CN111867942B - Lined container - Google Patents

Abstract

A container for heating food. The container includes a base layer of material and a liner releasably attached to an inner surface of the base layer. The liner is at least partially attached to the base layer by a heat seal layer and is separable from the base layer after heating the container. The container includes a bottom panel and a sidewall extending along the bottom panel.

Description

Lined container

Cross Reference to Related Applications

This application claims priority from U.S. provisional patent application 62/649159 (application date 3/28/2018) and U.S. provisional patent application 62/643914 (application date 3/16/2018).

The disclosures of U.S. provisional patent application 62/649159 (filed as 3/28/2018) and U.S. provisional patent application 62/643914 (filed as 3/16/2018) are incorporated herein by reference as if set forth in their entirety herein.

Technical Field

The present invention relates to blanks, containers, trays, structures and various features and methods for forming containers from blanks. More particularly, the present invention relates generally to a lined container suitable for heating food.

Disclosure of Invention

In general, one aspect of the invention relates generally to a container for heating food. The container includes a base layer of material and a liner releasably attached to an inner surface of the base layer. The liner is at least partially attached to the base layer by a heat seal layer, and the liner is separable from the base layer after heating the container. The container includes a bottom panel and a sidewall extending along the bottom panel.

In another aspect, the present disclosure is generally directed to a method of forming a container including a bottom panel and a sidewall extending along the bottom panel. The method can comprise the following steps: obtaining a blank, a liner material and a heat seal layer; forming the blank into an initial structure; activating the heat sealing layer; and applying at least a portion of the liner material to the inner surface of the initial structure, such that the liner material and the initial structure form respective liner and base layers of the container, and the liner is releasably attached to the inner surface of the base layer by the heat-seal layer. After heating the container, the liner can be separated from the base layer.

In another aspect, the present invention is generally directed to a container for heating food. The container may include a base layer of material and a liner releasably attached to an inner surface of the base layer. After heating the container, the liner can be separated from the base layer. The container may also include a bottom panel and a sidewall. The sidewall may include: at least one end panel foldably connected to the bottom panel; and a side panel foldably connected to the bottom panel. The sidewall may include: a lower portion extending along the bottom panel; and an upper portion extending upwardly from the lower portion along an intermediate fold line.

In another aspect, the present invention generally relates to a combination of a blank and a liner material for forming a container for heating a food product. The blank may comprise: a bottom panel; an end panel foldably connected to the bottom panel; and a side panel foldably connected to the bottom panel. When the container is formed from a blank and liner material, the end panels and side panels can be used to at least partially form a side wall comprising: a lower portion extending along the bottom panel; and an upper portion extending upwardly from the lower portion along an intermediate fold line. The blank can be used to form a base layer of a container. When the container is formed from a blank and a liner material, the liner material can be used to form a liner that is releasably attached to the inner surface of the base layer. The liner can be separated from the base layer after heating the container formed from the blank and liner material.

In another aspect, the present disclosure is generally directed to a method of forming a container. The method can comprise the following steps: obtaining a blank and a lining material, the blank comprising: a bottom panel; an end panel foldably connected to the bottom panel; and a side panel foldably connected to the bottom panel. The method may further comprise: the blank is formed into an initial structure and at least a portion of the liner material is attached to the inner surface of the initial structure such that the liner material and the initial structure form a respective liner and base layer of the container and the liner is releasably attached to the inner surface of the base layer by the heat seal layer. After heating the container, the liner can be separated from the base layer. The end panel and the side panel can at least partially form a sidewall comprising: a lower portion extending along the bottom panel; and an upper portion extending upwardly from the lower portion along an intermediate fold line.

The above advantages, as well as other advantages and benefits of various additional embodiments, will be readily apparent to those of ordinary skill in the art upon reading the following detailed description of the embodiments, and by referring to the accompanying drawings, which are set forth below.

Drawings

In accordance with common practice, the various features of the drawings discussed below are not necessarily drawn to scale. The dimensions of various features and elements in the drawings may be exaggerated or reduced to more clearly illustrate the embodiments of the present invention.

Fig. 1 is a plan view of a blank for forming a container according to a first exemplary embodiment of the invention.

Fig. 2A and 2B are perspective views of a container formed from the blank and liner of fig. 1 according to a first exemplary embodiment of the invention.

Fig. 3A and 3B are schematic cross-sectional views of a portion of the container of fig. 2A and 2B.

Fig. 4 is a schematic view of an apparatus for forming a container according to one embodiment of the present invention.

Figure 5 is a schematic view of a liner being applied to a base layer of a container according to one embodiment of the present invention.

Fig. 6 is a plan view of a blank for forming a container according to a second exemplary embodiment of the invention.

Fig. 7 is a perspective view of a container formed from the blank of fig. 6 and a liner according to a second exemplary embodiment of the invention.

Fig. 8 is a cross-sectional view of a portion of the container of fig. 7.

Fig. 9 is a plan view of a blank for forming a container according to a third exemplary embodiment of the present invention.

Fig. 10 is a perspective view of a container formed from the blank and liner of fig. 9 according to a third exemplary embodiment of the invention.

Fig. 11 is a cross-sectional view of a portion of the container of fig. 10.

Corresponding parts are designated by corresponding reference numerals throughout the drawings.

Detailed Description

The present invention relates generally to various aspects of containers, structures, trays, materials, packages, components, and articles and methods of making such containers, structures, trays, materials, packages, components, and articles. While a number of different aspects, embodiments, and examples are disclosed, a variety of interrelationships between various aspects, embodiments, and examples, combinations thereof, and variations thereof are contemplated. In one example embodiment, the present invention is directed to forming a container or tray for holding food or various other items. However, in other embodiments, the container or tray can be used to form other non-food containing items, or can be used for heating or cooking.

