Deep Draw Container Forming Method and Nutritional Product Containers

Abstract

Deep draw formed or shaped blister containers in various configurations are made from a two or more step process of shaping a blister recess in which a first step draws the film to provide the maximum amount of area ratio for the final blister recess and a second step shapes the blister recess. Containers can contain food or nutritional products including sterilized nutritional products for humans or for pets.

Claims

1. A process for manufacturing a shaped article for packaging and display of nutritional products with at least one formed recess, which comprises: (a) holding a film between at least one retaining tool and at least one die, wherein the die has at least one die opening defined by a continuous edge of the die opening; (b) driving a first plunger into the die opening, which causes the film to be formed into a primary contour, the contour having a depth of at least about 100% and up to about 150% of the depth of the formed recess, and an Area Ratio of from greater than 1.0 to about 3.0; and (c) driving a second plunger into the primary contour to a depth that is less than the depth of the primary contour, wherein the second plunger forms a second geometric shape with substantially the same Area Ratio as the primary contour, the second geometric shape comprising a portion distal from the die opening edge that is planar.

2. The process of claim 1, wherein the continuous opening forms a circle, a square, a rectangle, a hexagon, an octagon or an oval.

3. The process of claim 1, wherein, the planar portion has an interior surface and an exterior surface and wherein at least a portion of the exterior surface has a higher coefficient of friction than the interior surface.

4. The process of claim 1, wherein the film is a metal-plastic laminate.

5. The process of claim 1, wherein the film comprises 3 or more layers, wherein said layers comprise aluminum and one or more polymers selected from a polyester, a polyamide or a polyolefin.

6. The process of claim 5, wherein said layers comprise at least one of polypropylene, polyethylene, nylon, polyethylene terephthalate, or polyvinylchloride.

7. The process of claim 5, wherein at least 2 of said layers are laminated with an adhesive layer comprising polyethylene or polypropylene.

8. The process of claim 1, wherein the Area Ratio of the primary contour and the second geometric shape is about 2.0.

9. The process of claim 1, wherein step (b) is performed using a warm-forming step.

10. The process of claim 1, wherein step (b) is performed using a cold-forming step.

11. The process of claim 1, wherein step (c) is performed using a warm-forming step.

12. The process of claim 1, wherein step (c) is performed using a cold-forming step.

13. The process of claim 1, wherein steps (b) and (c) are performed using a warm-forming process.

14. The process of claim 1, wherein steps (b) and (c) are performed using a cold-forming process.

15. The process of claim 1, wherein the second plunger is driven into the primary contour to a depth of up to 95% of the formed recess.

16. The process of claim 1, wherein the second plunger redistributes the film which forms the different geometric shape for the formed recess.

17. The process of claim 1, wherein the shaped article comprises one or more shaped blisters.

18. The process of claim 17, wherein the shaped article comprises one or more multi-layer blisters with multiple chambers.

19. The process of claim 1, wherein the shaped article comprises one or more stacked blisters with lidding.

20. The process of claim 1, wherein the shaped article comprises two or more connected shaped blisters.

21. The process of claim 1, further comprising placing a nutritional product in the packaging recess.

22. The process of claim 1, further comprising placing a pet food product in the packaging recess.

23. The process of claim 21, further comprising heating the packaging recess under pressure.

24. The process of claim 1, wherein a foil lidding is sealed onto the shaped article.

25. The process of claim 1, wherein the retaining tool is an upper die plate and the die is a lower die plate.

26. The process of claim 25, wherein the upper die plate comprises a first plunger and a second plunger.

27. The process of claim 25, wherein the lower die plate comprises a primary forming chamber and a final forming chamber.

28. The process of claim 1, wherein the first plunger comprises a high friction forming surface.

29. The process of claim 1, wherein the second plunger comprises a low friction forming surface.

30. The process of claim 1, wherein driving the first plunger into the film creates a higher friction than driving the second plunger into the film.

31. The process of claim 1, wherein the die has a plurality of spaced die openings.

32. The process of claim 1, wherein the Area Ratio is from about 1.1 to about 3.

33. The process of claim 1, wherein the Area Ratio is from about 1.5 to about 2.5.

34. The process of claim 1, wherein step (b), step (c), step (d) or steps (b), (c) and (d) further comprise warming the die by exogenous heat to a temperature above ambient and below the melting point of the film.

35. The process of claim 34, wherein the die is warmed to a temperature between 35 C. and 95 C.

36. The process of claim 23, wherein the recessed package is heated to a temperature of from 100 C. to 250 C.

37. A container for a nutritional product, wherein the container is made by the process of claim 1.

38. The container of claim 34, wherein the container comprises a pet food container.

39. The process of claim 22, further comprising heating the packaging recess under pressure.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0036] The following drawings form part of the present specification and are included to further demonstrate certain aspects and embodiments of the present invention. The disclosure may be better understood by reference to one or more of these drawings in combination with the detailed description of specific embodiments presented herein.

