JP2004209917A - Composite molded piece and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low-cost composite molded piece excellent in strength and easy in manufacturing, and its manufacturing method. <P>SOLUTION: This composite molded piece 1 is made of a sheet molding compound molded body 2 and a foamed layer 3 arranged on one side of the sheet molding compound molded body 2. The sheet molding compound molded body 2 and the foamed layer 3 are bonded together through heat sealing. In order to manufacture this composite molded piece 1, a side facing the sheet molding compound molded body 2 is covered by a mold so as to charge prefoamed resin particles in a cavity formed between the mold and the sheet molding compound molded body 2 in order to introduce steam in the cavity for foaming and sealing the prefoamed resin particles under heat and, at the same time, heat-sealing to the sheet molding compound molded body 2. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
【Technical field】
The present invention relates to a composite molded article comprising a sheet molding compound molded body and a foamed layer, and a method for producing the same.
[0002]
[Prior art]
Conventionally, a composite member made of a foam molded body and a sheet molding compound molded body has been used in a bathtub of a unit bath (see Patent Document 1). By the way, the composite member which consists of a sheet molding compound molded object and a foaming molded object conventionally has bonded both molded objects with the adhesive agent.
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 6-143
[Problems to be solved]
However, as described above, in the conventional composite member, since the sheet molding compound molded body and the foam molded body are bonded with an adhesive, both molded bodies are bonded to each other only at the portion where the adhesive is applied. However, the strength is weak because the gap remains in other parts.
Therefore, in order to secure the adhesive strength between the sheet molding compound molded body and the foam molded body, it is necessary to apply a wide adhesive to the joint surfaces.
However, such a ceiling material, a flooring material, and a bathtub having a large joint area have problems that it takes time to apply the adhesive and the raw material cost is high.
[0005]
The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a composite molded article excellent in strength, easy to manufacture and inexpensive, and a manufacturing method thereof.
[0006]
[Means for solving problems]
The first invention is a composite molded article comprising a sheet molding compound molded body and a foam layer disposed on one side of the sheet molding compound molded body,
The sheet molding compound molded body and the foamed layer are bonded to each other by heat-sealing (Claim 1).
[0007]
Next, the effects of the present invention will be described.
Since the sheet molding compound molded body and the foamed layer are bonded by thermal fusion, the entire joint surface of both can be easily bonded. Therefore, it is possible to secure a bonding strength between the sheet molding compound molded body and the foamed layer and obtain a composite molded product having excellent strength.
Further, it is not necessary to use an adhesive, and no adhesive application work is required. Therefore, the raw material cost and the production cost can be reduced, and the manufacturing can be facilitated and the manufacturing period can be shortened.
[0008]
As described above, according to the present invention, it is possible to provide a composite molded product that is excellent in strength, easy to manufacture, and inexpensive.
[0009]
A second invention forms a sheet molding compound molded body using a mold, holds the sheet molding compound molded body with a shape holding jig, and forms a foam layer on the side facing the sheet molding compound molded body. Coating mold for
Next, pre-expanded resin particles are injected into a cavity formed between the mold and the sheet molding compound molded body, and then water is introduced into the cavity to heat the pre-expanded resin particles. The pre-foamed resin particles are foamed and fused together by heat fusion with the sheet molding compound molded body to obtain a composite molded product formed by adhering a foam layer to one side of the sheet molding compound molded body. It is in the manufacturing method of the composite molded article characterized by the above (Claim 5).
[0010]
In this production method, the pre-foamed resin particles are heated in the cavity to foam and fuse them, and to heat-seal the sheet molding compound molded body. Thereby, a foaming layer is adhere | attached on the single side | surface of this sheet | seat molding compound molded object. Therefore, it is possible to easily bond the substantially entire surface of the joint surface between the two. As a result, the bonding strength between the sheet molding compound molded body and the foamed layer can be secured, and a composite molded product having excellent strength can be manufactured.