Fig. 1 shows a blank 3 (fig. 2A and 2B) for forming a container 5 according to a first embodiment of the invention, the container 5 having a base layer 7 and a liner 9. In one embodiment, the base layer comprises paperboard (e.g., solid bleached kraft folded cardboard) or other suitable material that is recyclable and/or suitable for use in an oven (not shown), and the liner 9 comprises a plastic layer, such as polyethylene, polyethylene terephthalate (PET) material, or any other thermoplastic material, or a bioplastic, such as a vegetable oil or starch-based plastic. In the exemplary embodiment, liner 9 includes at least one layer that is heat sealed by heat seal layer 10Attached to the base layer 7 is PET or similar material (fig. 3A and 3B). For example, heat-sealable layer 10 may comprise a thermoformable sealant-grade clear polyester packaging film, such as that available from DuPont Teijin Films U.S. Limited Partnership, of Hopfwell, virginia

XMPOL12. Alternatively, heat-seal layer 10 may be any suitable thermoformable sealant or adhesive, any suitable heat-or pressure-activated adhesive, or any other suitable material. The container 5 is suitable for heating food (not shown) in an oven (not shown), such as a convection or conventional oven or microwave. In the embodiment shown, the liner 9 is at least partially attached to the base layer 7 and is in contact with the food product during heating. After heating the food product, the base layer 7 and the liner 9 can be separated so that both the base layer 7 and the liner 9 can be recycled separately. For this purpose, U.S. patent application No.2011/0259784 (published as 10/27/2011, corresponding to U.S. patent application No.12/992131, published as 2/2011, 11/2011) and PCT/GB/09/50506 (published as 5/13/2009) are hereby incorporated by reference.

The blank 3 may be formed from a single layer of material such as, but not limited to, paperboard, cardboard, paper or polymeric sheet material, but alternatively the blank may be formed from a laminate comprising multiple layers. In one embodiment, the blank 3 may include a microwave interactive layer (not shown), such as that available from Graphic Packaging International of GA, atlanta

A container. The microwave interactive layer may be generally referred to as or may have as one component thereof a foil, a microwave shielding layer, or any other term or component suitable for shielding microwave energy and/or heating-inducing material layers in a microwave oven.

As shown in fig. 1, the blank 3 has a longitudinal direction L1 and a transverse direction L2. In the embodiment shown, the blank 3 has: a bottom panel 11; a first end panel 13, the first end panel 13 being foldably connected to the bottom panel at a lateral fold line 15; a second end panel 17, the second end panel 17 being foldably connected to the bottom panel at a lateral fold line 19; the first side panel 21 is foldably connected to the bottom panel 11 at a longitudinal fold line 23; and a second side panel 25, the second side panel 25 being foldably connected to the bottom panel at a longitudinal fold line 27. In one embodiment, the blank 3 comprises four panels (two end panels 13, 17 and two side panels 21, 25) extending around the periphery of the bottom panel 11 such that the four fold lines 15, 19, 23, 27 form a rectangular periphery of the bottom panel 11.

As shown in fig. 1, the first end panel 13 includes a lower portion 13a, the lower portion 13a is foldably connected to an upper portion 13b along a transverse fold line 29, the second end panel 17 includes a lower portion 17a, the lower portion 17a is foldably connected to the upper portion 17b along a transverse fold line 31, the first side panel 21 includes a lower portion 21a, the lower portion 21a is foldably connected to the upper portion 21b along a transverse fold line 33, and the second side panel 25 includes a lower portion 25a, the lower portion 25a is foldably connected to the upper portion 25b along a transverse fold line 35. In the illustrated embodiment, the lower portions 13a,17a, 21a,25a of the respective panels 13, 17, 21, 25 are foldably connected to the bottom panel 11 along respective fold lines 15, 19, 23, 27. In one embodiment, each lower portion 13a,17a of the respective end panel 13, 17 has two lower beveled edges 37a and each upper portion 13b,17b of the respective end panel 13, 17 has two upper beveled edges 37b. Similarly, each lower portion 21a,25a of the respective side panel 21, 25 has two lower inclined edges 39a and each upper portion 21b,25b of the respective side panel 21, 25 has two upper inclined edges 39b. In the illustrated embodiment, at each corner of the blank 3, adjacent lower inclined edges 37a,39a of the respective end panels 13, 17 and side panels 21, 25 extend at a first angle A1 relative to one another and adjacent upper inclined edges 37b,39b of the respective end panels 13, 17 and side panels 21, 25 extend at a second angle A2 relative to one another. In one embodiment, angle A1 may be less than angle A2. In example embodiments, the first angle A1 may be about 25 degrees and the second angle A2 may be about 70 degrees or 80 degrees. Alternatively, the angles A1, A2 may be any suitable angle without departing from the invention.

In the illustrated embodiment, the end panels 13, 17 and side panels 21, 25 each include a respective flange portion 45, 47, 49, 51, the flange portions 45, 47, 49, 51 being at least partially defined by respective fold lines 61, 63, 65, 67 extending in the respective panels. In one embodiment, adjacent flange portions 45, 47, 49, 51 are arranged to at least partially overlap when the blank 3 is formed into the container 5. The blank 3 may be otherwise shaped, arranged and/or provided without departing from the invention. Additionally, any of the bottom panel 11, end panels 13, 17, side panels 21, 25, and/or flange portions 45, 47, 49, 51 may be omitted, or may be otherwise shaped, arranged, positioned, and/or provided without departing from the invention. For example, the blank 3 may have any suitable number of panels and any suitable shape around the periphery of the bottom panel 11.

As shown in fig. 2A and 2B, the container 5 may be formed from the blank 3 by folding the end panels 13, 17 and side panels 21, 23 upwardly along respective fold lines 15, 19, 23, 27 (to form side walls 77 extending around the periphery of the bottom panel 11). In one embodiment, the side wall 77 extends obliquely upwardly and outwardly from the bottom panel 11 around the perimeter of the container 5. As shown in fig. 2A and 2B, the lower portions 13a,17a, 21a,25a of the respective panels 13, 17, 21, 25 form a lower portion 77a of the side wall 77, and the upper portions 13B,17B, 21B,25B of the respective panels 13, 17, 21, 25 form an upper portion 77B of the side wall 77, wherein the fold lines 29, 31, 33, 35 can cooperate to at least partially form an intermediate fold line 99 extending about the side wall 77. In the illustrated embodiment, when the end panels 13, 17 and side panels 21, 23 are folded upwardly to form the side walls 77, the adjacent lower and upper beveled edges 37a,39a, 37b are brought together (e.g., engaged, abutted, at least partially in contact with, and/or slightly spaced apart) at each corner 90 of the container 5. As shown in fig. 1, 2A, and 2B, because angle A1 is different (e.g., smaller) than angle A2, the lower and upper portions 77a, 77B of the sidewall 77 extend at different angles relative to the bottom panel 11 (fig. 3A). For example, as shown in fig. 3A, the lower portion 77a may extend outward and upward from the bottom panel 11 at an obtuse angle A3 (e.g., greater than 90 degrees and less than 180 degrees), while the upper portion 77b extends upward from the lower portion 77a at an obtuse angle A4 (e.g., closer to or along the vertical direction than the lower portion 77 a). In example embodiments, the transition from the bottom panel 11 to the lower portion 77a and from the lower portion 77a to the upper portion 77b may be at an angle greater than 90 degrees, which can help increase contact between the liner 9 and the base layer 7 (e.g., increase the surface area of the liner 9 that engages the base layer).