[0037] FIG. 1 shows a cross section of progressive forming dies.

[0038] FIG. 2 shows a first stage of progressive forming

[0039] FIG. 3 shows a second stage of progressive forming.

[0040] FIG. 4 shows a third stage of progressive forming.

[0041] FIG. 5 shows the return to first stage of progressive forming.

[0042] FIG. 6 shows a plan view of single row of dies.

[0043] FIG. 7 shows a plan view of multiple rows of dies.

[0044] FIG. 8 shows a section of single row of dies.

[0045] FIG. 9 shows a section of multiple rows of dies.

[0046] FIG. 10 illustrates the difference between Draw Ratio and Area Ratio.

[0047] FIG. 11 shows a cross section of an embodiment of a rectangular die.

[0048] FIG. 12 shows an embodiment of a rectangular container as described.

[0049] FIG. 13 shows an embodiment of a square container as described.

[0050] FIG. 14 shows a perspective view of a rectangular die and die plate.

[0051] FIG. 15 shows an embodiment of a sealed dual compartment blister.

[0052] FIG. 16 shows an embodiment of a dual compartment blister as used to pour the contents of a first compartment into the second compartment.

[0053] FIG. 17 shows an embodiment of a dual compartment blister prior to sealing.

[0054] FIG. 18 shows an embodiment of a hemispherical blister.

[0055] FIG. 19 shows an embodiment of a circular blister with a flat bottom.

[0056] FIG. 20 shows a plan view of a blister as shown in FIG. 19.

[0057] FIG. 21 shows an embodiment of a rectangular container as described.

[0058] FIG. 22 shows another embodiment of a rectangular container as described.

DETAILED DESCRIPTION OF THE INVENTION

[0059] The present disclosure is directed to processes for manufacturing shaped articles such as shaped structures, containers, packaging, or blisters, suitable for unit-dose packaging. One purpose of the forming process is to produce a formed recess, such as a blister, suitable for holding pharmaceutical products, nutraceutical products, beverages, foodstuffs, including pet foods, luxury consumables, diagnostic agents, combustion agents and technical articles.

[0060] The processes disclosed herein are capable of creating shapes and degrees of stretch in the film material that cannot be obtained by conventional methods known in the art. The processes of this disclosure involve clamping a film such as a foil laminate and forcing a succession of stamping tools (i.e., plungers) into the film to produce a desired shaped recess (i.e., depression) in film. The process for manufacturing the shaped articles generally involves at least one retaining tool, at least one die, and at least two plungers. The retaining tool and the die are designed to hold a film between them, with the die having at least one opening, which allows the film layer to be deformed into the desired shape of the formed recess.

[0061] Plungers of various shape, size, number and surface finish (which exert, for example, varying degrees friction on the film) may be incorporated into the process. For example, a forming process may use a first plunger which exhibits a high degree of friction and a second or subsequent plungers which exhibit progressively higher or lower degrees of friction. The film layer may include a variety of different materials, including, but not limited to, thermoplastics, polymers, copolymers, composites and laminates. When the unit dose is a pharmaceutical dosage form or a nutritional product, the film will need to be able to undergo aseptic manufacturing processes or terminal sterilization processes to produce sterile shaped articles, for example gamma ray irradiation. Preferably the film is flexible but capable of holding its shape, creates a barrier, withstands the retort process, and has desirable chemical properties (e.g., does not react with the contents). For blister packs, the film is preferably a foil laminate, and more preferably a metal-plastic laminate. The metal-plastic laminate comprises a metal foil coated on at least one side, or on both sides, with one or more plastic polymer layer. If the metal-plastic laminate comprises a plastic polymer layer on both sides of the metal foil, the plastic polymer layers may be the same type of plastic polymer layer, or different types of plastic polymer layers.

