Master roll, film, lid and package with content

Abstract

To provide a master roll which can suppress swelling when being wound even when a processing part is provided, to provide a film, to provide a lid, and to provide a package with content.SOLUTION: A master roll 200 which can trim a film 3 that forms at least part of a package 1 with content heated in a microwave oven includes: a middle core 201; a sheet 202 wound around the middle core 201, and formed by a biaxially stretched oriented film 31, and a seal layer 33 laminated on the biaxially stretched oriented film; and a plurality of processing parts 3a formed at part of packaging body 2, 2A, containing a plurality of opposing orientation relaxing parts 31a formed at the biaxially stretched oriented film 31, containing a breaking part 3b breaking and opening by the increase in an internal pressure of the packaging body 2, 2A between the plurality of orientation relaxing parts 31a, and inclining at an angle larger than 0° with respect to MD of a sheet 202.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a raw material roll, a film, a lid, and a package containing contents, which are used in a container for heating in a microwave oven. [Background technology]

[0002] Packaging bodies that contain and seal contents and heat the contents in a microwave oven have been known for some time. However, when the contents of such packaging bodies are heated in a microwave oven, the internal pressure increases, and if the internal pressure exceeds the strength of the packaging body, the packaging body will burst. For this reason, the packaging body needs a steam exhaust means that can exhaust water vapor to the outside of the packaging body and prevent the packaging body from bursting. On the other hand, the packaging body may need to "pressure cook" or "steam cook" the contents using the steam generated by heating. Pressure cooking can shorten the heating time and save the energy required for heating. Furthermore, the ability to steam cooking can increase the variety of ingredients and recipes that can be cooked.

[0003] One type of packaging suitable for such applications is made of a laminated film, and when the internal pressure increases, a portion of the laminated film breaks, allowing water vapor to escape and preventing the package from bursting. Another type of packaging that can also be used for steam cooking when heated in a microwave oven is known, in which a lid is made of a laminated film in which an inner layer film of a polyolefin resin is laminated on the inside of an outer layer film, and a weakened processing line for steam release is formed in the lid by laser processing, the weakened processing line reaching the inside of the outer layer film but not penetrating the inner layer film (see, for example, Patent Document 1). Another known technology involves forming an orientation portion and an orientation relaxation portion as processed portions in the laminated film by laser processing or the like, and partially breaking the laminated film due to the difference in elongation when the internal pressure increases. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2014 / 061651 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when a processed portion is formed on a film, the thickness of the film increases locally. Therefore, in the raw roll state, a portion of the roll bulges in the axial direction, centered on the portion where the processed portion is formed, with each increase in the number of windings. As a result, the diameter of the raw roll increases locally in the region where the processed portion is formed, and this becomes more pronounced as the number of windings increases. Since the sheet is wound around the raw roll in a partially enlarged state, the roll develops a tendency in the winding direction, centered on the processed portion, resulting in wrinkles and unevenness. Therefore, if the raw roll is trimmed to a desired shape and used as a lid to be welded to the flange of a packaging container, tray container, or the like, the appearance will be poor. Furthermore, when a lid is welded to the flange, a gap may form between the lid and the flange, resulting in poor sealing. Furthermore, if the diameter of the raw roll varies locally in the axial direction, space will be required for storage and transportation. Therefore, a technology that can suppress bulging in raw rolls with processed portions is needed.

[0006] Therefore, an object of the present invention is to provide a raw roll, a film, a lid, and a package containing contents that can suppress bulging when wound even when a processed portion is provided. [Means for solving the problem]

[0007] One embodiment of the present invention provides a raw roll that can trim a film that forms at least a part of a package containing contents to be heated in a microwave oven, and includes a core, a sheet that is wound around the core and includes a biaxially oriented film and a sealing layer laminated to the biaxially oriented film, and a plurality of processed sections that are formed in a part of the package and include a plurality of opposing orientation relaxation sections formed in the biaxially oriented film, and include a tear section between the plurality of orientation relaxation sections that breaks and opens when the internal pressure of the package increases, and are inclined at an angle greater than 0° with respect to the MD of the sheet. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a raw roll, a film, a lid, and a package containing contents that can suppress swelling when wound even when a processed portion is provided. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a plan view showing the configuration of a package containing contents according to an embodiment of the present invention. [Figure 2] FIG. 10 is a perspective view schematically showing the configuration of another example of a packaging container used in the same package containing the contents. [Figure 3] FIG. 3 is a cross-sectional view showing an example of a layer structure of a film used in the packaging body. [Figure 4] FIG. 4 is a cross-sectional view showing another example of the layer structure of the film used in the packaging body. [Figure 5] FIG. 2 is a perspective view showing a schematic configuration of a raw roll used in the packaging body. [Figure 6] 4A to 4C are explanatory diagrams showing an example of a method for manufacturing a processed portion formed on the raw fabric roll. [Figure 7] FIG. [Figure 8] FIG. 10 is an explanatory diagram showing the results of an evaluation test. DETAILED DESCRIPTION OF THE INVENTION

