JP4722624B2 - Foamed synthetic resin container - Google Patents

Description

  The present invention relates to a foamed synthetic resin container, and more specifically, a foamed synthetic resin that enables a plurality of side plates to be erected and folded by rotating a plurality of side plates of the container with respect to a bottom plate. The present invention relates to a folding container.

  Generally, any container made of any material can be made compact if it can be easily folded during transportation or storage in the absence of stored items, which can reduce transportation and storage costs, and can be recovered. Since it can be easily reused, it is a matter of course that an application for its convenience is opened.

  Traditional paper containers such as cardboard boxes are thin, so if you make a crease, you can fold it as a hinge, and you can realize a considerable volume reduction ratio and it is inexpensive, so it was ideal until now It can be said that it was a typical packaging, transportation and storage container. However, cardboard boxes also have problems such as disposal on the receiving side, low frequency of repeated use, lack of waterproofness, and lack of cold insulation.

  In addition, in plastic containers, containers that can be folded and returned, such as food containers for convenience stores and household waste collection containers, have a variety of folding methods and are already used in large quantities, greatly improving their compactness for transportation and storage. Demonstrating. However, synthetic resin containers have little cold insulation.

  Therefore, applying the folding method to a foamed synthetic resin container is highly expected because it can provide cold insulation and light weight, but there are still many issues, although it has been studied in the past. There is.

  The above-mentioned many problems include the following.

  If the surface of foamed polystyrene or foamed hard urethane is used with its surface exposed, it may crack, be scratched, or become dirty, making it difficult to withstand repeated use. There are containers that can be folded using various hinges attached to the skin or the skin layer itself as a hinge. Such a foldable container is expensive due to a complicated manufacturing process, a large number of parts, and time required for assembling work, and a gap is easily formed between the side plates. There are problems such as bad and heavy to hold.

  In addition, when using synthetic resin foam exposed, there are containers that can be bent by attaching hinges such as unfoamed plastic plates, tapes, sheets, etc., but thick synthetic resin foam is thick. The hinge is folded with a hinge, so that the hinge is loose and misaligned, resulting in loss of hermeticity, and depending on the method of fixing to the synthetic resin foam, the hinge is lifted if it is a plastic part other than a rotating type. Since the load at the time is directly applied to the hinge, if it is used several times, the relatively weak foamed synthetic resin is destroyed, and the hinge is loosened or detached. Further, when the hinge is a tape or sheet, it peels off or shifts, and dirt tends to be conspicuous.

  Specifically, from the technology disclosed in the past, it consists of a foamed resin plate body with a reinforcing layer on the surface, and many folding points are hinged (screw fixing parts and screw fixings that are insert-molded in the foamed resin plate body) ) And support (a support embedded through the entire width of the foamed resin plate is fixed with a tightening screw), there is a cold storage box (Patent Document 1) that can be folded. There are problems that the manufacturing process is quite complicated, such as a stop insert and a hole that penetrates the support, the number of parts is large, and the assembly work takes time.

  In addition, it is a foldable container made of plastic raw material by blow molding method. The side wall can stand up and expand outward with respect to the bottom wall, and both the bottom wall and side wall are double walls. Although there is a filled cold storage container (Patent Document 2), it is expensive from the manufacturing process like the container of Patent Document 1, and if the skin is thickened, it becomes a heavy container. When joining plastic side plates having no buffering property, a gap is likely to be formed, and there is a concern that airtightness may be reduced.

  In the example of using synthetic resin foam by bare, it consists of bottom plate, front side plate, rear side plate, left side plate, right side plate and lid plate made of foamed synthetic resin material, each side plate standing up by hinge means against the bottom plate The front and rear side plates and the left and right side plates are first folded on the bottom plate, and the other side plates are placed on the both side plates. There is a heat insulating container (Patent Document 3) configured to be folded, but the hinge means is based on a method such as fixing or embedding such as an adhesive tape or a plastic hinge.