[0062] Materials which may be used in the plastic polymer layer of the laminate are well known by those skilled in the art and include, but are not limited to, a variety of commercially available polymers and copolymers, such as polyvinylchloride, nylon, nylon derivatives, polybutylene terephthalate, polyethylene terephthalate, polyethylene, polypropylene, polystyrene, polyacetal, vinylidene chloride, propylene ethylene copolymers, polyethylene napthalate, fluoropolymers, cyclic polyolefins, polyamides, and similar materials or combinations thereof. In certain embodiments the polymer material can include polyester (PET), nylon or bi-oriented polyamide, aluminum, food grade cast polypropylene. A sealing or bonding layer can include polypropylene or polyethylene. The plastic layer may be present in the laminate at a thickness of about 8 m to about 80 m, about 10 m to about 70 m, about 15 m to about 60 m, about 20 m to about 50 m, or about 25 m to about 40 m, and any ranges therein. The plastic components may be non-stretched, or alternatively uniaxially or biaxially stretched, or may be thermoplastics such as halogen-containing polymers, polyolefins, polyamides, polyesters, acrylnitrile copolymers, or polyvinylchlorides. Typical examples of thermoplastics of the polyolefin type are polyethylenes such as low density polyethylene (LDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), uniaxially, or biaxially stretched polypropylenes, polypropylenes such as cast polypropylene and uniaxially or biaxially stretched polyethylene terephthalate (PET) from the polyester series. The above examples are in no way meant to be limiting, as other materials known in the art may be used in the plastic layer as well.

[0063] Examples of plastics based on halogen-containing polymers include but are not limited to polymers of vinylchloride (PVC) and vinyl plastics, containing vinylchloride units in their structure, such as copolymers of vinylchloride and vinylesters of aliphatic acids, copolymers of vinylchloride and esters of acrylic or methacrylic acids or acrylnitrile, copolymers of diene compounds and unsaturated dicarboxyl acids or their anhydrides, copolymers of vinylchloride and vinylchloride with unsaturated aldehydes, ketones, etc., or polymers and copolymers of vinylidenchloride with vinylchloride or other polymerizable compounds. The vinyl-based thermoplastics may also be made soft or pliable in a conventional manner by means of primary or secondary softeners.

[0064] If the plastic films comprise polyesters (PET-films), examples of polyesters include but are not limited to polyalkylene-terephthalate or polyalkylene-isophthalate with alkylene groups or radicals with 2 to 10 carbon atoms or alkylene groups with 2 to 10 carbon atoms interrupted by at least one oxygen atom, such as, e.g., polyethylene-terephthalate, polypropylene-terephthalate, polybutylene-terephthalate (polytetramethylene-terephthalate), polydecamethylene-terephthalate, poly 1.4-cyclohexyldimethylol-terephthalate or polyethylene-2.6-naphthalene-dicarboxylate or mixed polymers of polyalkylene-terephthalate and polyalkylene-isophthalate, where the fraction of isophthalate amount, e.g., to 1 to 10 mol. %, mixed polymers and terpolymers, also block polymers and grafted modifications of the above mentioned materials. Other useful polyesters are known in the field by the abbreviation PEN. Other polyesters are copolymers of terephthalic acid, a polycarboxyl acid with at least one glycol, copolymers of terephthalic acid, ethyleneglycol and an additional glycol, polyalkylene-terephthalates with alkylene groups or radicals with 2 to 10 carbon atoms, polyalkylene-terephthalates with alkylene groups or radicals with 2 to 10 carbon atoms which are interrupted by one or two oxygen atoms, polyalkylene-terephthalates with alkylene groups or radicals with 2 to 4 carbon atoms, and polyethylene-terephthalates (e.g., A-PET, PETP, PETG, G-PET). Glycol-modified polyesters are also referred to as PETG.

[0065] Examples of polyolefins for plastic films include but are not limited to polyethylenes (PE), e.g., high density polyethylene (HDPE, density larger than 0.944 g/cm), medium density polyethylene (MDPE, density 0.926-0.940 g/cm), linear polyethylene of medium density (LMDPE, density 0.926.0.940 g/cm), low density polyethylene (LDPE, density 0.910-0.925 g/cm), and linear low density polyethylene (LLDPE, density 0.916-0.925 g/cm), for example as non oriented (PE film) or uniaxially or biaxially oriented films (oPE film), polypropylenes (PP), such as axially or biaxially oriented polypropylene (oPP film), or cast polypropylene (cPP film), amorphous or crystalline polypropylene or mixtures thereof, ataktic or isotaktic polypropylene or mixtures thereof, poly-1-butene, poly-3-methylbutene, poly-4-methylpententene and copolymers thereof, polyethylene with vinylacetate, vinylalcohol, acrylic acid, such as, e.g., ionomeric resins, such as copolymers of ethylene with 11% acrylic acid, methacrylic acid, acrylic esters, tetrafluorethylene or polypropylene, statistical copolymers, block polymers or olefin polymer-elastomer mixtures, ionomers, and ethylene-acrylic acid copolymers (EAA).

