Patent Application
20110097019
This invention relates to an easy-open package with a discrete panel section with an easy-open sealant, and to methods of making the package.
Food and non-food products, including produce, snack foods, cheese, meat, and the like have long been packaged in containers such as pouches, bags, or lidded trays or formed webs made from various thermoplastic materials such as polyethylene, polypropylene, or polyester (PET). These containers can be formed from a web or webs of thermoplastic material on packaging equipment, using various packaging processes, at a processing/packaging facility. Such equipment and processes includes horizontal form/fill/seal (HFFS), vertical form/fill/seal (VFFS), thermoforming/lidstock, and continuous horizontal packaging (sometimes referred to as Flow-wrap). In each case, the product is manually or automatically placed in a pouch, bag, formed web, tray, etc., the filled container is optionally vacuumized or gas flushed, and the mouth of the container is hermetically or non-hermetically sealed to close and finish the package.
Opening of the finished package (i.e. opening with the use of tools such as scissors or knives) can provide access to the product by the consumer.
Common in the industry is the use of plastic zipper closures; press-to-close or slide zippers; interlocking closures; reclosable fasteners with interlockable fastener elements; interlocking rib and groove elements having male and female profiles; interlocking alternating hook-shaped closure members, and the like. These terms appear in the patent literature, and to some extent may overlap in meaning. These features in some cases may provide an easy-open feature to the package.
There is need in the marketplace for a package, and methods of packaging that can be used in a manner that requires little or no modification to the packager's packaging equipment, while providing a manually (i.e. by hand, without the need for tools such as scissors or knives) openable feature, optionally while maintaining hermeticity of the package when made, and without the use of plastic zipper closures; press-to-close or slide zippers; interlocking closures; reclosable fasteners with interlockable fastener elements; interlocking rib and groove elements having male and female profiles; interlocking alternating hook-shaped closure members, and the like.
Some retail packages currently do not offer an easy-open feature. Examples are some produce bags and snack food bags. In the produce market, there is a need for a cost-effective way to manually open retail produce bags, or other packages made in HFFS, VFFS, thermoforming/lidstock, or continuous horizontal packaging processes.
The present invention relates to a package, and methods of making the package, which package is manually openable, and adapted to package non-food products, as well as food products such as e.g. produce, snack foods, cheese, meat, luncheon meat, sausage, culinary nuts, trail mix, etc. The package optionally maintains a hermetic seal until the package is opened.
There is also a need in the marketplace for a discrete panel section that can be anchored to a processor's packaging material of choice to provide easy-open functionality to a package made from that web/panel section combination with only relatively minor modifications to the processor's packaging material, packaging process or equipment.
In a first aspect, an easy-open package comprises:
a pouch comprising
Optionally, according to various embodiments of the first aspect of the invention:
Optionally, according to various embodiments of the second aspect of the invention:
In a third aspect, a method of making an easy-open package in a horizontal form/fill/seal process comprises
Optionally, according to various embodiments of the third aspect of the invention:
In a fourth aspect, a method of making an easy-open package in a horizontal form/fill/seal process comprises
Optionally, according to various embodiments of the fourth aspect of the invention:
In a fifth aspect, a method of making an easy-open package in a vertical form/fill/seal process comprises
Optionally, according to various embodiments of the fifth aspect of the invention:
In a sixth aspect, a method of making an easy-open package in a vertical form/fill/seal process comprises
Optionally, according to various embodiments of the sixth aspect of the invention:
In a seventh aspect, a method of making an easy-open package having a formed web comprises
Optionally, according to various embodiments of the seventh aspect of the invention:
In an eighth aspect, a method of making an easy-open package having a formed web comprises
Optionally, according to various embodiments of the eighth aspect of the invention:
In a ninth aspect, a method of making an easy-open package in a continuous horizontal packaging process comprises
Optionally, according to various embodiments of the ninth aspect of the invention:
In a tenth aspect, a method of making an easy-open package in a continuous horizontal packaging process comprises
Optionally, according to various embodiments of the tenth aspect of the invention:
In an eleventh aspect, a pouch comprises
a first and second side panel each comprising an outer and inner surface, a first and second side edge, and a first and second end, the first and second side panels joined together along their respective first and second side edges with a seal;
Optionally, according to various embodiments of the eleventh aspect of the invention:
In a twelfth aspect, a method of making a bag with a discrete panel section disposed thereon comprises
Optionally, according to various embodiments of the twelfth aspect of the invention:
The present invention is illustrated by reference to the following drawing figures, encompassing different views of various embodiments of the invention, wherein:
“Anchored”, “anchoring” and the like herein refers to sealing or adhering two surfaces together, and refers to the resulting bond between surfaces. Sealing is done by means of a sealant. Adhering is done by means of an adhesive.
In processes described herein where a discrete panel section is anchored to a web or side panel, either during the process wherein the web and discrete panel section are advanced, or when a discrete panel section has been pre-anchored to the web before the start of the process, anchoring can be done by use of any suitable continuous or discontinuous sealing or adhesive material and method. Such anchoring is done to hold the discrete panel section to the web or panel during the relevant packaging process.
In some embodiments, wherein the anchor is already relatively strong or continuous, e.g. a heat seal that constitutes either a relatively strong heat seal, or an easy-open seal as defined herein, the anchor functions not only to hold the discrete panel section to the web or panel during the relevant packaging process, but also as a final seal of that surface of the discrete panel section to the web (lay-flat or folded) or panel made from the web.
