The present invention relates to packaging structures and, in particular, to flexible packaging structures suitable for products, including food products and others, that are packaged utilizing flow wrap equipment.
Flexible film packages are known in the art to provide a bag or pouch for enclosing products for shipping, handling, and storage. Such packages may be formed of flow wrap type packaging which allows a continuous film to envelop the product during packaging. During the flow wrapping process, a fin seal extending in the machine direction is formed and transverse heat seals are formed at the ends.
The film material is typically a plastic film, such as polyethylene or polypropylene, or a laminate such as two layers of polypropylene or a polyester (PET) laminated to a polyethylene sealant. Flexible film packages have a number of advantages over rigid containers, including lower cost, lighter weight, and smaller storage footprint. Flexible sheet materials comprising paper or film ply laminated to a polymer material are generally known in the art. Laminations comprising a paper-containing ply and a polymer ply are advantageous in that the paper provides good mechanical strength, is made from a renewable resource, can be recyclable or compostable and has good printability, while the polymer ply can impart good barrier properties and heat scalability to the structure.
However, the presence of a paper outer ply requires a relatively longer scaling time to form the transverse end seals than an all plastic film material. Flow wrap equipment utilizing conventional rotary sealing heads may lack sufficient contact time with the film to transfer sufficient heat through the outer lamination to adequately melt the heat seal layers and produce an airtight seal. Similar problems may be seen with laminations comprising a non-paper outer ply where the outer ply is relatively thick or has high thermal resistance or where the heat sealing range or window is very narrow. Flow wrap equipment having long dwell sealing heads is known in the art to increase the dwell time. However, such equipment requires cam arrangements which allow the heat seal head to translate in the machine direction at the same speed as the film to extend the heating dwell time. Such systems include D-cam profile, box motion profile, oval cam profile, and so forth. While such systems provide increased heat sealing capabilities due to their ability to extend the length of time that the heat seal heads are in contact with the film, such systems also increase the complexity, cost, and footprint of the equipment.
It would be desirable to provide improved film structures having a paper component or other thermally resistant component that can be used for flow wrap applications utilizing rotary sealing heads while also providing high integrity heat seals.
In one aspect, a web of sheet material is provided which can be wrapped around a product to form a pack. The sheet material comprises a sealant ply laminated to an outer ply. The sealant ply has a first major surface and a second major surface opposite the first major surface, the first major surface comprising a heat sealable material. The outer ply has a third major surface and a fourth major surface opposite the third major surface, wherein the third major surface faces the second major surface. The web of sheet material comprises a plurality of connected blanks, each blank comprising a plurality of cutouts removing a portion of the outer ply, wherein the cutouts are aligned with overlapping portions of transverse heat seal regions of the sheet material.
In a further aspect, a method of forming a pack is provided.
Advantages and benefits of the present invention will become apparent to those of ordinary skill in the art upon reading and understanding the following detailed description of the preferred embodiments.
The invention may take form in various components and arrangements of components, and in various steps and arrangements of steps. The drawings are only for purposes of illustrating preferred embodiments and are not to be construed as limiting the invention.
Reference will now be made in detail to presently preferred embodiments of the invention, one or more examples of which are illustrated in the accompanying drawings. Each example is provided by way of explanation of the invention, not limitation of the invention, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present inventive concept in virtually any appropriately detailed structure. Further, the terms and phrases used herein are not intended to be limiting but rather to provide an understandable description of the present development. In fact, it will be apparent to those skilled in the art that modifications and variations can be made in the present invention without departing from the scope or spirit thereof. For instance, features illustrated or described as part of one embodiment may be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present invention cover such modifications and variations as come within the scope of the appended claims and their equivalents.
The terms “a” or “an,” as used herein, are defined as one or more than one. The term “another,” as used herein, is defined as at least a second or more. The terms “including” and/or “having” as used herein, are defined as comprising (i.e., open transition). The term “coupled” or “operatively coupled,” as used herein, is defined as indirectly or directly connected.