In the illustrated embodiment, the flange portions 45, 47, 49, 51 are folded along respective fold lines 61, 63, 65, 67 so as to extend outwardly from the respective end panels 13, 17 and side panels 21, 25 and generally parallel to the bottom panel 11. As shown in fig. 2A and 2B, the flange portions 45, 47, 49, 51 form a flange 8, the flange 8 extending outwardly from the sidewall 77 around the perimeter of the container 5. In one embodiment, the sidewall 77 may extend along substantially the entire perimeter of the bottom panel 11, and the flange 8 may extend along substantially the entire perimeter of the sidewall 77. As shown in fig. 2A and 2B, the side walls 77 and the bottom panel 11 define an interior 79 of the container 5, and have an inner surface 92 extending along the interior 79. The flange 8, sidewall 77 and/or bottom panel 11 may be omitted or may be otherwise shaped, arranged, positioned and/or provided without departing from the invention. Also, the container 5 may have one or more injection molded features that may reinforce the flange 8 and/or other portions of the container without departing from the invention.

In the illustrated embodiment, the container 5 further comprises a liner 9, the liner 9 being attached to an inner surface 81 of the base layer 7 formed from the blank 3. As shown in fig. 3A and 3B, the liner 9 may be attached to the base layer 7 by a heat seal layer 10 (e.g. for a PET liner). Alternatively, the heat-seal layer 10 may be applied to the base layer 7 without departing from the invention. Alternatively, heat seal layer 10 can be omitted (e.g., for a polyethylene liner). The sleeve 9 may extend over the bottom panel 11, the side wall 77 and the flange 8. In one embodiment, as shown in fig. 2A, 2B, and 3A, liner 9 may extend beyond flange 8 (e.g., such that edge 84 of liner 9 is spaced outwardly from edge 86 of flange 8). As shown in fig. 2A, 2B, and 3A, the rim 84 of the liner 9 may extend around the periphery of the container 5. Alternatively, edge 84 of liner 9 may be aligned with edge 86 of flange 8 and/or may be spaced inwardly from edge 86 (e.g., such that edge 86 of flange 8 extends around the perimeter of container 5). In the illustrated embodiment, the liner 9 may be attached to at least a portion of each of the bottom panel 11, end panels 13, 17, side panels 21, 25, and flange portions 45, 47, 49, 51. In one embodiment, the liner 9 may at least partially cause the base layer 7 to substantially retain the shape of the side wall 77 and the container 5 (e.g., may help prevent the end panels 13, 17 and side panels 21, 25 from separating from one another). As shown in fig. 3A and 3B, the thickness of liner 9 and heat-seal layer 10 is exaggerated to show the configuration of liner 9 and heat-seal layer 10 in container 5. The container 5, including the liner 9, heat seal layer 10, and/or base layer 7, may be otherwise shaped, arranged, positioned, and/or configured without departing from the invention.

Fig. 4 illustrates one embodiment of a system 101 and method for forming a container 5 having a base layer 7 formed from a blank 3 and an inner layer 9 attached to the base layer 7. As shown in fig. 4, the system comprises a stack 110 of blanks 3, these blanks 3 being transferred by a conveyor 103 to a container forming mechanism 120. In one embodiment, container forming mechanism 120 may be any suitable mechanism or forming tool capable of folding and/or pressing blank 3 into container 5, which may be similar to, and have similar features and/or components as, conventional forming tools, such as disclosed in U.S. patent No.8534460 (published 2013, 9, 17), which is incorporated herein in its entirety. Also, the forming tool may have similar features and components, such as the forming tool disclosed in U.S. patent No.8801995 (published 2014 8 and 12), which is incorporated herein by reference in its entirety), or any other suitable forming tool assembly. The mechanism 120 causes the end panels 13, 17 and the side panels 21, 25 to be folded relative to the bottom panel 11 so as to form an unlined initial structure 130 comprising only the base layer 7. The initial structure 130 may be fed by a conveyor 105 to a lower mold 140 and a PET plastic film web 150 may be fed from a supply roll 151 over the initial structure 130, the film web 150 having a thickness of between about 30 and 150 microns in one exemplary embodiment. In one example embodiment, the diaphragm 150 may be a PET film having a thickness of about 50 microns. Alternatively, the diaphragm 150 may have any suitable thickness. In the illustrated embodiment, the plurality of liners 9 may be formed (e.g., cut) from the diaphragm 150.

In the illustrated embodiment, the roll of sheet material 150 may be fed with heat seal layer 10 pre-applied, and sheet material 150 may be unwound from a feed roll 151 such that heat seal layer 10 is on the bottom side of sheet material 150, facing initial structure 130. In another embodiment, heat seal layer 10 may be applied to sheet 150 after sheet 150 is unwound from supply roll 151 (e.g., by a jet applicator or roller, not shown). Alternatively, heat-seal layer 10 may be omitted (for example, for sheet 150 of polyethylene or other suitable material), or the heat-seal layer may be pre-applied as a coating on web 3.

In one embodiment, the membrane 150 may have perforations or other features (not shown) to help separate the liner 9 from the rest of the sheet 150 when forming the container 5. The upper die 160 has a heater plate surface 164, the heater plate surface 164 having a PTFE coating, for example

And (4) coating. Alternatively, the heater plate surface 164 may have a coating of any suitable material, or the coating may be omitted. As schematically shown in fig. 4, the upper mold 160 may include a plurality of holes or conduits 162 in a heater plate surface 164 for applying vacuum and/or air pressure on the sheet 150. The conduits 162 may each have a cross-sectional dimension (e.g., diameter) of about 0.2 millimeters, and may be grouped in clusters on the heater plate surface 164 (e.g., clusters 164 of three conduits), which may be spaced apart on the heater plate. In another embodiment, the conduits 162 may be evenly spaced from one another and/or may have a cross-sectional dimension of about 1 millimeter. These example configurations of conduit 162 may help to be suitable (e.g., uniform)Ground) heat and air pressure/vacuum are applied to sheet 150 and heat-seal layer 10 to cause sheet 150 and heat-seal layer 10 to form on primary structure 140 and adhere to primary structure 140. The lower mold 140 and/or the upper mold 160, including the conduits 162 and/or the heater plate 164, may be otherwise shaped, arranged, positioned, and/or provided without departing from the invention. For example, the heater plate 164 may be omitted, and heat may optionally be applied to the sheet 150 (e.g., with a flow of hot air).