Any subsequent disclosed or recited step in the process of sealing one of the surfaces (i.e. the anchored surface) of the discrete panel section to a web or panel, is already completed by the anchoring step. In these embodiments, then, contact of a seal device, e.g. a seal bar in the region of the anchor, in a subsequent step, may in some embodiments add no further or separate seal to that surface of the discrete panel section.
Any subsequent step in the process of sealing the other surface of the discrete panel section to a web or panel, then, may in some embodiments add no further or separate seal to the anchored surface of the discrete panel section.
In some embodiments where the bond is a relatively weak or discontinuous one, e.g. a discontinuous seal, spots or narrow stripes of adhesive. etc., in a subsequent step of sealing one of the surfaces of the discrete panel section to the web or panel, a seal bar that seals one of the surfaces of the discrete panel section to the web or panel can contact the web or panel in the region where the anchor is already disposed. The seal in that region may be either enhanced, or initially created, by the subsequent sealing step.
Sealing of a surface of the discrete panel section to a web or panel, as a process step disclosed or recited herein, should be understood in this light.
“Die cut” herein refers to methods of cutting or scoring materials, including rotary die, steel rule die, platen die cutting, and laser cutting or scoring, and/or the resultant cut or score, other than a die cut used to create the perimeter of a lay-flat or folded web, or package made therefrom, or package made from a formed web and lidstock, or first or second side panel, or discrete panel section of the invention, or to make a hole in the lay-flat or folded web, first or second side panel, or discrete panel section for a hang-tab, gusset or the like. A package of the invention in several embodiments is absent a die cut, absent a die cut in the panel section, and/or absent a die cut in the first side panel.
“Discrete” with respect to the discrete panel section is used herein to mean independently made (the discrete panel section is not an integral part of the web when the web is made,) or constituting a separate entity from the web, and from a first or second side panel made from the web.
“Easy-open” herein refers to a package that can be manually opened relatively easily. The physical mode of opening may include a) actual peeling at the discrete panel section/web interface (adhesive failure), or b) a sealant layer of the panel section breaking completely through, and peeling then occurring between the sealant layer and an adjacent layer within the strip (delamination failure), or c) breaking within a sealant layer by rupturing of the sealant material itself (cohesive failure). The peel force required to open the package can be measured by an evaluation of seal strength or peel strength in accordance with the test procedure set out in ASTM F88, incorporated herein by reference in its entirety, using a cross-head speed of 8 to 12 inches/minute and an initial jaw gap of from 1.00 inch to 2.00 inch. Typical peel forces for opening the package of the invention can range from e.g. 25 grams/inch to 3 pounds/inch, e.g. from 100 grams/inch to 2 pounds/inch, such as from 200 grams/inch to 1.5 pounds/inch. In some cases, the sealant may actually peel away from the surface to which it is adhered (adhesive failure), or breakage of the sealant and delamination along an adjacent layer interface may occur (delamination failure) or a rupture of the sealant can occur (cohesive failure). Depending on the design and geometry of the seal, peel forces can in some embodiments be higher than 3 pounds/inch, e.g. 3.5, 4.0, 4.5, or 5 pounds/inch, or values intermediate these values.
“Easy-open seal” herein refers to a seal involving the discrete panel section and web in which materials and sealing conditions are chosen for the panel section and web such that the package is easy-open with a physical mode of opening of adhesive failure, delamination failure, or cohesive failure as described herein. An easy-open sealant can be used to provide the easy-open seal. Where the easy-open sealant is a removable adhesive, the easy-open seal mechanism is a form of “adhesive failure” discussed further below.
“Easy-open sealant” herein refers to a material chosen for one or both surfaces of the discrete panel section, such that when such surface is sealed to a web, it provides a package that is easy-open with a physical mode of opening of adhesive failure, delamination failure, or cohesive failure as described herein. Alternatively, the material can be a removable adhesive, such as certain PSA materials, that is coated on an external surface of a web or discrete panel section.
“Ethylene/alpha-olefin copolymer” (EAO) herein refers to copolymers of ethylene with one or more comonomers selected from C3 to C10 alpha-olefins such as propene, butene-1, hexene-1, octene-1, etc. EAO includes heterogeneous materials such as linear medium density polyethylene (LMDPE), linear low density polyethylene (LLDPE), and very low and ultra low density polyethylene (VLDPE and ULDPE); single-site catalyzed materials such as homogeneous linear ethylene/alpha olefin copolymers and long chain branched ethylene/alpha olefin copolymers; and multicomponent ethylene/alpha-olefin interpenetrating network resin (or “IPN resin”).
“Ethylene homopolymer or copolymer” herein refers to polyethylene (PE) such as ethylene homopolymer such as low density polyethylene (LDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE); ethylene/alpha olefin copolymer such as those defined herein; ethylene/vinyl acetate copolymer (EVA); ethylene/alkyl acrylate copolymer such as ethylene/methyl acrylate copolymer (EMA) or ethylene/ethyl acrylate copolymer (EEA), or ethylene/butyl acrylate copolymer (EBA); ethylene/(meth)acrylic acid copolymer; or ionomer resin (IO).
“Fig.” and the like herein refers to a drawing figure; “Figs.” and the like herein to drawing figures.
“Film” is used herein to mean a thermoplastic film, laminate, or web, either multilayer or monolayer, that may be used in connection with the present invention. Film can be of any suitable thickness, e.g. between 0.1 and 30 mils.
“Fin seal” is used herein to mean, in the case of a single web, folding one edge of the web towards the opposite edge of the web, and sealing the facing inner surfaces together. In the case of two webs, a fin seal is a seal formed by sealing the inner surface of the edge of one web to the inner surface of a corresponding edge of another web.