As used in this application, the terms “front,” “rear,” “upper,” “lower,” “upwardly,” “downwardly,” “left,” “right,” and other orientation descriptors are intended to facilitate the description of the exemplary embodiments of the present invention, and are not intended to limit the structure thereof to any particular position or orientation. The term “longitudinal” as used herein refers to a direction parallel to a machine direction as indicated by arrows in the drawings, unless specifically stated otherwise. The term “transverse” as used herein refers to a direction orthogonal to the machine direction, unless specifically stated otherwise.
The term “outer” in reference to a ply, layer, surface, etc., refers to an orientation toward the exterior of a package (i.e., away from the packaged product) when the film is used as a packaging film. The term “inner” in reference to a ply, layer, surface, etc., refers to an orientation toward the interior of a package (i.e., toward the packaged product) when the film is used as a packaging film. The terms “medial” and “lateral” as used herein refer to a position that is closer to or further away from a longitudinal center line 154 (see, e.g.,
All numbers herein are assumed to be modified by the term “about,” unless stated otherwise. The recitation of numerical ranges by endpoints includes all numbers subsumed within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5).
Referring now to the drawings,
The outer ply 104 has a first major surface and a second major surface opposite the first major surface, wherein the outer ply first major surface faces toward the sealant ply second major surface. The outer ply second major surface forms an outer surface of a pack formed of the sheet materials 100. The outer ply 104 includes transversely spaced apart, longitudinally extending edges 124 and longitudinally spaced apart, transversely extending edges 120.
An optional opening or window 110 may be formed in the outer ply 104. For example, when the outer ply is formed of paper or other opaque material, the optional window 110 may be provided to allow consumers to visualize the contents 174 (see
The blank 100 further includes first and second transversely extending scaling regions 140 spaced apart from each other in the machine direction on opposite sides of a transverse centerline 155. During a packaging operation, the blank 100 is folded along a first and second fold lines 148 when the first and second longitudinally edges 136 are brought together.
The first fold line 148 extends in the machine direction and is disposed intermediate the medial edge line 158 of the first longitudinally extending scaling region 144 and the axial centerline 154. In certain embodiments, the first fold line 148 is disposed midway between the medial edge line 158 of the first longitudinally extending sealing region 144 and the axial center line 154.
The second fold line 148 extends in the machine direction and is disposed intermediate the medial edge line 158 of the second longitudinally extending sealing region 144 and the axial centerline 154. In certain embodiments, the second fold line 148 is disposed midway between the medial edge line 158 of the second longitudinally extending sealing region 144 and the axial center line 154.
As best seen in
During a packaging operation, the first portion 190-1 of each transverse sealing region 140 is sealed to the second portion 190-2 of the respective transverse sealing region 140 and the third portion 190-3 of each transverse sealing region 140 is sealed to the fourth portion 190-4 of the respective transverse sealing region 140 to form the leading and trailing end seals 162 (see, e.g.,
In certain embodiments, the extent W of the notches in the machine direction is greater than or equal to the width of the scaling region 140. In certain embodiments, for typical package sizes contemplated hereunder, the extent W of the notches in the machine direction is in the range of 6 to 26 mm, and more preferably in the range of 9 to 13 mm.
The extent, e.g., D1, D2, or D3 of the notches 128 in the transverse direction may be less than, equal to, or greater than the transverse width of the respective heat seal portion 190-1 or 190-4. In preferred embodiments, the notches are all of equal dimensions and are symmetrically disposed with respect to the centerline 154,
In certain embodiments, the notches 128 extend in the transverse direction from the medial edge line 158 of the adjacent heat seal region 144 to the adjacent fold line 148 and have a transverse dimension of D1, which is equal to the transverse dimension of the corresponding first or fourth heat seal portion 190-1 or 190-4, as applicable.