[0010] The raw roll 200, film 3, packaging containers 2, 2A, and package 1 containing contents according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a plan view showing the configuration of a content-containing package 1 according to an embodiment of the present invention. FIG. 2 is a perspective view showing, as another example, the configuration of a package 2A used in the content-containing package 1. FIG. 3 is a cross-sectional view showing an example of the layer configuration of a film 3 used in the package 2, 2A, and FIG. 4 is a cross-sectional view showing another example of the layer configuration of a film 3 used in the package 2, 2A. FIG. 5 is a perspective view showing a schematic configuration of a raw roll 200 used in the package 2, 2A, and FIG. 6 is an explanatory diagram showing an example of a method for manufacturing the raw roll 200. FIG. 7 is an explanatory diagram showing a schematic configuration of a processing section 3a. FIG. 8 is an explanatory diagram showing the results of an evaluation test.

[0011] The raw roll 200 is used to form a film 3 having a desired shape to be used for at least a part of the packaging container 2, 2A for the content-containing package 1 that contains the content 100.

[0012] First, a content-filled package 1 formed using a raw material roll 200 will be described. The content-filled package 1 comprises a packaging container (package) 2, 2A, and a content 100 accommodated in the packaging container 2, 2A. The content-filled package 1 is a container for microwave heating in which the content 100 is heated in a microwave oven. Here, the content 100 contains moisture and can be heated in a microwave oven, and includes, for example, food that can be cooked in a microwave oven, or an article such as a hand towel that can be heated in a microwave oven.

[0013] Such packaging containers 2, 2A either use a film 3 having a processed portion 3a formed thereon as in the packaging container 2 shown in Fig. 1, or are formed from a film 3 having a processed portion 3a formed thereon as in the packaging container 2A shown in Fig. 2. The packaging containers 2, 2A are formed so that when the internal pressure increases as a result of heating the contents 100 in a microwave oven, the processed portion 3a breaks to form an opening through which steam can be released.

[0014] As a specific example, as shown in FIG. 1, a packaging container 2 includes a container body 11 and a lid 12 formed of a film 3 that seals the container body 11.

[0015] As shown in FIG. 1, the container body 11 is a bottomed container capable of accommodating the contents 100. The container body 11 is a cup-shaped, dish-shaped, tray-shaped, or other container. The container body 11 is formed, for example, in a cylindrical or polygonal shape. In this embodiment, the container body 11 is, for example, a rectangular tray container that is long in one direction. The container body 11 includes a body 21, a bottom 22, and a flange 23. The container body 11 is formed, for example, from a resin material, specifically, polypropylene (PP) or polystyrene (PS). The container body 11 is formed, for example, by vacuum forming or pressure forming.

[0016] The lower end of the body 21 is closed by the bottom 22, and the upper end is open where the flange 23 is integrally formed. The body 21 is, for example, integrally continuous with the bottom 22 and the flange 23, and the width of the body 21 gradually decreases from the flange 23 side toward the bottom 22.

[0017] The bottom 22 is formed integrally with the lower end of the body 21. The bottom 22 is formed in a flat plate shape. For example, the center of the bottom 22 may protrude further toward the flange 23 than the outer edge.

[0018] The flange 23 is formed, for example, integrally with the upper end (opening end) of the body portion 21. The flange 23 is formed in an annular shape extending from the upper edge of the body portion 21 along the outer circumferential shape of the body portion 21 in a direction perpendicular to or intersecting the axial direction of the body portion 21. For example, the flange 23 is formed in a flat plate shape, and the lid 12 is heat-sealed to the flange 23. The portion of the lid 12 that is heat-sealed to the flange 23 forms a sealed portion.