In addition, since it is not necessary to use an adhesive for bonding the sheet molding compound molded body and the foamed layer, the raw material cost and the production cost can be reduced as described above, and the manufacturing can be facilitated and the manufacturing period can be shortened. .
[0011]
As described above, according to the present invention, it is possible to provide a method for manufacturing a composite molded article that is excellent in strength, easy to manufacture, and inexpensive.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
In the first invention (invention 1), the sheet molding compound molded body is a sheet molding compound molded, and the sheet molding compound is a sheet-shaped sheet mainly formed by impregnating a resin with a reinforcing material. A material, generally referred to as SMC.
[0013]
The fiber content in the sheet molding compound molded body is preferably 5 to 70% by weight. When the content is less than 5% by weight, it may be difficult to ensure sufficient strength of the sheet molding compound molded body. On the other hand, when the content exceeds 70% by weight, the resin is not sufficiently cured, and it may be difficult to obtain a uniform molded body.
The content is more preferably 40 to 70% by weight.
[0014]
Examples of the foamed layer include those formed by foaming a foamable thermoplastic resin.
The composite molded product is used, for example, as a bathtub in a unit bath, a ceiling material, a floor material, a wall material, or a water receiving tank installed outdoors.
[0015]
The sheet molding compound molded body preferably contains an unsaturated polyester resin.
In this case, it is easy to adjust the viscosity and the curing time, and an inexpensive sheet molding compound molded body can be obtained.
The thermosetting resin contained in the sheet molding compound molded body may be an epoxy resin, a phenol resin, a urethane resin, or the like. Further, in consideration of the size, shape, durability, etc. of the sheet molding compound to be obtained, a vinyl ester resin can be used in combination.
[0016]
Moreover, it is preferable that the said sheet molding compound molded object contains one or both of glass fiber and organic fiber (Claim 3).
In this case, the strength of the sheet molding compound molded body can be improved with an inexpensive material.
Examples of the organic fiber include vinylon fiber, polyester fiber, phenol fiber, and carbon fiber.
[0017]
Moreover, when the said fiber is glass fiber, it is preferable that the length is 3-50 mm. If the length is less than 3 mm, it may be difficult to sufficiently improve the strength of the sheet molding compound molded body. On the other hand, when the length exceeds 50 mm, the fibers do not fully enter the gap of 50 mm or less, and molding may be difficult.
Further, the length of the glass fiber is more preferably 6 to 25 mm.
Moreover, the said sheet molding compound molded object can also be obtained using the said glass fiber and the chopped mat of organic fiber, a woven fabric, or a nonwoven fabric.
[0018]
The foamed layer is preferably made of a styrene resin.
In this case, there is an advantage of heat bonding with the polyester resin.
Examples of the styrenic resin include expanded polystyrene, expanded high impact polystyrene, expanded ABS, and expanded polyethylene-styrene copolymer resin.
[0019]
Next, in the second invention (invention 5), the shape holding jig is a jig for holding the shape of the sheet molding compound molded body and attaching it to the foam layer forming mold. As the shape holding jig, for example, one having a shape that can be detachably mounted in the recess of the sheet molding compound molded body is used. The shape holding jig is made of a material such as metal or resin.
[0020]
The pre-expanded resin particles are preferably injected in a state where the sheet molding compound molded body is at 100 ° C. or higher.
In this case, the pre-expanded resin particles are more easily heat-sealed to the sheet molding compound molded body. Thereby, the adhesive strength of a sheet molding compound molded object and a foamed layer can be improved.
Examples of the material of the pre-expanded resin particles include the styrene resin.
[0021]
Further, it is preferable that the sheet molding compound molded body is held by the shape holding jig in a state where the sheet molding compound molded body is taken out from the mold and heat during molding remains. .
In this case, when the pre-expanded resin particles introduced into the cavity are heated, heat at the time of molding the sheet molding compound molded body can be used. Therefore, it is possible to reduce the amount of heat to be given from the outside by water vapor and to save energy. In addition, this can reduce the manufacturing cost of the composite molded product and improve the production efficiency.
