Manufacturing method for packaging container using laminated sheet

Abstract

To provide a production method of a packaging container having a storage recessed part that is formed by suspending an internal body made of a non-woven fabric sheet over an external body made of a thermoplastic resin sheet in a hammock-like manner.SOLUTION: A production method of a packaging container comprises: applying a hot-melt adhesive to a surface of a thermoplastic resin sheet or a non-woven fabric sheet, overlapping the thermoplastic resin sheet and the non-woven fabric sheet; then, peeling off the thermoplastic resin sheet of a laminated sheet from the non-woven fabric sheet to bring the same into close contact with a female mold 52 to mold an external body 111; recessing the non-woven fabric sheet of the laminated sheet with a male mold 51 to form an internal body 121; hanging the internal body 121 over the external body 111 in a hammock-like shape to form a storage recessed part; and completely adhering the thermoplastic resin sheet and the non-woven fabric sheet by pressing the laminated sheet in a portion other than the storage recessed part.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] This invention relates to a method for manufacturing a packaging container whose material is a laminated sheet formed by laminating a thermoplastic resin sheet and a nonwoven fabric sheet, in which an inner body made of a nonwoven fabric sheet is draped like a hammock over an outer body made of a thermoplastic resin sheet in a storage recess in which the packaged item is stored. [Background technology]

[0002] Conventionally, there have been packaging containers for packaging fruits with soft surfaces that are easily damaged, such as strawberries, loquats, peaches, etc., that are made of a laminated sheet formed by laminating a thermoplastic resin sheet and a nonwoven fabric sheet, and in the storage recess for storing the packaged item, the laminated sheet is separated into a thermoplastic resin sheet and a nonwoven fabric sheet, a hollow portion is provided between the two sheets, and the storage recess is formed by hanging an inner body made of a nonwoven fabric sheet in a hammock-like manner over an outer body made of a thermoplastic resin sheet. In such a packaging container with a storage recess, the packaged item is stored on the inner body made of a nonwoven fabric sheet that has excellent breathability, flexibility, and stretchability, and is held in a state where it is not in contact with the outer body made of a relatively hard thermoplastic resin sheet, so that even fruits with soft surfaces that are easily damaged, such as strawberries, loquats, peaches, etc., can be packaged delicately.

[0003] As a method for producing such a packaging container, for example, Japanese Utility Model Application Laid-Open Publication No. 61-74514 proposes a method in which a thermoplastic resin sheet and a nonwoven fabric sheet are overlapped so as to be freely separable, heated to plasticize, and then fed between a convex mold and a concave mold configured to have a predetermined space in a clamped state, and the molds are clamped to form a recess in the nonwoven fabric sheet, and at the same time, a vacuum is drawn through a vacuum hole formed in the concave mold to separate the thermoplastic resin sheet from the nonwoven fabric sheet and make it fit the concave mold. As for the overlapping of the thermoplastic resin sheet and the nonwoven fabric sheet, it has been proposed to (a) simply fit the nonwoven fabric sheet to the thermoplastic resin sheet without bonding it, (b) lightly heat-seal the nonwoven fabric sheet to the thermoplastic resin sheet with a heated roll or the like, or (c) bond only the part other than the part where the storage recess is formed by adhesive or other means.

[0004] However, the overlapping of the thermoplastic resin sheet and the nonwoven fabric sheet in this manufacturing method has the following problems. (A) If the nonwoven fabric sheet is simply aligned with the thermoplastic resin sheet without being joined, when the nonwoven fabric sheet is overlapped with the thermoplastic resin sheet and wound up by the winding roller, the nonwoven fabric sheet will be overlapped with the thermoplastic resin sheet in a pulled and stretched state, which may affect the elasticity of the nonwoven fabric sheet in the storage recess after molding. (A) When a nonwoven fabric sheet is lightly heat-sealed to a thermoplastic resin sheet by a heating roll or the like, the nonwoven fabric sheet and the thermoplastic resin sheet are heat-sealed, and therefore the peelability is poor, and the thermoplastic resin sheet may not be properly separated from the nonwoven fabric sheet when the mold is clamped to form a storage recess. In addition, after the thermoplastic resin sheet is peeled from the nonwoven fabric sheet, a part of the heat-sealed thermoplastic resin sheet remains on the nonwoven fabric sheet, which has a negative effect on the breathability, flexibility, and stretchability of the nonwoven fabric sheet. (c) When only the portions other than the portion where the accommodating recess is formed are joined with an adhesive or other means, strict application control is required when applying the adhesive to ensure that the adhesive is applied only to the portions other than the portion where the accommodating recess is formed and that the adhesive is not applied to the portion where the accommodating recess is formed.