In certain embodiments, the notches 128 extend in the transverse direction from the medial edge line 158 of the adjacent heat seal region 144 a portion of the distance to the adjacent fold line 148 and have a transverse dimension of D2. In embodiments, the ratio of D2/D1 is in the range of 0.75 to 0.99. In embodiments, the ratio of D2/D1 is in the range of 0.80 to 0.95. In embodiments, the ratio of D2/D1 is in the range of 0.85 to 0.90. In certain embodiments, for typical package sizes contemplated hereunder, D1-D2 is in the range of from about 1-13 mm.
In certain embodiments, the notches 128 extend in the transverse direction from the medial edge line 158 of the adjacent heat seal region 144 beyond the adjacent fold line 148 and have a transverse dimension of D3. In embodiments, the ratio D3/D1 is in the range of 1.01 to 1.25. In embodiments, D3/D1 is in the range of 1.05 to 1.20. In embodiments, D3/D1 is in the range of 1.10 to 1.15. In certain embodiments, for typical package sizes contemplated hereunder, D3-D1 is in the range of from about 1-13 mm.
In certain embodiments, the notches 128 extend in the transverse direction from a point intermediate the lateral edge 136 and the medial edge line 158 of the adjacent heat seal region 144 to the adjacent fold line 148 and have a transverse dimension of D5, where D5-D1 represents the distance the notch 128 extends into the adjacent heat seal region 144. In embodiments, D5-D1 is equal to 1 to 50% of the transverse dimension of the adjacent heat seal region 144. In certain embodiments, D5-D1 is equal to 5 to 45% of the transverse dimension of the adjacent heat seal region 144. In certain embodiments, D5-D1 is equal to 10 to 40% of the transverse dimension of the adjacent heat seal region 144. In certain embodiments, D5-D1 is equal to 15 to 35% of the transverse dimension of the adjacent heat seal region 144. In certain embodiments, D5-D1 is equal to 15 to 35% of the transverse dimension of the adjacent heat seal region 144. In certain embodiments, D5-D1 is equal to 20 to 30% of the transverse dimension of the adjacent heat seal region 144. In certain embodiments, D5-D1 is equal to 25% of the transverse dimension of the adjacent heat seal region 144.
In certain embodiments, the notches 128 extend in the transverse direction from a point intermediate the lateral edge 136 and the medial edge line 158 of the adjacent heat seal region 144 a portion of the distance to the adjacent fold line 148 and have a transverse dimension of D6, where D6-D2 represents the distance the notch 128 extends into the adjacent heat seal region 144. In embodiments, D6-D2 is equal to 1 to 50% of the transverse dimension of the adjacent heat seal region 144. In certain embodiments, D6-D2 is equal to 5 to 45% of the transverse dimension of the adjacent heat seal region 144. In certain embodiments, D6-D2 is equal to 10 to 40% of the transverse dimension of the adjacent heat seal region 144. In certain embodiments, D6-D2 is equal to 15 to 35% of the transverse dimension of the adjacent heat seal region 144. In certain embodiments, D6-D2 is equal to 15 to 35% of the transverse dimension of the adjacent heat seal region 144. In certain embodiments, D6-D2 is equal to 20 to 30% of the transverse dimension of the adjacent heat seal region 144. In certain embodiments, D6-D2 is equal to 25% of the transverse dimension of the adjacent heat seal region 144.