[0022]
Moreover, it is preferable that a hollow portion is formed between the shape maintaining jig and the sheet molding compound molded body so that the two do not contact each other.
In this case, the heat of the water vapor introduced into the cavity can be suppressed from being taken away by the shape holding jig. As a result, the thermal fusion between the sheet molding compound molded body and the foamed layer is sufficiently advanced, and the adhesive strength between the two can be improved.
[0023]
【Example】
A composite molded article and a manufacturing method thereof according to an embodiment of the present invention will be described with reference to FIGS.
As shown in FIGS. 1 to 3, the composite molded product 1 includes a sheet molding compound molded body 2 and a foamed layer 3 disposed on one surface of the sheet molding compound molded body 2.
The sheet molding compound molded body 2 and the foam layer 3 are bonded together by heat sealing.
[0024]
The sheet molding compound molded body 2 contains an unsaturated polyester resin and glass fibers. The length of the glass fiber is 6 to 25 mm, and the content of the glass fiber in the sheet molding compound molded body is 40 to 70% by weight.
The foam layer 3 is made of a styrene resin, specifically, expanded polystyrene.
The composite molded product 1 of this example is a bathtub of a unit bath as shown in FIG. 1, the foamed layer 3 is disposed on the outer periphery of the sheet molding compound molded body 2, and the joint surface 11 of both is heated. It is fused.
[0025]
Next, the manufacturing method of the composite molded product 1 of this example will be described.
That is, first, as shown in FIGS. 4 and 5, the sheet molding compound molded body 2 is molded using the mold 4.
Then, as shown in FIG. 6, the sheet molding compound molded body 2 is held by the shape holding jig 5, and as shown in FIG. 7, a foam layer forming molding is formed on the side facing the sheet molding compound molded body 2. Cover the mold 6.
[0026]
Next, the prefoamed resin particles 31 are injected into a cavity 61 formed between the mold 6 and the sheet molding compound molded body 2.
Thereafter, water vapor is introduced into the cavity 61 to heat the pre-foamed resin particles 31 so that the pre-foamed resin particles 31 are foamed and fused together with the sheet molding compound molded body 2 ( FIG. 3).
Thereby, as shown in FIGS. 1-3, the bathtub as the composite molded product 1 formed by adhere | attaching the foam layer 3 on the single side | surface of the sheet molding compound molded object 2 is obtained.
[0027]
This will be described in detail below.
Specifically, as shown in FIG. 3, the foamed layer 3 is formed by fusing the foamed resin particles 310 obtained by foaming the pre-foamed resin particles 31 to each other. The foamed resin particles 310 in contact with the sheet molding compound molded body 2 are heat-sealed with the sheet molding compound molded body 2.
[0028]
As shown in FIGS. 4 and 5, the mold 4 for molding the sheet molding compound molded body 2 includes an upper mold 41 having a concave mold surface 411 and a lower mold 42 having a convex mold surface 421. .
And the laminated body 20 which piled up the sheet-like sheet molding compound 20 several sheets is arrange | positioned between the said lower mold | type 42 and the upper mold | type 41, and it shape | molds in the said bathtub shape by clamping. The mold temperature at this time is about 130 ° C., and the mold clamping pressure is about 60 kg / cm ² . The sheet molding compound molded body 2 is heat-cured for 5 minutes while being clamped. Thereafter, the sheet molding compound molded body 2 is taken out from the mold 4 and moved to the shape holding jig 5 and held as shown in FIG.
The shape holding jig 5 is a convex body having a size that can be fitted into the opening of the sheet molding compound molded body 2 and is made of metal.
[0029]
The temperature of the sheet molding compound molded body 2 at this time is about 130 ° C. which is substantially the same as that of the mold 4. That is, the sheet molding compound molded body 2 is held by the shape holding jig 5 in a state where the sheet molding compound molded body 2 is taken out from the mold 4 and heat during molding remains.
