JP2001129848A - Molded article, molding method, and housing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To freely set the wall thickness and shape of a skin or core layer while ensuring strength in a multilayered resin molded article. SOLUTION: In a multilayered resin molded article wherein at least both main surfaces of a core layer 103 are covered with skin layers, the skin layer of at least one main surface has either one of a rib 105 and a thick-walled part becoming a flow leader at a time of injection molding and the skin layers 102A, 102B arranged to both main surfaces are connected through a plurality of the through-holes 104 bord in the core layer 103.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer resin molded product in which a peripheral surface of a core layer is covered with a skin layer.

[0002]

2. Description of the Related Art As a method for producing a multilayer resin molded product, for example, Japanese Patent Application No. 26667594 is disclosed. Japanese Patent Application Laid-Open No. 11-188 describes an insert molded product having a window and its production method.
No. 755 has been proposed. In recent years, problems such as depletion of petroleum and tightness of industrial waste treatment plants have become more serious, and there is an urgent need to reuse resin materials.

[0003] For example, Japanese Patent Application Laid-Open No. 9-262334 discloses a method for forming a snowboard using a recycled material for a part of a multilayer structure.
JP-A-10-278105 discloses a blow-molded article using recycled pellets.

[0004] However, in the above-mentioned conventional proposal, a specific cross-sectional shape and manufacturing method in consideration of the moldability of a multilayer structure and the adhesive strength of a multilayer interface, and a method of forming a skin layer or a core layer to a desired thickness, etc. Does not specifically mention.

The sandwich injection molding method described in the above-mentioned Japanese Patent No. 2667594 is a molding method for a generally well-known multilayer resin structure, and has a concept similar to that of the gas assist injection molding method. That is, while the gas assist injection molding method injects a gas into the resin, Japanese Patent No. 26667594 injects a core layer forming resin into the resin.

[0006] In the gas-assisted injection molding method, when observing the state of gas injection into a molded article, it is possible to control the gas flow path to some extent by arranging the gas channels. In this case, an extremely thick portion and an extremely thin portion occur. This phenomenon also occurs in the sandwich injection molding method, and it has been difficult to form the skin layer or the core layer to a desired thickness. As a result, there was a problem that the strength and flame retardancy of the molded product could not be guaranteed.

Further, the sandwich injection molding method has a structure in which a highly viscous resin is injected into the resin, so that the moldability at the time of injection molding is poor, and it is difficult to inject the core layer resin to the flow end of the resin. Therefore, a high injection ratio of the core layer resin cannot be expected. In addition, a dedicated molding machine is required for sandwich injection molding, and there is a problem that capital investment is increased.

The insert molding method described in the above-mentioned Japanese Patent Application Laid-Open No. 11-188755 is a method in which a resin is injection-molded in a state in which the insert material is in close contact with the inner surface of one of the mold cavities, and is fused and integrated. . For this reason, it is difficult to obtain a multilayer structure in which the entire surface (peripheral surface) of the insert material is covered with the injection resin. Further, since a roll-shaped sheet member is used as the insert material, a step of removing an excess sheet member after removing the molded product is required.

In the snowboard molding method described in Japanese Patent Application Laid-Open No. 9-262334, a hollow body is formed by blow molding, and then a resin is injected into the hollow portion to form a snowboard body. Alternatively, a snowboard having a multilayer structure is formed by a sandwich injection molding method.

In the former blow molding method, compatibility of the skin layer and the core layer cannot be expected because the core layer resin is injected into the already cooled and solidified skin layer. Warpage and distortion occur, and the adhesive strength at the layer interface becomes extremely weak. In addition, there is a problem that the thickness of the skin layer cannot be freely set according to the portion. As a result, in order to guarantee the strength, it was necessary to form the skin layer of the entire product with the maximum thickness, and many materials were used. In addition, there is a problem in equipment that both a blow molding machine and an injection molding machine are required to form the snowboard.

In the latter sandwich molding method, although the bonding strength at the interface is satisfactory, it is difficult to form the skin layer or the core layer to a desired thickness as described above.