In certain embodiments, the notches 128 extend in the transverse direction from a point intermediate the lateral edge 136 and the medial edge line 158 of the adjacent heat seal region 144 beyond the adjacent fold line 148 and have a transverse dimension of D7, where D7-D3 represents the distance the notch 128 extends into the adjacent heat seal region 144. In embodiments, D7-D3 is equal to 1 to 50% of the transverse dimension of the adjacent heat seal region 144. In certain embodiments, D7-D3 is equal to 5 to 45% of the transverse dimension of the adjacent heat seal region 144. In certain embodiments, D7-D3 is equal to 10 to 40% of the transverse dimension of the adjacent heat seal region 144. In certain embodiments, D7-D3 is equal to 15 to 35% of the transverse dimension of the adjacent heat seal region 144. In certain embodiments, D7-D3 is equal to 15 to 35% of the transverse dimension of the adjacent heat seal region 144. In certain embodiments, D7-D3 is equal to 20 to 30% of the transverse dimension of the adjacent heat seal region 144. In certain embodiments, D7-D3 is equal to 25% of the transverse dimension of the adjacent heat seal region 144.
In certain embodiments, the sealant ply 108 comprises one or more active agents such as anti-fogging agents, oxygen absorbers, moisture absorbers, or antimicrobial/antibacterial agents that are effective to provide a desired property to a surface of the sealant ply. In embodiments, the one or more active agents are provided to convey the desired property or properties to the inward facing surface of the sealant ply 108, i.e., the surface that faces or contacts the product.
In certain embodiments, the active agent may be provided in the form of a coating applied onto the heat-scalable layer. Conventional techniques can be used for the application of the active agent to the heat-scalable layer, such as gravure coating, reverse kiss coating, blade coating, knife over roll coating, fountain bar coating, spray coating, slot coating, and others. In embodiments, the amount of active agent coating is in the range of from 0.1 to 10 g/m2, or from 0.5 to 8 g/m2, or from 1 to 5 g/m2. The application of the active agent coating may be carried out either by an in-line method involving application during the manufacture of the film 100 or by an off-line coating method involving application after the manufacture of the film 100.
Alternatively, one or more active agents may be compounded directly into the polymer resin of the heat-scalable layer before extrusion of the heat seal layer of the sealant ply 108. In embodiments, the amount of active agent added to the heat-scalable layer is generally from 0.25 to 10%, or from 0.5% to 8%, or from 1 to 3%, by weight, of the heat-scalable layer.
Suitable anti-fogging agents for use as the active agent include but are not limited to non-ionic surfactants such as polyhydric alcohol fatty acid esters, higher fatty acid amines, higher fatty acid amides, polyoxyethylene ethers of higher fatty alcohols, and ethylene oxide adducts of higher fatty acid amines or amides, non-ionic fluorinated surfactants, such as alkylester fluorides, perfluoroalkyl ethylene oxides, anionic fluorinated surfactants, such as quaternary ammonium salt of perfluoroalkyl sulfonates, and the like.
The antimicrobial agent may be substantially any appropriate antimicrobial composition useful for the intended purpose of inhibiting the growth of microbes, such as bacteria, fungi, viruses, or protozoa. In embodiments, the antimicrobial agent may be selected from inorganic metal based or organic antimicrobial agents or the like, although it will be recognized that the antimicrobial agent may other antimicrobial agents as known in the art, including antibiotics, antiseptics, antiviral agents, antifungal agents, and disinfectants. In certain embodiments, the antimicrobial agent is selected from silver nanoparticles, silver nitrate.
Suitable moisture absorbing agents include nitrate salts, disodium phosphate, calcium chloride, potassium carbonate, and others.
Suitable antioxidants include vitamin E (tocopherol), ascorbic acid (vitamin C), butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), propyl gallate, and others.
Suitable oxygen absorbers include potassium sulfite, sodium sulfite: ascorbic acid, ferrous sulfate: Ferrous sulfate is a chemical compound that can act as an oxygen absorber. It reacts with oxygen to form ferric sulfate, tannins, and activated carbon.
In certain embodiments, the sealant ply 108 further comprises a metallization layer. In embodiments, the metallization layer is formed is aluminum. In embodiments, the metallization layer is on an outward facing surface of the sealant ply 108. In embodiments, the metallization layer is formed via a deposition process on the sealant ply 108 such as sputter deposition (including magnetron or ion beam sputter deposition), thermal evaporation physical vapor deposition, and chemical vapor deposition.