“Lap seal” is used herein to mean a seal made by sealing an inside surface of a web to an outside surface of a web. The inside and outside surfaces can both be on a single web; or the inside surface can be of one web, and the outside surface of a second web.
“Lidstock” herein refers to a film used to cover a container or tray that carries a product, and can be sealed to the tray, typically as a perimeter heat seal. Lidstock typically is supplied to a food processor in a lay flat film rolled onto a roll.
“Longitudinal seal” herein refers to a fin seal or lap seal.
“Near” herein means, with respect to the position of the discrete panel section in relation to the package, that the edge of the discrete panel section closest to the first end of the pouch and package will be typically within about three inches of the first end of the pouch. The panel section can be closer than this, such as within about two inches, one inch, 0.75 inches, 0.5, 0.4, 0.3, 0.2, or 0.1 inches of the first end of the pouch.
“Olefinic” and the like herein refers to a polymer or copolymer derived at least in part from an olefinic monomer.
“Oxygen barrier” and the like herein refers to materials having an oxygen permeability, of the barrier material, less than 500 cm3 O2/m2·day·atmosphere (tested at 1 mil thick and at 25° C., 0% RH according to ASTM D3985), such as less than 100, less than 50, less than 25, less than 10, less than 5, and less than 1 cm3 O2/m2·day·atmosphere. Examples of polymeric materials useful as oxygen barrier materials are ethylene/vinyl alcohol copolymer (EVOH), polyvinylidene dichloride (PVDC), vinylidene chloride/methyl acrylate copolymer, vinylidene chloride/vinyl chloride copolymer, polyamide (nylon), and polyester (PET).
“Pouch” herein means a pouch or bag.
“Polymer” and the like herein means a homopolymer, but also a copolymer thereof, including terpolymer, tetrapolymer, block copolymer, etc.
“Repositionable adhesive” as used herein refers to an adhesive, such as certain pressure sensitive adhesives (PSA) that bond firmly with the application of light pressure; can be easily removed; and can be repositioned and reused multiple times, i.e. it can be adhered to a surface, removed, and reapplied to a surface with significant adhesive capability. It adheres to most surfaces with very slight pressure; is available in solvent, latex or water based forms, and hot melt forms, and is often based on non-crosslinked rubber adhesives, acrylics, or polyurethanes. PSA forms viscoelastic bonds that are aggressively and permanently tacky; adhere without the need for more than hand pressure; and require no activation by water, solvent, or heat. Some PSA materials are cured by hot air, electron beam, UV, or chemical (peroxide) means. They are available in a wide variety of chemical compositions and systems including acrylic and methacrylate adhesives, emulsion-based acrylic adhesive; rubber-based pressure sensitive adhesive, styrene copolymers (styrene/isoprene/styrene and styrene/butadiene/styrene block copolymers), and silicones. PSA herein can include hot melt adhesives. A hot melt adhesive is a thermoplastic adhesive compound, usually solid or highly viscous at room temperature which becomes more fluid on heating for application. Repositionable adhesive as used herein is not a removable adhesive as used herein.
“Registration device” herein refers to any mark, pattern, or feature of a web or discrete panel section, that facilitates the advancement of the web or discrete panel section, or a component thereof, in a controlled manner, into a packaging machine, where the web and/or discrete panel section is used to make individual packages. The device can be e.g. printed or placed in uniformly spaced fashion along or near an edge of the web or discrete panel section, i.e. registration marks, or in an area near the middle of a web that does not interfere with decorative printed graphics. These marks are used in connection with appropriate sensors to controllably advance the web or discrete panel section.
“Removable adhesive” herein refers to an adhesive which exhibits a low initial peel strength to allow for easy removal of the web or discrete panel section after it has been stuck to the desired surface, with no significant residual adhesive capability once it has been removed. Removable adhesive can be used to make an easy-open seal as disclosed herein. Removable adhesive as used herein is not a repositionable adhesive.
“Seal” herein means a bond between two thermoplastic surfaces, e.g. as produced by heat sealing, radio frequency (RF) sealing, ultrasonic sealing, or permanent adhesive.
“Sealant” is a polymeric material or blend of materials, such as olefinic polymer or copolymer such as an ethylenic polymer or copolymer, that can form a surface of the discrete panel section of the invention, or a web to which the discrete panel section is sealed, and form a bond between two thermoplastic surfaces. A permanent adhesive can also be a sealant. “Sealant” herein, with respect to the discrete panel section, or a web to which the discrete panel section is attached, excludes a repositionable adhesive. “Discrete panel section” herein refers to an elongate piece of thermoplastic material, typically but not necessarily longer in a first direction than in a direction perpendicular to the first direction, e.g. rectangular; but can also be square, round, oblong, elliptical, or any appropriate shape in plan view. The discrete panel section can be of any suitable thickness, e.g. between 0.1 and 30 mils.
“Tamper evidence”, “tampering”, and the like herein refers to visual evidence of a breach in a package; i.e. that someone has accidentally or intentionally opened or partially opened the package, or attempted to do so.
“Thermoplastic” herein includes plastic materials that when heated to a softening or melting point may be reshaped without significant thermal degradation (burning). Thermoplastic includes both materials that are not crosslinked, or that are crosslinked by chemical or radiation means.
“Tray” herein refers to a formed member that has a tray bottom, tray sides, and a tray flange around the upper perimeter of the tray, where the tray bottom and tray sides form an internal cavity within which a product can be placed. The cavity can be enclosed by a lidstock sealed to the tray flange.