JP-A-10-27 using recycled pellets
Also in the 8105 publication, a skin layer is formed by a blow molding method in the same manner as the snowboard molding method described above,
It is configured to inject a recycled material into the hollow portion, and does not mention a method of forming the skin layer to a desired thickness or a method of improving the adhesive strength between the skin layer and the core layer.

[0013]

DISCLOSURE OF THE INVENTION The present invention relates to a multilayer resin molded article: 1) The thickness and shape of a skin layer or a core layer can be freely set. 2) The strength of the multilayer resin molded product can be guaranteed even when a material having low strength is used for the core layer. 3) The material can be molded even when the skin layer is thin and the fluidity of the skin layer resin is low, for example, when a material such as polystyrene or a mixture of polystyrene and PPE is used. 4) A high core layer injection ratio of 30% or more can be achieved. 5) Being able to be molded using a conventional injection molding machine. With the goal.

[0014]

Means for Solving the Problems In order to solve the above-mentioned problems, a molded article, a molding method and a housing of the present invention are as follows: 1) At least a skin layer disposed on one main surface of a core layer is used for injection molding. The structure was provided with either a rib or a thick portion serving as a flow leader. 2) Skin layers provided on both main surfaces of the core layer are connected via a plurality of through holes formed in the core layer. 3) A configuration using a virgin material for the skin layer and a reclaimed material for the core layer. 4) A molding method in which a skin layer is disposed on one main surface and a side surface of the core layer or on the entire peripheral surface of the core layer by injecting the skin layer resin after disposing the core layer in the cavity of the molding die. And 5) A flange was provided on a pair of opposed end surfaces of the molded product, and the molded products were combined to form a housing having at least one main surface.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The first invention of the present invention is a multilayer resin molded product in which at least both main surfaces of a core layer are covered with a skin layer, and at least one of the main surfaces has a skin layer at the time of injection molding. A molded product comprising either a rib or a thick portion serving as a flow leader, wherein skin layers provided on both main surfaces are connected via a plurality of through holes formed in the core layer. By the action of the flow leader and the through hole, the fluidity of the resin constituting the skin layer is improved, and the resin is easily filled. Further, the thickness of the skin layer can be reduced. Further, the rigidity of the multilayer resin molded product is improved by the ribs or thick portions provided on the skin layer. further,
The injection pressure of the skin layer resin can be reduced. Furthermore, a single-sided molding die can be obtained without requiring a plurality of molding dies.

According to a second aspect of the present invention, there is provided a multilayer resin molded product in which a plate is attached to one main surface of a core layer and at least the other main surface of the core layer is covered with a skin layer. It is provided with either a rib or a thick portion that becomes a flow leader at the time of injection molding, and the plate material and the skin layer are connected through a plurality of through holes formed in the core layer. This is a molded article. In addition to the function of the first invention, the fluidity of the skin layer is further improved by eliminating the skin layer on one main surface, and appearance defects such as sink marks and welds are suppressed.

According to a third aspect of the present invention, the plurality of through holes formed in the core layer have a large diameter on the plate material side and a small diameter on the skin layer side, and further, the end surface of the core layer is formed as an inclined surface from the plate material side. The molded article according to the second aspect, wherein the width dimension of the core layer is increased toward the skin layer side, and the peeling of the skin layer and the core layer is further suppressed.

In a fourth aspect, a virgin material is used for the skin layer,
A molded product characterized by using a recycled material for the core layer. The recycled material can be used by compensating physical property deterioration of the recycled material with a virgin material. For example, a recycled material whose Young's modulus is significantly reduced is made into a core layer having a thickness of about 3 mm,
When the skin layer thickness of the virgin material is about 0.3 mm, a bending strength equivalent to about 2.5 mm thickness can be obtained with the virgin material. As a result, the amount of resin used for the skin layer can be reduced and cost can be reduced.

The fifth invention is a molded article using a flame-retardant resin for the skin layer, and uses an inexpensive HB material for the core layer or a recycled material whose flame retardancy is significantly deteriorated. Even if there is, sufficient flame retardancy can be secured.