Referring now to
The blank 100a includes a first longitudinal edge 136 extending in a machine direction and a second longitudinal edge 136 extending in the machine direction, wherein the first longitudinal edge 136 is opposite the second longitudinal edge 136. A first transverse edge 132 extends in a transverse direction perpendicular to the longitudinal edges 136. A second transverse edge 132 extends in the transverse direction, wherein the second transverse edge 132 is spaced apart from the first transverse edge 132 in the machine direction 106. A longitudinally extending hidden region 138 represents the region of the back panel 300a which is beneath the fin seal 146.
A first longitudinal heat seal region 144 extends along the first longitudinal edge 136 from the first transverse edge 132 to the second transverse edge 132. A second longitudinal heat seal region 144 extends along the second longitudinal edge 136 from the first transverse edge 132 to the second transverse edge 132. The first longitudinal heat seal region 144 is heat scalable to the second longitudinal heat seal region 144 to form a longitudinal heat seal 146, which runs the longitudinal length of the finished pack 300a. In the illustrated embodiment, the longitudinal heat seal 146 is a fin seal formed wherein the first major surface of the sealant ply is sealed to itself in the first and second longitudinal heat seal regions 144. In alternative embodiments (not shown), the fin seal 146 may be replaced with a lap seal in cases where the second major surface of the outer ply 104 comprises a heat sealable material.
A first longitudinal fold line 148 extends in the machine direction from the first transverse edge 132 to the second transverse edge 132. The first longitudinal fold line 148 is disposed intermediate a longitudinal center axis 154 and the first longitudinal edge 136. A second longitudinal fold line 148 extends from the first transverse edge 132 to the second transverse edge 132, the second longitudinal fold line 148 being disposed intermediate the longitudinal center axis 154 and the second longitudinal edge 136. An optional longitudinally extending region 142 may be provided comprising a pattern of perforations formed in the sealant ply 108. In the illustrated embodiment, the optional perforated region 142 is transversely coaligned with the centerline 154 although it will be recognized that other perforation patterns are contemplated. A transverse centerline 155 bisects the blank 100a in the transverse direction.
A first transverse heat seal region 140 extends along the first transverse edge 132 from the first longitudinal edge 136 to the second longitudinal edge 136. A first portion 190-1 of the first transverse heat seal region 140 is configured to form a heat seal with a second portion 190-2 of the first transverse heat seal region 140 wherein the first portion 190-1 of the first transverse heat seal region 140 faces or overlies the second portion 190-2 of the first transverse heat seal region 140 when the blank 100a is folded along the first longitudinal fold line 148. A third portion 190-3 of the first transverse heat seal region 140 is configured to form a heat seal with a fourth portion 190-4 of the first transverse heat seal region 140, wherein the third portion 190-3 of the first transverse heat seal 140 region faces or overlies the fourth portion 190-4 of the first transverse heat seal region when the blank is folded along the second longitudinal fold line 148.
In embodiments, the first portion 190-1 of the first transverse heat seal region 140 extends between a medial edge 158 of the first longitudinal heat seal region 144 and the first longitudinal fold line 148; the second portion 190-2 of the first transverse heat seal region 140 extends between the first longitudinal fold line 148 and the axial center line 154; the third portion 190-3 of the first transverse heat seal region 140 extends between the axial center line 154 and the second longitudinal fold line 148; and the fourth portion 190-4 of the first transverse heat seal region 140 extends between the second longitudinal fold line 148 and a medial edge 158 of the second longitudinal heat seal region 144.