“Web” is used herein to mean a thermoplastic film, laminate, or web, either multilayer or monolayer, that may be used in connection with the present invention, either as a first or second side panel or a discrete panel section. The web can be of any suitable thickness, e.g. between 0.1 and 30 mils, and the web can be of any suitable length and width.
“Zipper” and the like herein refers to a plastic zipper closure; press-to-close or slide zipper; interlocking closure; reclosable fastener with interlockable fastener elements; interlocking rib and groove elements having male and female profiles; interlocking alternating hook-shaped closure, and the like.
All compositional percentages used herein are presented on a “by weight” basis, unless designated otherwise.
Drawings herein are not necessarily to scale, and certain features of the invention may be graphically exaggerated for clarity.
Referring to the drawings, a package 5 according to the invention is shown. Package 5 includes a pouch 7 that can be made from either a single web, or two webs, to form a first side panel 12, and a second side panel 14.
A. Web(s)
In either embodiment, the web or webs comprises a thermoplastic material of any suitable composition, including those having as at least one component olefinic materials such as ethylene or propylene polymers or copolymers, e.g. polyethylene or ethylene/alpha olefin copolymers; polyethylene terephthalate (PET); and including webs typically used in, or useful in, HFFS, VFFS, lidstock/tray, continuous horizontal packaging, and bag making apparatus and processes. The web or webs can be monolayer or multilayer in construction, can be coextruded, laminated, or made by any suitable film making process, and can have any suitable thickness.
Examples of web(s) that can be used with a discrete panel section of the invention include H7225B™, a barrier hybrid material used for products requiring a high oxygen barrier, such as shredded cheese; H7525B™, a barrier hybrid material used for products requiring a high oxygen barrier, such as bacon and smoked and processed meat; CP04140™, a low barrier (high OTR) material used in produce packaging, CPM4090, a microwaveable packaging film for fresh cut produce; and T7225B™, a barrier material used as lidstock (non-forming web) for products requiring a high oxygen barrier, such as luncheon meat. These are all commercial products produced by the Cryovac business unit of Sealed Air Corporation.
H7225B™ is a laminate having the construction PET//adhesive//coextruded barrier film, where the PET is a biaxially oriented polyester film, and the barrier film has the construction LDPE (low density polyethylene)/EVA tie/nylon/EVOH+nylon/nylon/EVA tie/EAO. The overall thickness of the laminate can be any of several gauges, being typically about 2.5 mils. The LDPE is the surface of the barrier film adhered, by the adhesive, to the PET film. The EAO typically acts as the heat sealant layer of the film, and finished laminate, and in packaging made from the laminate, the EAO will form the inner or sealant surface of the package, facing the contained product, and the PET will form the outer or skin surface of the package. H7225B™ can be used as a lidstock (non-forming) web.
H7525B™ is a laminate having the construction PET//adhesive//coextruded barrier film, where the PET is a biaxially oriented polyester film, and the barrier film has in one embodiment the construction LDPE (low density polyethylene)/EVA/LLDPE tie/EVOH/LLDPE tie/EVA/EAO. The overall thickness of the laminate can be any of several gauges, being typically about 2.5 mils. The LDPE is the surface of the barrier film adhered, by the adhesive, to the PET film. The EAO typically acts as the heat sealant layer of the film, and finished laminate, and in packaging made from the laminate, the EAO will form the inner or sealant surface of the package, facing the contained product, and the PET will form the outer or skin CP04140™ is a laminate having the construction BOPP//adhesive/monolayer LLDPE film. A typical gauge for the laminate is about 1.8 mils. The LLDPE typically acts as the heat sealant layer of the finished laminate, and in packaging made from the laminate, the LLDPE will form the inner or sealant surface of the package, facing the contained product, and the BOPP will form the outer or skin surface of the package.
CPM4090™ is a laminate having the construction BOPP//adhesive/monolayer LLDPE+LDPE film. A typical gauge for the laminate is about 2 mils. The LLDPE+LDPE layer typically acts as the heat sealant layer of the finished laminate, and in packaging made from the laminate, the LLDPE+LDPE will form the inner or sealant surface of the package, facing the contained product, and the BOPP will form the outer or skin surface of the package.
T7225B™ film has the construction EAO/EAO/LLDPE tie/nylon/EVOH/nylon/EVA tie/EVA tie/nylon. The first layer of EAO typically acts as the heat sealant layer of the film, and in packaging made from the laminate, the EAO will form the inner or sealant surface of the package, facing the contained product, and the nylon of the last layer will form the outer or skin surface of the package.
Referring to the drawings, the first side panel 12 has a top portion 9, a first side edge 31, a second side edge 33, and a lower portion 17. The second side panel 14 has a top portion 11, a first side edge 35, a second side edge 37, and a lower portion 18. The first and second side panels 12 and 14 are joined together along their respective first and second side edges by either a seal or a fold. As shown, first side edge 31 of first side panel 12 is joined to first side edge 35 of second side panel 14 by a seal 30. Second side edge 33 of first side panel 12 is joined to second side edge 37 of second side panel 14 by a heat seal 32. The second end 34 of the pouch 7 can be either a seal or a fold. Where a single web is used to make the pouch, second end 34 will typically be a fold, although even after the web is folded, a seal such as a heat seal can optionally be installed in the area of the fold. Where two webs of film are used to make panels 12 and 14, second end 34 will be a seal that joins panels 12 and 14 together along their respective lower portions 17 and 18. The two webs can be from the same material, or can be different in composition, structure, etc.