[0005] Also, JP 2010-260308 A discloses a method for manufacturing a packaging container using a laminated sheet made by laminating a synthetic resin sheet and a nonwoven fabric sheet as a material, separating the laminated sheet into a synthetic resin sheet and a nonwoven fabric sheet to provide a hollow space between the two sheets in a storage recess in which an item to be packaged is stored, and draping an inner body made of a nonwoven fabric sheet over an outer body made of a synthetic resin sheet in a hammock shape to form a storage recess. In this method for manufacturing a packaging container, it is proposed that the synthetic resin sheet and the nonwoven fabric sheet are laminated by firmly attaching the nonwoven fabric sheet to the synthetic resin sheet at a portion that will become the periphery corresponding to the size of the container to be processed, and attaching the nonwoven fabric sheet to the synthetic resin sheet at a portion that will become the inside of the periphery with a weaker adhesive strength than the periphery to form a laminated sheet.

[0006] In this manufacturing method of laminating a synthetic resin sheet and a nonwoven fabric sheet, the synthetic resin sheet and the nonwoven fabric sheet are firmly attached to each other at the peripheral portion corresponding to the size to be processed into a single container, and the adhesive strength of the inside of this peripheral portion is weaker than that of the peripheral portion. Therefore, when the synthetic resin sheet and the nonwoven fabric sheet are bonded to form a laminated sheet, it is not necessary to separate the portion where the storage recess is to be formed from the other portion and perform meticulous coating control so that only the portion other than the portion where the storage recess is to be formed is firmly attached. However, there is a problem in that coating control must be performed by dividing the peripheral portion, which is firmly attached, and the inner portion, which is weakly attached, for each size to be processed into a single container. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Utility Model Application Publication No. 61-74514

[0008] [Patent Document 2] JP 2010-260308 A DISCLOSURE OF THEINVENTION [Problem to be solved by the invention]

[0009] The present invention relates to a method for manufacturing a packaging container that uses a laminated sheet made of a thermoplastic resin sheet and a nonwoven fabric sheet as a material, in which the laminated sheet is separated into a thermoplastic resin sheet and a nonwoven fabric sheet at a storage recess where an item to be packaged is stored, and in which a storage recess is formed by draping an inner body made of a nonwoven fabric sheet like a hammock over an outer body made of a thermoplastic resin sheet. The present invention aims to provide a method for manufacturing a packaging container that can easily separate the thermoplastic resin sheet and the nonwoven fabric sheet at the part where the storage recess is formed when the packaging container is molded, without the need to manage the application of adhesive by dividing the laminated sheet into areas with strong adhesive strength and areas with weak adhesive strength, and can completely bond the thermoplastic resin sheet and the nonwoven fabric sheet in areas other than the part where the storage recess is formed. [Means for solving the problem]