A second transverse heat seal region 140 extends along the second transverse edge 132 from the first longitudinal edge 136 to the second longitudinal edge 136, wherein a first portion 190-1 of the second transverse heat seal region 140 is configured to form a heat seal with a second portion 190-2 of the second transverse heat seal region 140, wherein the first portion 190-1 of the second transverse heat seal region faces the second portion 190-2 of the second transverse heat seal region when the blank 100a is folded along the first longitudinal fold line 148, and wherein a third portion 190-3 of the second transverse heat seal region 140 is configured to form a heat seal with a fourth portion 190-4 of the second transverse heat seal region 140, wherein the third portion 190-3 of the first transverse heat seal region 140 faces the fourth portion 190-4 of the first transverse heat seal region 140 when the blank is folded along the second longitudinal fold line 148.
In embodiments, the first portion 190-1 of the second transverse heat seal region 140 extends between a medial edge 158 of the first longitudinal heat seal region 144 and the first longitudinal fold line 148; the second portion 190-2 of the second transverse heat seal region 140 extends between the first longitudinal fold line 148 and the axial center line 154; the third portion 190-3 of the second transverse heat seal region 140 extends between the axial center line 154 and the second longitudinal fold line 148; and the fourth portion 190-4 of the second transverse heat seal region 140 extends between the second longitudinal fold line 148 and a medial edge 158 of the second longitudinal heat seal region 144.
A first cutout 128 is formed in the outer ply 104 and removes a portion of the outer ply 104 along the first transverse edge 120. The first cutout 128 is at least partially overlapping with the first portion 190-1 of the first transverse heat seal region 140. A second cutout 128 is formed in the outer ply 104 and removes a portion of the outer ply 104 along the first transverse edge 120. The second cutout 128 is at least partially overlapping with the fourth portion 190-4 of the first transverse heat seal region 140.
A third cutout 128 is formed in the outer ply 104 and removes a portion of outer ply 104 along the second transverse edge 120. The third cutout 128 is at least partially aligned with the first portion 190-1 of the second transverse heat seal region 140. A fourth cutout 128 is formed in the outer ply 104 and removes a portion of the outer ply 104 along the second transverse edge 120. The fourth cutout 128 is at least partially overlapping with the fourth portion 190-4 of the second transverse heat seal region 140.
By forming the notches 128 to remove the outer ply material along portions of the transverse heat seal regions 140, the thermal resistivity of the outer ply 104 is removed in the region of the notches 128 such that the sealant material of the sealant ply 108 may soften and seal at lower dwell times than if the notches 128 were not present, thereby making the film structures herein advantageous for use with flow wrap equipment utilizing a rotary sealing head to provide greater seal integrity, increased packaging speed, or both. The notches 128 may also advantageously allow the sealant material of the sealant ply 108 to soften and seal at a lower sealing temperature than if the notches 128 in the outer ply 104 were not present.
In certain embodiments, the first and second cutouts 128 have a longitudinal extent in the machine direction which is greater than or equal to the longitudinal extent of the first transverse heat seal region 140, and the third and fourth cutouts 128 have a longitudinal extent in the machine direction which is greater than or equal to the longitudinal extent (seal width) of the second transverse heat seal region 140. As best seen in
In certain embodiments, the first and third cutouts 128 have a transverse extent which is greater than or equal to the transverse distance between the medial edge 158 of the first longitudinal heat seal region 144 and the first longitudinal fold line 148, and the second and fourth cutouts 128 have a transverse extent which is greater than or equal to the transverse distance between the medial edge 158 of the second longitudinal heat seal region 144 and the second longitudinal fold line 148.
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The second and fourth cutouts 128b have a transverse extent that extends from the second longitudinal edge 136 to a position intermediate the medial edge 158 of the second longitudinal heat seal region 144 and the second fold line 148, wherein a portion 156b of the second and fourth cutouts 128b comprises the entire intersection between the second longitudinal heat seal region 144 and the respective first and second longitudinal heat seal regions. By removing the outer ply material at the entire intersection between the second longitudinal heat seal region 144 and the respective first and second transverse heat seal regions 140, heat seal efficiency is improved in the first and second longitudinal heat seal regions 144 and adjacent to the transition between the fin seal 146 and the end seals. In addition, by removing the outer ply material at the entire intersection between the second longitudinal heat seal region 144 and the respective first and second transverse heat seal regions 140, while leaving the outer ply to cover all or substantially all of the intersection between the first longitudinal heat seal region 144 and the respective first and second longitudinal heat seal regions 140, there is no visible line on the fin seal where the fin seal intersects the end seals.
