EASY OPEN POUCHES

The present invention relates to improved easy-open packages for packaging beverages and wet food products for use with form-fill-seal machines, especially vertical form-fill-seal machines, and/or under hot fill or retort sterilization conditions. The packages comprise a frangible first seal connecting the first side of the web to the second side of the web and defining a tube member having an inner surface, an outer surface, a first package wall, a second package wall, opposing first and second package edges, a first package end and an opposing second package end; wherein the frangible first seal exposes a cross-sectional edge of the multilayer film inside the product receiving chamber. The packages further include a protective strip having a frangible fourth seal provided through the strip and the inner surface of the tube member; wherein the protective strip covers the exposed cross-sectional edge of the multilayer film

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Description
BACKGROUND OF THE INVENTION

The present invention relates to food packages and particularly to vertical form fill seal and horizontal form fill seal pouches suitable for use in applications where the food product must undergo a retort or aseptic process while remaining inside the package.

It is common practice in packaging many goods, including food items, to use what is generally known as form-fill-seal equipment. In the vertical form-fill-seal arrangement, flexible packaging material is fed from a rollstock to a tube former where a tube is fashioned from the web material into a vertically dependent, upwardly open tube having overlapping longitudinal edges. These overlapping edges are subsequently sealed together longitudinally and the end of the tube is sealed together by a pair of transverse heat seals which are vertically spaced apart. At this point the tube is filled with a measured quantity of the product to be packaged. Often, the packaging material may be squeezed in some cases so that the air in the headspace of the pouch is eliminated. Shortly thereafter, a second heat sealing operation, typically performed after the filled tube has been downwardly advanced, completes enclosure of the product. Simultaneously with or shortly after the transverse heat sealing step the tube is completely transversely severed by cutting in a space between the vertically spaced apart pair of transverse heat seals. Finally, the tube is downwardly advanced and the cycle is successively repeated so as to form a multiplicity of individually packaged products.

In recent years, continuous vertical form-fill-seal packaging machines with constant motion of the packaging web through the packaging machine have become available to the packaging industry. The packaging operation is performed on a continuously moving web without interrupting moving packaging web. Continuous vertical form-fill-seal packaging machines provide a significant higher output compared to intermittent operation machines because the packaging web does not need to stop when the forming, filling and sealing operations are performed. Typically, a lap-type or butt-type seal is used to form the longitudinal back-seam of the package in order to minimize the total amount packaging web that must be sealed through and because of the relatively short dwell times associated with the sealing operation. These seals must have sufficient seal strength in order to resist the physical and mechanical abuse imposed by the form-fill-seal process.

In order to store food without refrigeration, a food product may be sterilized by a hot fill operation during packaging, aseptic processing or a retort operation after packaging the product. Sterilization by hot filling or retorting imposes several restrictions on the choice of materials for the package. The heat seals of the package must survive sterilization temperatures of over 71° C. (160° F.) or typical retort conditions of steam or water at 121° C. (250° F.) or more under pressure for one half hour or more. The seals of package need to have sufficient seal strength to resist the shearing and/or compression forces resulting from the relatively high temperatures and pressures during the sterilization process. Furthermore, the packaging materials must not delaminate, shrink, or wrinkle as a result of the sterilization. Oxygen and water barrier properties of the packaging material must not be adversely affected by the conditions of sterilization or by the contents of the package. Conventional hot fill or retort pouches are not vertical form-fill-seal pouches, but rather stand-up pouches or three or four-sided sealed formed with fin-type seals. It is generally recognized by those skilled in the art that hot fill or retort pouches formed with lap-type or butt-type seals will expose a cross-section of the packaging web to the contents of the package. This exposed cross-section of the packaging film is unprotected and liquids from within the package can leach into the film structure through the exposed cross-section. The barrier properties of these packages may easily deteriorate when acidic beverages or foodstuffs, such as tomato paste and other tomato products interact with the various materials used to construct the packaging web. Pinholes in a foil or metal oxide layer can be created by oxidation in connection with these undesirable interactions. Delamination between the laminate layers can also occur because the acid in some beverages or foodstuffs chemically degrades the adhesive bond holding these layers together. Furthermore, ink layers may also delaminate from the surface of a film after chemically interacting with acidic liquids of the package contents.

Opening of the finished package can create a safety issue when tools such as scissors or knives are used to gain access to the packaged contents. Notwithstanding the risk of being injured by these tools by accidentally cutting or puncturing oneself or others, these tools may also introduce the risk of contamination from one package to another when multiply packages are opened at the same time. Thus, to mitigate these risks, it would be desirable fabricate packages that do not require the use of scissors or knives to open package.

Thus, there is a need in the art for improved packages that address at least some of the above concerns, and which are simple in construction, can be made easily and inexpensively manufactured,

BRIEF SUMMARY OF THE INVENTION

The present invention is concerned with easy-open packages for packaging beverages and wet food products for use with form-fill-seal machines, especially vertical form-fill-seal machines, and/or under hot fill or retort sterilization conditions. The inventive packages are formed from a web of a film comprising an oxygen barrier. The package includes a frangible first seal connecting the first side of the web to the second side of the web which defines a tube member having an inner surface, an outer surface, a first package wall, a second package wall, opposing first and second package edges, a first package end and an opposing second package end. The package further comprises a second seal provided through the first and second package walls and extending laterally across the width of both the first and second package walls at a position proximate the first package end, and a third seal provided through the first and second package walls and extending laterally across the width of both the first and second package walls at a position proximate the second package end, whereby defining a product receiving chamber by the first package wall, the second package wall, the second seal and the third seal. The frangible first seal exposes a cross-sectional edge of the multilayer film inside the product receiving chamber which is protected by a protective strip frangibly sealed to the inner surface of the tube member and covering the exposed cross-sectional edge of the multilayer film.