[0010] The method for producing a packaging container of the present invention is to whole A hot melt adhesive is applied to the thermoplastic resin sheet and the nonwoven fabric sheet, and the thermoplastic resin sheet and the nonwoven fabric sheet are laminated together. The whole surface The thermoplastic resin sheet and the nonwoven fabric sheet are pressed together. On the whole A laminated sheet is formed by temporarily bonding the male and female molds together, and a predetermined space is formed between the male and female molds when the molds are closed. In a heated state The laminated sheet 、The nonwoven fabric sheet side is fed toward the male mold side and the thermoplastic resin sheet side is fed toward the female mold side, and the male mold and the female mold are clamped together to apply vacuum suction through a suction hole in the female mold, thereby peeling the thermoplastic resin sheet of the laminated sheet from the nonwoven fabric sheet and adhering it to the female mold to form an outer body, while the nonwoven fabric sheet of the laminated sheet is recessed by the male mold to form an inner body, thereby forming a storage recess in which the inner body is suspended around the outer body like a hammock, and the laminated sheet in areas other than the storage recess is pressed to completely bond the thermoplastic resin sheet and the nonwoven fabric sheet.

[0011] The hot melt adhesive may be applied to the surface of the thermoplastic resin sheet or nonwoven fabric sheet by a known application method using a roll coater or a dispenser, but it is preferable to apply the hot melt adhesive by spraying so that the adhesive layer of the applied hot melt adhesive has countless voids (Claim 2). The adhesive layer having countless voids can be obtained, for example, by spraying the hot melt adhesive in various patterns such as a spider web, fiber, spiral, wavy, or striped pattern.

[0012] In this invention, "pressing in a non-heated state" refers to pressing at a temperature at which the applied hot melt adhesive does not melt, and is a concept that includes not only pressing in a state where no heat is being applied, but also pressing while cooling. Effect of the Invention

[0013] According to the present invention, the surface of a thermoplastic resin sheet or a nonwoven fabric sheet whole A hot melt adhesive is applied to the thermoplastic resin sheet and the nonwoven fabric sheet, and the thermoplastic resin sheet and the nonwoven fabric sheet are laminated together. The whole surface The thermoplastic resin sheet and the nonwoven fabric sheet are pressed together. On the wholeSince the packaging container is formed using the laminated sheet formed by temporary bonding, the thermoplastic resin sheet and the nonwoven fabric sheet can be easily separated at the portion where the storage recess is formed when the packaging container is formed, and the thermoplastic resin sheet and the nonwoven fabric sheet can be completely bonded to each other at the portion other than the portion where the storage recess is formed to manufacture the packaging container. That is, in the laminated sheet in which the thermoplastic resin sheet and the nonwoven fabric sheet are temporarily bonded via a hot melt adhesive, the thermoplastic resin sheet and the nonwoven fabric sheet are not completely bonded, so that they can be easily peeled off by applying a force in the direction in which they are peeled off, and the molten hot melt adhesive can be used to firmly bond the two sheets when the sheets are heated and pressed. As a result, the thermoplastic resin sheet and the nonwoven fabric sheet can be easily separated at the portion where the storage recess is formed when the packaging container is formed, and the thermoplastic resin sheet and the nonwoven fabric sheet can be completely bonded to each other at the portion other than the portion where the storage recess is formed. Therefore, when forming the laminated sheet, it is not necessary to carry out troublesome coating management such as applying adhesive separately to a section with weak adhesive strength (a section where the storage recess is formed) and a section with strong adhesive strength (a section other than the portion where the storage recess is formed) as in the conventional method.

[0014] According to the invention of claim 2, the hot melt adhesive is applied to the surface of the thermoplastic resin sheet or nonwoven fabric sheet by spray application, and the applied hot melt adhesive layer has numerous voids, so that the adhesive strength in the temporary adhesive state is further weakened, and the thermoplastic resin sheet and the nonwoven fabric sheet can be further easily peeled off. Furthermore, even if the hot melt adhesive layer remains attached to the inner body side made of the nonwoven fabric sheet after the storage recess is formed, the hot melt adhesive layer has numerous voids, so there is no risk of adversely affecting the breathability, flexibility, and stretchability of the nonwoven fabric sheet. Furthermore, by applying the hot melt adhesive by spraying, the amount of hot melt adhesive used can be reduced. [Brief description of the drawings]