The blank embodiment 100e appearing in
Referring now to
In yet a further embodiment, a sixth embodiment blank, web, and pack are as shown described above by way of reference to the blank 100e, corresponding web 200e, and pack 300e appearing in
Referring now to
Referring now to
The printing indicia layer 114 can be applied to the outer surface of the outer ply 104 via any conventional printing method as would be understood by persons skilled in the art, including without limitation, using a rotogravure printing apparatus, flexographic printing apparatus, offset printing apparatus, digital printing apparatus, ink jet printing apparatus, or the like.
In certain embodiments, the outer ply 104 comprises a paper layer. In embodiments, the paper layer is a bleached paper or natural paper, e.g., bleached or natural Kraft paper. Other preferred embodiments the paper is coated one side, C1S, or coated two side C2S to help with printing or further converting. In a CIS paper, the coating has been applied to only one side of the paper. C2S the coating is on both sides. In preferred embodiments, the paper is a bleached paper to provide improved printing characteristics as compared to its natural/unbleached counterpart. Bleached paper also has a lower stiffness as compared to its natural/unbleached counterpart to allow for improved runnability on flow wrap equipment. In embodiments, the basis weight of paper suitable for use in the outer ply 104 is in the range of 25 gsm to 170 gsm. In embodiments, the basis weight of paper suitable for use in the outer ply 104 is in the range of 28 gsm to 160 gsm. In embodiments, the basis weight of paper suitable for use in the outer ply 104 is in the range of 35 gsm to 150 gsm. In embodiments, the basis weight of paper suitable for use in the outer ply 104 is in the range of 55 gsm to 140 gsm. In embodiments, the basis weight of paper suitable for use in the outer ply 104 is in the range of 60 gsm to 130 gsm. In embodiments, the basis weight of paper suitable for use in the outer ply 104 is in the range of 70 gsm to 120 gsm. In embodiments, the basis weight of paper suitable for use in the outer ply 104 is in the range of 80 gsm to 120 gsm. In embodiments, the basis weight of paper suitable for use in the outer ply 104 is in the range of 70 gsm to 120 gsm. In embodiments, the basis weight of paper suitable for use in the outer ply 104 is in the range of 80 gsm to 110 gsm. In embodiments, the basis weight of paper suitable for use in the outer ply 104 is in the range of 90 gsm to 100 gsm. In preferred embodiments, the basis weight of paper suitable for use in the outer ply 104 is in the range of 60 gsm to 90 gsm, and more preferably 70 gsm. It will be recognized that paper basis weights other that those listed above are also contemplated.
In certain embodiments, the outer ply 104 comprises a monolayer or multilayer polymer material. If the outer ply 104 comprises a monolayer polymer material, it preferably includes polyolefins, such as polyethylene, polypropylene, including blends thereof and copolymers thereof (including ethylene vinyl acetate (EVA) and ethylene vinyl alcohol (EVOH), polyesters, such as polyethylene terephthalate, vinyl polymers, including polyvinylchloride (PVC) and polyvinyl alcohol (PVOH), biopolymers such as cellulose, starch, or sugar-based polymers, natural or synthetic biopolymers, or other films suitable as an outer web for packaging. In embodiments, such polymers further include a barrier coating such as metal oxides, such as silicone oxide, aluminum oxide, or combinations thereof, polymer barriers including polyvinyl alcohol, and other forms of barrier coatings, including metallization layers comprising aluminum or other metal metallization layer is formed from a deposition process on the polymer layer including sputter deposition physical vapor deposition (PVD) (including magnetron or ion beam), thermal evaporation PVD, and chemical vapor deposition CVD. Layers of foil or other barrier materials are also contemplated.