One particularly useful feature of the packages of the present invention is its usefulness in packaging food products currently packaged in No. 10 metal cans. These cans are expensive and bulky, and present significant inbound freight costs due to the weight of the cans, significant warehouse space issues for can inventory, and a disposal problem after use of the contained food product. Utilizing the material's of the present invention, many food products now packaged in the No. 10 can may be conveniently and quickly packaged, stored for an extended period of time, shipped, marketed, and sold to the end user such as a commercial or institutional user or a consumer. After use, the emptied package of the present invention provides a much less bulky and expensive package for disposal.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a schematic view of a film suitable for making the packages according to the present invention.

FIG. 2 illustrates a schematic view of a preferred embodiment of a package according to the present invention, in an “opened state” and substantially lay-flat position.

FIG. 3 illustrates a transverse cross-sectional view of the package illustrated in FIG. 2, taken through section A-A of FIG. 2.

FIG. 4 illustrates a schematic view of a preferred embodiment of a package illustrated in FIG. 2, in a “closed state” and substantially lay-flat position.

FIG. 5 illustrates a fragmentary cross-sectional view taken along lines A-A of FIG. 2 depicting an enlarged, not to scale, lap seal area of a preferred film for use in fabricating the package illustrated in FIGS. 2, 3 and 4.

FIG. 6 illustrates a fragmentary cross-sectional view taken along lines A-A of FIG. 2 depicting an enlarged, not to scale, lap seal area of another preferred film for use in fabricating the package illustrated in FIGS. 2, 3 and 4.

FIG, 7 illustrates a fragmentary cross-sectional view taken along lines A-A of FIG. 2 depicting an enlarged, not to scale, lap seal area of a preferred film for use in fabricating the protective strip as illustrated in FIGS. 2, 3 and 4.

FIG. 8 illustrates a fragmentary cross-sectional view taken along lines A-A of FIG. 2 depicting an enlarged, not to scale, lap seal area of another preferred film for use in fabricating the protective strip as illustrated in FIGS. 2, 3 and 4.

FIG. 9 illustrates a schematic view of another preferred embodiment of a package according to the present invention having a pull flap, in an “open state” and substantially lay-flat position.

FIG. 10 illustrates a transverse cross-sectional view of the package illustrated in FIG. 9, taken through section C-C of FIG. 9.

FIG. 11 illustrates a schematic view of another preferred embodiment of a package according to the present invention having a butt-seal tape backseam, in an “open state” and substantially lay-flat position.

FIG. 12 illustrates a transverse cross-sectional view of the package illustrated in FIG. 11, taken through section D-D of FIG. 11

FIG. 13 illustrates a fragmentary cross-sectional of a preferred embodiment of a film suitable for use in fabricating the packages of the present invention.

FIG. 14 illustrates a fragmentary cross-sectional of a preferred embodiment of a film suitable for use in fabricating the protective strip of the present invention.

 DETAILED DESCRIPTION OF THE INVENTION

The present inventions now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the inventions are shown indeed, these inventions may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like numbers refer to like elements throughout.

A preferred embodiment of the package of the present invention is made from a web 10 of a film 11 having a first side edge 12a and opposing, second side edge 12b connected by a third side edge 12c and a fourth side edge 12d. First side edges 12a and second 12b are preferably parallel to each other when film 11 is in a long flat planar state. Third side edge 12c and fourth side 12d are preferably parallel to each other when film 11 is in a lay flat planar state. First and second side edges 12a, 12b are also preferably perpendicular to third and fourth side edges 12c, 12d when film 11 is in a lay flat planar state. Film 11 has four corners at the intersections of the four sides with first corner 12ac defined by the junction of first side edge 12a with third side edge 12c; second corner 12b defined by the junction of first side edge 12a with third side edge 12c; second corner 12bc defined by the junction of second side edge 12b with third side edge 12c; third corner 12ad defined by the junction of first side edge 12a with fourth side edge 12d; and fourth corner 12bd defined by the junction of second side edge 12b with fourth side edge 12d. Film 11 has a top surface 13a circumscribed by a perimeter 14 formed by sides 12a, 12c, 12b and 12d with an opposing bottom surface 13b also circumscribed by said perimeter 14. FIG. 1 depicts corner 12ad of film 11 turned upward to reveal said bottom surface 13b.

Referring now to FIGS. 2 and 4, a preferred embodiment of the present invention is depicted generally as a pouch 15 made from film 11 in an “opened state” and “closed state,” respectively. While FIG. 3 illustrates a cross-sectional view of the pouch 15 illustrated in FIG. 2, taken through section A-A. The pouch 15 is formed by overlapping the first side edge 12a with the second side edge 12b and sealing preferably by heat to produce a frangible fusion bond lap seal 16 defined by parallel spaced apart dotted lines 17a and 17b, and third side edge 12c and fourth side edge 12d. It should be noted that while said frangible lap seal 16 is depicted as a continuous elongated rectangle extending from side 12c to side 12d, the invention further contemplates that the seal shape may vary and could, for example, form a wavy line or zigzag shape or other shapes as desired. Also, the width of the seal may be varied to be thicker or thinner as desired. Also the seal may optionally be made by alternatives or additional means including, e.g., by applications of suitable glue or adhesive material known in the art for sealing together films. It is further contemplated that said frangible lap seal 16, while depicted as a continuous lap seal 16 suitable for forming a hermetic package, it is also contemplated that for some applications, e.g., for certain industrial or non-perishable items, a noncontinuous seal having, e.g., the appearance of a dotted or dashed line, may be employed. Optionally, the strength of the seal may be varied by one skilled in the art in view of the teachings of the present application by selection of aforesaid parameters such as seal shape, thickness, continuous or intermittent nature material selection type of and known parameter for varying the strength of different types of seals, e.g., by adjusting dwell time or temperature for producing heat seals. Such variations and adjustments may be made by those skilled in the art without undue experimentation.