[0015] [Figure 1]FIG. 1 is a diagram for explaining an outline of a method for manufacturing a packaging container according to the present invention. [Diagram 2] FIG. 1 is a diagram showing an outline of the laminated sheet forming process. [Diagram 3] A diagram showing the outline of the laminated sheet. [Figure 4] FIG. 1 is a diagram illustrating a heating process of a laminated sheet. [Diagram 5] Schematic diagram of a molding die used in the packaging container molding process. [Figure 6] FIG. 14 is a diagram illustrating the feeding process to the mold. [Figure 7] FIG. 10 is a diagram illustrating the mold clamping and vacuum molding process. [Figure 8] A diagram showing the outline of the completed packaging container. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] As shown in FIG. 1, the manufacturing method for a packaging container of the present invention is broadly divided into a laminated sheet forming process for forming a laminated sheet used as a material for the packaging container, and a container forming process for forming a packaging container using the laminated sheet formed in the laminated sheet forming process.

[0017] <Laminated sheet forming process> FIG. 2 is a diagram showing an outline of the laminated sheet forming process. In the process of forming the laminated sheet, first, molten PP (polypropylene)-based hot melt adhesive B is sprayed uniformly in a spider web pattern by a spray 2 onto the entire surface of a thermoplastic resin sheet 11 made of A-PET (amorphous polyethylene terephthalate) with a thickness of 0.3 mm. The amount of hot melt adhesive B applied at this time is 5 g / m 2 There is a degree to it. Next, a nonwoven fabric sheet 12 (100 g / m2) made of PET (polyethylene terephthalate) produced by a needle punch method is applied to the thermoplastic resin sheet 11 on which the hot melt adhesive B has been applied. 2The thermoplastic resin sheet 11 and the nonwoven fabric sheet 12 are then laminated on each other with two unheated rollers 3, which sandwich and press the sheet from both sides to send it out, bonding the thermoplastic resin sheet 11 and the nonwoven fabric sheet 12. At this time, the temperature of the hot melt adhesive B drops between the time it is sprayed onto the surface of the thermoplastic resin sheet 11 by the spray 2 and the time it is pressed by the two unheated rollers 3, and it becomes semi-cured and is in a state in which it is unable to exert its original adhesive strength, so that a laminated sheet 1 is formed in which the thermoplastic resin sheet 11 and the nonwoven fabric sheet 12 are temporarily bonded with an adhesive strength that allows them to be easily peeled off. When this laminated sheet 1 is wound up into a roll using a winding roller or the like, the thermoplastic resin sheet 11 and the nonwoven fabric sheet 12 are wound up together in a temporarily bonded state, so there is no risk of the laminated sheet 1 being formed in a state where only the nonwoven fabric sheet 12 is pulled and stretched.

[0018] FIG. 3 is a diagram showing an outline of the laminated sheet 1 formed by the above-mentioned method. Since the laminated sheet 1 is formed by pressing in an unheated state, the hot melt adhesive B interposed between the thermoplastic resin sheet 11 and the nonwoven fabric sheet 12 does not exert its inherent adhesive strength, and the thermoplastic resin sheet 11 and the nonwoven fabric sheet 12 are bonded in a state of weak adhesive strength. Therefore, when a force is applied to separate the thermoplastic resin sheet 11 and the nonwoven fabric sheet 12 in a direction perpendicular to the sheet surface, the thermoplastic resin sheet 11 and the nonwoven fabric sheet 12 are easily peeled off. In addition, since the hot melt adhesive B is not melted when pressed by the unheated roller 3, the state (spider web shape) when applied to the surface of the thermoplastic resin sheet 11 is maintained even after pressing.

[0019] In this embodiment, the laminated sheet 1 is formed by applying hot melt adhesive B to the surface of a thermoplastic resin sheet 11 as a base material and overlapping a nonwoven fabric sheet 12, but the laminated sheet 1 can also be formed by applying hot melt adhesive B to the surface of a nonwoven fabric sheet 12 as a base material and overlapping a thermoplastic resin sheet 11. In addition, although the hot melt adhesive B is spray-applied in a spider web pattern in this embodiment, it is also possible to spray-apply in various patterns such as fibrous, spiral, wavy, and striped. In short, it is sufficient that the hot melt adhesive layer formed by spray application is not a solid adhesive layer but an adhesive layer having numerous voids.