[0066] If the plastic films comprise polyamide films (PA), examples of polyamides include but are not limited to polyamide 6, a homo-polymer of []-caprolactam (polycaprolactam); polyamide 11, polyamide 12, a homo-polymer of []-laurinlactam (polylaurinlactam); polyamide 6.6, a homo-polycondensate of hexamethylenediamine and adipinic acid (polyhexa-methylene-adi-amide); polyamide 6.10, a homo-polycondensate of hexa-methylene-diamine and sebacinic acid (poly-hexa-methylene-sebacamide); polyamide 6.12, a homo-polycondensate of hexa-methylene-diamine and dodecandic acid (poly-hexa-methylene-dodecanamide) or polyamide 6-3-T, a homo-polycondensate of trimethyl-hexa-methylene-diamine and terephthalic acid (poly-trimethyl-hexa-methylene-terephthalic-amide), and mixtures thereof.

[0067] If the plastic comprise acrylnitrile-copolymers, examples of acrylnitrile-copolymers include but are not limited to copolymers of acrylnitrile or methacrylnitrile with acrylic acid esters, vinyl-carboxylate esters, vinyl halides, aromatic vinyl compounds or unsaturated carboxylic acid and diene, and acrylnitrile-methylacrylate copolymers.

[0068] Metals which may be useful in the foil component of the laminate are those that can be formed into a foil with the physical and chemical properties (e.g., thickness, malleability, temperature resistance and chemical compatibility) sufficient to adhere to the plastic layer(s) and remain intact during the forming processes disclosed herein. Such metals include, but are not limited to, aluminum, iron, nickel, tin, bronze, brass, gold, silver, chrome, zinc, titanium, and copper, combinations thereof, as well as alloys including the aforementioned metals, such as steel and stainless steel. The metal foil may be present in the laminate, for example, at a thickness of about 8 m to about 200 m, about 10 m to about 150 m, about 15 m to about 125 m, about 20 m to about 100 m, or about 25 m to about 80 m, and any ranges therein. In certain embodiments the foils, e.g., aluminum foil, may have a purity of at least about 98.0%, more preferably at least about 98.3%, still more preferably at least about 98.5%, and most particularly at least about 98.6%. Aluminum foils of the aluminum-iron-silicon or aluminum-iron-silicon-manganese types may also be used. Other suitable metal foils known in the art may be used as well.

[0069] The laminate may also include one or more adhesive layers between a foil layer and a plastic layer. The same or different adhesives may be used to adhere the plastic to the metal foil on each side. The adhesive layer should be capable of forming a bond with the plastic layer and the foil layer, and generally should be of a thickness of between about 0.1 m and about 12 m, more typically between about 2 m and about 8 m, and any ranges therein. Any number of adhesives known in the art may be used, and the adhesives may be applied using a number of known techniques. Suitable adhesives may contain one or more solvents, be solvent-free, or may be acrylic adhesives or polyurethane adhesives. The adhesive may also be a thermal bonding adhesive, for example an ethylene-vinylacetate copolymer or a polyester resin. The adhesive may also be of a type which hardens upon exposure to electromagnetic rays, for example ultraviolet rays. The laminate may also be formed by hot calendaring, extrusion coating, co-extrusion coating or through a combination of processes. Example adhesives that may be used in the present disclosure include but are not limited to polyethylene (PE) homopolymers, such as LDPE, MDPE, LLDPE, and HDPE; PE copolymers, such as ethylene-acrylic acid copolymers (EAA), ethylene methacrylic acid copolymer (EMAA); polypropylene (PP); PP copolymers; ionomers; and maleic anhydride grafted polymers.

[0070] In another embodiment, the film, e.g., a metal-plastic laminate, may feature a sealing layer in the form of a sealable film or a sealable coating on one of the outer lying sides, or on both of the outer sides. The sealing layer will be the outermost layer in the laminate. In particular, the sealing layer may be on one outer side of the film, which is directed towards the contents of the shaped packaging, in order to enable the lid foil or the like to be sealed into place.

[0071] One or more of the outerlying areas may also provide a surface with a high coefficient of friction. In one embodiment the high coefficient of friction may be achieved through the selection of material of the outer lying side, such as a polyurethane coating. A second embodiment is by the addition of a light adhesive to a section of the outer lying surface, such as an adhesive designed to provide adhesion with low release force as in the case of post-it notes or painter's masking tape. Another embodiment for forming blister packaging is a laminate of aluminum, where the metal foil is coated with a plastic on each side. Aluminum foil is known to provide superior barrier properties to protect the contents of the package. The plastic coating provides an effective means of sealing the package plus provides a protective coating for the aluminum, and may also provide the ability to print on the package.