[0030]
Next, as shown in FIG. 7, the foaming layer forming mold 6 is covered and fixed from above the sheet molding compound molded body 2 held by the shape holding jig 5. The mold wall 611 of the mold 6 is formed in a concave shape, and when the mold 6 is disposed from above the sheet molding compound molded body 2, the sheet wall 611 is interposed between the sheet molding compound molded body 2 and the mold wall 611. A cavity 61 for forming the foam layer 3 is formed.
[0031]
As shown in FIG. 6, the shape holding jig 5 has a convex portion 52 having a shape along the opening 21 of the sheet molding compound molded body 2. The convex portion 52 is formed lower than the depth of the concave portion 22 of the sheet molding compound molded body 2. Thereby, when the sheet molding compound molded body 2 is held by the shape holding jig 5, the convex portion 52 is fitted into the opening 21. A cavity 51 is formed between the recess 22 and the shape holding jig 5.
[0032]
The mold 6 has a chamber 62 for introducing water vapor therein. A large number of vapor holes 63 are formed in the mold wall 611 of the cavity 61. In addition, a steam introduction pipe 641, a cooling water introduction pipe 642, and a cooling water discharge pipe 643 are connected to the chamber 62, respectively. In addition, an air introduction pipe 644 is connected to the steam introduction pipe 641, and a suction pipe 645 for evacuation is connected to the cooling water discharge pipe 643. Each of these pipes is provided with an open / close valve 649 that can be freely opened and closed.
[0033]
The mold wall 611 is connected to a filling gun 65 for filling the pre-expanded resin particles 31 into the cavity 61.
In addition, a cavity 51 is formed between the shape holding jig 5 and the sheet molding compound molded body 2 so that they do not come into contact with each other.
[0034]
Injecting the pre-expanded resin particles 31 into the cavity 61 is performed in a state where the sheet molding compound molded body 2 is 100 ° C. or higher. The pre-expanded resin particles 31 are filled through the filling gun 65 with air having a pressure of 5 kg / cm ² .
[0035]
Next, in forming the foamed layer 3, water vapor is introduced into the chamber 62 from the steam introduction pipe 641, and is sent into the prefoamed resin particles 31 in the cavity 61 from the vapor hole 63. The pressure of water vapor is 1.0 kg / cm ² G.
Thereby, the pre-foamed resin particles 31 in the cavity 61 are heated, foamed, and fused together. At the same time, as shown in FIG. 3, the pre-foamed resin particles 31 located on the contact surface with the sheet molding compound molded body 2 and the sheet molding compound molded body 2 are thermally fused. Thereby, the foamed layer 3 is formed.
[0036]
Next, cooling water is introduced into the chamber 62 from the cooling water introduction pipe 642 to cool the foam layer 3 and the sheet molding compound molded body 2.
Next, the mold is opened to obtain the composite molded product 1 shown in FIGS.
[0037]
Next, the effect of this example will be described.
Since the sheet molding compound molded body 2 and the foamed layer 3 are bonded by thermal fusion, the entire joint surface 11 of both can be easily bonded. Therefore, it is possible to secure the bonding strength between the sheet molding compound molded body 2 and the foamed layer 3 and obtain the composite molded product 1 having excellent strength.
Further, it is not necessary to use an adhesive, and no adhesive application work is required. Therefore, the raw material cost and the production cost can be reduced, and the manufacturing can be facilitated and the manufacturing period can be shortened.
[0038]
Moreover, since the said sheet molding compound molded object 2 contains unsaturated polyester resin, adjustment of a viscosity and adjustment of hardening time are easy, and it is cheap.
Moreover, since the said sheet molding compound molded object 2 contains glass fiber, there exists an advantage that intensity | strength is high.
[0039]
In addition, since the injection of the pre-expanded resin particles 31 is performed in a state where the sheet molding compound molded body 2 is 100 ° C. or higher, the pre-expanded resin particles 31 are further thermally fused to the sheet molding compound molded body 2. It becomes easy. Thereby, the adhesive strength between the sheet molding compound molded body 2 and the foamed layer 3 can be improved.