In the illustrated embodiment, the lower die 140 may hold the structure 130 in its upright shape (schematically represented in fig. 4 and 5) when the liner 9 is applied to the base layer, and may be raised in the direction of arrow B toward the upper die 160 by a pneumatic ram 142, an initial vacuum being applied to the conduit 162 to draw the film 150 with the heat seal layer 10 toward the upper die 160. In the illustrated embodiment, upper mold 160 is heated to a suitable temperature (e.g., about 110 to 200 degrees celsius, or any other suitable temperature) to cause film sheet 150 and heat seal layer 10 to soften and form a dome shape (not shown) under the influence of the initial vacuum. In one embodiment, the membrane may at least partially conform to the concave heater plate surface 164 to form a dome shape. Instead of, or in addition to, an initial vacuum, air pressure under the diaphragm 150 may be used, with similar or equal effect.

In the illustrated embodiment, when the film sheet 150 and heat seal layer 10 are dome-shaped, the heat seal layer 10 is activated for causing the sheet 150 to attach or adhere or bond to the original structure 130 (e.g., its temperature is raised so that it becomes tacky). Subsequently, the film sheet 150 may be pressed against the inner surfaces 81 of the recesses 79 of the initial structure 130 with the adhesive heat seal layer 10 therebetween. In one embodiment, the sheet 150 may be urged downward by the air pressure applied on the conduit 162 at this time and/or by another vacuum applied from the bottom side of the membrane 150. For example, a vacuum may be applied through the lower mold 140 and the initial structure 130, which may help to retain the initial structure 130 in the cavity of the lower mold 140 during application of the sheet 150 and heat seal layer 10. In one embodiment, at least some of fold lines 15, 19, 23, 27, 29, 31, 33, 35 may be formed at least partially by spaced-apart cuts in blank 3 (e.g., fold lines in a cut crease pattern), and vacuum may be applied to sheet 150 through the cuts of fold lines 15, 19, 23, 27, 29, 31, 33, 35. Alternatively, other apertures (not shown) may be provided in the initial structure 130 for allowing vacuum pressure to pass through the initial structure 130.

In one embodiment, air pressure and/or vacuum causes the dome shape of the film 150 to invert and the now tacky and stretched heat seal layer 10 may be smoothly adhered to the inner surface 81 of the precursor structure 130 supported on the lower die 140. In one embodiment, the adhesiveness of heat seal layer 10 may be such that the portion of film 150 that forms liner 9 adheres to base layer 7. The PTFE coated surface 164 may help release a portion of the liner material (e.g., liner 9) of the diaphragm 150 if the diaphragm 150 is in contact with the surface 164. In embodiments where heat seal layer 10 is omitted (e.g., for polyethylene liner material), the liner material itself may become tacky due to the heating by upper die 160, and the tackiness of the liner material may cause the liner material to bond to inner surface 81 of original structure 130. In the illustrated embodiment, excess or waste portions of the film sheet 150 are cut from the edges of the container 5 (the container 5 now comprising the base layer 7 formed by the structure 130 and the liner 9 formed by the film sheet 150 with the heat seal layer 10 therebetween, as shown in fig. 3B) (e.g. by a cutting device, not shown) so as to leave an unused film portion 152 having a tray-sized aperture. In one embodiment, the unused film portion 152 has an edge portion that remains intact around the hole formed by removing the interior layer 9 from the film 150, so the unused film portion 152 can continue to the take-up spool 153. Alternatively or additionally, the membrane 150 may have a sacrificial carrier layer (not shown) wherein the liner material is separated from the carrier sheet when the liner material is attached to the base layer 7. In another alternative, the unused membrane portion 152 may be in the form of, for example, chips that are removed by air pressure and/or vacuum pressure.

In the illustrated embodiment, the lower die 140 is lowered by reversing the direction of the ram 142, and as the ram 142 descends, the product support plate 144 may push the lined container 5 from the supporting lower die 140 to cause the container 5 to be ejected from the lower die 140. In one embodiment, the product support plate 144 may include an upwardly extending portion 146, the upwardly extending portion 146 extending through the lower die 140 and engaging the bottom of the container 5 as the product support plate 144 and the lower die 140 are moved toward each other. In the illustrated embodiment, the upwardly extending portion 146 may position the containers 5 relative to the lower mold 140 such that a push rod, air flow, or other suitable mechanism may push the containers 5 onto the downstream conveyor 107. The lined containers 5 may then be conveyed by the conveyor 107 for packaging and/or further processing.

In one embodiment, the above process may be repeated so that the lined vessel 5 may be produced substantially continuously. Since the above process may be used for a variety of products and with different materials, the step of heating the film may need to be repeated and then the film may need to be further pressed against the tray by air pressure, vacuum, and/or other suitable mechanism. In particular, where a thicker sheet of backing film is used for the inner layer 9 and various thicknesses of cardboard or other material are used for the base layer 7, the heating and pressing steps may need to be repeated one or more times in order to effectively bond the film 9 to the base layer 7 tray.

The system 101 and methods described herein may include other features, steps, and/or the features and steps described herein may be omitted or modified without departing from the scope of the present invention. For example, heat may be applied to diaphragm 150 in any suitable manner (e.g., by a flow of hot air) instead of or in addition to heater plate 164. In another example, the film sheet 150 may be heated in order to activate (e.g., soften) the heat-seal layer 10 without softening and/or deforming the remainder of the film sheet 150.

In the illustrated embodiment, the shape of the initial structure 130 may help to increase the contact between the liner 9 and the heat-seal layer 10 and the base layer 7. For example, since the angle between the bottom panel 11 and the lower portion 77a of the sidewall 77 and between the lower portion 77a and the upper portion 77b of the sidewall 77 may be greater than 90 degrees, the original structure 130 may have corners of less tightness. In an example embodiment, it may be difficult to force the sheet 150 into tighter corners (e.g., corners of about 90 degrees or less). Thus, the shape of the side walls 77 may help the entire liner 9 or substantially the entire liner 9 to contact and adhere to the base layer 7, which base layer 7 is contained in all or almost all of the corners of the original structure 130.