[0019] The lid 12 is formed from a film 3. The lid 12 is formed so as to be heat-sealable, for example, to a flange 23. As such, one example of the packaging container 2 is a so-called tray container in which the lid 12 is heat-sealed to the container body 11 as a top seal.

[0020] Next, other examples of the packaging container 2A will be described. As another example, as shown in Fig. 2, the packaging container 2A used for the content-containing package 1 is formed into a bag, pillow, or pouch shape by folding one sheet of film 3 and heat-sealing the edges, or by stacking two or more sheets of film 3 and heat-sealing the edges. The packaging container 2A is formed into a rectangular bag or pouch shape, and has a sealed portion 2a formed by heat-sealing two or more sides. Note that the packaging container 2A may also be formed into a circular bag shape, and have a sealed portion 2a that is heat-sealed in an annular shape.

[0021] As described above, the film 3 is used as a lid 12 as part of the packaging container 2, or one or more sheets are heat-sealed into a bag to form a packaging container 2A.

[0022] Next, the film 3 used in such packaging containers 2, 2A will be described. As shown in Figs. 1 to 4, the film 3 is formed of a multilayer film having a base layer 31 on the outer surface side. The film 3 has a processed portion 3a in a portion thereof. When a plurality of films 3 are used in the packaging container 2A, the processed portion 3a is formed in any one of the films 3.

[0023] 3, the film 3 includes a base layer 31, an adhesive layer 32, and a seal layer 33. Furthermore, for example, as shown in FIG. 4, the film 3 may have one or more intermediate layers 34 that form part of the base layer 31. In other words, the layer structure of the film 3 is not limited to this, and can be appropriately set as long as it has two or more layers including at least the base layer 31 and the seal layer 33.

[0024] The base layer 31 includes an orientation relaxation portion 31a formed by heating a portion of the base layer 31 to a predetermined temperature near the melting point or higher. The orientation relaxation portion 31a constitutes a part of the processed portion 3a.

[0025] The substrate layer 31 is a crystalline biaxially oriented film. The substrate layer 31 is composed of, for example, a general-purpose biaxially oriented film such as a biaxially oriented PET film, a biaxially oriented nylon film, or a biaxially oriented PP film, or a composite film of these. Other suitable examples of the substrate layer 31 include biaxially oriented films with barrier properties, such as a biaxially oriented PBT film, a biaxially oriented NY film, a biaxially oriented PP film, a biaxially oriented PVA film, a biaxially oriented EVOH film, or a biaxially oriented NY film laminated with PET, as well as coextruded biaxially oriented films having a barrier resin, such as PP / EVOH / PP, NY / EVOH / NY, or NY / MXD-NY / NY, in the intermediate layer 34. Alternatively, films in which a general-purpose biaxially oriented film is coated with a PVA-, PVDC-, or PAA-based barrier resin, or hybrid-coated films in which an inorganic substance is dispersed in the aforementioned barrier resin, can also be suitably used for the substrate layer 31.

[0026] The orientation-reduced portions 31a are formed by heating the substrate layer 31 to a predetermined temperature or higher near the melting point to relax or eliminate the orientation. That is, the orientation-reduced portions 31a are formed by amorphization. When the substrate layer 31 includes an intermediate layer 34, the orientation-reduced portions 31a may be formed in the substrate layer 31 and the intermediate layer 34. As a result, the substrate layer 31 of the film 3 has orientation-reduced portions 31a heated to a predetermined temperature or higher near the melting point in a portion of the orientation-reduced portions 31b that have not been heated to a predetermined temperature or higher near the melting point. While the predetermined temperature near the melting point varies depending on the substrate layer 31, it is at least a temperature that relaxes the orientation and allows the tensile modulus and breaking elongation of the orientation-reduced portions 31a and the orientation-reduced portions 31b to achieve the desired relationship. Here, breaking elongation refers to tensile elongation, and may be referred to as elongation percentage hereinafter. The thickness of the substrate layer 31 is preferably 12 μm or more and 50 μm or less.

[0027] This is because if the thickness of the base material layer 31 is less than 12 μm, the physical strength of the film 3 may be reduced, and film formation may be technically difficult, resulting in increased costs. Also, if the thickness of the base material layer 31 exceeds 50 μm, the film 3 including the base material layer 31 becomes difficult to stretch. However, the thickness of the base material layer 31 is not limited as long as the breaking portion 3b is configured to break due to the shape of the orientation relaxation portion 31a, etc.