[0072] In some embodiments, the thicknesses and compositions of the laminate include but are not limited to:

[0073] i. OPA/ALU/PE (12 m/60 m/30 g/m.sup.2);

[0074] ii. OPA/ALU/PE (12 m/45 m/30 g/m.sup.2);

[0075] iii. OPA/ALU/PVC (12 m/60 m/30 g/m.sup.2);

[0076] iv. OPA/ALU/PVC (12 m/45 m/30 g/m.sup.2);

[0077] v. OPA/ALU/PP (12 m/60 m/30 g/m.sup.2); and

[0078] vi. OPA/ALU/PP (12 m/45 m/30 g/m.sup.2). As used above, OPA stands for oriented polyamide, ALU stands for aluminum, PE stands for polyethylene, PVC stands for polyvinylchloride, and PP stands for polypropylene.

[0079] Prior to the present disclosure, those of skill in the art used the ratio of the diameter of the depression in the original surface of the film to the depth of the formed depression in the film to describe the degree of deformation of a film after forming. While this ratio is simple and easy to calculate, it does not describe the amount of stretch of the material, which is a more accurate reflection of the deformation of the film. Therefore, the diameter to depth ratio is limited in its ability to reflect the success of a particular process to reliably and repeatedly stretch a film such as a foil laminate. A better description of the degree of deformation is the Area Ratio. The Area Ratio is the ratio of the area of the stretched or final recess formed in the film (Area.sub.F) to the area of the original surface of the film (Area.sub.1). The Area Ratio takes into account the stretch of the material and shape of the formed recess, not just its depth. The techniques of forming described in this application are known to successfully produce a formed recess, such as a blister, with an Area Ratio of about 1.0, about 1.1, about 1.2, about 1.3, about 1.4, about 1.5, about 1.6, about 1.7, about 1.8, about 1.9, about 2.0, about 2.1, about 2.2, about 2.3, about 2.4, about 2.5, about 2.6, about 2.7, about 2.8, about 2.9, or about 3.0, to 1. As used herein, an Area Ratio of, for example, about 3.0 is equivalent to an Area Ratio of about 3.0/1.

[0080] Prior to the present disclosure, shaped articles made of laminates containing metal foils in the art were generally shaped into the desired structure using a cold-forming process. As used herein, the term cold forming refers to pressure forming under ambient conditions, e.g., without the application of exogenous heat. Cold-forming utilizes a temperature that is no higher than about 40 C., and more typically is no higher than about 35 C. As disclosed herein, a warm-forming process includes a warm forming step for manufacturing shaped articles using a film such as a metal foil containing laminate. The warm-forming process may comprise only warm-forming steps, or may comprise both warm-forming and cold-forming steps. When forming materials consisting of plastic film laminated to one or both sides of a metal foil, it is beneficial to warm the material during the forming step. Warming the laminate may help prevent delamination, allow the plastic to form with less tendency to warp back to the original shape, and result in a more uniform stretch of the material. To stretch and form the plastic without extruding it, the temperature of the material should be kept below the melting temperature of the plastic film during the warm-forming step. Warm-forming is therefore defined herein as forming a film such as a metal-plastic laminate in the temperature range of 45 C. to 95 C.; for example between 55 C. and 70 C., and any ranges therein. In other embodiments, the warm-forming step is performed at a temperature at or above 45 C., 46 C., 47 C., 48 C., 49 C., 50 C., 51 C., 52 C., 53 C., 54 C., 55 C., 56 C., 57 C., 58 C., 59 C., 60 C., 61 C., 62 C., 63 C., 64 C., 65 C., 66 C., 67 C., 68 C., 69 C., 70 C., 71 C., 72 C., 73 C., 74 C., 75 C., 76 C., 77 C., 78 C., 79 C., 80 C., 81 C., 82 C., 83 C., 84 C., 85 C., 86 C., 87 C., 88 C., 89 C., 90 C., 91 C., 92 C., 93 C., 94 C., or 95 C. In some embodiments disclosed herein, the process uses only warm-forming steps, cold-forming steps, or a combination of warm-forming and cold-forming steps.

[0081] The film layer is deformed into the desired shape of the formed recess using two or more plungers. The plungers employed in the present disclosure may be of any shape, including but not limited to cylindrical, conical, cone, blunted cone, pyramid, blunted pyramid, segment of a sphere or cap, or barrel shaped, or a hemispherical shape with a planar top. When describing the blisters, top and bottom are relative terms. During the forming process, the greatest depth below the surface of the mold can be considered the bottom of the recess and form the bottom of the blister. However, in referring to a hemispherical shape, the bottom of the blister is considered the top of the hemisphere. The plungers may comprise particular vertical or steep side walls, vertical or sloping side walls, and the edges or periphery at the bottom of the plungers may have a small radius, or may be round or roundish in shape. It is preferred that the geometry of the shape-forming surface of the plungers vary to progressively form the desired recess, for example by using plungers with gradually different surface geometries. The recesses formed in the film according to the processes disclosed herein may be of any desired shape or depth, including but not limited circular, ovoid, square, triangular, rectangular, polygonal, and elliptical shapes, as well as complicated blister shapes such as deep blisters, blisters with steep angled or vertical walls, and deep blisters with a small inner radius and vertical walls. The base portion of the formed recess may be planar or hyperbolic, and may have a uniform width or a tapered width.