The above-described manufacturing method results in an easily sealable tray which is mainly manufactured from easily recyclable materials, such as cardboard or hardboard and thermoplastic materials. If desired, the paperboard base layer may be easily removed from the thermoplastic film liner (e.g., after use of the container to hold food during heating in a microwave oven and/or a conventional oven) because the degree of adhesion between the base layer 7 and the liner 9 may be controlled to provide sufficient adhesion to allow the liner and base layer to remain attached before, during, and/or after heating of the items held in the container, while the base layer and liner may be selectively separated after use. When using the above parameters, it was found that the base layer 7 and liner 9 of the container 5 were separable after heating the food in the container, and thus in one example embodiment, the two were peeled apart, leaving no more than 5% of the thickness of the base layer 7 material adhered to the film of the inner layer 9. The separated paperboard of the base layer 7 and thermoplastic film of the inner layer 9 can be more easily recycled in separate waste streams (e.g., one for paper products and one for polymers), while minimizing material contamination of the inner layer 9 by the paperboard.

Preferably, heating the film sheet 150 and heat-seal layer 10 using the heater plate 164 prior to applying the film sheet 150 and heat-seal layer 10 to the precursor structure 130 provides control over the temperature of the film sheet 150 and heat-seal layer 10 and control over the strength of its bond to the precursor structure 130. The use of heater plate 164 also allows for differential heating so that, for example, film sheet 150 and heat seal layer 10 can be heated to a higher temperature in the flange region 8 of container 5, which in turn allows the liner 9 formed from film sheet 150 to bond more firmly to flange 8 (as compared to the remainder of container 5) and therefore, the other tray sealing film applied to liner 9 in the flange region is more securely anchored to container 5. In one embodiment, the injection molding feature is not used for container 5 and a thinner plastic film can be used, which can reduce the non-recyclable material content of the tray.

The PET plastic film 150 has been described above, but it should be understood that other plastic films may be used, for example, other polymers based on polyester may be used. Polyethylene films may also be used and are advantageous for non-heated food packaging (e.g., sandwich packaging). It can be seen that in one embodiment the present invention provides a food package having a composite structure of a plastic inner food contact layer 9, the inner food contact layer 9 being bonded to an outer recyclable layer 7, the inner and outer layers being separable after use such that, after separation, no more than 5% of the thickness of the outer layer is disposed on the inner layer.

In one embodiment, the lid (not shown) may comprise a packaging film, which is a thin plastic layer for preserving and protecting the food items contained in the tray, and may be removably attached to the flange 8 of the container 5. Any plastic film may be used to form the lid, such as polyethylene, polypropylene, polyethylene terephthalate, polyvinyl chloride, polyamide and ethylene vinyl alcohol or other suitable material, which is sealed against the sealing surface of the flange 8. Moreover, adhesive may be used between the lid and the sealing surface of the flange 8 without departing from the invention.

Fig. 6 is a plan view of a blank 203 for forming a container 205 (fig. 7) in accordance with a second embodiment of the present invention. This second embodiment is substantially similar to the first embodiment except for the noted variations and variations as would be apparent to one of ordinary skill in the art. Therefore, similar or identical features of the embodiments are given similar or identical reference numerals. As shown in fig. 6, the blank 203 is similar to the blank 3 of the first embodiment, but the blank 203 comprises corner panels 251, 253, 255, 257, the corner panels 251, 253, 255, 257 being foldably connected to the bottom panel 11 at respective oblique fold lines 252, 254, 256, 258. As shown in fig. 6, the corner panels 251, 253, 255, 257 are arranged between the respective adjacent end panel 13, 17 and side panel 21, 25. In one embodiment, the blank 203 comprises eight panels (two end panels 13, 17, two side panels 21, 25 and four corner panels 251, 253, 255, 257) extending around the periphery of the bottom panel 11, so that the eight fold lines 15, 17, 23, 27, 252, 254, 256, 258 form an octagonal periphery of the bottom panel 11. As shown in fig. 6, each fold line 15, 17, 23, 27, 252, 254, 256, 258 may be oblique relative to its respective adjacent fold line and may form an obtuse angle with its respective adjacent fold line.

As shown in fig. 6, each corner panel 251, 253, 255, 257 may include a respective intermediate fold line 269, 270, 271, 272, such that each corner panel includes a lower portion 251a, 253a, 255a, 257a foldably connected to a respective upper portion 251b, 253b, 255b, 257b along a respective fold line 269, 270, 271, 272. Thus, in one embodiment, the lower portions 251a, 253a, 255a, 257a of the corner panels 251, 253, 255, 257 can cooperate with the lower portions 13a,17a of the end panels 13, 17 and the lower portions 21a,25a of the side panels 21, 25 to form the lower portion 277a of the side wall 277, and the upper portions 251b, 253b, 255b, 257b of the corner panels 251, 253, 255, 257 can cooperate with the upper portions 13b,17b of the end panels 13, 15 and the upper portions 21b,25b of the side panels 21, 25 to form the upper portion 277b of the side wall 277 (fig. 7). In the illustrated embodiment, the flange portions 273, 274, 275, 276 can be foldably connected to respective corner panels 251, 253, 255, 257 along respective fold lines 278, 280, 282, 283 and can cooperate with the flange portions 45, 47, 49, 51 to form the flange 208. In one embodiment, the blank 203 may be similar to the blank of the second embodiment, as shown and described in the referenced U.S. patent application No.15/654814 (application date 2017, 7 and 20). The blank 203 may be otherwise shaped, arranged, and/or provided without departing from the invention.

In the illustrated embodiment, the container 205 may be formed from the blank 203 and a liner material (e.g., the film 150) in the same or similar manner as described above for the first embodiment. Thus, the container 205 may include a base layer 207 formed from the blank 203 and a liner 209 formed from the film 150. In one embodiment, the liner 209 may be attached to the base layer 207 by a heat seal layer 210 (fig. 8), similar to the first embodiment described above. As shown in fig. 7, each corner flange portion 273, 274, 275, 276 may overlap a portion of the respective adjacent flange portions of the end and side panels to form the flange 208.

As shown in fig. 7, the transverse fold lines 229, 231, the longitudinal fold lines 233, 235, and the oblique fold lines 269, 270, 271, 272 may cooperate to form an intermediate fold line 299 extending about the side wall 277. In addition, the lower portion 277a and the upper portion 277b of the side wall 277 may each extend from an intermediate fold line 299, wherein the portions of the side wall 277 are inclined with respect to each other. In one embodiment, the upper and lower portions of the side walls 277 may cooperate to form an obtuse angle, and the lower portion 277a of the side walls 277 may form an obtuse angle with the bottom panel 11. The obtuse angle 277 in the sidewall 277 may cause the base layer 207 to more completely conform to the liner 209, which may increase contact between the base layer 207 and the surface of the liner 209 (e.g., at the transition between the panels of the container 205).