[0028] The orientation-relaxed portions 31a are formed by heating the base layer 31 to a predetermined temperature or higher near the melting point to relax the orientation or eliminate the orientation. That is, the orientation-relaxed portions 31a are formed by amorphization. When the base layer 31 has an intermediate layer 34, the orientation-relaxed portions 31a may be formed in the base layer 31 and the intermediate layer 34. As a result, the base layer 31 of the film 3 has orientation-relaxed portions 31a heated to a predetermined temperature or higher near the melting point in a part of the orientation portion 31b that has orientation and is not heated to a predetermined temperature or higher near the melting point. The predetermined temperature near the melting point differs depending on the base layer 31, but is at least a temperature that relaxes the orientation and allows the tensile modulus and breaking elongation of the orientation-relaxed portions 31a and the orientation portion 31b to have the desired relationship.

[0029] Laser beam processing, in which heating is performed with laser beams, is used as a method for heating the base layer 31 to form the orientation relaxation portions 31a in the base layer 31. If the base layer 31 used has poor laser beam absorption properties and it is difficult to form the orientation relaxation portions 31a, a laser beam absorbing material that improves the laser beam absorption properties of the base layer 31 may be blended into the material of the base layer 31 in advance, or the base layer 31 may be coated with the laser beam absorbing material.

[0030] As for the type of laser beam, it is preferable to use a carbon dioxide gas laser, since many of the resin materials used in the base layer 31 have relatively high absorption. The laser beam absorbent can be selected appropriately depending on the type of laser beam. These heating methods can be selected appropriately depending on the material of the base layer 31 to be used, etc.

[0031] Furthermore, whether the orientation relaxation portions 31a are properly formed or not can be determined by inspecting the formed base material layer 31. This inspection method can be performed using X-ray diffraction, Fourier transform infrared spectroscopy (FT-IR), crystallinity measurement by DSC (differential scanning calorimetry), or an orientation viewer using a polarizing plate.

[0032] The adhesive layer 32 can be appropriately selected from among general dry lamination adhesives for food applications, but since the film 3 is used for heating in a microwave oven, the adhesive layer 32 is preferably heat resistant.

[0033] The sealing layer 33 is formed of, for example, a sealant film. The sealing layer is composed of, for example, an unstretched low-density polyethylene (LDPE) film, an unstretched linear low-density polyethylene (LLDPE) film, an unstretched polypropylene (PP) film, an unstretched polyethylene terephthalate film, or the like. The thickness of the sealing layer 33 is preferably 10 μm or more and 100 μm or less. The thickness of the sealing layer 33 is more preferably 20 μm or more and 60 μm or less.

[0034] This is because if the thickness of the sealing layer 33 is less than 10 μm, the practical strength of the film 3 may be insufficient, and the sealed portion may be easily broken by vibration during transportation or impact from being dropped. Also, if the thickness of the sealing layer 33 exceeds 100 μm, it becomes difficult to stretch, which may cause problems with the reliability of steam release.

[0035] Next, the raw roll 200 will be described with reference to Figures 5 to 7. The raw roll 200 is formed of a core 201 and a single sheet 202 that is wound around the core 201 and allows multiple trimmings of the films 3 that form the lid 12 or the packaging container 2A in an area including the processed portion 3a.

[0036] The raw roll 200 is constructed by forming a plurality of processed portions 3a on a sheet 202, which is formed, for example, from a base layer 31, an adhesive layer 32, and a sealing layer 33. For example, the sheet 202 is trimmed to a predetermined length to form blanks before welding of a plurality of lids 12 or a plurality of packaging containers 2A. Furthermore, since the base layer 31 of the sheet 202 (film 3) is formed from a biaxially stretched oriented film, as shown in FIG. 5, the direction in which the sheet 202 is wound around the core, i.e., the longitudinal direction of the sheet 202, is the machine direction (MD), and the direction perpendicular to the longitudinal direction is the transverse direction (TD). Therefore, the MD / TD is also specified for the film 3 from which the sheet 202 is trimmed to form the lids 12 or packaging containers 2A.