[0020] In addition, materials that can be used for the thermoplastic resin sheet include A-PET (amorphous polyethylene terephthalate), OPS (biaxially oriented polystyrene), PS (polystyrene), PSP (expanded polystyrene), PP (polypropylene), PLA (polylactic acid), etc.

[0021] <Packaging container forming process> 4 to 8 are diagrams illustrating the process of forming a packaging container 10 using the laminated sheet 1. FIG. In the process of forming a packaging container, first, the laminated sheet 1, in which the thermoplastic resin sheet 11 and the nonwoven fabric sheet 12 are temporarily bonded with the hot melt adhesive B, is heated and softened by a heater 4 (FIG. 4). Next, the heated laminated sheet 1 is fed to the mold 5 with the nonwoven fabric sheet 12 side facing the male mold 51 and the thermoplastic resin sheet 11 side facing the female mold 52 (FIG. 6), and the mold is closed to vacuum suction through the suction hole 52h provided in the female mold 52 (FIG. 7). The male mold 51 and the female mold 52 are shaped so that the convex shape of the male mold 51 is smaller than the concave shape of the female mold 52 so that a space S is formed when the mold is closed (FIG. 5). When the mold is closed and vacuum suction is performed through the suction hole 52h of the female mold 52, the thermoplastic resin sheet 11 of the laminated sheet 1 is peeled off from the nonwoven fabric sheet 12 and adheres to the female mold 52 to form the exterior body 111, and the nonwoven fabric sheet 12 is recessed by the male mold 51 to form the interior body 121, thereby forming the storage recess 101 in a state in which the interior body 121 is hung around the exterior body 111 in a hammock-like manner. In addition, the laminated sheet 1 is pressed by the male mold 51 and the female mold 52 in the portion 102 other than the accommodating recess. At this time, the hot melt adhesive B is heated and in a molten state, so that the inherent adhesive strength of the hot melt adhesive B is exerted, completely bonding the thermoplastic resin sheet 11 and the nonwoven fabric sheet 12. After cooling in this state, the container is released from the mold, thereby obtaining the packaging container 10 shown in FIG.

[0022] The molded packaging container 10 is configured such that the laminated sheet 1 is separated into the thermoplastic resin sheet 11 and the nonwoven fabric sheet 12 in the storage recess 101, and the inner body 121 made of the nonwoven fabric sheet 12 is hung in a hammock-like manner on the outer body 111 made of the thermoplastic resin sheet 11, and a hollow portion is formed between the inner body 121 and the outer body 111. Meanwhile, in the portion 102 other than the storage recess, the thermoplastic resin sheet 11 and the nonwoven fabric sheet 12 are completely bonded by the hot melt adhesive B. Therefore, when an item to be packaged is placed on the inner body 121 in the storage recess 101, the inner body 121 expands and contracts appropriately in accordance with the weight of the item to be packaged inside the outer body 111, with the portion 102 other than the storage recess where the thermoplastic resin sheet 11 and the nonwoven fabric sheet 12 are completely bonded as a fulcrum, and the item to be packaged is held in a floating state. This inner body 121 is composed of a nonwoven fabric sheet 12 and is flexible, stretchable, and breathable, so it not only functions as a cushioning material to protect the packaged items, but also helps to maintain the freshness of the packaged items, such as fruit, if they are perishable goods.

[0023] In addition, the hot melt adhesive B in the accommodating recess 101 will adhere as residue to either or both of the thermoplastic resin sheet 11 side (outer body 111 side) and the nonwoven fabric sheet 12 side (inner body 121 side). However, since the hot melt adhesive B is applied in a spider web pattern with the fibers intertwined like nonwoven fabric to form countless voids, even if it adheres to the nonwoven fabric sheet 12 side (inner body 121 side), it will not adversely affect the flexibility, stretchability, or breathability of the nonwoven fabric sheet 12.