Frangible lap seal 16 is preferably a heat seal forming a peelable fusion bond between surface 13a and surface 13b of film 11. The overlapped sealed film 11 defines a tube member 18 having an inner film surface 19 of said tube member 18. Connecting first package edge 22 and second package edge 23 defines a first package wall 30 and connected opposing package wall 31. A second seal 20 extends laterally across said tube member 18 adjacent the third side edge 12c of film 11 thereby forming a closed package end 21. A variety of seals may be used. Preferably second seal 20 will be a heat seal which fusion bonds the pouch film inner surface 19 to itself The second seal 20 by closing package end 21 both forms a first package edge 22 and opposing second package edge 23, and the second seal extends across the tube member 18 from the first package edge 22 to the second package edge 23. The second seal may also employ a variety of shapes, thicknesses, structures, etc, as for the previously described lap seal 16. The frangible lap seal does not need to be centered between edges 22 and 23 but preferably is positioned anywhere therebetween.

As noted above, FIGS. 2 and 3 illustrate package 15 in the “opened state” having an opening formed by lap sealed film under fourth side edge 12d through which a product (not depicted) may be placed into a product receiving chamber 25 defined by tube member 18, closed package end 21 and package opening 24. Tube member 18 has an inner surface 19 and an outer surface 33. The first package wall 30 has first package wall side 30a proximate second side edge 12b and extending to second package edge 23. The first package wall 30 also has an opposing first package wall seamed side 30b proximate first side edge 12a and extending to first bag edge 22. Preferably, the second seal 20 is positioned within one of the first and second package walls 30 and 31, thereby forming an “end seal” of the package. Additionally, the second seal 20 may take any shape, whether straight or curved, so long as the second seal 20 operates to close the end 21.

As also noted above, FIG. 4 illustrates package 15 in the “closed state” having a third seal 35 which extends laterally across said tube member 18 adjacent to the fourth side edge 12d of film ii thereby forming an “end seal” or closed package end 34. Preferably third seal 35 will be a heat seal which fusion bonds the pouch film inner surface 19 to itself. Additionally, the third seal 35 may take any shape, whether straight or curved, so long as the third seal 35 operates to close the end 25. The third seal may also employ a variety of shapes, thicknesses, structures, etc.

A protective strip SO is tangibly sealed to the inner surface 19 of the tube member 18 extending along the entire length of lap seal 16 such that the exposed first side edge 12a of film 11 is entirely covered by said strip. The frangible seal 51 of strip 50 is preferably formed by heat to produce a peelable fusion seal between an outer surface 52 of the strip and the inner surface 19 defined by parallel spaced apart dotted lines 17c and 17d. Also, the width of the strip may be varied to be thicker or thinner as desired. Strip 50 may optionally be frangibly sealed to inner surface 19 by alternatives or additional means, including. e.g., by applications of suitable glue or adhesive material known in the art far sealing together films. Preferably, strip 50 is formed from multilayer film 11a and includes an inner surface 53 which is adapted to form a non-peelable heat seal to inner surface 19 of tube member 18.

At least the first seal 16 of package 15 and seal 51 protective strip 50 each comprise a frangible seal. “Frangible seal” and like terminology is used herein to refer to a seal, and especially heat seals, which are engineered to be readily peelable without uncontrolled or random tearing or rupturing the packaging materials which may result in premature destruction of the package and/or inadvertent contamination or spillage of the contents of the package. A frangible seal is one that can be manually peeled and/or fractured apart to open the package at the seal without resort to a knife or other implement to open the package. In the present invention, the frangible seal must have a seal strength sufficient to prevent failure of the seal during the normal hot fill and/or retort process and further normal handling and transport of the packaged article. The seal strength must also be low enough to permit manual opening of the seal. Preferably seal parameters such as choice of materials and sealing conditions will be used to adjust the seal strength to the desired level for the particular package and application. The frangible seals of the present invention may have peelable seal strengths of between 100 grams and 2000 grams, or between 200 grams and 1500 grams, or between 200 grams and 1200 grams. In contrast, non-peelable seals have seal strengths greater than 2000 grams, or greater than 2500 grams, or greater than 3000 grams. Typically, the end seals of the present invention are non-peelable.