[0082] One unique aspect of the present disclosure involves the application of the first plunger to the film. While processes known in the art typically drive the first plunger into the film from 50% to less than 100% of the final desired depth, the processes disclosed herein drive the first plunger into the film to at least about 100% or greater of the final desired depth. For example, when two plungers are used, the first plunger is driven into the die opening, which causes the film to be formed into a primary contour, which has a depth of at least about 100% and up to about 150% of the depth of the formed recess, and any ranges therein. In other embodiments, the first plunger is driven into the film to a depth of about 105%, about 110%, about 115%, about 120%, about 125%, about 130%, about 135%, about 140%, or about 145%. The first plunger may also be driven to a diameter to depth ratio of less than about 2.5, about 2.4, about 2.3, about 2.2, about 2.1, about 2.0, about 1.9, about 1.8, about 1.7, about 1.6, or about 1.5. Thus, unlike other methods known in the art, the first step of the process disclosed herein produces substantially all of the draw of the film required for the final formed recess. Heat may be used to help accomplish this stretch in one or more warm-forming steps. In addition, the Area Ratio of the primary contour is from greater than 1.0/1 to 3.0/1, and any ranges therein, as described herein.

[0083] After the formation of the primary contour, a second or subsequent plunger is driven into the primary contour to a depth that is generally less than the depth of the primary contour, such that the second plunger forms a different geometric shape for the formed recess with substantially the same Area Ratio as the primary contour. Thus, the processes disclosed herein are again different from those known in the art, which typically involve driving a second or subsequent plunger to a depth greater than the depth achieved by the previous plunger, thereby producing additional draw of the film beyond that achieved by the first or previous plunger. In other methods known in the art, the second or subsequent plunger may also be driven to a depth beyond the final desired depth of the depression formed to compensate for films that spring back towards the original plane of the film. In contrast, for example, in the processes disclosed herein, the second (or subsequent) plunger is driven to a depth that is less deep than the first or previous plunger. The second (or subsequent plunger) may also be driven to a depth that is less than the final depth (i.e., less than about 100%) of the formed recess desired. In certain embodiments, the second (or subsequent plunger) plunger is driven into the film to a depth that is less than about 99%, about 98%, about 97%, about 96%, about 95%, about 94%, about 93%, about 92%, about 91%, about 90%, about 89%, about 88%, about 87%, about 86%, about 85%, about 84%, about 83%, about 82%, about 81%, or about 80% of the primary contour or of the formed recess. The second or subsequent plunger may reshape, stretch, or redistribute the previously drawn surface of the primary contour to form the geometric detail desired in the final formed recess. Thus, the second (or subsequent) plunger is not designed to substantially draw the film beyond the final shaped depth. Instead, the second (or subsequent) plunger reshapes, stretches, or redistributes the recess, which often results in decreasing the depth of the recess through directing the film into the desired shape. The application of heat in a warm-forming step with the second or subsequent plunger can help form the detail of the final recess.

[0084] Applying the second (or subsequent) plunger in a warm forming step can help to reduce elastic spring-back of the film, for example a metal-plastic laminate, and can assist in reducing potential delamination of the plastic layer(s) from the foil. Although the process described herein uses a first and second plunger, it is understood that more than two plungers may be used to achieve the desired shape of formed recess. Additionally, the forming of the desired formed recess may take place in a single line of sequential steps or in several parallel lines of sequential steps. For example, multiple plungers may be used to produce blister packs with a plurality of formed recesses.

[0085] The plungers disclosed herein may have the same or different degrees of friction when contacted with the film. For example, the plungers may be coated with a high friction layer or a low friction layer. In certain embodiments, the degree of friction is decreased with each successive plunger, while in other embodiments, the degree of friction is increased with each successive plunger. It is well within the skill of those in the art to vary the degree of friction of each successive plunger as desired, including increasing and/or decreasing the degree of friction as appropriate, even within a single series of plungers. The friction layer of the forming surface may comprise one or more plastics such as polytetrafluoroethylene (PTFE), polyoxymethylene (POM), polyethylene, polyacetal, polyethyleneterephthalate (PET), rubber (e.g., hard rubber), caoutchoucs, acrylic polymers, glass, ceramic, graphite, boron nitride, molybdenum disulphide, or mixtures thereof Alternatively, the friction layer may comprise one or more metals, for example an aluminum, chromium, or steel layer (particularly polished metal layers), or a ceramic layer containing graphite, boron nitride or molybdenum disulphide. The surfaces of the plunger when metal may also be designed to achieve low friction values, for example by polishing.