In one embodiment, a container 205 having corner panels 251, 253, 255, 257 extending obliquely between adjacent end panels 13, 17 and side panels 21, 25 generally includes only obtuse angles between the panels, rather than right angles. This may help to bring the liner material forming the liner 9 into contact with a greater surface area of the base layer (e.g., relative to a base layer having a right or acute angle, where the liner material may be more difficult to extend into such corners). Thus, the octagonal shape of the side walls 277 can help the liner 9 adhere to the entire surface or substantially the entire surface of the base layer of the container. In one embodiment, the octagonal shape of the side walls 277 may more closely approximate rounded corners or circular side walls than a container having four orthogonal sides. The container 205 may be otherwise shaped, arranged, and/or configured without departing from the invention.

Fig. 9 is a plan view of a blank 303 for forming a container 305 (fig. 10) according to a third embodiment of the present invention. This third embodiment is substantially similar to the previous embodiments, except for the variations noted and variations that would be apparent to one of ordinary skill in the art. Therefore, similar or identical features of the embodiments are given similar or identical reference numerals. As shown in fig. 9, the blank 303 is similar to the blank 3 of fig. 1 of the first embodiment, but the blank 303 includes two portions 304a, 304b for forming two respective compartments 306a,306b in the container 305 (fig. 10). In one embodiment, the portions 304a, 304b are similar to the blank 3 of the first embodiment. The first portion 304a includes a bottom panel 311 foldably connected to end panels 313, 317 along respective fold lines 315, 319 and to side panels 321, 325 along respective fold lines 323, 327. Each end panel 313, 317 can have a lower portion 313a, 317a foldably connected to a respective upper portion 313b, 317b along a respective fold line 329, 331, and each side panel 321, 325 can include a lower portion 321a, 325a foldably connected to a respective upper portion 321b, 325b along a respective fold line 333, 335. The flange portions 345, 347, 351 are foldably connected to respective panels 313, 317, 325 along respective fold lines 361, 363, 367 in the first portion 304 a. The first portion may be otherwise shaped, arranged and/or configured without departing from the invention.

As shown in fig. 9, the second portion 304b may be provided similarly to the first portion 304a, with the bottom panel 312 foldably connected to the end panels 314, 318 along respective fold lines 316, 320 and to the side panels 322, 326 along respective fold lines 324, 328. Each end panel 314, 318 can have a lower portion 314a, 318a that is foldably connected to a respective upper portion 314b,318b along a respective fold line 330, 332, and each side panel 322, 326 can include a lower portion 322a, 326a that is foldably connected to a respective upper portion 322b,326b along a respective fold line 334, 336. The flange portions 346, 348, 352 are foldably connected to respective panels 314, 318, 326 along respective fold lines 362, 364, 368 in the second portion 304 b. The second portion may be otherwise shaped, arranged and/or configured without departing from the invention.

In the illustrated embodiment, the first portion 304a and the second portion 304b may be connected by a common central flange portion 349 that is foldably connected to the side panel 321 of the first portion 304a and the side panel 322 of the second portion 304b along respective fold lines 365, 366. As shown in fig. 9, the flange portions 345, 346, 347, 348 may have inboard square ends where the flange portions 345, 346 and 347, 348 overlap when the flange 308 is formed (fig. 10). In one embodiment, adjacent lower edges 37a,39a at each of the eight corners of the blank 303 may extend at an angle A1 relative to each other, and each upper edge 37b,39b may extend at an angle A5 relative to the respective fold line 361, 362, 363, 364, 365, 366, 367, 368. In one example, angle A1 may be about 25 degrees and angle A5 may be about 80 degrees (and adjacent upper edges 37b,39b may extend at an angle of about 70 degrees relative to each other). The blank 303 may be otherwise shaped, arranged, and/or provided without departing from the invention. For example, the portions 304a, 304b may be connected at different panels (e.g., at the end panels), and/or the central flange portion 349 may be omitted such that the connected panels are connected along fold lines.

In the illustrated embodiment, a container 305 (e.g., a dual compartment container) may be formed from a blank 303 and a liner material (e.g., film stock 150) in a manner similar or identical to that described above for the first embodiment. Thus, the container 305 may include a base layer 307 formed from the blank 303 and a liner 309 formed from the film sheet 150. In one embodiment, liner 309 may be attached to base layer 307 by heat seal layer 310 (fig. 11), as described above. As shown in fig. 10, each portion 304a, 304b of the blank 303 forms a respective compartment 306a,306b of the container 305, wherein the end panels 313, 317 and side panels 321, 325 of the first portion 304a are folded relative to the bottom panel 311 to form a first side wall 377 of the first compartment 306a, and the end panels 314, 318 and side panels 322, 326 of the second portion 304b are folded relative to the bottom panel 312 to form a second side wall 378 of the second compartment 306b. As shown in fig. 10, the side walls 377, 378 may include respective side panels 321, 322, the side panels 321, 322 extending between the compartments 306a,306b, joined at a central flange portion 349, the central flange portion 349 cooperating with the flange portions 345, 346, 347, 348, 352 to form the flange 308 of the container 305. In one embodiment, the side panels 321, 322 and the central flange portion 349 may form a divider 398 that at least partially divides the container 305 into the compartments 306a,306 b. In the illustrated embodiment, the sidewall 377 may extend along a perimeter of the bottom panel 311, and the sidewall 377 and the bottom panel 311 may extend along the interior 379 of the first compartment 306 a. Similarly, the side wall 378 may extend along a perimeter of the bottom panel 312, and the side wall 378 and the bottom panel 312 may extend along an interior 380 of the second compartment 306b. As shown in fig. 10, liner 309 may extend beyond edge 386 of base material 307 such that edge 384 of liner 309 is spaced apart from edge 386 of base material 307.

As shown in fig. 10, the fold lines 329, 331, 333, 335 and the fold lines 330, 332, 334, 336 may cooperate to form respective intermediate fold lines 399 extending about the respective side walls 377, 378. Accordingly, a lower portion 377a and an upper portion 377b of the first sidewall 377 may each extend from an intermediate fold line 399 in the first compartment 306a, wherein these portions of the sidewall 377 are inclined relative to each other. In one embodiment, the upper and lower portions of the sidewalls 377 may cooperate to form an obtuse angle, and the lower portion 377a of the sidewalls 377 may form an obtuse angle with the bottom panel 311 in the first compartment 306 a. Similarly, the lower portion 378a and the upper portion 378b of the second side wall 378 may each extend from the intermediate fold line 399 in the second compartment 306b, wherein these portions of the side wall 378 are angled with respect to each other. In one embodiment, the upper and lower portions of the side walls 378 may cooperate to form an obtuse angle, and the lower portion 378a of the side walls 378 may form an obtuse angle with the bottom panel 312 in the second compartment 306b. The obtuse angles in the sidewalls 377, 378 may cause the base layer 307 to more completely conform to the liner 309, which may increase contact between the surfaces of the base layer 307 and the liner 309 in both compartments 306a,306b (e.g., at the transition between the panels of the container 305).