  Further, there is a foamed synthetic resin container (Patent Document 4) in which a hinge is provided between four side plates to form a rectangular tube shape and fixed with a bottom plate and a lid plate. This is a method of reducing the volume by folding a square tube shape with a hinge to make a rhombus, but this is also due to the thermal bonding of the synthetic resin sheet, adhesive tape, or plastic parts. In addition, since the folded shape does not become a rectangular shape, there is a problem that it is difficult to organize at the time of transportation and storage.

  Further, Patent Documents 5 and 6 disclose a technique for folding a hinge as a rotation type hinge (self-hinge) made of the same foamed synthetic resin. Both are used for hinges of a lid of a foamed synthetic resin container. This example is neither described nor suggested to be used as a hinge of a folded portion that requires strength such as a side wall with respect to the bottom plate.

The above-mentioned rotary type self-hinge that is integrally foam-molded with the same foamed synthetic resin has rotating convex pieces and recesses. Therefore, in a general bead method in-mold foam molding method, gold after foam molding is used. Release from the mold is difficult (when the male and female molds are opened, if there is an undercut part in the molded product, there is a tendency to cause mold release). There is a problem that foam molding is necessary and cannot be easily manufactured.
JP 2003-26257 A JP 2000-153833 A JP 2001-58682 A JP 07-277327 A Japanese Utility Model Publication No. 4-23661 JP-A-7-330045

  The present inventor intends to provide a container that can be molded by a general bead method in-mold foam molding method in a folding container that uses a foamed synthetic resin in a bare manner to improve hinge durability. is there.

  As a result of intensive studies, the inventor found that the hinge of the rotating convex piece and the recessed portion on the hinge that folds the side plate with respect to the bottom plate is the most stable when folding a thick synthetic resin foam. If it is confirmed that it is a hinge, the hinge part material is made into a separate part and made into a pivoting hinge, the container body does not have an undercut part and can be molded by a general bead method in-mold foam molding method Moreover, even when a heavy product is stored in a container, when it is lifted with a side plate, it can be used as a hinge that can sufficiently withstand the load and withstand repeated folding, The present invention has been completed.

That is, the first of the present invention is a foamed synthetic resin container formed from a bottom plate and a side plate that can be erected or folded around the bottom plate, which is foam-molded by an in-mold foam molding method ,
In the side plate standing direction of the side plate standing position of the bottom plate, a protruding portion having a recess or a rotating convex piece is provided on the side portion, and the side plate is placed on one side of the side plate so as to substantially contact the protruding portion. to form a cutout portion having a pivot projecting piece or recess in part, in the recess / or rotating convex piece with cutouts or foamed synthetic resin container obtained by coupling connecting fitting recesses of the projections Yes,
A part of the bottom plate and / or side plate including the recess and / or the rotating convex piece is foam-molded by a bead-type in-mold foam molding method, and is produced as a separate part having a higher density and bonded. In addition, the present invention relates to a foamed synthetic resin container characterized by being joined to a corresponding position of a bottom plate and / or a side plate by a locking shape .

As a preferred embodiment,
( 1 ) The separate part and the bottom plate are made of the same material.
(2) in the recess to be produced as said other component, it is opened in a direction other than the side plates standing direction of the side plate surface, providing the defect for Kaidototsu piece insertion,
(3) in the recess to be produced as said other component, is opened in a direction other than the side plates standing direction of the side plate surface, provided with a cut portion for Kaidototsu piece insertion, after Kaidototsu piece insertion, Closing or narrowing the defect provided in the recess;
( 4 ) When a plurality of the side plates are erected with respect to the bottom plate, a component that can lock adjacent side plates is produced as a separate component, and the material of the separate component is the same material as the side plate. Being
( 5 ) The foamed synthetic resin forming the container body is a polyolefin foam,
(6) to said further part, integrally foamed molded with foam as a base of said another component, may cut off from the base after the foam molding,
The foamed synthetic resin container as described above.

