JP2003221080A - Foamed resin molded container with skin and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a gap or peeling from occurring at a joint portion between two films in a foamed resin molded container with a skin in which skin films 11 and 12 are laminated on a surface of a core layer 13 which is a foamed resin body. I do. SOLUTION: An inner skin film 11 having a portion 11k integrally protruding laterally from a cavity space 70 formed by a female mold 60 and a male mold 50 when the mold is clamped is used, This portion is heat-sealed and joined integrally to the outer wall surface portion of the core layer 13 in a state of being superimposed on the outer skin film 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foamed resin molded container with a skin and a method for producing the same, and in particular, it is effective as a container for transporting food, a container for keeping cold food, or a container for keeping heat for a certain period of time. The present invention relates to a foamed resin molded container with a skin that can be used and a method for producing the same.

[0002]

2. Description of the Related Art A foamed resin molded container is known in which a foamed resin molded article is used as a core layer, and a skin film is integrally laminated on the entire surface by heat fusion or the like. JP-A-1-101141
In the publication, as a method of manufacturing such a container, after mounting a skin film preformed in a shape along the cavity surface on the male mold cavity surface (inner skin film),
The mold is clamped, the expandable resin particles are filled and the particles are heated and foamed to form an intermediate molded product with a skin film adhered to the inner surface side, and then the exposed surface of the intermediate molded product is renewed. Core film, which is a foamed resin molded product, by applying a different skin film (outer surface skin film), clamping again, and heat-bonding the intermediate molded product and the skin film that has been applied later in the cavity. A molding method is described which forms a final product with a skin film applied to the entire surface of the layer.

The expandable resin particles are polystyrene,
Bulk density of polypropylene, cross-linked polyethylene, etc. is 8 ~
Pre-expanded thermoplastic resin particles of 100 g / L are used, and as the skin film, polypropylene resin, high impact polystyrene, polyethylene, ethylene
A normal thermoplastic resin such as a vinyl acetate copolymer having a thickness of about 0.1 to 2 mm is used.

The foamed resin molded container with a skin produced in this manner has excellent heat insulating properties, light weight and impact resistance, and the surface of the core layer, which is a foamed resin molded product, is covered with a skin film. Therefore, it can be effectively used as a container for transporting food, a container for keeping cold food, a container for keeping heat, etc. Further, such a foamed resin molded container with a skin can be manufactured at low cost, is lightweight, is easy to handle, and is extremely effective as a returnable box repeatedly used for a certain period.

[0005]

As shown in the exploded view of FIG. 5a, the foamed resin molded container A with a skin manufactured by the manufacturing method as described in the above-mentioned JP-A-1-101141 has an inner surface. The side skin film 11, the core layer 13, and the outer surface side skin film 12 have a three-layer structure.
As shown in the cross-sectional view of the container A in the vicinity of the open end side upper edge thereof, the end portion 11a of the inner surface skin film 11 and the end portion 12a of the outer surface skin film 12 are located on the open end side of the core layer 13. The outer corner portion 14 is in a state of being butted over the entire circumference.

In the abutting portion 15 as described above, although the core layer 13 which is a foamed resin molded product and the skin films 11 and 12 are heat-fused by the surfaces and integrally heat-bonded to each other, the corner portion 14 is formed. When an impact is applied to the vicinity, there is a drawback that peeling easily occurs from the butted portion 15. When peeling occurs, not only does it look bad, but water and foreign substances easily enter there, making it unusable as a container for containing food. In addition, during the molding process, the skin film tends to be displaced in the mold and deformed and shrunk due to heat. In particular, the heat shrinkage of the outer skin film 12 causes the outer surface on the outer wall surface side of the molded product obtained after mold opening. A part not covered with the side skin film 12 may occur. For this reason, the yield of the foamed resin molded container A with the skin is inevitably lowered.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an inner skin film and an outer skin film in a foamed resin molded container with a skin having the above three-layer structure. It is an object of the present invention to provide a foamed resin molded container with a skin and a method for manufacturing the same, which is capable of avoiding the occurrence of a gap or peeling at the joint between the edges of the film as much as possible.