The container 305 may be otherwise shaped, arranged, and/or configured without departing from the invention. For example, one or both of the compartments 306a,306b may include one or more corner panels similar to or the same as the corner panels shown and described in the second embodiment of the present invention.

Any features of the various embodiments of the invention may be combined, substituted or otherwise arranged with other features of other embodiments of the invention without departing from the scope of the invention.

Optionally, one or more portions of the blank or other structure described herein or contemplated thereby may be coated with varnish, clay, or other material, alone or in combination. Product advertising or other information or images may then be printed on top of the coating. The blank or other structure may also be selectively coated and/or printed such that less than the entire surface area or substantially the entire surface area of the blank may be coated and/or printed.

Any of the blanks, containers, or other structures of the present invention optionally include one or more features that alter the effect of microwave energy during heating or cooking of the food product associated with the tray or other structure. For example, a blank, tray, container, or other structure may be at least partially formed from one or more microwave energy interactive elements (hereinafter sometimes referred to as "microwave interactive elements") that promote heating, browning, and/or crisping of particular areas of the food item, such that the particular areas of the food item are shielded from microwave energy to prevent overcooking, or the microwave energy is transmitted toward or away from the particular areas of the food item. Each microwave interactive element includes one or more microwave energy interactive materials or segments arranged in a particular configuration so as to absorb microwave energy, transmit microwave energy, reflect microwave energy, or direct microwave energy as needed or desired due to the particular structure and food item.

In the case of a receptacle or shield, the microwave energy interactive material may comprise a conductive or semiconductive material, such as a vacuum deposited metal or metal alloy, or a metallic ink, organic ink, inorganic ink, metallic paste, organic paste, inorganic paste, or any combination thereof. Examples of potentially suitable metals and metal alloys include, but are not limited to: aluminum, chromium, copper, inconel (nickel-chromium-molybdenum alloys and niobium), iron, magnesium, nickel, stainless steel, tin, titanium, tungsten, and any combination or alloy thereof.

Alternatively, the microwave energy interactive material may include metal oxides, such as oxides of aluminum, iron, and tin, optionally in combination with conductive materials. Another metal oxide that may be suitable is Indium Tin Oxide (ITO). ITO has a more uniform crystal structure and is therefore transparent at most coating thicknesses.

Alternatively, the microwave energy interactive material may comprise a suitable conductive, semiconductive or nonconductive synthetic dielectric or ferroelectric material. The artificial dielectric comprises a conductive finely divided material in a polymer or other suitable matrix or binder and may comprise a conductive metal foil, such as aluminum.

In other embodiments, the microwave energy interactive material may be carbon-based, for example, as disclosed in U.S. patent nos. 4943456, 5002826, 5118747, and 5410135.

In other embodiments, the microwave energy interactive material may interact with a magnetic portion of electromagnetic energy in a microwave oven. This properly selected material may be self-limiting based on the loss of interaction upon reaching the curie temperature of the material. An example of such an interactive coating is described in U.S. Pat. No. 4283427.

Other microwave energy interactive elements are also contemplated. In one example, the microwave energy interactive element may comprise a foil or high optical density evaporative material having a thickness sufficient to reflect a substantial portion of incident microwave energy. Such elements are typically formed from a conductive, reflective metal or metal alloy (e.g., aluminum, copper, or stainless steel) in the form of a solid "patch" that is typically about 0.000285 inches to about 0.005 inches thick, e.g., from about 0.0003 inches to about 0.003 inches. Other such elements may have a thickness of about 0.00035 inches to about 0.002 inches, such as 0.0016 inches.

In some cases, the microwave energy reflective (or reflective) element may serve as a shielding element when the food item is susceptible to charring or drying during heating. In other cases, a smaller microwave energy reflective element may be used to diffuse or reduce the intensity of the microwave energy. One example of a material that utilizes such microwave energy reflective elements is commercially available from Graphic Packaging International 1, inc. (Atlanta, GA)

And (7) packaging the materials. In other examples, a plurality of microwave energy reflective elements may be arranged to form a microwave energy distributing element in order to direct microwave energy to specific areas of the food item. The length of the loop may be such that the microwave energy resonates, if desired, thereby improving the distribution effect. Microwave energy distributing elements are described in U.S. patent nos. 6204492, 6433322, 6552315 and 6677563, each of which is incorporated herein in its entirety by reference.

If desired, any of the numerous microwave energy interactive elements described herein or contemplated thereby may be substantially continuous, i.e., substantially free of breaks or interruptions, or may be discontinuous, such as by including one or more breaks or apertures that transmit microwave energy. The breaks or holes may extend through the entire structure or only through one or more layers. The number, shape, size and location of such breaks or holes may vary for a particular application depending on the type of structure being formed, the food product to be heated therein or thereon, the appropriate degree of heating, browning and/or crisping, whether direct exposure to microwave energy is needed or desired in order to obtain uniform heating of the food product, the need for regulating temperature changes of the food product by direct heating, and whether and to what extent ventilation is needed.

For example, the microwave energy interactive element may include one or more transparent regions to enable dielectric heating of the food item. However, where the microwave energy interactive element includes a susceptor, such apertures reduce the total microwave energy interactive area and, thus, the amount of microwave energy interactive material available to heat, brown and/or crisp the surface of the food item. Thus, the relative amounts of microwave energy interactive areas and microwave energy transparent areas may be balanced to achieve desired overall heating characteristics for a particular food item.

As another example, one or more portions of the susceptor may be designed to be microwave energy inactive to ensure that microwave energy is efficiently focused on the area to be heated, browned and/or crisped, and not lost to portions of the food item not intended to be browned or crisped or to the heating environment. Additionally or alternatively, it may be advantageous to create one or more discrete or inactive areas to prevent overheating or charring of the food product and/or the structure comprising the receptacle.

As another example, the receptacle may include one or more "fuse" elements that limit crack propagation in the receptacle, thereby controlling overheating in areas of the receptacle where heat transfer to the food is low and the receptacle may become too hot. The size and shape of the fuse may vary as desired. Examples of receptacles including such fuses are provided in, for example, U.S. patent No.5412187, U.S. patent No.5530231, U.S. patent application publication No. us2008/0035634A1 (published as 2008/14/2), and PCT application publication No. wo2007/127371 (published as 2007/8/11/2007), each of which is incorporated herein in its entirety.