Many varieties of peelable seals are known in the art and are suitable for use with the present invention. Peelable seals are generally made from thermoplastic films having a peelable system designed therein. Suitable peelable films and/or peelable systems are disclosed in U.S. Pat. No. 4,944,409 (Busche et al.); U.S. Pat. No. 4.875, 587 (Lulham et al.); U.S. Pat. No. 3,655,503 (Stanley et al.); U.S. Pat. No. 4,058,632 (Evans et al.); U.S. Pat. No. 4,252,846 (Romesberg et al.); U.S. Pat. No. 4,615.926 (Hsu et al.) U.S. Pat. No. 4,666,778 (Hwo); U.S. Pat. No. 4,784,885 (Carespodi); U.S. Pat. No. 4,882,229 (Hwo); U.S. Pat. No. 6,476,137 (Longo); U.S. Pat. No. 5,997,968 (Dries, et al.); U.S. Pat. No. 4,189,519 (Ticknor); U.S. Pat. No. 5,547,752 (Yanidis): U.S. Pat. No. 5,128,414 (Hwo); U.S. Pat. No. 5,023,121 (Pockat, et al.); U.S. Pat. No. 4,937,139 (Genske,et al.); U.S. Pat. No. 4,916,190 (Hwo); U.S. Pat. No. 4,550,141 (Hoh); U.S. Pat. No. 7,314,669 B2 (Galloway) and U.S. Pat. No. 8,147,934 B2 (Berbert), the disclosures of which are incorporated herein in their entirety by reference thereto, Preferred films for use in fabricating packages according to the invention may be selected from multilayer, shrinkable or non-shrinkable films capable of forming a peelable seal. In one preferred embodiment, at least one heat-sealing layer is peelable and/or fracturable and comprises a blend of at least two resins selected from the group consisting of polyethylene, polypropylene, polybutene, ethylene butene copolymer, ethylene vinyl acetate copolymer, propylene ethylene copolymer, ethylene acrylic acid copolymer, ethylene n-butyl acrylate, ethylene methyl acrylic acid copolymer, and ethylene methylacrylate copolymer. In another preferred embodiment, a layer adjacent to and in contact with one of the heat-sealing layers is peelable and/or fracturable and comprises a blend of at least two resins selected from the group consisting of polyethylene, polypropylene, polybutene, ethylene butene copolymer, ethylene vinyl acetate copolymer, propylene ethylene copolymer, ethylene acrylic acid copolymer, ethylene n-butyl acrylate, ethylene methyl acrylic acid copolymer, and ethylene methylacrylate copolymer. It is also contemplated that at least one heat sealing layer and the layer adjacent to and in contact with said heat sealing layer are each peelable and/or fracturable and comprises a blend of at least two resins selected from the group consisting of polyethylene, polypropylene, polybutene, ethylene butene copolymer, ethylene vinyl acetate copolymer. propylene ethylene copolymer, ethylene acrylic acid copolymer, ethylene n-butyl acrylate, ethylene methyl acrylic acid copolymer, and ethylene methylacrylate copolymer.

Preferred films may also provide a beneficial combination of one or more or all of the below noted properties including high puncture resistance (e.g.. as measured by the ram and/or hot water puncture tests), low shrinkage values, low haze, high gloss, high seal strengths and printability. Since the inventive packages may advantageously be used to hold oxygen or moisture sensitive articles, it is preferred to use a thermoplastic film which includes an oxygen and/or moisture barrier layer. The terms “barrier” or “barrier layer” as used herein means a layer of a multilayer film which acts as a physical barrier to moisture or oxygen molecules.

It is particularly preferred to include an oxygen barrier material in the film used in the present invention. Oxygen barrier materials which may include, but are not limited to, ethylene vinyl alcohol copolymers (EVOH), polyacrylonitriles, polyamides and vinylidene chloride copolymers (PVDC). For some applications, the oxygen barrier material may also include metal foils, such as aluminum foil and barrier coatings deposited onto a polymer layer such as silica, alumina and the like. The phrase “barrier coating” refers to a coating that may be applied to one or both surfaces of a film by any known method such as sputtering, vacuum deposition or electroplating (all of which involve some act or method of “depositing” a continuous inorganic material, metal, metal oxide, metal alloy, silicon or silicon oxide layer onto the surface of a polymer substrate). The metal used can vary, though aluminum, zinc, gold, silver or appropriate alloys of such are preferred, with aluminum or aluminum-containing alloys being particularly preferred. As will be recognized by those skilled in the art, while the metal coating predominantly consists of the identified metal (such as aluminum), amounts of other additives may be present to improve assorted physical and optical properties of the deposited metal layer. In some occasions, pure aluminum (or the metal of choice) may be used. Other additives maybe used in minor amounts such that aluminum (or the metal of choice) is the major component. Vacuum deposition is a preferred method of metallization in terms of processing and cost. Preferred values for the average thickness of the metal coating layer are within the range of about 1.0 to 100 nanometers, with the preferred average thickness being within the range of about 3 to 25 nanometers. (1 micron equals 10-7 meters, and 1 nanometer equals 10-8 meters.) Regardless, the metal coating preferably has a thickness less than the polymer substrate on which it is deposited, preferably substantially less than said substrate. In contrast. typical metal foils used in packaging film application have a thickness of between 4.3 to 150 microns, as noted in “Foil, Aluminum” in The Wiley Encyclopedia of Packaging Technology, 2nd. Ed., by Foil Division of the Aluminum Association, Inc., pp. 458-463, which is incorporated herein by reference. For an aluminized coating layer, the key conditions are optical density (metal deposition) of approximately 0.75 to 4, preferably 1.0-3.0.