[0037] Such a raw roll 200 is manufactured, for example, by forming a plurality of processed portions 3a at predetermined intervals in the circumferential direction on a sheet 202 elongated in one direction, the sheet 202 being formed by integrally forming a base layer 31 and a seal layer 33 with an adhesive layer 32 wound around a core 201. One example of a method for manufacturing such a raw roll 200 involves first laminating two or more films including the base layer 31 and the seal layer 33 and winding the laminate into a roll to form a raw roll 200 in which the processed portions 3a are not formed on the sheet 202. Next, as shown in FIG. 6 , the sheet 202 is fed by a conveying device 301 along a conveying path formed by multiple rollers 301a, and a laser beam irradiation device 302 irradiates the sheet 202 with laser light to form processed portions 3a in which multiple orientation relaxation portions 31a are aligned in one direction, and the sheet is then wound around the core 201. This produces a raw roll 200 in which multiple processed portions 3a are formed on the sheet 202.

[0038] Next, the processed portions 3a formed on the sheet 202 (film 3) will be described. A plurality of processed portions 3a are formed at predetermined intervals in a portion of the sheet 202. One or more rupture portions 3b that rupture due to an increase in internal pressure are formed in each processed portion 3a on the sheet 202, and these rupture portions 3b form steam ports through which steam can escape. Specifically, the processed portion 3a is formed long in one direction and is composed of a plurality of orientation relaxation portions 31a formed at predetermined intervals, and the orientation portions 31b between adjacent orientation relaxation portions 31a form the rupture portions 3b. For example, in the packaging container 2 of FIG. 1, the processed portion 3a is formed by four orientation relaxation portions 31a, thereby forming three rupture portions 3b, and in the packaging container 2A of FIG. 2, the processed portion 3a is formed by three orientation relaxation portions 31a, thereby forming two rupture portions 3b. The breaking portion 3b formed in the processed portion 3a is set to an opening pressure, which is the internal pressure at which the packaging container 2, 2A can be broken (opened) when the internal pressure of the packaging container 2, 2A reaches a predetermined pressure. Here, the opening pressure of the breaking portion 3b is set to be lower than the seal strength at which the welded lid 12 and flange 23 peel off.

[0039] The oriented portions 31b between the multiple orientation relaxation portions 31a form the break portions 3b. The orientation relaxation portions 31a are formed long in one direction along the arrangement direction of the multiple orientation relaxation portions 31a. The break portions 3b are formed by the orientation portions 31b arranged between adjacent orientation relaxation portions 31a that face each other. For example, the break portions 3b are provided in a part of the film 3 and extend in one direction in a linear shape such as a long straight line or curve. The break portions 3b are formed by the orientation portions 31b that exist between the orientation relaxation portions 31a, as a result of multiple orientation relaxation portions 31a being arranged facing each other. In other words, the break portions 3b are formed by parts of the orientation relaxation portions 31a that face each other, with the orientation portions 31b of the base material layer 31 that have not been heated above a predetermined temperature near the melting point of the base material layer 31 interposed therebetween. In this embodiment, the orientation relaxation section 31a is formed in a linear shape, and four orientation relaxation sections 31a are arranged in a line in one direction with a predetermined interval between them, so that three break sections 3b are formed by the orientation sections 31b between adjacent orientation relaxation sections 31a.

[0040] When the internal pressure in the packaging container 2, 2A increases and reaches a predetermined internal pressure, the rupture portion 3b ruptures and opens, and water vapor is released from the opened rupture portion 3b. If the internal pressure continues to increase after opening, the opening area of ​​the rupture portion 3b increases. Furthermore, if the internal pressure in the packaging container 2, 2A decreases after rupture, the opening area of ​​the rupture portion 3b decreases.

[0041] This is because when the orientation relaxation section 31a stretches in the short-side direction of the orientation relaxation section 31a, the fracture section 3b breaks due to the difference in the amount of stretch between the orientation relaxation section 31a and the orientation section 31b. The fracture of the fracture section 3b occurs when the orientation relaxation section 31a stretches by an amount smaller than the maximum amount of stretch of the orientation relaxation section 31a. Therefore, as the internal pressure continues to increase, the amount of stretch in the short-side direction of the orientation relaxation section 31a increases, and the opening area of ​​the fracture section 3b increases. Furthermore, as the internal pressure decreases, the stretched orientation relaxation section 31a bends, and the opening area of ​​the fracture section 3b decreases.

[0042] In this way, even if the output of the processed portion 3a is increased to heat the contents 100 in a microwave oven, excess water vapor can be expelled from the opening of the rupture portion 3b while maintaining a moderate internal pressure.