According to a sixth aspect of the present invention, there is provided a method of molding a multilayer resin molded product, comprising a heat insulating layer provided on a surface of the molding die in contact with the resin. Transmission is suppressed and there is no rapid formation of a solidified layer, so that the molten state of the skin layer resin can be maintained for a long time. As a result, good moldability can be obtained even when the skin layer is as thin as about 0.3 mm.

According to a seventh aspect of the present invention, there is provided a multilayer resin molded product in which a peripheral surface of a core layer is covered with a skin layer, wherein at least one main surface of the skin layer has a rib or a thick portion serving as a flow leader for injection molding. Either one is provided, and the skin layers provided on the both main surfaces are connected by a plurality of through holes formed in the core layer, and a flange portion is provided on a pair of opposed end faces of the core layer. A molded product characterized by the above features, and by combining the molded product with a part of the housing to form a main surface, the resin recycling rate can be improved.

An eighth invention is a multilayer resin molded product in which a plate material is attached to one main surface of a core layer, and at least the other main surface of the core layer is covered with a skin layer. Either a rib or a thick portion serving as a flow leader for injection molding is provided, and the plate material and the skin layer are connected to each other by a plurality of through holes formed in the core layer. It is a molded product characterized by providing a flange portion on the opposite end surface side, by forming the main surface by coupling the molded product to a part of the housing,
The resin recycling rate can be improved.

Hereinafter, a molded product, a molding method, and a housing according to an embodiment of the present invention will be described with reference to the drawings.

(Embodiment 1) FIG. 2 is a bottom view of an example of a molded product according to Embodiment 1 of the present invention, and FIG. 1 is a sectional view of FIG. 2 taken along section line S1-S1. 1 and 2, reference numeral 100 denotes a multilayer resin molded product, 102 denotes a skin layer, 102A denotes a top skin layer, 102B denotes a bottom skin layer, 102C denotes a side skin layer, 103 denotes a core layer,
Reference numeral 104 denotes a through hole, 105 denotes a rib, and 106 denotes a resin injection gate.

The molded article shown in FIGS. 1 and 2 is a multilayer resin molded article 1 in which at least both main surfaces of the core layer 103 are covered with skin layers.
00, wherein at least one of the main surface skin layers has either a rib 105 or a thick portion serving as a flow leader at the time of injection molding, and a plurality of through holes 104 formed in the core layer 103 are formed. The skin layers 102A and 102B disposed on the two main surfaces are connected to each other via an interposition.
The core layer 103 is a substantially uniform plate material.

1 and 2, the core layer 103 has through holes 10 at four positions facing the ribs 105.
4 are drilled. The rib 105 serves as a flow leader. In the initial stage of the injection, the resin member injected from the gate 106 first starts flowing from the left side of the core layer 103, and is sequentially filled in the left side skin layer 102C and the rib 105. Further, the filled resin passes through the four through holes 104 and the top skin layer 102A.
In addition, a right side skin layer 102C is formed.

The multilayer resin molded product 100 shown in FIG.
Core layer 10 having a configuration in which
The resin easily flows over the entire surface (front surface, back surface, and four side surfaces) of No. 3.

FIG. 3 is a sectional view of another molded product according to the first embodiment, FIG. 4 is a plan view of FIG. 3, and FIG. 5 is a bottom view of FIG. 3 to 5, reference numeral 200 denotes a multilayer resin molded product, 202A denotes a top skin layer, 202B denotes a bottom skin layer, 202C denotes a top skin layer, 203 denotes a core layer, 204 denotes a through hole, and 205 denotes a through hole. A rib 206 indicates a gate.

In this case, the position of the resin injection gate 206 of the molded product 200 is different from that of the molded product 100 of FIG. Other configurations are the same. That is, resin injection gates 206 are provided at four locations on the top surface corresponding to the through holes 204 provided in the core layer 203. With this configuration, the core layer 203
The vertical force acting on the main surface (top surface) of the core layer 203 is reduced.
To prevent deformation. Further, the through hole 204 is formed in the core layer 203.
Facilitates filling the front and back surfaces with resin.