In accordance with the present invention, the oxygen barrier material in the film provides the package with an oxygen transmission rate of less than about 1.0 cm3/100 in2/24 h at 73° F., 0% RH and 1 atm (or about 15.5 cm3/m2/24 h at 23° C., 0% RH and 1 atm), preferably, less than about 0.5 cm3/100 in2/24 h at 73° F. 0% RH and 1 atm (or about 7.75 cm/m2/24 h at 23° C., 0% RH and 1 atm), and most preferably, about 0.2 cm3/100 in2/24 h at 73° F. 0% RH and 1 atm (or about 3.1 cm3/m2/24 h at 23° C., 0% RH and 1 atm).

In accordance with the present invention, the multilayer, barrier film for use in forming packages may be either heat shrinkable or non-heat shrinkable. In this application, the term “heat shrinkable” means that a film has an unrestrained shrinkage of at least 10% in each of the transverse direction (TD) and machine direction (MD) measured at 90° C. (194° F.), Preferably, a heat shrinkable film has an unrestrained shrinkage of at least 20% in each direction and most preferably the shrink is at least 40% or more in both directions. Measuring the unrestrained shrink value of a thermoplastic film is accomplished by a procedure described below, which is derived from ASTM D2732. In contrast, the term “non-heat shrinkable” means that a film has an unrestrained shrinkage of less than 20% in each of the transverse direction (TD) and machine direction (MD) measured at 90° C. (194° F.). Preferably, a non-heat shrinkable film has an unrestrained shrinkage of less than 15% in each direction and most preferably is less than 10% or more in both directions.

A preferred multilayer, barrier film for use in forming packages according to the present invention is illustrated in FIG. 5, which depicts an enlarged, cross-sectional view of the frangible first seal 16 of FIG. 2 made from film 11 and protective strip 50. In this illustration, a preferred film 11 is shown having a five-layer structure configured as a lap-type seal such that the inner surface 19a overlaps with an opposing outer surface 33b of tube member 18 (see FIG. 2). Protective strip 50 is shown formed form a generic film 11a having an outer surface 53 sealed to inner surfaces 19a and 19b and covering the exposed first side edge 12a of film 11. While this cross-sectional view of frangible first seal 16 is depicted as having a void at the interface between inner surface 19a and outer surface 53, it is possible that no void exists at said interface when the frangible first seal 16 is made. In this preferred embodiment, film 11 has the following structure:

    • 11(i)—an outer surface peelable and/or fracturable heat sealing layer;
    • 11(ii)—an adhesive layer
    • 11(iii)—an oxygen barrier layer,
    • 11(iv)—an adhesive layer; and
    • 11(v)—an inner surface heat sealing layer.

Another preferred multilayer, barrier film for use in forming packages according to the present invention is illustrated in FIG. 6, which depicts an enlarged, cross-sectional view of the frangible first seal 16 of FIG. 2 made from film 11 sealed to protective strip 50. In this illustration, a preferred film 11 is shown having a six-layer structure configured as a lap-type seal such that the inner surface 19a overlaps with an opposing outer surface 33b of tube member 18 (see FIG. 2). Protective strip 50 is shown formed form a generic film 11a having an outer surface 53 sealed to inner surfaces 19a and 19b and covering the exposed first side edge 12a of film 11. While this cross-sectional view of frangible first seal 16 is depicted as having a void at the interface between inner surface 19a and outer surface 53, it is possible that no void exists at said interface when the frangible first seal 16 is made. In this preferred embodiment, film 11 has the following structure:

    • 11(vi)—an outer surface heat sealing layer;
    • 11(vii)—a peelable and/or fracturable layer;
    • 11(viii)—an adhesive layer;
    • 11(ix)—an oxygen barrier layer;
    • 11(x)—an adhesive layer; and
    • 11(xi)—an inner heat sealing layer,

In the above-illustrated structure, it is also contemplated that film 11 may include both an outer surface peelable and/or fracturable heat sealing layer, and a peelable and/or fracturable layer in contact with said heat sealing layer.

A preferred multilayer film for use in forming protective strip 50 according to the present invention is illustrated in FIG. 7, which depicts an enlarged, cross-sectional view of the frangible first seal 16 of FIG. 2 made from a generic film 11 sealed to protective strip 50 made from film 11a. In this illustration, a preferred film 11a is shown having a two-layer structure covering the exposed first side edge 12a of film 11. As shown, a lap seal 16 is formed by overlapping inner surface 19a with an opposing outer surface 33b of tube member 18 (see FIG. 2). While this cross-sectional view of seal 16 is depicted as having a void at the interface between inner surface 19a and outer surface 53, it is possible that no void exists at said interface when the frangible first seal 16 is made. In this preferred embodiment, film 11a has the following structure:

    • 11a(i)—an outer surface peelable and/or fracturable heat sealing layer; and
    • 11a(ii)—an inner heat sealing layer.

Another preferred multilayer film for use in forming protective strip 50 according to the present invention is illustrated in FIG. 8, which depicts an enlarged, cross-sectional view of the frangible first seal 16 of FIG. 2 made from a generic film 11 sealed to protective strip 50 made from film 11a. In this illustration, a preferred film 11a is shown having a three-layer structure covering the exposed first side edge 12a of film 11. As shown, a lap seal 16 is formed by overlapping inner surface 19a with an opposing outer surface 33b of tube member 18 (see FIG. 2). While this cross-sectional view of seal 16 is depicted as having a void at the interface between inner surface 19a and outer surface 53, it is possible that no void exists at said interface when the frangible first seal 16 is made. In this preferred embodiment, film 11a has the following structure:

    • 11a(ii)—an outer surface heat sealing layer,
    • 11a(iv)—peelable and/or fracturable layer; and
    • 11a(v)—an inner heat sealing layer.