B. Discrete Panel Section
A discrete panel section 6 (see
Discrete panel section 6 comprises an outer surface 66 and an inner surface 67. At least a portion of second surface 67 comprises an easy open sealant. Outer surface 66 in some embodiments comprises a sealant. Panel section 6 is anchored to first side panel 12. In one embodiment, the inner surface 67 is sealed to the inner surface 29 of the second side panel 14 with an easy-open seal.
The panel section 6 can be of multilayer or monolayer construction.
When a product 24 is placed in the pouch 7, by any suitable process such as processes herein disclosed, and the pouch 7 is closed, the package 5 is made.
Any suitable materials, including those disclosed herein for web or webs for making the first and side panels, e.g. a thermoplastic material of any suitable composition, monolayer or multilayer in construction, coextruded, laminated, or made by any suitable film making process, and of any suitable thickness, including hybrid materials of the type described herein for web materials, e.g. H7225B or a non-barrier analog of such material, can be used to make the discrete panel section 6.
The discrete panel section 6 is anchored to the first side panel. In one embodiment, panel section 6 is anchored to the inner surface 27 of first side panel 12 in anchor region “A” (see
In embodiments disclosed in the drawings, the first portion of the outer surface of the panel section 6 is closer to the first end of the pouch than the second portion. In some embodiments, the second portion of the outer surface is anchored to the inner surface of the first side panel at anchor region “A”.
In an alternative embodiment, discrete panel section 6 is anchored to the first side panel by sealing a second part of the inner surface 67 of discrete panel section 6 to the outer surface 59 of first side panel 12.
C. Opening Mechanisms and Panel Section Construction
The package of the invention can be easily manually opened. Any suitable mechanism or combination of mechanisms for obtaining this functionality and feature can be used according to the invention. The following are examples of such mechanisms.
1. Adhesive Failure
In this embodiment, inner surface 67 of panel section 6 and inner surface 29 of second side panel 14 each comprises a polymeric composition that, when surface 67 is sealed to surface 29, forms an easy-open seal. This seal provides an interface that breaks apart upon manually opening the package. The interlaminar bonds between layers of the panel section itself (where the panel section is of multilayer construction), the cohesive strength of each layer within the panel section or of the single layer of a monolayer strip, and the anchor that holds outer surface 66 of panel section 6 to inner surface 27, are stronger than the seal that holds surface 67 to surface 29.
In some embodiments, the polymeric composition of surfaces 67 and 29 will be the same or similar. Useful in these embodiments are the peel systems disclosed in U.S. Pat. Nos. 4,189,519 (Ticknor) (blend of EVA or EMA or EEA with crystalline isotactic polybutylene, and optionally with anhydride grafted EVA); 4,252,846 (Romesberg et al.) (blend of EVA and HDPE, optionally with IO or polybutylene (PBU)); 4,550,141 (Hoh) (blend of IO and polypropylene/ethylene copolymer (EPC)); 4,666,778 (Hwo) (three component blend of PE, that can be LLDPE, LDPE, MDPE, or HDPE, or EVA or EMA, with PBU, and PP or EPC); 4,882,229 (Hwo) (butene-1 polymer or copolymer blended with modified or unmodified LDPE); 4,916,190 (Hwo) (blend of butylene polymer or copolymer, with PE polymer or copolymer (LLDPE, LDPE, MDPE, EVA, EMA, EEA, EBA, or HDPE), with propylene polymer or copolymer); 4,937,139 (Genske, et al.) (propylene polymer or copolymer blended with HDPE); 5,547,752 (Yanidis) (blend of PBU and IO); and 5,997,968 (Dries et al.) (blend of Component 1 (a copolymer of ethylene and propylene or ethylene and butylene or propylene and butylene or ethylene and another -olefin having 5 to 10 carbon atoms or propylene and another -olefin having 5 to 10 carbon atoms or a terpolymer of ethylene and propylene and butylene or ethylene and propylene and another -olefin having 5 to 10 carbon atoms) and Component 2 (HDPE, MDPE, LDPE, LLDPE or VLDPE); these U.S. patents all incorporated herein by reference in their entirety.
In other embodiments, the composition of surfaces 67 and 29 will differ, i.e. dissimilar sealants are used. Useful in these embodiments are the peel systems disclosed in U.S. Pat. Nos. 3,655,503 (Stanley et al.) (LDPE or MDPE sealed to polypropylene (PP), EPC, saran, nylon 6, polycarbonate (PC), polyvinyl chloride (PVC), or polyethylene oxide (PEO); PP sealed to saran, nylon 6, PC, PVC, PEO, IO, phenoxy, or EVA; or nylon sealed to IO); 4,729,476 (Lulham et al.) (a blend of EVA and IO sealed to 10); 4,784,885 (Carespodi) (PP, HDPE, or LLDPE sealed to substantially linear PE (HDPE, LLDPE) blended with a polyolefinic thermoplastic elastomer such as ethylene propylene diene monomer (EPDM), EPM, butyl rubber, halogenated butyl rubber, isoprene rubber, and styrene butadiene rubber); 4,859,514 ((Friedrich et al.) (IO or IO blended with EVA, sealed to a blend of EVA and ethylene butene copolymer (EBC) and PP); 5,023,121 (Pockat, et al.) (a blend of PBU and PP and a third polymeric material selected from EVA, LDPE, LDPE, and IO, sealed to EVA, LDPE, LLDPE, or IO); these U.S. patents all incorporated herein by reference in their entirety.
In an alternative embodiment, instead of or in addition to the polymeric composition disclosed above, a removable adhesive, such as certain PSA materials, can be coated on one or both surfaces that are to be adhered, i.e. an external surface of a strip, discrete panel section, and/or web as desired, to provide the easy-open seal mechanism.
