Peel testing. T Peel was measured after 1, 5, and 10 laminations. The results are shown in Table 6.
TABLE-US-00005 TABLE 6 PSA Detack T peel after coat Pattern Air Pump coat Detack reclosures, Width of the PSA wt. pressure Speed Detack weight surface N/inch Friction detack Example type gsm (psi) (rpm) Material gsm coverage % 1 5 10 test, lb filament, Control 1 mil 0 None 0 0 0.11 Mylar, No PSA 6.1 A 30 10 15 E 4.1 37.1 7.2 9 8.5 0.35 30-120 6.2 A 30 10 20 E 5.2 41.3 4.9 4 4 0.42 25-95 6.3 A 30 12 15 E 5.7 50.7 4.1 4.7 5.7 0.56 20-120 6.4 A 30 12 10 E 2.5 46 5.8 7 8.3 6.5 A 30 10 25 E 7 44.4 2.3 3.1 3.3 0.36 6.6 A 30 14 10 E 2.9 52.7 8 7.4 8.2 0.78 6.7 A 30 14 6 E 43.9 5.8 7.5 8.5 1.11 15-50 6.8 B 30 10 15 E 4.2 25.4 4.9 4.2 5.7 1.8 20-50 6.9 C 30 10 15 E 3.8 28.5 3.1 5.4 4.6 1.6 6.10 D 44 10 15 E 38.7 1.2 0.8 0.7 1.76 (transfer)* 6.11 A 30 10 15 F 4.3 25.5 3.9 4.3 8 6.12 B 30 10 20 F 5.9 19.8 5.3 6.3 7.5 2.15 6.13 C 30 10 25 F 6.4 27.7 3.2 4.8 6.1 1.78 6.14 D 44 10 15 F 5.4 29.2 0.4 0 0 2.2 (transfer)* *Some of the detack layer transferred to the SS panel
Example 7
[0138] T Peel data after a different number of reclosures was evaluated with and without cereal poured across the tape. Cheerios were employed as the cereal and in each case, 1 cup of cereal was poured across each time. Table 7 shows results of these tests.
TABLE-US-00006 TABLE 7 Finger slide rating Detack PSA before T Peel after coat coat Detack and reclosures, N/inch weight, wt, Surface after Friction Ex. Sample 1 5 10 gsm gsm Coverage % reclosures test, lb Control 1 mil Mylar film 0.11 (Chemsultants) 7.1 Avery Z3000 11 9.2 8.73 30 1 Too high, CNM* 7.2 Avery Z3000 + 5 2.53 0.82 30 Cheerios 7.3 Fuller Swiftmelt 32 38 26 30 1 Too 82674 high, CNM* 7.4 Fuller Swiftmelt 20 6.67 2.3 30 82674 + Cheerios 7.5 Fuller HL2811 PW 18.83 17.7 16.1 30 1 Too high, CNM* 7.6 Fuller HL2811 8.67 4.1 1.73 30 PW + Cheerios 7.7 Avery Z3000 11 9.2 8.73 30 1 Too high, CNM* 7.8 Avery Z3000 + 9200 7.2 9 8.5 4.1 30 37.1 5 0.35 detack (Ex 6.1) 7.9 Avery Z3000 + 5 2.53 0.82 30 Cheerios 7.10 Avery Z3000 + 9200 4.6 1.71 0.4 4.1 30 5 detack(Ex 6.1) + Cheerios 7.11 Avery Z3000 + 9200 6.2 3.93 0.85 2.94 30 52.7 5 detack(Ex6.6) + Cheerios 7.12 Avery Z3000 + 9200 4.4 2.5 0.68 4.1 30 43.9 5 detack(Ex 6.7) + Cheerios 7.13 Avery FA 20 4.13 4.3 4.63 30 Too high, CNM* 7.14 Avery 3.9 2.13 0.53 30 FA20 + Cheerios 7.15 Avery R128 3.6 2.8 2.4 30 1 Too high, CNM* 7.16 Avery R128 + 9200 3.1 5.4 4.6 3.8 30 28.5 5 1.6 detack (Ex 6.9) 7.17 Avery R128 + 9200 2.4 1.37 0.86 30 detack(Ex 6.9) + Cheerios 7.18 Fuller 8005 1.2 0.8 0.7 44 1 Too high, CNM* 7.19 Fuller 8005 + 9200 0.24 0 0 44 detack(Ex 6.10) + Cheerios *CNM = could not measure - PSA was sticking to the SS panel too strongly and it was not possible to pull it along
In the case of the tape without the detack layer, the surface is very sticky and the cereal sticks to the tape. The cereal remained stuck to the tape and had to be shaken off. With the detack layer, the surface is slidable to the finger, and the cereal slid right off the surface without sticking as illustrated by the high finger slide rating and low friction test. The surface of the 1 mil Mylar film against the stainless steel had a friction of 0.11 lb. Example 1 with Z3000 PSA with Fuller PHC 9200 as the detack layer gave a friction of 0.35 lb. The Z3000 adhesive without the detack layer had a friction that was too high to measure.
[0139] The T Peel values drop with the number of reclosures due to contamination of the adhesive surface. The openings between detack filaments or the features on the surface for getting the finger slidability are chosen so that they are smaller than the cereal being poured across the tape surface. Some fine food particles that are present in the bag, however, may fall between the filaments or other features used for detackifying the surface, leading to a reduction in T Peel. The adhesive choice, amount of detack layer, the pattern, the overall stiffness of the laminate, etc., are used to regulate the peel such that even after multiple pours across the tape surface, the tape still retains adequate adhesion to tightly seal the bag contents. A T Peel after 10 such reclosures on the order of 0.4 N/in or higher is generally sufficient to tightly seal a package.
Example 8
[0140] Table 8 shows data from tests evaluating a metallized Mylar bag of potato chips (Lays). Example 6.1 of Table 6 was used as the pressure sensitive adhesive/detack layer on 1 mil Mylar. The PSA/detack layer was attached to the metallized bag using the S 246 transfer tape.
TABLE-US-00007 TABLE 8 T Peel after Detack reclosures, coat PSA Detack N/inch weight, coat wt, Surface Friction Example 1 5 10 gsm gsm Coverage, % test, lb 8.1 1.9 1.7 0.6 4.1 30 37.1 0.35
Example 9
[0141] Two half inch by half inch strips of the tape of Example 6.1 were put together in such a way that the overlap area was 0.5 inches by 0.5 inches. This laminate was placed on a hard surface and the overlapped area was rolled up and down with a 2 kg rubber roller. After a 30 minute dwell time, the ends of the tape were placed in the jaws of the Labthink tester and separated at a speed of 300 mm/min. The dynamic shear value was measured to be 26 N/0.25 square inches.
[0142] What has been described above includes examples of the present specification. It is, of course, not possible to describe every conceivable combination of components or methodologies for purposes of describing the present specification, but one of ordinary skill in the art may recognize that many further combinations and permutations of the present specification are possible. Accordingly, the present specification is intended to embrace all such alterations, modifications and variations that fall within the spirit and scope of the appended claims. Furthermore, to the extent that the term includes is used in either the detailed description or the claims, such term is intended to be inclusive in a manner similar to the term comprising as comprising is interpreted when employed as a transitional word in a claim.
[0143] The foregoing description identifies various, non-limiting embodiments of a tape closure system. Modifications may occur to those skilled in the art and to those who may make and use the invention. The disclosed embodiments are merely for illustrative purposes and not intended to limit the scope of the invention or the subject matter set forth in the claims.