If the outer ply 104 comprises a multilayer polymer material, it may include multiple layers formed of the polymer materials described above, and any adhesive layers, tie layers, primer layers, and so forth, intermediate the polymer layers to promote adhesion or bonding of adjacent layers. If the outer ply 104 comprises a multilayer polymer material, the multilayer structure may be achieved through a single coextrusion process or through successive extrusion lamination, extrusion coating, or other type of coating operations.
In certain embodiments, the sealant ply 108 comprises a monolayer or multilayer material. If the sealant ply 108 comprises a monolayer material, it should be formed of a material which is capable of forming a bond with itself or like material upon exposure to heat and pressure for a relatively short dwell time. If the sealant ply 108 comprises a monolayer material, it may include the materials described above, more preferably scalable paper, polyethylene, polypropylene, polyester, any biopolymers such as cellulose, starch or sugar-based polymers, natural or synthetic biopolymers, or other films suitable as a sealing web for flexible packaging. Such layers may also include a metalized, coated or vacuum coated barrier coating such as aluminum oxide, silicon oxide, PVOH or other barrier coatings. If the sealant ply 108 comprises a multilayer material, it preferably includes scalable paper, propylene ethylene copolymer, high density ethylene copolymer, polypropylene copolymer, polyester copolymer, and laminations of the above to a range of barrier or non-barrier films. If the sealant ply 108 comprises a multilayer material, the multilayer structure may be achieved through a single coextrusion process or through successive extrusion lamination, extrusion coating, or other coating operations.
Referring now to
The sealant ply web 108 is unrolled from a roll 167 and fed toward a laminating station 170 where the outer ply web 104 and the sealant ply web 108 are adhesively joined via the adhesive 106 to form the laminate 200. In certain embodiments, the adhesive 106 may be continuously applied or pattern applied to outer major surface of sealant ply web 108 or inner major surface of the of outer ply web 104. The adhesive may be applied using any suitable coating technique, such as roll coating, roll-to-roll coating, various types of gravure coating, flexographic coating, bar coating, doctor blade coating, comma coating, spraying, or brush coating, in any suitable pattern.
Lamination may be accomplished using a laminating machine comprising two rollers forming a nip therebetween, or may be accomplished using any other method as would be known to persons skilled in the art. The adhesive 106 may optionally be dried using an oven or the like, or could crosslink through a chemical reaction or using UV, E-beam or other curing methods. Optional vents or windows can be applied to either layer. Adhesive is generally void in these areas. After exiting the adhesive coating and laminating station 170, the web 200 is wound up on a wind-up roll 172. Alternatively, in embodiments, the wind up roll 172 may be omitted and the web 200 may be fed directly to a flow wrap fixture 178 as shown in
Referring now to
The conveyor system 176 then feeds the products 174 disposed within the flow wrapper 200t to a sealing and cutting station 180. The sealing and cutting station 180 includes a rotary drum 182 having one or more heated sealing and cutting heads 184 which simultaneously form the end seals 162 in the heat seal regions 140 and separate the flow wrapper 200t into the individual packs 300.
In alternative embodiments, the sealing and cutting station 180 is replaced with a sealing station 180a and a separate cutting station 186 as shown in
The invention has been described with reference to the preferred embodiments. Modifications and alterations will occur to others upon a reading and understanding of the preceding detailed description. It is intended that the invention be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.
This application claims the priority benefit of U.S. Provisional Patent Application Ser. No. 63/452,593 filed Mar. 16, 2023 and U.S. Provisional Patent Application Ser. No. 63/536,005 filed Aug. 31, 2023. Each of the aforementioned applications is incorporated herein by reference in its entirety.
Number | Date | Country | |
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63452593 | Mar 2023 | US | |
63536005 | Aug 2023 | US |