[0008]

A foamed resin molded container with a skin according to the present invention for solving the above-mentioned problems comprises a skin film on the inner surface and a skin film on the outer surface on the surface of a foamed resin molded article which is a core layer. In the foamed resin molded container with a skin in which and are laminated, the inner skin film is protruding beyond the upper edge of the core layer to the outer wall surface portion, and the protruding portion is at the outer wall surface portion of the core layer. , And is integrally joined in a state of being superposed on the outer surface side skin film.

In the foamed resin molded container with the skin according to the present invention, as described above, the end region of the inner skin film (the whole or a part of the protruding portion) has an outer surface on the outer wall surface of the core layer. It is integrally joined in a state of being superposed on the side skin film. Therefore, in a normal use mode, no gap or peeling occurs at the joint between the inner surface skin film and the outer surface skin film, water or foreign matter enters between the core layer and the appearance is deteriorated. Things can be avoided. Therefore, it becomes possible to use the foamed resin molded container with the skin in a safe state for a long period of time. The overall shape of the foamed resin molded container with a skin according to the present invention is arbitrary provided that it can be molded with a molding die, and the shape viewed from the top may be a square or a round shape. The open-side upper edge of the core layer may be a flat surface or a curved surface.

An adhesive may be used to join the protruding portion of the inner skin film to the outer skin film in the outer wall surface portion of the core layer in a state of being superposed on the outer skin film. It may be a garment. In the case of heat fusion, it is possible to use a local heating means by impulse sealing (thermal shock bonding). It may be an external heating means such as a hot platen or a heating means incorporated in a molding die. It is preferable that the heating means can be moved slightly so that pressure can be applied to the heat-sealed portion. When using a heating means, it is necessary to avoid heat damage to the inner skin film, outer skin film or core layer due to overheating. Therefore, it is preferable that the inner skin film is thinner than the outer skin film so that the heat-sealed state can be easily generated. As a result, it is possible to prevent heat damage from occurring during heat fusion.

The present invention further provides a manufacturing method suitable for manufacturing a foamed resin molded container with a skin having the above-mentioned structure, which is formed by a female mold and a male mold when the inner skin film is clamped. Using the one integrally having a portion protruding laterally from the cavity space, and the step of laminating the inner surface skin film and the outer surface skin film on the surface of the core layer, and the core layer in the laminated state. A portion of the inner surface skin film protruding to the outside, at the outer wall surface portion of the core layer, a step of integrally joining in a state of being superimposed on the outer surface skin film, and a manufacturing method characterized by the above-mentioned. Disclose.

In the above-mentioned manufacturing method, the inner surface skin film, the core layer, and the outer surface skin film are preformed in advance by using a preforming die, and those which are integrally assembled are used as a female die and a male die. After clamping the mold with and, the laminating step and the step of integrally joining the protruding portions may be performed.
Further, by using a preforming mold, the outer surface skin film integrally laminated on the outer surface of the core layer and the inner surface skin film are preformed in advance, or on the inner surface of the core layer. One in which the inner skin film is integrally laminated, and the outer skin film are preformed in advance, and the one obtained by integrally assembling them is clamped with a female mold and a male mold, and then the laminating step is performed. You may make it perform the integral joining process of the protruding part.

In any of the manufacturing methods, an adhesive may be used to integrally bond the protruding portion of the inner skin film on the outer wall film of the core layer in a state of being superposed on the outer skin film. Alternatively, heat fusion by heating may be used. In the case of the former, the required assembly is carried out in a state where a thermosetting adhesive is preferably applied, and the female and male molds are clamped together, and the core layer and the skin film are heated by the molds. It is preferable that the step of laminating and the step of integrally joining the protruding portions are simultaneously performed. In the case of the latter, the forming step is performed by laminating the core layer and the skin film by heating the die, and integrating the protruding portion by heat fusion by a heating means incorporated in the forming die. This may be done simultaneously, or the intermediate molded product after the laminating step may be taken out from the mold, and the protruding portion may be separately integrated by heat fusion.