Alternatively, the seal between surfaces 66 and 27, instead of or in addition to the seal between surfaces 67 and 29, can function as the easy-open seal.
2. Delamination Failure
In this embodiment, one of the interlaminar bonds between layers of the panel section itself (where the panel section is of multilayer construction) can be broken. Thus, the interlaminar bond provides the interface that will break apart upon manually opening the package. The seal between surfaces 67 and 29, and between surfaces 66 and 27, and the cohesive strength of each layer within the strip, are stronger than the interlaminar bond. Useful in this embodiment are the peel systems disclosed in U.S. Pat. No. 4,944,409 (Busche et al.), this patent incorporated herein by reference in its entirety.
3. Cohesive Failure
In this embodiment, one of the layers of the panel section itself (where the panel section is of multilayer construction) or the monolayer base strip, fractures when the package is opened. The seal between surfaces 67 and 29, and between surfaces 66 and 27, and the interlaminar bonds between layers of the panel section itself (where the panel section is of multilayer construction) are stronger than the layer that fractures. Useful in this embodiment is the peel system disclosed in U.S. Pat. No. 6,476,137 (Longo) (internal rupture of a sealant layer comprising a blend of an ionomer having a melt flow index of less than 5, and a modified ethylene/vinyl acetate copolymer having a substantially higher melt flow index, where the melt flow indices of the two polymers in the seal layer differ by at least 10), this patent incorporated herein by reference in its entirety.
Other peel systems useful in connection with the present invention are those disclosed in U.S. Pat. Nos. 4,058,632 (Evans et al.), 4,615,926 (Hsu et al.); 5,128,414 (Hwo); 6,395,321 (Schaft et al.), 7,055,683 (Bourque et al.), and US Patent Publication Nos. 20030152669 (Vadhar et al.) and 2008/0260305 (Shah et al.) (disclosing as easy-open sealant), DuPont APPEEL™ resins, such as those based on EVA, modified EVA, EAA, or modified EAA; polyethylenes such as LDPE and/or EVA blended with PP; LDPE or EVA blended with polybutene-1, or random propylene/ethylene copolymer blended with polybutene-1; EVA or LDPE blended with PP; LDPE blended with EVA and PP; such blends provide an easy-open sealant when adhered to polyethylene sealants); these U.S. patents and publications all incorporated herein by reference in their entirety.
The panel section 6 can have any suitable number of layers. In
Alternatively, panel section 6 is of monolayer construction, with innermost and outermost surfaces 66 and 67 like those disclosed herein for a multilayer panel section.
Referring to
A representative film structure “A1” suitable for use as the panel section 6 according to the invention is shown in
This example of a material suitable as the panel section 6 is a barrier film with an easy-open sealant, and is currently used as a barrier/easy-open component of various laminated materials that also include a polyester film component, sold commercially by the Cryovac business unit of Sealed Air Corporation, under designations including H52XXBZ, and H72XXBZ. These are sold as primary packaging materials, i.e. webs that form the main body of the package, not as discrete laminates to be used in combination with a primary web.
When used according to the invention, the easy-open sealant layer 122 of A1 exhibits a peel force of typically about 2 pounds/inch (ASTM F88). Layer 128 of A1 yields a peel force of typically 8 pounds/inch.
The resins disclosed in Table 1 are identified in Table 2.
AD1 is a maleic anhydride modified EVA that acts as a polymeric adhesive (tie layer material).
AD2 is a maleic anhydride modified EVA that acts as a polymeric adhesive (tie layer material).
EZ1 is a compound polymer blend of 65% ionomer (SURLYN™ 1650SB), 30% EVA (ELVAX™ 3134Q), and 5% polybutylene (MONTELL™ PB8640), each by weight of the blend.
NY1 is nylon 6 (polycaprolactam).
NY2 is an amorphous copolyamide (6I/6T) derived from hexamethylene diamine, isophthalic acid, and terephthalic acid.
OB1 is EVOH with about 38 mole % ethylene.
PE1 is LDPE.
Example 1 as shown has a total thickness ranging from about 2.0 mils to 3.5 mils.
Core layer 112 of the above film structure can comprise any suitable oxygen barrier material, such as EVOH, and can be blended in any suitable proportion with other polymeric materials or organic or inorganic additives as desired. In one embodiment, intermediate layers 114 and 116 can each comprise 100% semicrystalline polyamide such as nylon 6.
In another embodiment, Intermediate layers 114 and 116 each comprise a blend of an amorphous polyamide and a semicrystalline polyamide.
Tie layers 118 and 120 can comprise any suitable polymeric adhesive that functions to bond two layers together, e.g. EVA, EAO, LDPE, EMA, and anhydride grafted derivatives of these polymers. Tie layers 118 and 120 can be the same, or can differ.
Bulk layer 124 can comprise a suitable polyolefin, such as an EAO; and/or a polymeric adhesive such as those disclosed herein for tie layers 118 and 120.
In one embodiment, first outer layer 122 functions as an easy-open sealant layer of the film, and provides a surface 67 that can be sealed to the inner surface 29. Layer 122 can comprise any suitable material or blend of materials that provides an easy-open peelable seal when adhered to the inner surface 29. Layer 122 comprises EZ1 or any suitable resin or resin blend or removable adhesive that provides an easy-open peelable sealant.