[0086] In another embodiment, the process disclosure herein may be performed using plungers that are arranged coaxial or telescopically inside each other. For example, a first plunger can form the first contour, and then be raised within the first contour followed by the lowering of a second plunger, which slides telescopically in the first plunger, to effect the final forming of the desired recess in the film.

[0087] After the desired recess is formed, it may be sealed by the application of a coating such as a lidding over the opening of the formed recess. Sealing methodologies are well known to those of skill in the art, including but not limited to flat seals, diamond patterns, or otherwise applying heat and/or pressure (e.g., using a press, hot roller, platen press or a heated platen press) to the surfaces of the film and the coating. In certain embodiments, the lid stock material is puncturable at a limited distance, is capable of splitting, minimizes the generation of particulates, creates a barrier, withstands radiation, has desirable chemical properties (e.g., does not react with the contents), and/or can be printed on. For pharmaceuticals, industry guidelines suggest a seal width in the range of 0.1 inch. When packaging pharmaceutical dosage forms, it is important to achieve a good seal such that gases or other environmental elements cannot diffuse into the formed recess and damage the dosage form packaged therein. In certain embodiments, particularly when the unit dose is small, it is desirable to minimize the area of the seal. For applications such as foodstuffs or pet foods, the packaging is larger, designed to hold from 1 gram to 150 grams, from 5 grams to 100 grams, or from 5 grams to 50 grams, for example. As larger sized blisters are made, the seal area is contemplated to increase proportionally.

[0088] The sealing of a coating such as a lid stock onto a plane of film with one or more formed recesses may be accomplished in an area (e.g., circular area) around the shaped recess. When narrow seals are required, the flat seal may not provide sufficient seal strength to resist dynamic pressure when the formed recess (e.g., a blister) is crushed. Although such a seal is usually adequate to prevent water vapor or oxygen transmission, it may be more likely to leak when the contents are placed under the pressures caused during the dispensing process. Diamond pattern seals may provide a stronger seal by utilizing concentrated points of pressure to create a more robust seal. But diamond pattern seals, which are usually in a linear array pattern, may not uniformly encircle a round blister and may not be consistent around the circumference of the seal, especially in a narrow-width seal on a small blister. Thus, in certain embodiments, it may be desirable to add contours to the sealing area to reduce the width required by at least half or, conversely, produce a substantially stronger seal when using the suggested width. For example, creating annular seals (corrugated in the cross section) may provide the same benefits as the diamond pattern, but in a manner that is uniform around the circumference of the blister seal.

[0089] The following embodiments are included to illustrate the compositions and methods disclosed herein. It should be appreciated by those of skill in the art, in light of the present disclosure, that many changes can be made in the specific embodiments which are disclosed herein and still obtain a like or similar result without departing from the spirit and scope of the invention.

[0090] FIG. 1 shows an embodiment of progressive forming dies with a die set 10 comprising a lower die plate 11 and an upper die plate 12. The lower die plate 11 has a primary forming chamber 15 and final forming chamber 16. The upper die plate 12 has a primary shaping plunger 13 and a second, final shaping plunger 14, such that the primary forming chamber 15 and the primary shaping plunger 13 are aligned. Likewise, the final forming chamber 16 and the final shaping plunger 14 are aligned. The upper die plate 12 may be movable upwards from lower die plate 11, or the lower die plate 11 may be movable downwards from the upper die plate 12, thereby creating a space 19 between the die plates allowing a film, for example a laminate containing a metal foil-plastic layer 20 to be inserted between the die plates. The primary shaping plunger 13 has a shaped surface 17, which is positioned to drive into the film 20 and produce a primary contour 21 (shown in FIG. 2). Final shaping plunger 14 has a shaped surface 18 which is positioned to drive into the film 20 and produce a final contour 22 (shown in FIG. 3).

[0091] The embodiment of FIG. 2 shows the upper die plate 12 pressed against the lower die plate 11 by forces 30 and 31 clamping the film 20 firmly between the die plates. The primary contour 21 has already been formed in the film 20 and positioned under the final shaping plunger 14. The embodiment of FIG. 3 shows the primary shaping plunger 13 being driven into the film 20 by force 33, creating primary contour 21 in the film 20. Simultaneously, the final shaping plunger 14 is driven into the primary contour 21 by force 34 creating final contour 22. The depth of the primary contour 21 is greater than the final contour 22.