[0043] 5, the inclination angle θ of the processed portion 3a relative to the MD, more specifically, the inclination angle θ of the arrangement direction of the plurality of orientation relaxing portions 31a relative to the MD, is greater than 0° and less than 90°. Preferably, the inclination angle θ is set to be greater than 2° and less than 90° relative to the MD. More preferably, the inclination angle θ is set to be greater than 2° and less than 90°. More preferably, the inclination angle θ is set to be greater than 2° and less than 15°. Most preferably, the inclination angle θ is set to be greater than 2° and less than 8°.

[0044] When the sheet 202 is irradiated with laser light to form the orientation relaxation portion 31a of the processed portion 3a, the orientation relaxation portion 31a is formed in a range L2 inside the laser light irradiation region L1, as shown in Fig. 7. At this time, the thickness t2 of the orientation relaxation portion 31a is thinner than the thickness t1 of the sheet 202, so that the laser light irradiation region L1 adjacent to the orientation relaxation portion 31a, i.e., the region of the irradiation region L1 where the orientation relaxation portion 31a is not formed, rises, forming a raised portion 31c. As a result, the thickness t3 of this raised portion 31c becomes thicker than the thickness t1 of the sheet 202.

[0045] Therefore, if the alignment direction of the multiple orientation relaxation portions 31a is aligned with the MD, which is the same direction as the winding direction of the sheet 202 of the raw web roll 200 (i.e., θ = 0°), when the sheet 202 is wound, the processed portions 3a all overlap at the same position in the axial direction of the raw web roll 200, causing the portions of the raw web roll 200 where the processed portions 3a are formed to bulge and become partially larger in diameter. However, by making the inclination angle θ of the processed portions 3a with respect to the MD greater than 0°, the overlapping area of ​​the processed portions 3a in the winding direction, i.e., the circumferential direction of the raw web roll 200, can be reduced when the raw web roll 200 is wound. This reduces the amount of bulging caused by the processed portions 3a of the raw web roll 200, i.e., the height of the bumps formed by the portions of the raw web roll 200 that protrude like bumps. Therefore, to reduce the height of the bumps, it is preferable that the inclination angle θ of the processed portions 3a with respect to the MD be greater than 0°.

[0046] Furthermore, as for the MD / TD physical properties of biaxially stretched oriented films, the MD tensile strength (MPa) tends to be lower than the TD tensile strength (MPa), while the breaking elongation (%) tends to be higher in the machine direction than in the transverse direction. In the processed portion 3a, the difference between the elongation in the short-side direction of the orientation relaxation portion 31a and the elongation in the same direction of the orientation portion 31b between adjacent orientation relaxation portions 31a causes the orientation portion 31b between adjacent orientation relaxation portions 31a to break. Therefore, by aligning the longitudinal direction of the orientation relaxation portion 31a along the MD of the base layer 31 or at a predetermined angle to the MD, a difference in elongation is likely to occur between the non-crystallized orientation relaxation portion 31a and the crystallized orientation portion 31b, making it easier for the film to break at the breaking portion 3b.

[0047] For these reasons, if the focus is on facilitating the breaking of the breaking portion 3b, it is preferable to set the inclination angle θ of the processed portion 3a of the raw roll 200 relative to the MD to a range of 0° or more and less than 45°. As described above, the inclination angle θ is set to a value greater than 0° and less than 90° based on the hump height and the breaking performance of the breaking portion 3b.

[0048] Next, an evaluation test of such a raw roll 200 will be described. For the evaluation test, raw rolls 200 with a sheet 202 length of 200 m were prepared as raw rolls 200 of Examples 1 to 4 and the Comparative Example. The height of the region where the processed portions 3 a of the raw roll 200 were provided, i.e., the height (mm) of the nodules formed on the raw roll 200, was measured using a Mitutoyo Contracer (CV-3000) based on the region where the processed portions 3 a were not provided. The film structure of the raw roll 200 was PET#16 / EP#30. The overall length of the processed portions 3 a was 46 mm, and the longitudinal length of each orientation relaxation portion 31 a was 10.5 mm, with four portions formed. The lateral length of each orientation relaxation portion 31 a, which is the processed width, was 0.7 mm. The inclination angle θ of the processed portions 3 a relative to the MD was set as follows in Examples 1 to 4 and the Comparative Example. In each of Examples 1 to 4 and the comparative example, the plurality of processed portions 3a were formed with the same intervals in the MD, and the intervals between the orientation relaxing portions 31a of each processed portion 3a were also the same.