Second outer layer 128 can function as a sealant layer of the film, and provides a surface 66 that can be sealed in one embodiment to inner surface 27 of first side panel 12. Layer 128 can comprise any suitable material or blend of materials, e.g. materials that provides a relatively strong seal when adhered to inner surface 67. Layer 128 comprises PE1 or any EAO such as EXACT™ 3024, a single-site catalyzed linear ethylene/butene copolymer from ExxonMobil with a density of 0.905 g/cc; or AFFINITY™ PL 1888G, a single-site catalyzed branched ethylene/octene copolymer from Dow with a density of 0.9035 g/cc.
Additional materials that can optionally be incorporated into one or more of the film layers, as appropriate, include antiblock agents, slip agents, antifog agents, fillers, pigments, dyestuffs, antioxidants, stabilizers, processing aids, plasticizers, fire retardants, UV absorbers, etc.
Alternatively, layer 122 can be sealed to inner surface 27, and layer 128 can be sealed to inner surface 29.
In general, panel section 6 can have any total thickness desired, and each layer can have any thickness desired, so long as the strip and package provide the desired functionalities. Typical total film thicknesses are from 0.1 mils to 15 mils, such as 0.2 to 12 mils, such as 0.5 mils to 10 mils, 0.8 mils to 8 mils, and 1 mil to 4 mils. Suitable gauges include 1.5 mils, 2 mils (as in Example 1); and 3 mils.
Thus, by way of example,
Two, three, four, five, six, seven, and eight layer films can thus alternatively be produced, that each include the layers described above with respect to the film strip of
In some embodiments, such as the panel section of
In each of the embodiments of the package and process disclosed herein, a non-hermetic or hermetic package can be made in accordance with the invention.
In one embodiment, layer 128 or 228 comprises a sealant that provides a relatively strong seal when layer 128 or 228 is sealed to surface 27. An example of a material suitable as a panel section for this embodiment is a barrier film with a sealant that provides a relatively strong seal, and is currently used as a barrier/sealant component of various laminated materials that also include a polyester film component, sold commercially by the Cryovac business unit of Sealed Air Corporation, under designations including H52XXB, and H72XXB. These are sold as primary packaging materials, i.e. webs that form the main body of the package, not as a panel section to be used in combination with a primary web.
A. Horizontal Form/Fill/Seal (HFFS)
HFFS packaging systems are generally well known to those of skill in the packaging industry, and can be used to make packages of the present invention.
Referring to
Discrete panel section 310, equivalent to discrete panel section 6 of
Discrete panel section 310 includes an inner surface 67 (see
Alternatively, and referring to
The embodiment of
B. Vertical Form/Fill/Seal (VFFS)
Apparatus 40 utilizes a lay-flat web 41 as a rollstock. Product 42 is manually or mechanically supplied to apparatus 40 from a source (not illustrated), from which a predetermined quantity of product 42 reaches the upper end portion of forming tube 44 via funnel 43, or other conventional means. The packages are formed in a lower portion of apparatus 40, and web 41 from which the packages are formed is fed from feed roll 51 over certain forming bars (not illustrated), is wrapped about forming tube 44 (sometimes known as a “sailor's collar” or “forming collar”) and is provided with a longitudinal fin seal or lap seal 47 by longitudinal heat sealing device 46, resulting in the formation of a vertically-oriented folded web in the form of a tube 48. Transverse heat seal bars 45 operate to close and seal horizontally across the lower end of vertically-sealed tube 48, to form a pouch 49 which is thereafter packed with product 42. Film drive belts 52, powered and directed by rollers, as illustrated, or by suitable alternative motive means, advance tube 48 and pouch 49 a predetermined distance, after which seal bars 45 close and simultaneously seal horizontally across the lower end of vertically-sealed tube 48 as well as simultaneously sealing horizontally across upper end of sealed pouch 49, to form a product packaged in sealed pouch 49. The next pouch 50, thereabove, is then filled with a metered quantity of product 42, forwarded, and the packaging cycle is repeated. It is conventional to incorporate with the seal bars 45 a cut-off knife (not shown) which operates to sever a lower sealed pouch 49 from the bottom of upstream pouch 50.
Lay-flat web 41 of
Alternatively, and referring to
In some embodiments, at least one of the web and the discrete panel section carries a registration device. Printed indicia can be in the form of registration marks, such as eyespots. Those skilled in the art will be familiar with the use of eye-spots and registration marks in processing web material in packaging operations. Registration marks are printed in uniformly spaced fashion along or near an edge of the web or discrete panel section, and facilitate the controlled production of packages of the invention, and can be printed in conjunction with other decorative printing.
The discrete panel section in accordance with the invention includes an outer surface, an inner surface, a first side edge, a second side edge, a first end, and a second end 352 (see
In
Alternatively (
C. Lidstock/Formed Web
Each tray 602 has a tray bottom 604, tray sides 606, and a tray flange 608 along its perimeter to which the lidstock 612 can be sealed by heat or other means. Tray bottom 604 and tray sides 606 define tray cavity 610. Prior to any thermoforming step, tray 602 can be of any suitable thickness, e.g. from 2 to 30 mils thick, and any suitable construction.
If a pre-made tray is used according to the invention, it can be rigid or semi-rigid, can be in the form of a flat or shaped tray, and can be made from any suitable material, including solid or expanded embodiments, such as PP, polystyrene, polyamide, 1,4-polymethylpentene (e.g. TPX™ available from Mitsui), or crystallized polyethylene terephthalate (CPET). A tray liner can optionally be used that adheres to the surface of the pre-made tray on which the product is to be placed. This liner can be of any suitable design, and can be a multi-layer structure with at least one layer with gas-barrier properties. Such a liner can be adhered to the tray by heat lamination, extrusion lamination, extrusion coating, adhesives, corona treatment, etc. Tray 602 can be a flexible or semi-rigid, or rigid formed web. Referring to
Referring to
D. Continuous Horizontal Packaging
In another embodiment, and referring to
Alternatively, the sealing function of transverse sealing device 716 and the cutting function of cutting device 718a and 718b can be combined at a single station, rather than being performed at separate locations on the production path.