The molded articles 100 and 20 shown in the first embodiment
At 0, since the core layer 103 or 203 is formed as a substantially uniform plate material and the skin layer and the rib are formed to cover the surface of the plate material, the resin injection pressure can be reduced. Even if the skin layer is as thin as about 0.3 mm, filling is easy. Furthermore, injection molding is possible with one molding die.
(See below).

(Embodiment 2) FIG. 6 is a sectional view of a molded product according to Embodiment 2 of the present invention, and FIGS. 7 and 8 are a plan view and a bottom view of FIG. FIG. 6 shows a cross-sectional shape of FIG. 8 as viewed from a cutting line S3-S3. 6 to 8, reference numeral 302 denotes a skin layer, 303 denotes a core layer plate, 304 denotes a tapered through hole, 305 denotes a rib, and 306 denotes a gate. The skin layer 302 is made of a top skin layer plate material 3.
02A and a bottom skin layer 302B and a side skin layer 302C which are injection molded.

Further, the top side skin layer 302A and the core layer plate 303 are pre-bonded. The four through holes 304 provided in the core layer plate 303 are formed, for example, on the top side skin layer plate 302.
It has a large diameter on the A side and a small diameter on the bottom skin layer 302B side. The shape of the through hole 304 may be a stepped hole or the like in addition to the tapered shape. Of course,
The hole shape is not limited to a circle, but may be an arbitrary shape such as an ellipse.

Further, the outer peripheral end face of the core layer plate material 303 has such a slope that the outer dimensions are small on the top surface side skin layer plate material 302A side and large on the bottom surface side skin layer 302B side. The shape of the outer peripheral end face may be a stepped shape.

In the present embodiment, the skin material 3
By using 02A, the portions formed by injection molding become the bottom skin layer 302B and the side skin layers 302C on which the ribs 305 are arranged, and the portions (volume) to be injection molded are reduced. As a result, the moldability of the skin layer and the rib portion is improved, and molding defects such as sink marks and welds can be reduced.

The through-hole 304 is formed in the bottom skin layer 302.
B, It functions as a flow leader during the injection molding of the side skin layer 302C. Also, the top side skin layer plate material 302A
And the bottom skin layer 302B. Furthermore, the tapered shape of the through hole 304 and the inclined surface of the outer peripheral end surface of the core layer plate material 303 correspond to the core layer plate material 303 and the bottom skin layer 302.
B and the bonding strength with the side skin layer 302C are improved.

Next, the types of resin members of the skin layer and the core layer in the first and second embodiments will be described. In general,
It is known that the strength and the flame retardancy of a recycled resin material are deteriorated. In order to avoid this, in the multilayer resin molded product 100 of the present invention, the skin layer 102 is molded from a virgin material, and the recycled material is used for the core layer 103. By coating the core layer 103 made of a recycled material with the skin layer 102 made of a virgin material, it becomes possible to compensate for the deterioration of the physical properties of the resin.

For example, when the thickness of the core layer 103 is about 3 mm and the thickness of the skin layer 102 is about 0.3 mm,
A bending strength equivalent to the 2.5 mm thickness of the virgin material can be obtained. That is, even if the skin layer 102 is made as thin as about 0.3 mm, sufficient strength can be guaranteed. As described above, the skin layer thin molding of about 0.3 mm is performed by the core layer 1.
This is made possible by a plurality of through-holes 104 provided on the skin layer 103 and the rib shape 105 provided on at least one of the skin layers 102B.

In the embodiment of the present invention, as another structural example of the resin member, the skin layer 102 is made of a flame-retardant resin. That is, an inexpensive HB material or a recycled material having deteriorated flame retardancy was used for the core layer 103, and the skin layer 102 was made of a virgin flame retardant resin. Further, as another configuration example of the resin member in the present invention, one of polystyrene or a mixture of polystyrene and PPE (polyphenylene ether) is used for the skin layer 102. Polystyrene is inexpensive with high rigidity and high impact properties.

In general, the flowability of a resin to which a flame retardant is added often deteriorates, and it is known that polystyrene and a mixture of polystyrene and PPE (polyphenylene ether) also have low flowability. However, the core layer 10
By the action (flow leader) of the through-hole 104 provided in 3 and the rib 105 provided in the bottom skin layer 102B, the skin layer 102 can be formed thin even with the resin member having low fluidity.