When the intermediate molded product after the laminating step is taken out of the mold and the protruding portion is separately heat-sealed by an external heating means, the protruding portion of the inner surface side skin film and its vicinity are blown with hot air. It is preferable to further include a step of heating and softening by, for example, approaching a heating plate or a heating plate, whereby it is possible to easily position the protruding portion of the inner surface skin film along the side surface of the core layer, The protruding portion of the inner surface side skin film and the outer surface side skin film can be more surely superposed and integrated.

Further, in any of the above-mentioned manufacturing methods, a portion where the protruding portion of the inner skin film is integrally joined in a state of being superposed on the outer skin film and the vicinity thereof are hot air. After heating and softening by spraying or bringing a hot platen close, the overlapped part is pressed against the side wall surface so that the overlapped part and the other part of the side wall surface are flush with each other. It is effective to further carry out the above step, whereby a foamed resin molded container with a skin having a higher appearance design can be obtained.

In the present invention, when the inner skin film and the outer skin film are laminated on the surface of the foamed resin molded product which is the core layer, the skin film is relatively thick and has good shape retention. In some cases, the molded product and the skin film do not necessarily have to be bonded as long as they can be assembled together. However, when the skin film is relatively thin and lacks strength and shape retention, wrinkles and swelling are likely to occur between the molded product and the skin film if adhesive is not applied. It is preferable to perform the lamination by the above-mentioned adhesion or the lamination by the heat adhesion which is heat-fused by heating. Of these, the lamination by heat bonding is most preferable because the production efficiency can be industrially improved and the product can be surely integrated regardless of whether the skin film is thick or thin.

In the foamed resin molded container with a skin according to the present invention, the larger the area where the protruding portion of the inner skin film overlaps with the outer skin film, the larger the peeling or the gap at that portion. Can be prevented more completely. However, the material cost and the cost required for integration increase accordingly. If the area is too small, there is a possibility that partial peeling or a gap may occur in the overlapping portion during use. Considering them, in the actual product, due to the heat shrinkage of the outer surface side skin film in the heat treatment after the mold clamping, only a gap is not formed between the end portion of the inner surface side skin film and the end portion of the outer surface side skin film. It is necessary to secure the width of at least the above-mentioned "portion protruding laterally from the cavity space formed by the female mold and the male mold when the mold is clamped". On the other hand, the maximum width of the overlapping portion may be set to an optimum width in consideration of the intended use mode and manufacturing cost of the container.
In the experiments conducted by the present inventors, it was desirable to provide the overlapping width of at least about 3 mm in the vertical direction.

In the present invention, the expandable resin particles and the skin film used for molding the core layer may be the same as those used in the conventional foamed resin molded container with the skin. For example, as the expandable resin particles, pre-expanded thermoplastic resin particles having a bulk density of 8 to 100 g / L such as polystyrene-based resin, polypropylene-based resin, polyethylene-based resin, and aromatic polyester-based resin are used. Foam molding conditions may be the same as conventional ones.

The skin film is a usual thermoplastic resin such as polypropylene resin, polyester resin, high-impact polystyrene resin, polyethylene resin, ethylene / vinyl acetate copolymer resin and has a thickness of 0.1. A film or sheet of about 3.0 mm is used. When the thickness is less than 0.1 mm, it is difficult to preform the shape along the cavity surface of the molding die, and the original function as the skin material cannot be achieved. If it is thicker than 3.0 mm, the lightness of the container is lost, which is not preferable. A non-foamed resin film or sheet is desirable as the skin film or sheet, but a foamed resin sheet having a lower expansion ratio than the foamed resin body that is the core layer (for example, the foaming ratio of the foamed resin body that is the core layer is 30). It will be understood that, in the case of ˜60 times, if it is 10 times or less of the foamed resin sheet), even if it is used as the skin sheet, the intended purpose can be achieved.
In that case, the thickness is preferably about 1.0 to 3.5 mm.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION A foamed resin molded container with a skin and a method for producing the same according to the present invention will be described below with reference to preferred embodiments. 1a and 1b show two embodiments of a foamed resin molded container with a skin according to the present invention. The overall configuration of the container 10 is the same as that of the foamed resin molded container with a skin shown in FIG.
And has a three-layer structure. Preferably, the inner skin film 11 is thinner than the outer skin film 12.