  As in the present invention, in a foamed synthetic resin foldable container comprising a bottom plate and side plates that are erected around the bottom plate, by folding the folding hinges into separate parts, the container body is a general bead method type It can be molded by the inner foam molding method, and if a rotating hinge is employed, the hinge is stable and highly durable, and can cope with the load of the product stored in the container.

  Further, by providing a deficient portion for inserting the rotating convex piece in the recess of the rotating hinge, it can be inserted later, can withstand the load, and is difficult to come off.

  In addition, the parts that can be locked by connecting adjacent side plates can also be molded by a general bead method in-mold foam molding method if they are produced as separate parts, and the connection locking performance If the connection locking part with good durability is adopted, the connection between the side plates becomes strong, the strength reduction of the container itself can be suppressed, and the confidentiality can be prevented from decreasing.

  Furthermore, by making the foamed synthetic resin forming the container body into a polyolefin-based foam that is foam-molded by an in-mold foam molding method, a foldable container that can be used repeatedly even if the foamed synthetic resin is exposed can be provided.

The present invention relates to a bottom plate and a foamed synthetic resin container that can be erected and folded around the bottom plate with a rotary hinge. However, the shape of the bottom plate is not particularly limited, and can be adopted if it is a rectangular or more polygonal container. Generally, it is preferable to employ a rectangular parallelepiped container in which four surrounding side plates can be erected and folded on a rectangular bottom plate. (Figure 1)
In the present invention, for example, as shown in FIG. 3, the side plate is provided with a protrusion provided with a recess or a rotating convex piece on the side in the side plate standing direction, and the side plate is substantially in contact with the protrusion. In addition, the side plate is formed with a notched portion having a rotating convex piece or a concave portion on one side, and the concave portion of the protruding portion / or the rotating convex piece and the notched portion or the concave portion are combined. It is a connected synthetic resin container, and one or both of the bottom plate and / or the side plate including the recess and / or the rotating convex piece are produced as separate parts.

  A part of the bottom plate and / or the side plate including the concave part and / or the rotating convex piece produced as a separate part (hereinafter may be simply referred to as “recessed part” or “rotating convex part”) Preferably, the rotating hinge is formed by bonding and / or engaging with a corresponding portion of the bottom plate or the side plate. The shape and the number of the recesses and the rotating protrusions are not limited to 12 pieces in FIG. 1 respectively, but due to factors such as the thickness of the foamed synthetic resin, the length of the side plates, and the required load resistance, It is arbitrarily determined including the diameter and depth of the rotating convex piece.

  In general, the width of the parts of the rotating hinge is the same as the thickness of the foamed synthetic resin. For example, the adhesive area can be increased, and the smoothness of the container side surface and the foamed synthetic resin of the rotating hinge. From the viewpoint of joining with the container body, specifically, it is preferably about 10 to 50 mm, more preferably 15 to 30 mm, and the length of the parts of the rotary hinge is, for example, that of parts such as plastic. If it is large, it may become a heat loss part itself, so from the viewpoint of component cost and heat insulation effect, the shorter one is preferable, specifically 50 mm or less, more preferably about 20 mm. Further, the larger the diameter of the recess and the rotating convex piece is, the more preferable from the viewpoint of stability and durability at the time of rotation of the rotating hinge and load resistance of the rotating hinge. % And 75% or less is preferable, and the depth of the recess and the rotating convex piece is determined together with the number of the load-bearing load. The following is preferable, and more preferably 5 mm or less.

  The material of the recessed part and / or the rotating convex piece used as separate parts for the present invention is not limited, but various selections can be made regarding the foam synthetic resin, resin type, density, etc. of the bottom plate forming the container body. Can do. A preferred embodiment includes a mode in which the separate part and the bottom plate are made of the same material. Another preferred mode is a mode in which the separate part and the bottom plate differ in at least one of resin type and density. Can be mentioned.

  If it is the former mode, when it is molded by the bead method in-mold foam molding method, it can be molded at the same time as the container body.