In the above-illustrated structure, it is also contemplated that film 11a may include both an outer surface peelable and/or fracturable heat sealing, and a peelable and/or fracturable layer in contact with said heat sealing layer.

Turning now to FIGS. 9 and 10, another embodiment of the present invention is illustrated generally as package 15a in the “opened state.” Identical reference numerals have been used with respect to elements of package 15a, which are also found in package 15. In this embodiment, package 15a further includes a pull flap 40. The pull flap 40 is formed by providing additional overlap by moving the first and second sides edge 12a and 12b further apart and positioning the first lap seal 16 such that a portion of the first package wall, first side 30a, that overlaps the first package wall second side 30b outside of the product receiving chamber 25 is not sealed to the second side 30b. The pull flap 40 may be readily grasped by the end user and pulled to easily open the package, without resort to a cutting instrument, as is often required when opening packages without a peelable system. Although shown as extending the entire length of the bag 15a, a skilled artisan will appreciate that the pull flap 40 may be cut to a desired shape or that any other known device known to aid initiation of peeling may be incorporated. It should be appreciated that package 15a may further include a third seal 35 as described above for package 15.

Another embodiment of the present invention is illustrated in FIGS. 11 and 12 generally as package 15b. Again, like elements include like reference numerals. Package 15b includes a frangible first seal 116 comprising a butt-seal tape 141 comprising a butt-seal film 111 having a first border 107, a second border 109, a sealing surface 115 and an exterior surface 114. The first seal 116 includes a first heat seal 118 longitudinally joining the first side 30a of package wall 30 to the first border 107 of the butt-seal tape 141, and a second heat seal 119 longitudinally joining the second side 30b of package wall 30 to the second border 109 of the butt-seal tape 141. Thus, first and second sides 30a and 30b are joined in an abutting edge-to-edge relationship thereby forming package wall 30 without a heat seal directly there between. Preferably, the butt-seal film 111 may comprise the same film as described in reference to bags 15 and 15a described above, comprising the inner surface 115. Thus, package 15b may be manufactured from a film that includes a peelable system included in the butt-seal tape 141 used to form the first seal 116. Alternatively, package 15b may be manufactured from a film that includes a peelable system while the butt-seal tape 141 does not. The butt-seal film 111 is preferably non-heat shrinkable. In one embodiment, a portion of butt-seal tape 141 between first border 107 and second border 109 is sealed to protective strip 50. In another embodiment, butt-seal tape 141 is not sealed to protective strip 50. In yet another embodiment, a pull flap 40 may be provided in the butt-seal tape 141 to provide an area for the consumer to manually grasp and pull to easily open the bag 15b.

WORKING EXAMPLES

The following examples illustrate certain particular embodiments of films suitable for use in forming packages and protective strips and are not to be interpreted as limiting. In the following example, resin composition percentages are based on the total weight of each film layer.

Example 1

A package according to the present invention, as generally illustrated in FIG. 2, is produced from a film $00 comprising a laminated structure as illustrated in FIG. 13. The package also includes a protective strip as generally illustrated in FIG. 2, which is produced from a film 600 comprising a peelable/fracturable heat sealing layer 601, a peelable/fracturable second layer 602, and a third heat sealing layer 603, as illustrated in FIG. 14. In this example, film 500 includes a 2.0 mil thick, seven-layer blown coextruded film comprising a first peelable/fracturable heat sealing layer 501, a peelable/fracturable second layer 502, a third layer 503, a fourth layer 604, a fifth layer 505, a sixth layer 506, and a seventh layer 507. The seven-layer blown film was adhesively laminated via adhesive layer 508 to a 35-gauge thick, aluminum foil layer 509. A second adhesive layer 510 adhesively laminated a 60-gauge thick, biaxially oriented cast film of polyamide 511 to the foil layer 509. A third adhesive layer 512 then adhesively laminated a 3 mil thick, monolayer cast film 513 of polypropylene to the polyamide film 511. Film 600 was heat sealed to film 500 such that peelable/fracturable heat sealing layer 601 is in direct contact with polypropylene film layer 513. Film 500 had the following structure and layer compositions:

    • Layer 501 (Peelable Sealant): 75 wt.-% polypropylene copolymer (PP)-Pro-fax SA861 (LyondellBasell Industries Holdings, B.V., The Netherlands)+25 wt.-% low-density polyethylene (PE)-Dow™ 608A (Dow Chemical Company, Midland, Mich., USA)
    • Layer 502 (Peelable): 75 wt.-% polypropylene copolymer (PP)-Pro-fax SA861 (LyondellBasell Industries Holdings, B.V., The Netherlands)+25 wt.-% low-density polyethylene (PE)-Dow™ 608A (Dow Chemical Company, Midland, Mich., USA)
    • Layer 503: 82% wt.-% Impact polypropylene copolymer (PP)-Total 4170 copolymer (Total Petrochemical Company, Houston, Tex., USA)+18 wt.-% very low-density polyethylene (VLDPE)-ATTANE™ NG 4701G (Dow Chemical Company, Midland, Mich., USA)
    • Layer 504: 82% wt.-% Impact polypropylene copolymer (PP)-Total 4170 copolymer (Total Petrochemical Company, Houston, Tex., USA)+18 wt-% very low-density polyethylene (VLDPE)-ATTANE™ NG 4701G (Dow Chemical Company, Midland, Mich., USA)
    • Layer 505: 82% wt.-% Impact polypropylene copolymer (PP)-Total 4170 copolymer (Total Petrochemical Company, Houston, Tex., USA)+18 wt.-% very low-density polyethylene (VLDPE)-ATTANE™ NG 47010 (Dow Chemical Company, Midland, Mich., USA)
    • Layer 506: 82% wt.-% Impact polypropylene copolymer (PP)-Total 4170 copolymer (Total Petrochemical Company, Houston, Tex., USA)+18 wt.-% very low-density polyethylene (VLDPE)-ATTANE™ NG 4701G (Dow Chemical Company, Midland, Mich., USA)
    • Layer 507: 100 wt.-% Impact polypropylene copolymer (PP)-Total 4170 copolymer (Total Petrochemical Company, Houston, Tex., USA)
    • Layer 608: 100 wt.-% two-component polyurethane adhesive-Liofol® UR2790-22/UR5026-21 (Henkel Corporation, Düsseldorf, Germany)
    • Layer 509: 100 wt.-% aluminum foil
    • Layer 510: 100 wt-% two-component polyurethane adhesive-Liofol® UR2790-22/UR5026-21 (Henkel Corporation, Düsseldorf, Germany)
    • Layer 511: 100-% 60 gauge thick biaxially oriented nylon 6 film
    • Layer 512: 100 wt.-% two-component polyurethane adhesive-Liofol® UR2790-22/UR5026-21 (Henkel Corporation, Düsseldorf, Germany)
    • Layer 513: 100 wt-% 3.0 mil thick cast polypropylene

The total thickness of film 500 was about 5.95 mils.

Film 600 had the folio ng structure and layer compositions.

    • Layer 601 (Peelable Sealant): 75 wt-% polypropylene copolymer (PP)-Pro-fax SA861 (Lyondel1Basell Industries Holdings, B.V., The Netherlands)+25 wt-% low-density polyethylene (PE)-Dow™ 608A (Dow Chemical Company, Midland, Mich., USA)
    • Layer 602 (Peelable): 75 wt.-% polypropylene copolymer (PP)-Pro-fax SA861 (LyondellBasell Industries Holdings. B.V., The Netherlands)+25 wt.-% low-density polyethylene (PE)-Dow™ 608A (Dow Chemical Company, Midland, Mich., USA)
    • Layer 603: 100 wt.-% polypropylene copolymer (PP)-Pro-fax SA861 (LyondellBasell Industries Holdings, B.V., The Netherlands)

Example 2

A package according to the present invention was made, as generally described above for Example 1 with films 500 and 600, except for film layers 501 and 502 of film 500 had the following structure and layer compositions:

Layer 501 (Sealant): 99 wt.-% polypropylene copolymer (PP)-Pro-fax SA861 (LyondellBasell Industries Holdings, B.V., The Netherlands)+1.0 wt.-% processing additives

Layer 502 (Peelable): 81 wt.-% ethylene vinyl acetate copolymer (EVA)-DuPont™ Elvax® 3135X (E.I. du Pont de Nemours and Company, Inc., Wilmington, Del., USA)+19 wt.-% polybutene-1 (PB)-PB 8640M (LyondellBasell Industries Holdings, B.V , The Netherlands)

The packages according to the invention are preferably fabricated continuously from a continuous web or roll stock. The roll stock is slit to a desired width and fed into a bag making equipment, wherein the first and second sides of the packaging film are brought together to form a tube member in a lap-type or butt-type tape seal configuration. Simultaneously, a tape of protective strip film is fed to the inside surface of the tube member so that the first, second sides and protective strip film are sealed together longitudinally by a set of hot sealing jaws, to form a continuous single-seamed tube, or tube member having the protective strip covering the inside surface of the lap-type or butt-type tape seal. Alternatively, the first and second sides of the film may be sealed together longitudinally first followed by sealing of the protective strip of the seal over the lap-type or butt-type tape seal on the interior surface of the tube member. In yet another alternative method, the protective strip may first be pre-tacked to the edge of one side of the film prior to forming the tube member. The first and second sides of the packaging film are then brought together to form a tube member in a lap-type or butt-type tape seal configuration, followed by simultaneously sealing the first side, the second side and protective strip film together as a single-seam. In either case, an additional overlap portion is provided when the first and second sides of the film are brought together that will act as a pull flap. One or more tear notches or cuts on the outer edges of the pull flag may be added to assist with opening of the package. A second seal is provided transversely across the entire width of the tube member at a desired location spaced from the open mouth of the tube which defines a first “end seal” of the package. A food product is then introduced into the open mouth of the tube member to a desired volume. Stripper jaws then engage the film effectively stripping any food product from the area above the food product. The stripping process ensures that there is substantially zero head space inside the package between the contents of the package and the final seal. Following this process, a third seal is formed thereby hermetically closing the package. The third seal defines the second “end seal” of the package. A parallel, spaced apart, transverse cut is made within the area of the third seal to separate the package product. The length of the package can easily be varied by changing the distance between transverse seals and cuts. The width of the packages can also by easily varied by changing the width of the film by slitting the standard rollstock.