In FIG. 1a, the outer skin film 12 is shown.
Is laminated on the outer surface of the core layer 13 so as to cover almost the entire outer surface of the core layer 13, and the upper edge 12a thereof is
It reaches the vicinity of the upper edge 13a of the core layer 13. The inner skin film 11 includes the inner surface of the core layer 13 and the upper edge 13a.
Is laminated on the inner side surface of the core layer 13 and the upper edge 13a so as to cover the entire surface of the core layer 13. The inner surface side skin film 11 further integrally has a protruding portion 11k extending beyond the upper edge 13a of the core layer 13 to the outside, and the protruding portion 11k extends along the outer wall surface of the core layer 13. The outer edge of the outer skin film 12 has a top edge 12
It exceeds a and reaches a distance ha further downward.
The protruding portion 11k is also integrally joined to the outer wall surface portion of the core layer 13 and the overlapped region of the outer surface skin film 12.

A foamed resin molded container 1 with a skin shown in FIG. 1b.
0 has the same structure as the container shown in FIG. 1a, but the width of the distance hb at which the end region of the protruding portion 11k of the inner skin film 11 overlaps with the upper end region of the outer skin film 12. However, the only difference is that it is smaller than ha. The overlapping width, that is, the distance h, is appropriately selected within a range that does not cause partial peeling or a gap in the overlapping portion when the foamed resin molded container with a skin 10 is used.

In the foamed resin molded container 10 with the skin according to the present invention having the above-mentioned structure, the inner skin film 11 and the outer skin film 12 are used in a normal usage mode.
There is no gap or peeling in the joint portion (region of overlapping distance h), and it is possible to prevent water or foreign matter from entering the core layer 13 and deterioration of appearance. Therefore, it becomes possible to use the foamed resin molded container with the skin in a safe state for a long period of time.

Foamed resin molding container 1 with a skin according to the present invention
A manufacturing method of 0 will be described. 2 and 3 show one example thereof. In this example, as shown in FIG. 2, an inner surface skin film 11 and a core preformed in a shape substantially conforming to the shape of the container 10 by using a preforming mold (not shown). The layer 13 and the outer skin film 12 are used, and the one obtained by integrally assembling the above three parts is mounted in a male mold 50 and a female mold 60 and clamped as shown in FIG. Core layer 1
The inner surface skin film 11 and the outer surface skin film 12 are laminated on the surface of No. 3 by heat bonding, and at the same time, the protruding portion 11k of the inner surface skin film 11 is attached to the core layer 13
In the outer wall surface portion, the outer surface skin film 12 is heat-sealed and integrally joined in a state of being superposed on the outer surface skin film 12. Preferably, the inner skin film 11 is thinner than the outer skin film 12.

As shown in FIG. 2A, the outer surface skin film 12 used here has a shape that conforms to the outer shape of the core layer 13, and the height of the peripheral side wall 121 thereof is equal to that of the outer wall surface portion of the core layer 13. It is equal to or somewhat lower than the height. The inner skin film 11 has a region portion 111 that follows the shape of the inner side of the core layer 13, a region portion 112 that follows it, and a region portion 112 that follows the upper edge 13a of the core layer 13, and that follows. The core layer 13 includes a region portion (the protruding portion 11k) that is folded back along the outer wall surface of the core layer 13.

First, as shown in FIG. 2b, the core layer 13 is inserted into the inside of the outer surface side skin film 12 to assemble them, and then the inner space of the inner side surface skin film 11 is placed in the inner space of the core layer 13. Insert 111. Thereby, FIG. 2c
As shown in FIG. 3, an assembly 100 having a three-layer structure is formed. The length of the folded-back region portion 112 of the inner skin film 11 is such that the end region portion is the end portion of the outer skin film 12 when the three members are assembled as shown in FIG. 2c. The length is set so that it can overlap the area portion by the distance h.

The male mold 50 and the female mold 60 may be those conventionally used for in-mold foam molding. As shown in Figure 3b,
The depth w of the cavity of the female die 60 is the same as that of the assembled body 10 described above.
The depth is set such that, when 0 is attached, the parting surface 62 abuts against the tip of the protruding portion 11k of the inner surface side skin film 11 or is positioned slightly above it.