  In the latter case, when the resin type of the container body and the separate part is the same and only the separate part has a high density, there is a merit that the durability of the hinge can be improved in addition to the above characteristics. .

Specifically, the density of the foamed synthetic resin forming the container body is approximately 0.02 g / cm ³ or more and 0.10 g / cm ³ or less. material from those same but is high density, is approximately 0.05 g / cm ³ or more 0.3 g / cm ³ or less.

  In addition, the synthetic resin of another material formed by injection foaming and extrusion foam molding method, or unfoamed plastic molded by injection, extrusion molding method and vacuum molding method, etc., and / or a rotating convex piece However, it is possible to select the number and shape of the plastics obtained by the injection molding method as the rotation type hinges according to the load. It is also advantageously employed from the standpoint of jointability. In this case, it is preferable to unify the foamed synthetic resin container main body and the resin type, because they can be melted together and the discardability is improved.

  In the present invention, the insertion of the rotating convex piece is provided by providing a recess for insertion of the rotating convex piece, which is opened in a direction other than the side plate standing direction of the side plate surface in the recess made of a separate part. By preventing the direction from overlapping with the side plate standing direction, it is possible to prevent the rotating convex piece from coming out of the recess when lifted. If the concave and / or rotating convex piece is a flexible synthetic resin foam, it will be difficult to remove if the convex piece is made larger than the concave and forcibly inserted, and the concave and rotating convex piece may be a plastic part. Since it cannot be forcibly inserted, it will be difficult to come off by closing or narrowing the defective part provided in the recess after the insertion of the rotating convex piece in order to prevent the rotating convex piece from being removed from the recess. preferable.

  Furthermore, when a plurality of the side plates are erected with respect to the bottom plate, at least one of the locking portions is preferably produced as separate components for the components that can lock the adjacent side plates. Adopting the bonding and / or locking method is preferable because the foamed synthetic resin container body has no undercut portion and can be molded by a general bead method in-mold foam molding method. If the material of the separate part is the same as the foamed synthetic resin forming the container body, it can be molded by a general bead method in-mold foam molding method.

  Moreover, it is also possible to make different at least one of the resin type and density of a separate part and a side plate different. For example, foamed synthetic resin or non-foamed plastic can be selected as a separate part. However, if plastic is used, a connection locking part with good connection locking performance and high durability is obtained. In any case, by strengthening the connection between the side plates, it is possible to suppress a decrease in strength of the container itself, which can be said to be the greatest weakness because it is a folding type, and it is also possible to prevent a decrease in confidentiality.

  In the present invention, the foamed synthetic resin that forms the container body is not particularly limited. However, as a preferred embodiment, a synthetic resin is preferably used as a polyolefin-based foam that is foam-molded by a bead method in-mold foam molding method. Since the polyolefin-based foam is a flexible and durable foam, it has an advantage of withstanding repeated use. In addition, the concave part and the rotating convex piece produced as separate parts, and the parts that can lock the adjacent side plates produced as separate parts are also bead method molds of the same material with the same density or high density By using a polyolefin-based foam that is foam-molded by the internal foam-molding method, a durable rotating hinge can be obtained, and a part that is not easily broken even when opening and closing of adjacent side plates is repeated can be obtained.

  As used herein, the polyolefin-based foam means that the base resin is an α-olefin monomer having 2 to 8 carbon atoms such as ethylene, propylene, butene, pentene, hexene, heptene, octene or a cyclic olefin monomer such as norbornene. A resin obtained by polymerizing a single or two or more kinds of resins or a resin containing the same as a main component is foamed. The in-mold foam molding method is a pre-foamed particle in which a resin is foamed into beads. This is a method of foam-molding into various shapes with a mold mounted on the.

  Actually, a foamed synthetic resin that has already been widely used is economically preferable, and a foamed body of pre-expanded particles such as a polypropylene resin foam, a polyethylene resin, and a styrene-modified polyolefin resin can be suitably used. The styrene-modified polyolefin resin preferably has an olefin content of 30% or more, more preferably 50% or more.