(Embodiment 3) FIG. 9 is a sectional view showing the concept of a method for molding a multilayer resin molded product according to Embodiment 3 of the present invention. In FIG. 9, reference numeral 2 denotes a skin layer resin, 3 denotes a core layer plate, 4 denotes a through hole, 7 denotes a pair of divided molds, 7A denotes a movable side, 7B denotes a fixed side, and 8 denotes a core layer plate. The support pins 9 are core layer plate positioning pins.

The molding step will be briefly described. FIG. 9A shows a state in which the molding die 7 is opened. Injection molding, compression molding,
The core layer plate material 3 prepared in advance by any one of the extrusion molding method and the sheet molding method is disposed in the cavity (fixed side) of the molding die 7. The position of the core layer plate 3 in the two-dimensional direction is regulated by the positioning pins 9. Next, FIG.
As shown in (b), the molding die 7 is brought into a clamped state. At this time, the core layer plate 3 disposed in the cavity of the molding die 7 is held by the core layer support pins 8.
Next, as shown in FIG. 9C, the core layer plate 3 is held at an intermediate position of the cavity so that a skin layer can be formed while opening the molding die 7B, and then the resin member is injected. In this step, a skin layer is formed. In addition, the positioning pin 9 is fitted in the through hole 4, and the resin does not flow into the through hole 4. Finally, as shown in FIG. 9D, the molding die 7B is again clamped to a position where a predetermined skin layer thickness is obtained, and at the same time, the core layer support pins 8 and the positioning pins 9 are formed.
Are drawn to a predetermined position in the molding die 7B. Resin is also injected. By this operation, the resin is filled into the through hole 4 and the hole formed in the skin layer, and a molded product is completed.

The arrangement of the resin injection gate may be arbitrarily implemented by the configuration shown in FIG. 1 or FIG. 4 or by a general method.

As described above, according to the molding method of the present invention, the core layer plate 3 can be held (arranged) at an arbitrary position in the molding die cavity. That is, the thickness of the skin layer can be varied between the front and back surfaces, or can be set to an arbitrary thickness. In addition, the use of the core layer plate material 3 reduces the injection molding pressure.
That is, the thickness of the skin layer can be reduced. Furthermore, there is no need for a special molding machine such as a sandwich injection molding machine,
It can be manufactured by a conventional injection molding machine. One molding die may be used.

FIG. 10 is a sectional view of another multilayer resin molded product using the injection molding method according to the third embodiment. FIG.
In the figure, reference numeral 402 denotes a skin layer, 403 denotes a core layer plate material, 404 denotes a through hole, 405 denotes a rib shape, and 406 denotes a resin injection gate.

In this case, the multilayer resin molded product 400 does not have a shape in which the entire surface of the core layer plate 403 is covered with the skin layer. It is characterized in that the surface of the core layer plate 403 is exposed on the back side of the core layer plate 403 provided with the ribs 405. Since the skin layer is not formed on the back side (bottom side) of the layer resin molded product 400, the core layer plate support pins shown in FIG. 9 are not required for positioning in the cavity.

In the injection molding method of the present invention, the core layer plate material is preheated to about 60 degrees Celsius inside or outside the molding die, and then the resin is injected and molded. When the heated resin is suddenly injected into the core layer at room temperature, the temperature difference between the core layer plate and the skin layer is large, causing problems such as warpage and distortion, and a decrease in the adhesive strength at the interface. The injection molding method in the present invention is to reduce the temperature difference from the resin for forming the skin layer by preheating the core layer sheet material, and to prevent warpage, distortion, and a decrease in adhesive strength at the interface.

In the molding method of the present invention, the temperature of the molding die was set to about 60 ° C. This aims at slowing down the solidification rate of the skin layer, the ribs and the like. The injected resin is deprived of heat on the surface of the mold and is cooled to form a solidified layer. As described above, by setting the temperature of the molding die 7 higher than the conventional die temperature and delaying the formation of the solidified layer, the fluidity of the resin is improved, and the skin layer can be made thinner.