The parting surface 52 of the male die 50 has a recess for accommodating a portion exposed downward in the drawing from the parting surface 62 when the assembly 100 is mounted in the cavity of the female die 60. A place 53 is formed. The outer peripheral edge 54 of the recess 53 is more preferably than the outer edge 74 (see FIG. 3a) of the cavity space 70 formed by the male die 50 and the female die 60, of the protruding portion 11k of the inner skin film 11. It is located outside by the thickness. Further, a heating means 80 (see FIG. 3c) such as an impulse seal is arranged around the outer peripheral edge 54 of the recess 53 of the male die 50 over the entire circumference.

The male mold 50 and the female mold 60 are constructed as described above. As shown in FIG. 3b, the assembled body 100 is attached to one of the male mold 50 and the female mold 60 and the mold is clamped by the other mold. As a result, as shown in FIG. 3c, the assembled body 100 is entirely housed in the cavity space 70 (FIG. 3a) formed by the male die 50 and the female die 60. The above-mentioned folded back area portion of the inner skin film 11 serves as a portion 11k that laterally protrudes from the cavity space 70 formed by the female die 60 and the male die 50, outside the recess 53 of the male die 50. It will be located along the peripheral edge 54.

After the mold is clamped, the male mold 50 and the female mold 60 are heated, and the heating means 80 is heated. Thereby, the inner surface side skin film 11 and the outer surface side skin film 12 become the core layer 1
A portion 1 which is heat-sealed and laminated on the surface of No. 3 and protrudes outside the core layer 13 of the inner skin film 11.
1k (the folded back portion of the inner surface skin film 11 is
At least the end portions of the outer wall surface portion of the core layer 13 are integrally heat-sealed and joined together in a state of being superposed on the outer surface side skin film 12. The outer surface side skin film 12 may undergo heat shrinkage in the heat treatment process after the mold clamping. In consideration of this, it is necessary to set the length of the protruding portion 11k (folded region) of the inner surface side skin film 11. After that, the mold is opened to obtain the foamed resin molded container with a skin 10 according to the present invention as shown in FIG.

In the above, the inner skin film 11, the core layer 13 and the outer skin film 12 which have been formed in advance are used, but the present invention is not limited to this, and a preforming die is used.
The outer surface skin film 12 integrally laminated on the outer surface of the core layer 13 and the inner surface skin film 11 may be preformed, and they may be integrally assembled,
Alternatively, the inner skin film 1 is formed on the inner surface of the core layer 13.
1 integrally laminated with the outer surface skin film 12
It is also possible to pre-form and to assemble them integrally. The process mode in which the integrally assembled product is clamped by the female mold 60 and the male mold 50, and then the stacked and protruding portions are integrally bonded is the same as that described above.

Further, a step of heat-sealing and laminating the inner skin film 11 and the outer skin film 12 on the surface of the core layer 13 and the protrusion of the inner skin film 11 outside the core layer 13. Part 11k is the outer surface skin film 1
It is not necessary to simultaneously perform the step of integrally heat-sealing and joining to the upper surface of the two, and after the outer skin films 11 and 12 are heat-sealed and laminated on the surface of the core layer 13, the mold is opened to form an intermediate molded product. It is also possible to take out, and then perform an integral joining process of the protruding portion 11k to the outer surface side skin film 12 by an appropriate external heating means.

FIG. 4 is a partially enlarged view showing another example of the foamed resin molded container with a skin made according to the present invention. Here, the protruding portion 11 of the inner skin film 11
After k is superposed on the outer surface side skin film 12 and the part integrally joined and its vicinity are heated and softened by blowing hot air (not shown) or bringing a hot platen close to them, the superposed part 11k is pressed against the side wall surface of the core layer 13 and processed so that the overlapped portion 11k and the other side wall surface are flush with each other. This makes it possible to obtain a foamed resin molded container with a skin, which has a higher appearance design.

[0034]

In the foamed resin molded container with the skin according to the present invention, the end region of the inner skin film is integrally joined in the outer wall surface portion of the core layer while being superposed on the outer skin film. Therefore, in a normal use mode, no gap or peeling occurs at the joint between the inner skin film and the outer skin film. Therefore, it is possible to prevent water or foreign matter from entering between the core layer and deterioration of appearance. As a result, it can be used in a safe state for a long period of time as a returnable container, a food transport container, a fresh food cold storage container, a heat insulation container, or the like.