  Among these, a polypropylene resin foam having both hardness and flexibility is preferably used. There are many types of polypropylene resin foams, and as the base resin, propylene homopolymer, ethylene-propylene random copolymer, ethylene-propylene block copolymer, butene-propylene random or block copolymer, butene -Random or block copolymers of ethylene-propylene or cross-linked resins thereof. Generally, ethylene-propylene random copolymer resin foams having a content of 1 to 5% by weight of ethylene to propylene are performances. This is preferable in terms of cost.

  The above-described parts having recesses and rotating convex pieces produced as separate parts, and parts that can lock adjacent side plates produced as separate parts are foam-molded by the foam-in-mold foam molding method. In this case, since the parts are too small, it is difficult to fill the bead raw material or release after molding, and it may be difficult to mold by the usual in-mold foam molding method. It is preferable to install the recess and the rotating convex piece in the direction without the undercut shape, integrally foam-mold with the pedestal, and cut off from the pedestal after foam molding to obtain another part.

  Moreover, since this invention exists in employ | adopting the rotation type hinge which consists of another parts for the hinge of the folding part of a foaming synthetic resin foldable container, it is not restrict | limited to other shapes and methods. For example, if the height of the side plate is approximately ½ or less of the width of the bottom plate (width ≦ length), the folding is easy. The present invention can be adopted even if the position is folded one step higher, or the side plate itself can be folded, and the folding method is not limited. In addition, any shape and method such as the shape of the lid, the method for joining the lid and the container, the method for attaching the lid to the folded container, and the method for stealing the lid and the entire container can be adopted with the present invention.

  The specific contents of the present invention will be described below with reference to examples, but the present invention is not limited thereto.

Example 1
FIG. 2 shows the foamed synthetic resin container of FIG. 1 provided with a pivoting hinge, in which the recess and the part having the pivoting protrusion are produced as separate parts, and the bottom plate and the side plate are later bonded with an adhesive. The foamed synthetic resin container of FIG. 1 has the remaining 11 rotating hinges, but it is also made as a separate part, and the recess and the rotating convex piece are engaged with each other. After that, an adhesive was applied to necessary portions, and a foamed synthetic resin container was obtained by adhesive bonding.

  The foamed synthetic resin container body is made of foamed polypropylene (base resin = ethylene-propylene random copolymer having an ethylene content of 3%) with a foaming ratio of 20 times (density = 45 g / liter) by the in-mold foam molding method. The place and the rotating convex piece are made of the same material, but have a foaming magnification of 5 times (density = 180 g / liter), and were obtained by an in-mold foam molding method according to Example 4 described later. The recess and the rotating convex piece can also be implemented with unfoamed plastic obtained by injection molding. When obtaining a part with a concave part and rotating convex piece made of separate parts with unfoamed plastic, give it a shape that can be locked to the container body as shown in Fig. 4, and apply and bond as necessary. Is preferred.

(Example 2)
FIG. 3 also shows an example in which a defective part for inserting a rotating convex piece opened in a direction other than the side plate standing direction of the side plate surface is provided in a recess produced as a separate part. A recess and a rotating convex piece formed as separate parts were placed on the protrusion and the cutout portion by bonding or the like, and the side plate was erected on the bottom plate later. The concave part is made of foamed synthetic resin, and the method of forcibly inserting the rotating convex piece using its elasticity is adopted. Further, FIG. 5 shows that, when the recess produced as a separate part is an unfoamed plastic, after the rotating convex piece is inserted (1), the defect portion provided in the recess is covered and closed (2). An example of the method is shown. This example is a method of locking and / or adhering the lid, but there are many other methods and shapes for closing the defect, such as sliding the lid to close it, and there are numerous methods.