[0024] According to the manufacturing method described above, when forming the laminated sheet 1 used as the material for the packaging container 10, there is no need to carry out tedious coating management such as applying adhesive to a section with weak adhesive strength (the section where the accommodating recess 101 is formed) and a section with strong adhesive strength (the section 102 other than the section where the accommodating recess is formed).In this way, when molding the packaging container 10, the laminated sheet 1 can be easily separated into the thermoplastic resin sheet 11 and the nonwoven fabric sheet 12 in the section where the accommodating recess 101 is formed to form the outer body 111 and the inner body 121, and the thermoplastic resin sheet 11 and the nonwoven fabric sheet 12 can be completely bonded to each other in the section 102 other than the section where the accommodating recess is formed to form the packaging container 10.

[0025] In addition, the hot melt adhesive B is applied by spraying in a spider web pattern, and the hot melt adhesive layer in the laminated sheet 1 is in a state in which fine fibers are entangled like nonwoven fabric and countless voids are formed, so that the thermoplastic resin sheet 11 and the nonwoven fabric sheet 12 are even easier to peel off, and even if after the accommodating recess 101 is formed, there is residual hot melt adhesive B adhering to the inner body 121 side consisting of the nonwoven fabric sheet 12, it does not adversely affect the breathability, flexibility, and elasticity of the nonwoven fabric sheet 12.

[0026] The above describes the examples using simplified schematic diagrams, but as long as the packaging container can be manufactured by the above-mentioned method, various shapes can be considered, for example, by increasing the number of storage recesses or changing their shapes, and the shape is not limited to the shapes described above. [Industrial Applicability]

[0027] This invention relates to a method for manufacturing a packaging container whose material is a laminated sheet formed by laminating a thermoplastic resin sheet and a nonwoven fabric sheet, in which an inner body made of a nonwoven fabric sheet is draped like a hammock over an outer body made of a thermoplastic resin sheet in a storage recess in which the item to be packaged is stored, and has industrial applicability. [Explanation of symbols]

[0028] 1 Laminated sheet 11 Thermoplastic resin sheet 111 Exterior body 12 Non-woven sheet 121 Interior Body 2 Spray 3 Non-heated roller 4. Heater 5 Molding mold 51 Male type 52 Female 52h suction hole 10 Packaging containers 101 Recessed portion 102 Parts other than the receiving recess B. Hot melt adhesive S space

Claims

1. A hot melt adhesive is applied to the entire surface of a thermoplastic resin sheet or a nonwoven fabric sheet, the thermoplastic resin sheet and the nonwoven fabric sheet are overlapped, and then the entire surface is pressed in an unheated state to temporarily bond the thermoplastic resin sheet and the nonwoven fabric sheet over their entire surfaces to form a laminated sheet; Between the male mold and the female mold, a predetermined space is formed inside when the molds are clamped. The heated laminated sheet is fed with the nonwoven fabric sheet side facing the male mold and the thermoplastic resin sheet side facing the female mold; The male mold and the female mold are clamped together and vacuum is applied through a suction hole provided in the female mold, whereby the thermoplastic resin sheet of the laminated sheet is peeled off from the nonwoven fabric sheet and brought into close contact with the female mold to form an outer body, while the nonwoven fabric sheet of the laminated sheet is recessed by the male mold to form an inner body, thereby forming a storage recess in which the inner body is hung around the outer body in a hammock-like shape, and the laminated sheet in a portion other than the storage recess is pressed to completely adhere the thermoplastic resin sheet to the nonwoven fabric sheet. A method for manufacturing a packaging container.

2. 2. The method for manufacturing a packaging container according to claim 1, wherein the hot melt adhesive is applied by spray coating, and the adhesive layer of the applied hot melt adhesive has numerous voids.

Images