Claims

1.) A package for a beverage or wet foodstuff and formed from a web of a multilayer film; the web having a first side, an opposing second side; the package comprising:

a frangible first seal connecting the first side of the web to the second side of the web and defining a tube member having an inner surface, an outer surface, a first package wall, a second package wall, opposing first and second package edges, a first package end and an opposing second package end; wherein the frangible first seal exposes a cross-sectional edge of the multilayer film inside the product receiving chamber; wherein the multilayer film comprises an oxygen barrier layer;
a second seal provided through the first and second package walls and extending laterally across the width of both the first and second package walls at a position proximate the first package end;
a third seal provided through the first and second package walls and extending laterally across the width of both the first and second package walls at a position proximate the second package end, whereby a product receiving chamber is defined by the first package wall, the second package wall, the second seal and the third seal; and
a protective strip having a frangible fourth seal provided through the strip and the inner surface of the tube member; wherein the protective strip covers the exposed cross-sectional edge of the multilayer film.)

2.) The package according to claim, wherein the multilayer film is a non-heat shrinkable film.

3.) The package according to claim 1, wherein the oxygen barrier layer comprises a material selected from the group consisting of ethylene vinyl alcohol copolymers, polyacrylonitriles, polyamides, polyvinylidene chloride copolymers, metal foils and barrier coatings.

4.) The package according to claim 3, wherein the multilayer film comprises a first adhesive layer positioned in contact with the oxygen barrier layer.)

5.) The package according to claim 4, wherein the multilayer film comprises a second adhesive layer positioned in contact with the oxygen barrier layer.)

6.) The package according to claim 1, wherein the multilayer film comprises a first heat-sealing layer.

7.) The package according to claim 6, wherein the multilayer film comprises a layer in contact with the first heat-sealing layer.

8.) The package according to claim 7, wherein the first heat-sealing layer or the layer in contact with the first heat-sealing layer is peelable and/or fracturable.)

9.) The package according to claim 7, wherein both the first heat-sealing layer and the layer positioned in contact with the first heat-sealing layer are peelable and/or fracturable.

10.) The package according to claim 9, wherein the first heat-sealing layer or the layer in contact with the first heat-sealing layer comprises a blend of at least two resins selected from the group consisting of polyethylene, polypropylene, polybutene, ethylene butene copolymer, ethylene vinyl acetate copolymer, propylene ethylene copolymer, ethylene acrylic acid copolymer, ethylene n-butyl acrylate, acrylate, ethylene methyl acrylic acid copolymer, and ethylene methylacrylate copolymer.

11.) The package according to claim 1, wherein the multilayer film comprises an second heat-sealing layer.)

12.) The package according to claim 11, wherein the second heat-sealing layer comprises a resin selected from the group consisting of polyethylene, polypropylene, ethylene vinyl acetate copolymer, propylene ethylene copolymer, ethylene acrylic acid copolymer, ethylene n-butyl acrylate, ethylene methyl acrylic acid copolymer, and ethylene methylacrylate copolymer.

13.) The package according to claim 1, wherein the frangible first seal is a lap seal or a butt-seal tape positioned on the outer surface of the tube member.

14.) The package according to claim 13, wherein the frangible first seal is a lap seal.

15.) The package according to claim 1, further comprising a beverage or wet foodstuff which exhibits an acidic pH.

16.) The package according to claim 1, wherein the protective strip comprises a first heat-sealing layer.

17.) The package according to claim 16, wherein the protective strip comprises a second heat-sealing layer.

18.) The package according to claim 17, wherein the protective strip comprises a third layer positioned between the first and second heat-sealing layers.

19.) The package according to claim 16, wherein the first heat-sealing layer comprises a blend of at least two resins selected from the group consisting of polyethylene, polypropylene, polybutene, ethylene butene copolymer, ethylene vinyl acetate copolymer, propylene ethylene copolymer, ethylene acrylic acid copolymer, ethylene n-butyl acrylate, ethylene methyl acrylic acid copolymer, and ethylene methylacrylate copolymer.

20.) The package according to claim 17, wherein the second heat-sealing layer comprises a resin selected from the group consisting of polyethylene, polypropylene, ethylene vinyl acetate copolymer, propylene ethylene copolymer, ethylene acrylic acid copolymer, ethylene n-butyl acrylate, ethylene methyl acrylic acid copolymer, and ethylene methylacrylate copolymer.

21.) The package according to claim 18, wherein the third layer comprises a blend of at least two resins selected from the group consisting of polyethylene, polypropylene, polybutene, ethylene butene copolymer, ethylene vinyl acetate copolymer, propylene ethylene copolymer, ethylene acrylic acid copolymer. ethylene n-butyl acrylate, ethylene methyl acrylic acid copolymer, and ethylene methylacrylate copolymer.

22.) The package according to claim 1 wherein both the second seal and the third seal are each an end seal.

23.) The package according to claim herein the multilayer film has a shrinkage value of less than 10% at 90° C.

24.) The package according to claim 1, further comprising a beverage or wet foodstuff wherein there is substantially zero head space inside the package between the third seal and the beverage or wet foodstuff.

25.) The package according to claim 1, wherein the frangible first seal does not delaminate after the package is cooked under pressure in water or steam at a temperature of 121° C. (250° F.) for 30 minutes.

26.) The package according to claim 1, wherein the package is a vertical form-fill-seal pouch.

27.) The package according to claim 26, wherein the package is a retortable vertical form-fill-seal pouch.

Patent History
Publication number: 20160332797
Type: Application
Filed: Feb 25, 2014
Publication Date: Nov 17, 2016
Inventors: Donald C. Schnabel (Oshkosh, WI), Scott J. Kelly (Kimberly, WI)
Application Number: 15/112,271
Classifications
International Classification: B65D 81/34 (20060101); B65D 85/72 (20060101); B65D 30/08 (20060101); B65D 75/48 (20060101); B65D 81/20 (20060101);