Further, in the molding method of the present invention, a heat insulating layer (not shown) is provided on the surface (cavity side) of the molding die in contact with the resin. The purpose of this is to suppress the heat transfer from the molten resin forming the skin layer to the molding die, thereby delaying the formation of the solidified layer and improving the fluidity of the resin. With this configuration, it is possible to form a thin skin layer.

(Embodiment 4) FIG. 11 is a perspective view of a television receiver housing before assembling according to a fourth embodiment of the present invention, FIG. 12 is an enlarged perspective view of a main part of FIG. 11, and FIG. FIG. 4 shows a perspective view of another housing of the invention before assembly. FIG.
In FIG. 13, reference numeral 1 denotes a multilayer resin molded product manufactured in a separate process in advance, 10 and 20 denote a housing for a television receiver, 1
Reference numeral 1 denotes a flange portion, and 12 denotes a slit.

The housing shown in FIGS. 11 and 13 is characterized in that a multilayer resin molded product is incorporated in a part of the housing, and at least one of the top surface, the bottom surface, and the side surface is formed. The multilayer resin molded product 1 is a multilayer resin molded product in which at least both main surfaces of a core layer are covered with a skin layer, and at least one of the main surfaces has a rib or a thick wall serving as a flow leader during injection molding. A plurality of through-holes formed in the core layer to connect the skin layers disposed on the two main surfaces, and a flange portion 11 is formed on a pair of opposed end surfaces of the molded product. Is provided.

Further, a multi-layer resin molded product in which a plate material is in contact with one main surface of the core layer and at least the other main surface of the core layer is covered with a skin layer, wherein the skin layer is formed by injection molding. Either a rib or a thick portion serving as a flow leader is provided, the plate and the skin layer are connected through a plurality of through holes formed in the core layer, and a pair of opposed end faces of a molded product are provided. It is characterized in that a flange portion 11 is provided on the side.

FIGS. 11 and 12 show an example in which a slit 12 is provided on the bottom surface of the housing 10 and the multilayer resin molded product 1 is inserted into the slit 12 and joined. Screw or glue after insertion,
It is fixed by means such as welding. Of course, a configuration in which the flange portion is press-fitted into the slit may be adopted. FIG. 13 shows the top surface,
Another example of a television receiver housing is shown in which a multilayer resin molded product is inserted and fitted to the bottom surface and both side surfaces, respectively.

With the above configuration, the recycled resin can be easily used for the housing and can be easily expanded to a large-sized housing.

In each of the above embodiments, the molded product is not limited to a flat plate, but may be a member having a curved surface or an arbitrary three-dimensional shape. Further, the housing is not limited to the one for the television receiver. further,
The flange portion 11 provided on the multilayer resin molded product 1 can be formed by using a molding die having a predetermined slide core portion. (Not shown)

[0055]

As described above, according to the present invention, the moldability of a multilayer resin molded product can be improved and a desired skin layer thickness can be formed. In addition, impact resistance, flame retardancy, rigidity, and the like can be maintained.
Further, the adhesive strength between the skin layer and the core layer can be satisfied. Further, the recycled material can be used for a casing of a large-sized television receiver or the like.

[Brief description of the drawings]

FIG. 1 is a sectional view of a molded product according to a first embodiment of the present invention.

FIG. 2 is a bottom view of FIG. 1;

FIG. 3 is a sectional view of another molded product according to the first embodiment of the present invention.

FIG. 4 is a plan view of FIG. 3;

FIG. 5 is a bottom view of FIG. 3;

FIG. 6 is a sectional view of a molded product according to the second embodiment of the present invention.

FIG. 7 is a plan view of FIG. 6;

8 is a bottom view of FIG.

FIG. 9 is a sectional view of a method for molding a multilayer resin molded product according to Embodiment 3 of the present invention.

FIG. 10 is a sectional view of another multilayer resin molded product using the injection molding method of FIG. 9;

FIG. 11 is a perspective view of a television receiver housing before assembling according to a fourth embodiment of the present invention.