[0049] In the raw web roll 200 of Example 1, the inclination angle θ of the processing portion 3a relative to the MD was 2°, and in the raw web roll 200 of Example 2, the inclination angle θ of the processing portion 3a relative to the MD was 4°. In the raw web roll 200 of Example 3, the inclination angle θ of the processing portion 3a relative to the MD was 6°, and in the raw web roll 200 of Example 4, the inclination angle θ of the processing portion 3a relative to the MD was 8°.

[0050] The results of the evaluation test and the captured photographs are shown in FIG. 8. As shown in FIG. 8, the raw roll of the comparative example had a nodule height of 0.38 mm. In contrast, the raw roll 200 of Example 1 had a nodule height of 0.25 mm, and the raw roll 200 of Example 2 had a nodule height of 0.14 mm. The raw roll 200 of Example 3 had a nodule height of 0.12 mm, and the raw roll 200 of Example 4 had a nodule height of 0.06 mm. As is clear from these results, by tilting the alignment direction of the multiple orientation relaxation portions 31a of the processed portion 3a at an angle greater than 0° with respect to the MD, it is clear that the outer diameter (nodule height) of the region where the processed portion 3a is provided can be reduced. It was also clear that the nodule height decreases as the tilt angle θ increases.

[0051] With the raw roll 200, film 3, lid 12, and content-containing package 1 configured as described above, by making the inclination angle θ of the processed portion 3a relative to the MD of the raw roll 200 (film 3) greater than 0, it is possible to suppress bulging when wound, even when the processed portion 3a is formed. Because bulging can be suppressed, the winding direction of the sheet 202 becomes twisted, resulting in wrinkles and unevenness in the sheet 202. Therefore, even when the lid 12 or packaging container 2A is formed using the raw roll 200 and the film 3 trimmed from the raw roll 200 to a desired shape in an area including the processed portion 3a, it is possible to prevent a deterioration in appearance and the occurrence of a gap between the lid 12 and the flange 23 when welding the lid 12 to the flange 23. Furthermore, because the raw roll 200 can be prevented from partially increasing in diameter in the axial direction, it is possible to suppress an increase in the space required for storage and transportation of the manufactured raw roll 200.

[0052] The present invention is not limited to the above-described embodiments, and various modifications can be made in the implementation stage without departing from the spirit of the invention. Furthermore, the embodiments may be implemented in appropriate combinations, in which case the combined effects can be obtained. Furthermore, the above-described embodiments include various inventions, and various inventions can be extracted by combining selected elements from the disclosed elements. For example, if the problem can be solved and the desired effect can be obtained even if some elements are deleted from all elements shown in the embodiments, the configuration from which these elements are deleted can be extracted as an invention. [Explanation of symbols]

[0053] 1...packaging containing contents, 2, 2A...packaging container, 3...film, 3a...processed portion, 3b...breaking portion, 11...container body, 12...lid, 21...body portion, 22...bottom, 23...flange, 31...base material layer (biaxially stretched oriented film), 31a...orientation relaxation portion, 31b...orientation portion, 32...adhesive layer, 33...sealing layer, 34...intermediate layer, 200...raw roll, 201...core, 202...sheet, 301...conveyor device, 301a...roller, 302...laser light irradiation device.

Claims

1. A trimmable raw roll of film that forms at least a part of a package containing a content to be heated in a microwave oven, The core and a sheet including a biaxially stretched oriented film wound around the core and a seal layer laminated on the biaxially stretched oriented film; a plurality of processed sections formed in a portion of the packaging body, including a plurality of opposing orientation relaxation sections formed in the biaxially stretched oriented film, the processed sections including a breaking section between the plurality of orientation relaxation sections that breaks and opens due to an increase in internal pressure of the packaging body, the processed sections being inclined at an angle greater than 0° with respect to the MD of the sheet; A raw material roll comprising:

2. The raw roll according to claim 1 , wherein the inclination angle of the processed portion relative to the MD is 90° or less.

3. A film formed by trimming a part of the raw roll of claim 1 or claim 2 in a region including the processed portion.

4. A lid formed from the film according to claim 3 and welded to a container body for accommodating contents.

5. The container body and Contents to be contained in the container body; The lid according to claim 4 welded to the container body; A package containing a content comprising:

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