[0092] The embodiment of FIG. 4 shows the plungers retracted by force 35 and the upper die plate 12 opened upward by force 34. The opening of the die set 10 allows the film 20 to be advanced as shown by the arrow such that an unformed area 23 of the film 20 is positioned below the primary shaping plunger 13, the primary contour 21 is repositioned under the final shaping plunger 14, and the final contour 22 is removed from the die set 10. The embodiment of FIG. 5 shows the die set 10 clamped by forces 30 and 31 and the film 20 in position for the next forming step similar to step 1 shown in FIG. 2. Thus, by repeating the steps, final contours 22 are produced and are ready for placement of medication, pills, devices, etc. into the formed blister for sealing into the complete package.

[0093] FIG. 6 shows a plan view of a single strip of film 20 positioned over the lower die plate 11 with a single row of forming chambers 15 and 16. Such a configuration produces a strip of formed blister shapes in a single row. FIG. 7 shows a strip of film 50 that is wide enough for five rows of forming dies over a lower die set 41 which contains five rows of forming chambers 45 and 46. It will be obvious to one of skill in the art that any number of rows of shaping dies and chambers can be incorporated into a die set. Five are shown to illustrate the principle only. FIG. 8 shows a cross section through the single row die set 10 with final contours 22 produced in a single row. FIG. 9 shows a cross section through the primary shaping plungers 43 of the five station die set 40. A cross section through any one of the five rows of forming dies would look like FIG. 8.

[0094] FIG. 10 shows the difference in Area Ratio and Draw Ratio for three different shapes with the same draw ratio. Shapes 1, 2 and 3 represent vastly different amounts of stretch of the film, as well as varying levels of difficulty to form. As shown, while the Draw Ratio does not distinguish between these differences, the Area Ratio is very descriptive of the degree of film forming in each case. If the film is drawn substantially uniform in the formed recess, the new thickness could be calculated as the Original Material Thickness/Area Ratio.

[0095] The Area Ratio for each of the three shapes shown in FIG. 10 is calculated as follows:

[0096] Beginning Surface Area Within Mold Clamp (Area.sub.1)=r.sup.2=(0.5.sup.2)=0.78 in.sup.2

[0097] For each of the three shapes, the Formed Surface Area (Area.sub.F) is:

[0098] Shape 1: Curved surface of a cone=r {square root over (r.sup.2+h.sup.2)}=(0.5) {square root over (0.5.sup.2+0.5.sup.2)}1.11 in.sup.2

[0099] Shape 2: Hemisphere surface=2r.sup.2=2(0.5.sup.2)=1.57 in.sup.2

[0100] Shape 3: Cylinder bottom+side=2rh+r.sup.2=2(0.5)(0.5)+(0.5.sup.2)=2.35 in.sup.2

[0101] The Area Ratio=Area.sub.F/Area .sub.1

[0102] Shape 1: 1.11/0.78=1.41

[0103] Shape 2: 1.57/0.78=2.0

[0104] Shape 3: 2.35/0.78=3.0

[0105] A cross sectional view of a rectangular die and plunger is show in FIG. 11. A rectangular or square die can be used in the practice of the disclosed methods, advantageously for forming the primary contour for articles for pet food trays, for example. In the disclosed methods, a second plunger is a different geometric shape is then driven into the primary contour to create the final formed recess. Another view of a rectangular die and plate is shown in FIG. 14. FIGS. 12, 13, and 15-22 are examples of articles produced by the disclosed methods, including a rectangular container (FIG. 12), a square container (FIG. 13), a sealed dual compartment blister (FIG. 15), a dual compartment blister as used to pour the contents of a first compartment into the second compartment, (FIG. 16), a dual compartment blister prior to sealing (FIG. 17), a hemispherical blister (FIG. 18), a circular blister with a flat bottom (FIG. 19), a plan view of a blister as shown in FIG. 19 (FIG. 20), another embodiment of a rectangular container (FIG. 21) and another embodiment of a rectangular container (FIG. 22).

[0106] All of the compositions and methods disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure. While the compositions and methods of this invention have been described in terms of preferred embodiments, it will be apparent to those of skill in the art that variations may be applied to the compositions and/or methods and in the steps or in the sequence of steps of the methods described herein without departing from the concept, spirit and scope of the invention. More specifically, it will be apparent that certain agents that are chemically or physiologically related may be substituted for the agents described herein while the same or similar results would be achieved. All such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the spirit, scope and concept of the invention as defined by the appended claims.