FIG. 12 is an enlarged perspective view of a main part of FIG. 11;

FIG. 13 is a perspective view of another housing before assembling according to the fourth embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 multilayer resin molded product 2 skin layer resin 3 core layer plate material 4 through hole 5 rib 6 gate 7A molding die (movable side) 7B molding die (fixed side) 8 core layer material support pin 9 core layer material positioning pin 10, Reference Signs List 20 television receiver housing 11 flange portion 12 slit 100, 200, 300, 400 multilayer resin molded product 102A, 202A top skin layer 102B, 202B, 302B bottom skin layer 102C, 202C, 302C side skin layer 103 , 203 Core layer 104, 204, 304, 404 Through hole 105, 205, 305, 405 Rib 106, 206, 306, 406 Gate 302A Top side skin layer plate 303, 403 Core layer plate 402 Skin layer

Claims (17)

[Claims] 1. A multilayer resin molded product in which at least both main surfaces of a core layer are covered with a skin layer, wherein at least one of the main surface skin layers is a rib or a thick portion serving as a flow leader during injection molding. A molded product comprising: a plurality of through-holes formed in the core layer; and skin layers disposed on the main surfaces are connected to each other through a plurality of through holes formed in the core layer. 2. The molded article according to claim 1, wherein the core layer is a substantially uniform plate material. 3. A multilayer resin molded product in which a plate material is attached to one main surface of a core layer and at least the other main surface of the core layer is covered with a skin layer, wherein the skin layer is formed by injection molding. It is characterized in that the plate member and the skin layer on the one main surface are connected to each other through a plurality of through holes formed in the core layer, provided with either a rib or a thick portion serving as a flow leader. Molding. 4. The molded product according to claim 3, wherein the plurality of through holes formed in the core layer have a large diameter on the plate material side and a small diameter on the skin layer side. 5. The molded product according to claim 4, wherein the end face of the core layer is an inclined surface, and the width dimension of the core layer increases from the plate material side toward the skin layer side. 6. The molded article according to claim 1, wherein a virgin material is used for the skin layer and a recycled material is used for the core layer. 7. The molded article according to claim 6, wherein the skin layer is a flame-retardant resin. 8. The resin material of the skin layer is made of polystyrene or polystyrene and PPE (polyphenylene ether).
The molded article according to claim 6, wherein the mixture is any one of a mixture with the above. 9. A core layer is formed by any one of injection molding, compression molding, extrusion molding, and sheet molding, and the core layer is disposed in a mold, and then a skin layer is formed so as to cover the core layer. The method of molding a multilayer resin molded product according to any one of claims 1 to 8, wherein the resin is injected. 10. The method for molding a multilayer resin molded product according to claim 9, wherein after preheating the core layer, the skin layer resin is injection molded. 11. The method for molding a multilayer resin molded product according to claim 10, wherein the temperature of the molding die is set to 60 ° C. or higher. 12. The method for molding a multilayer resin molded product according to claim 11, wherein a heat insulating layer is provided on a surface of the molding die in contact with the resin. 13. A multilayer resin molded product in which at least both main surfaces of a core layer are covered with a skin layer, wherein at least one of the main surface skin layers is a rib or a thick portion serving as a flow leader during injection molding. And the skin layers disposed on the two main surfaces are connected via a plurality of through holes formed in the core layer, and a flange is provided on a pair of opposed end surfaces of the molded product. Molded product characterized by the following. 14. A plate material is attached to one main surface of the core layer,
A multilayer resin molded product in which at least the other main surface of the core layer is covered with a skin layer, wherein the skin layer includes one of a rib or a thick portion serving as a flow leader during injection molding, and the core A molded product, wherein the plate material and the skin layer are connected through a plurality of through holes formed in the layer, and a flange portion is provided on a pair of opposed end surfaces of the molded product. 15. A casing, wherein the molded article according to claim 13 is combined to form at least one main surface. 16. The housing according to claim 15, wherein the main surface is any one of a top surface, a bottom surface, and a side surface. 17. A step of arranging a core layer prepared beforehand in an opened mold, clamping the mold, holding the core layer at an intermediate position of the mold cavity, and injecting a resin member. Process and again until the position where the skin layer thickness is obtained,
And clamping the resin member into the recessed holes of the core layer support pins and the positioning pins.