[0040]
The sheet molding compound molded body 2 is held by the shape holding jig 5 in a state in which the sheet molding compound molded body 2 is taken out from the mold 4 and heat during molding remains. As a result, when the pre-expanded resin particles 31 introduced into the cavity 61 are heated, the heat at the time of molding the sheet molding compound molded body 2 can be used, so that the amount of heat to be given by water vapor from the outside is reduced. be able to. Therefore, the manufacturing cost of the composite molded product 1 can be reduced.
Further, since the sheet molding compound molded body 2 is immediately held by the shape holding jig 5 after being taken out from the mold 4, it is not deformed or contracted.
[0041]
In addition, a cavity 51 is formed between the shape holding jig 5 and the sheet molding compound molded body 2 so that they do not come into contact with each other. In this case, the heat of the water vapor introduced into the cavity 61 can be suppressed from being taken away by the shape holding jig 5. Therefore, the heat fusion between the sheet molding compound molded body 2 and the foamed layer 3 is sufficiently advanced, and the adhesive strength between the two can be improved.
[0042]
As described above, according to this example, it is possible to provide a composite molded article excellent in strength, easy to manufacture and inexpensive, and a manufacturing method thereof.
[Brief description of the drawings]
FIG. 1 is a perspective view of a composite molded product in an embodiment.
2 is a cross-sectional view taken along line AA in FIG.
FIG. 3 is a partially enlarged cross-sectional view of a sheet molding compound molded body and a foamed layer in an example.
FIG. 4 is an explanatory view of a molding method of a sheet molding compound molded body in an example.
FIG. 5 is an explanatory diagram of a molding method for the sheet molding compound molded body, continued from FIG. 4;
FIG. 6 is an explanatory view of a sheet molding compound molded body held by a shape holding jig in the embodiment.
FIG. 7 is an explanatory diagram of a method for forming a foam layer in an example.
[Explanation of symbols]
1. . . Composite molded products,
2. . . Sheet molding compound molded body,
3. . . Foam layer,
4). . . Mold,
5. . . Shape retention jig,
6). . . Mold,

Claims (8)

A composite molded article comprising a sheet molding compound molded body and a foam layer disposed on one side of the sheet molding compound molded body,
A composite molded article, wherein the sheet molding compound molded body and the foamed layer are bonded together by heat fusion. The composite molded article according to claim 1, wherein the sheet molding compound molded body contains an unsaturated polyester resin. 3. The composite molded product according to claim 1, wherein the sheet molding compound molded body contains one or both of glass fiber and organic fiber. The composite molded article according to any one of claims 1 to 3, wherein the foamed layer is made of a styrene resin. A sheet molding compound molded body is molded using a mold, the sheet molding compound molded body is held by a shape-holding jig, and a mold for forming a foam layer is coated on the side facing the sheet molding compound molded body. And
Next, pre-expanded resin particles are injected into a cavity formed between the mold and the sheet molding compound molded body, and then water is introduced into the cavity to heat the pre-expanded resin particles. The pre-foamed resin particles are foamed and fused together with the sheet molding compound molded body, and a composite molded product is obtained by bonding a foamed layer to one side of the sheet molding compound molded body. A method for producing a composite molded product. 6. The method of manufacturing a composite molded product according to claim 5, wherein the injection of the pre-expanded resin particles is performed in a state where the sheet molding compound molded body is at a temperature of 100 ° C. or higher. The sheet molding compound molded body is held by the shape holding jig according to claim 5 or 6 in a state in which the sheet molding compound molded body is taken out of a mold and heat during molding remains. A method for producing a composite molded product. The composite material according to any one of claims 5 to 7, wherein a cavity portion is formed between a part of the shape maintaining jig and the sheet molding compound molded body so as not to contact both of them. Manufacturing method of molded products.

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