[Brief description of drawings]

FIG. 1 is a view for explaining a foamed resin molded container with a skin according to the present invention.

FIG. 2 is a diagram illustrating a method for manufacturing a foamed resin molded container with a skin according to the present invention.

FIG. 3 is a diagram illustrating a method for manufacturing a foamed resin molded container with a skin according to the present invention.

FIG. 4 is a view for explaining another embodiment of the foamed resin molded container with the skin according to the present invention.

FIG. 5 is a view for explaining a foamed resin molded container with a skin, which is manufactured by another manufacturing method.

[Explanation of symbols]

10 ... Foamed resin molded container with skin, 11 ... Inner surface skin film, 11a ... Overhanging portion of inner surface skin film,
12 ... Outer surface side skin film, 13 ... Core layer which is a foamed resin body, 50 ... Male type, 60 ... Female type, 70 ... Cavity space

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B29L 9:00 B29L 9:00 F term (reference) 3E061 AA02 AB12 AB16 AD04 AD07 DB01 DB06 3E067 AA11 AB01 BA05A BB14A BB17A BB25A CA18 FA01 GA14 4F211 AC03 AE02 AG03 AG23 AH55 AH56 SA07 SC07 SC07 SD09 SH06 SK06 SW26

Claims (8)

[Claims] 1. A foamed resin molded container with a skin in which an inner skin film and an outer skin film are laminated on the surface of a foamed resin molded product that is a core layer, wherein the inner skin film is the core layer. Is protruded beyond the upper edge to the outer wall surface portion, and the protruding portion is integrally joined in the outer wall surface portion of the core layer in a state of being superimposed on the outer surface side skin film. Foamed resin molded container with skin. 2. The foamed resin molded container with skin according to claim 1, wherein the thickness of the inner skin film is thinner than the thickness of the outer skin film. 3. The inner skin film has a thickness of 0.1 to 10.
The foamed resin molded container with a skin according to claim 1 or 2, which has a length of 3.0 mm. 4. A foamed resin molded container with a skin in which a skin film on the inner surface side and a skin film on the outer surface side are laminated on the surface of a foamed resin molded product that is a core layer, using a female mold and a male mold. A method using an inner surface skin film that integrally has a portion laterally protruding from a cavity space formed by a female mold and a male mold when clamped, and on the surface of the core layer The step of laminating the inner surface skin film and the outer surface skin film, and the portion of the inner surface skin film protruding outside the core layer in the stacked state, at the outer wall surface portion of the core layer, on the outer surface skin film. And a step of joining them integrally with each other in a state of being superposed on each other, and a method for producing a foamed resin molded container with a skin. 5. A preforming die is used to preform an inner surface skin film, a core layer, and an outer surface skin film in advance, and these are integrally assembled and clamped with a female mold and a male mold. After that, the step of laminating and the step of integrally joining the protruding portions are performed, and the method for producing a foamed resin molded container with a skin according to claim 4, characterized in that. 6. A preforming die is used to preform an outer surface skin film integrally laminated on the outer surface of the core layer and an inner surface skin film in advance, and both are assembled together. The method for producing a foamed resin-molded container with a skin according to claim 4, wherein the step of laminating and the step of integrally joining the protruding portions are performed after the objects are clamped by a female mold and a male mold. 7. A preforming die is used to preform an inner surface skin film integrally laminated on the inner surface of the core layer and an outer surface skin film in advance, and both are assembled together. The method for producing a foamed resin-molded container with a skin according to claim 4, wherein the step of laminating and the step of integrally joining the protruding portions are performed after the objects are clamped by a female mold and a male mold. 8. An inner surface skin film is integrally joined on the outer surface skin film in a state of being superposed on each other, and the vicinity thereof is heated, and at least the superposed portion is pressed against the side wall surface, 8. The method for manufacturing a foamed resin molded container with a skin according to claim 4, further comprising a step of processing such that the overlapped portion and the other portion of the side wall surface are flush with each other.