All dimensional information described herein is intended to illustrate certain aspects, features, etc. of various embodiments of the invention, and is not intended to limit the scope of the invention. The dimensions of the blank, container, forming tool, feature, or any other dimension may be greater than or less than those shown and described herein without departing from the scope of the invention, and may be within the listed dimensions for each feature or outside the listed dimensions for each feature without departing from the scope of the invention.

The blank according to the invention may for example be formed from coated cardboard and similar materials. For example, the inside and/or outside of the blank may be coated with a clay coating. The clay coating may then be printed over with product, advertising, price coding, and other information or images. The blank may then be coated with a varnish to protect any information printed on the blank. The blank may also be coated on either or both sides with, for example, a moisture barrier.

According to an example embodiment, the blank may be constructed of caliper paperboard such that it is heavier and stiffer than plain paper. The blank may also be constructed of other materials, such as cardboard, hard paper, or any other material having properties suitable to enable the carton package to function at least generally as described above.

The foregoing description shows and describes various embodiments of the present invention. As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. Moreover, the scope of the present invention covers various changes, combinations, and alterations of the above-described embodiments. Additionally, the invention has been shown and described with respect to only selected embodiments, but various other combinations, variations, and environments are contemplated and are within the scope of the inventive concept as expressed herein, commensurate with the above teachings, and/or within the skill or knowledge of the relevant art. Moreover, certain features and characteristics of the various embodiments may be selectively interchanged and applied to other illustrated and non-illustrated embodiments without departing from the scope of the invention.

Claims (16)

1. A container for heating food, the container comprising:

a base layer of material;

a liner releasably attached to the inner surface of the base layer, wherein the liner is at least partially attached to the base layer by a heat seal layer, the liner being separable from the base layer upon heating of the container;

a bottom panel; and

a sidewall extending along the bottom panel, the sidewall including a lower portion extending upwardly and outwardly from the bottom panel and an upper portion extending from the lower portion, wherein the lower portion and the upper portion of the sidewall are foldably connected along an intermediate fold line, the lower portion is oblique to the bottom panel, and the upper portion is oblique to the lower portion; and

a flange extending outwardly from the sidewall;

the side wall includes: at least one end panel foldably connected to the bottom panel; and a side panel foldably connected to the bottom panel; wherein the end panel comprises a first lower edge extending from the bottom panel along a lower portion of the side wall to the intermediate fold line and a first upper edge extending from the intermediate fold line along an upper portion of the side wall to the flange, the side panel comprises a second lower edge extending from the bottom panel along a lower portion of the side wall to the intermediate fold line and a second upper edge extending from the intermediate fold line along an upper portion of the side wall to the flange, the first lower edge and first upper edge abutting respective second lower edge and second upper edge at a corner of the container.

2. The container of claim 1, wherein: the liner comprises polyethylene terephthalate and the heat seal layer comprises polyester.

3. The container of claim 2, wherein: the heat seal layer comprises a sealant grade transparent polyester packaging film.

4. The container of claim 1, wherein: the side wall extends upwardly from the bottom panel along a perimeter of the bottom panel.

5. The container of claim 1, wherein: the lower portion extends at a first angle relative to the bottom panel, the upper portion extends at a second angle relative to the lower portion, and both the first and second angles are obtuse angles.

6. The container of claim 1, wherein: the liner is releasably attached to the base layer along at least a portion of each of the bottom panel and the lower and upper portions of the sidewalls.

7. The container of claim 1, wherein: the lower portion extends along a perimeter of the bottom panel.

8. A method of forming a container comprising a bottom panel and a sidewall extending along the bottom panel, the method comprising:

obtaining a blank, a liner material and a heat seal layer, the blank comprising: the bottom panel, an end panel foldably connected to the bottom panel; a side panel foldably connected to the bottom panel; a first flange portion extending from the end panel; a second flange portion extending from the side panel; wherein the end panel comprises a first lower edge and a first upper edge, the side panel comprises a second lower edge and a second upper edge;

forming the blank into an initial structure comprising: folding the end and side panels relative to the bottom panel such that the first lower and upper edges abut the respective second lower and upper edges at the corners of the container and flange the first and second flange portions;

activating the heat seal layer; and

applying at least a portion of the liner material to the inner surface of the initial structure such that the liner material and initial structure form respective liner and base layers of the container, the liner being releasably attached to the inner surface of the base layer by the heat seal layer, wherein, after heating the container, the liner is separable from the base layer;

wherein the side wall comprises at least the end panel and a side panel, the flange extending outwardly from the side wall, the side wall comprising a lower portion extending upwardly and outwardly from the bottom panel and an upper portion extending from the lower portion along an intermediate fold line, the lower portion being inclined relative to the bottom panel and the upper portion being inclined relative to the lower portion;

wherein each of the first lower edge of the end panel and the second lower edge of the side panel extend from the bottom panel to the intermediate fold line and each of the first upper edge of the end panel and the second upper edge of the side panel extend from the intermediate fold line to the flange.

9. The method of claim 8, wherein: activating the heat-seal layer comprises: heating the heat-seal layer to a temperature of about 110 degrees Celsius to about 200 degrees Celsius.

10. The method of claim 8, wherein: obtaining a blank, a liner material and a heat seal layer comprising: obtaining a film sheet comprising a heat seal layer on at least one side of the liner material, activating the heat seal layer comprising: the membrane is heated.

11. The method of claim 10, wherein: applying at least a portion of the liner material onto the inner surface of the initial structure comprises: moving at least a portion of the film sheet toward the inner surface of the initial structure such that the activated heat-seal layer engages the inner surface of the initial structure.

12. The method of claim 11, wherein: applying at least a portion of the liner material onto the inner surface of the initial structure comprises: such that the activated heat seal layer is engaged with the inner surface of the initial structure along at least a portion of the bottom panel, the lower portion of the side wall, and the upper portion of the side wall.

13. The method of claim 12, wherein: the lower portion extends at a first angle relative to the bottom panel, the upper portion extends at a second angle relative to the lower portion, and both the first angle and the second angle are obtuse angles.

14. The method of claim 8, wherein: the liner comprises polyethylene terephthalate and the heat seal layer comprises polyester.

15. The method of claim 14, wherein: the heat seal layer comprises a sealant grade transparent polyester packaging film.

16. The method of claim 8, wherein: the lower portion extends at a first angle relative to the bottom panel, the upper portion extends at a second angle relative to the lower portion, and both the first angle and the second angle are obtuse angles.

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