(Example 3)
FIG. 6 shows an example in which, when a side plate is erected with respect to a bottom plate, two parts that connect and lock adjacent side plates are manufactured as separate parts, and then joined to each side plate by bonding. In this example, using a locking shape by a recess and a convex piece, the foaming magnification of 5 times (density = 180 g / liter) by the ethylene-propylene random copolymer as in Example 1, It was obtained by a bead method in-mold foam molding method. These separate parts can be implemented even with unfoamed plastic, although there are various locking methods and shapes.

Example 4
FIG. 7 shows a bead-method in-mold foam-molding of a part having a recess and a rotating convex piece produced as separate parts, and a part capable of connecting and locking adjacent side plates produced as separate parts. In the case of foam molding by the method, a method is shown in which another part is integrally foam molded with a foam serving as a pedestal and is cut off from the pedestal after foam molding, and is cut off with a hot-wire slicer or cutter in the direction of →.

1 is a perspective view of a foamed synthetic resin container of the present invention. An example is shown in which the recess and the rotating convex piece are produced as separate parts and later joined to the bottom plate and the side plate with an adhesive. It is the figure which produced the concave part and the rotation convex piece as another parts, and showed one specific example which carries out joint connection using the defect | deletion part provided in the concave part after joining with a container main body. It is the perspective view which showed the example which gave the shape which can be latched with a container main body in the recess and rotation convex piece which were made into another parts with plastic. An example of a method of closing a defect portion provided in the recess by closing it after inserting the rotating convex piece when the recess produced as a separate part is plastic will be shown. This is an example in which two parts that can be locked together by connecting adjacent side plates are manufactured as separate parts and later joined to each side plate by bonding. A method is shown in which a connecting part between a recess, a rotating convex piece, and adjacent side plates is integrally foamed together with a foam serving as a base and then cut off from the base.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Bottom plate 2 Side plate 3 Protruding part 4 Notch part 5 Recessed part made into separate parts 6 Turning convex piece made into another parts 7 Separate parts which have a shape which can be locked with a container main body 8 Locking part on the container main body side 9 Cover of plastic recess part 10 Two parts that can be connected and locked 11 Top view of container corner 12 Pedestal

Claims (7)

A foamed synthetic resin container formed from a bottom plate and a side plate that can be erected or folded around the bottom plate and formed by foam molding using a bead method in-mold foam molding method ,
In the side plate standing direction of the side plate standing position of the bottom plate, a protruding portion having a recess or a rotating convex piece is provided on the side portion, and the side plate is placed on one side of the side plate so as to substantially contact the protruding portion. to form a cutout portion having a pivot projecting piece or recess in part, in the recess / or rotating convex piece with cutouts or foamed synthetic resin container obtained by coupling connecting fitting recesses of the projections Yes,
A part of the bottom plate and / or side plate including the recess and / or the rotating convex piece is foam-molded by a bead-type in-mold foam molding method, and is produced as a separate part having a higher density and bonded. And / or a foamed synthetic resin container, wherein the container is joined to a corresponding position of the bottom plate and / or the side plate by a locking shape . It said further component and the bottom plate, characterized by comprising the same material, foamed synthetic resin container according to claim 1. Said recess being produced as said another part is opened in a direction other than the side plates standing direction of the side plate plane, and providing a defect for Kaidototsu piece insertion, according to claim 1 or 2 A foamed synthetic resin container as described in 1. Provided in the recess produced as the separate part is a missing portion for inserting a rotating convex piece that is opened in a direction other than the side plate standing direction of the side plate surface. occlude the該欠loss section provided, or, characterized thereby narrowed, foamed synthetic resin container according to claim 3. When a plurality of side plates are erected with respect to the bottom plate, the parts that can lock adjacent side plates are made as separate parts, and the material of the separate parts is the same material as the side wall and wherein, foamed synthetic resin container according to any one of claims 1-4. Foamed synthetic resin forming the container body, characterized in that it is a polyolefin foam, foamed synthetic resin container according to any one of claims 1-5. Said further part, integrally foamed molded with said another part of the seat foam, characterized in that get cut off from the base after the foam molding, foam according to any one of claims 1 to 6 Synthetic resin container.

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