Web 702 and discrete panel section 724 can be of any suitable dimension and composition, such as those disclosed herein. As discrete panel section 724 is fed to forming device 710, it can be brought into contact with, and optionally anchored to a surface of web 702. This embodiment is shown in
E. Side Seal Bags
In one embodiment, and referring to
A bag can be made by extruding a thermoplastic tube to make a bag tubing; slitting the tubing at one longitudinal edge thereof to make a slit bag tubing; anchoring at least one of the base strip and discrete panel section of the discrete panel section as described herein to the slit bag tubing; and transversely cutting and sealing the bag tubing at predetermined intervals to make a plurality of individual bags each with the discrete panel section disposed thereon. The discrete panel section can function as described herein for other embodiments and processes, in providing an easy-open package. Some of the steps set out in US 2008/0138478 A1, for making a bag, are optional with respect to the present invention; such steps including irradiation and orientation of the tubing.
The discrete panel section can be anchored to the first side panel of a web, pouch, or package in a number of different configurations. An example is that shown in
In other alternatives:
For each of these alternatives, in the event that the anchor is in the form of a seal, appropriate sealants should be present at surfaces to be anchored by sealing.
Method of Operation
In opening the package of
In an alternative mode, and referring to
The panel section can be applied to a web by any suitable method. For example, the supplier of the web and/or panel section, or a converter can
1) advance a web by suitable motive means, such as a motor, from a first roll;
2) advance panel section 6 from a second roll; and
3) bringing the web and panel section 6 together at a pair of nip rolls such that the web is attached to the panel section.
Alternatively, the panel section is anchored to the web as disclosed herein at the package facility where it will be used to make packages. This can be done as described herein by feeding the panel section into the packaging process, e.g. from an in-feed roll, to be anchored to the web or webs used to make the package.
Where two webs are used in conjunction with a discrete panel section, a combination of the above alternatives can be used.
The above descriptions are those of embodiments of the invention. All parts and percentages are by weight, unless otherwise indicated or well understood in the art. Except in the claims and the specific examples, or where otherwise expressly indicated, all numerical quantities in this description indicating amounts of material, reaction conditions, use conditions, molecular weights, and/or number of carbon atoms, and the like, are to be understood as modified by the word “about” in describing the broadest scope of the invention. Any reference to an item in the disclosure or to an element in the claim in the singular using the articles “a,” “an,” “the,” or “said” is not to be construed as limiting the item or element to the singular unless expressly so stated. All references to ASTM tests are to the most recent, currently approved, and published version of the ASTM test identified, as of the priority filing date of this application. Each such published ASTM test method is incorporated herein in its entirety by reference.
Terms referring to polymers, such as polyester, polyamide, and polyolefin, refer herein to both homopolymers and copolymers thereof, unless otherwise specified.
With reference to the drawings, the flow of materials is in the direction of the arrows.
Those of skill in the art will recognize that the drawings herein are not necessarily to scale, and certain features of the invention may be graphically exaggerated for clarity.
Both the web or webs used in the manufacture of the package according to the invention, and the discrete panel section of the invention, can be made by any suitable process, including coextrusion, extrusion coating, extrusion lamination, and conventional lamination using polyurethane or other adhesives. These manufacturing processes are well known in the art. Extrusion can be done in annular or flat dies. The extrudate can be hot blown or cast, and optionally solid-state oriented as desired. Chemical or electronic crosslinking of one or more layers of the webs or the strip can be done. Both web and discrete panel section can be advanced by suitable motive means (not shown, and well known in the art, such as a motor) from their respective rolls.
A package according to the invention can optionally carry printed indicia, which can be decorative or informational in nature. Decorative printed indicia can include a logo, a trademark, product information, etc. with text and/or graphics.
Printed indicia can be in the form of a message e.g. “easy open” or “open here”. This can be printed in scattered process (i.e. registration is not required) on or near the first end of the package. The message is surface printed or reverse printed.
The present invention, including the package, pouch, and methods as disclosed herein, is provided in several embodiments in the absence of: plastic zipper closures; press-to-close or slide zippers; interlocking closures; reclosable fasteners with interlockable fastener elements; interlocking rib and groove elements having male and female profiles; interlocking alternating hook-shaped closure members, and the like. None of these aforementioned closures, zippers, elements, etc. is present in the package of the invention.
The package of the invention is provided herein in several embodiments in the absence of a repositionable adhesive between the discrete panel section and a base strip.
Although the invention is described in some embodiments herein as a package comprising a thermoplastic pouch comprising a first and second side panel each having a first end, a first side edge, and a second side edge, those skilled in the art will understand, after a review of this disclosure, that in some embodiments, wherein a single web is used, terms such as “second end”, and the like are used for convenience to describe the relative locations or regions on a single web made into a pouch, so that the overall geometry of the package, and relative positions of the various features of the invention can be described. Although the first and second side panels are shown in various embodiments as having the same length, the second side panel can be longer than the first side panel, i.e. extend beyond the first end of the first side panel. The extended portion can accommodate a hang tab with a hole therein.
This application claims the benefit of U.S. Provisional Application No. 61/279,556, filed Oct. 22, 2009, that application incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 61279556 | Oct 2009 | US |
