JP6984843B2 - A method for manufacturing a foam molded product made of different types of foam molded resin members. - Google Patents

Description

The present invention relates to a foam molded product molded in one molding mold, and the present invention relates to a method for producing a foam molded product made of different types of foam molded resin members.

Conventionally, foam moldings have been widely used for packaging materials, fish boxes, building materials for heat insulation, etc., but recently, attention has been paid to lightness, sound absorption, strength characteristics, etc., for example, bumper core materials for automobiles and floors. It has also come to be used for materials. However, when applied to automobile parts, the shape is complicated, and the entire part is not uniformly molded with one material, for example, a high-density foam-molded resin member and a low-density foam-molded resin. In some cases, a foam-molded body made of a different type of foam-molded resin member combined with the member has been required.

Therefore, as shown in Patent Document 1, a bumper core material in which foam-molded resin members having different densities are alternately provided has been proposed. However, in the present invention, foam molded resin members having different densities are separately molded, and these are joined and integrated using an adhesive, which complicates the molding process and makes it difficult to keep the quality constant. There was a problem.

On the other hand, two partition plates and comb-shaped partition members that can move forward and backward are provided in the molding die, and each section is filled with effervescent raw material beads having different expansion ratios, and then the partition members are retracted and then heated. A molding method for integrally molding a foam-molded body made of different types of foam-molded resin members has been proposed (see, for example, Patent Document 2 and Patent Document 3). However, these inventions have a problem that the molding mold becomes complicated and a problem that the adhesive strength of the joint surface of different types of foam molded resin members is not sufficient. Furthermore, the use of a foam-molded resin member having air permeability is not considered, and effects such as soundproofing, sound absorbing property, hygroscopic property, and heat retaining property cannot be obtained.

Jikkenhei 6-12221 Gazette Japanese Patent No. 5219521 Japanese Patent No. 5104243

The present invention solves the above-mentioned conventional problems and can be molded in one molding mold, and can sufficiently increase the bonding strength of the joint surfaces of different types of foam molded resin members. Furthermore, it is possible to combine and integrate a foam-molded resin member having breathability and a foam-molded resin member having no breathability, and exhibit soundproofing, sound-absorbing, moisture-absorbing, heat-retaining properties, etc. It is an object of the present invention to provide a method for producing a foam molded product made of different types of foam molded resin members.

The method for manufacturing a foam molded product made of different types of foam molded resin members of the present invention, which has been made to solve the above problems, is a manufacturing method for molding a foam molded product made of different types of foam molded resin members in one molding mold. The inside of one molding die is divided into a molding cavity of one foam molding resin member and a molding cavity of the other foam molding resin member, and one foam molding resin member is used for one molding. After molding in the cavity, the end of the one foam molding resin member in contact with the boundary between the two molding cavities is heated and melted to form a molten layer, and then the other foamable raw material bead is placed in the other molding cavity. A foam molded product made of different types of foam-molded resin members, characterized in that the other foamable raw material beads are mixed with the molten layer to form a mixed layer in which both are melted and solidified by supplying and heat-molding. This is the manufacturing method of the above, and this is the invention according to claim 1.

In the invention according to claim 1, it can be molded in one molding mold, the bonding strength of the joint surfaces of different types of foam molded resin members can be sufficiently large, and it has air permeability. From different types of foam-molded resin members that can be integrated by combining a foam-molded resin member and a non-breathable foam-molded resin member, and can also exhibit soundproofing, sound-absorbing, moisture-absorbing, heat-retaining properties, etc. Can provide a method for producing a foam molded article.

It is a front sectional view which shows an example of the foam molded article manufactured by this invention. It is a top sectional view which shows an example of the foam molded article manufactured by this invention. It is explanatory drawing which shows the manufacturing method of the foam molded body which concerns on this invention. It is explanatory drawing which shows the manufacturing method of the foam molded article which concerns on this invention. It is explanatory drawing which shows the manufacturing method of the foam molded article which concerns on this invention.

Hereinafter, preferred embodiments of the present invention are shown with reference to the drawings.
The drawings show, as an example, a case where the present invention is applied to a foamed molded body for a floor spacer for an automobile. FIG. 1 is a front sectional view and FIG. 2 is a plan sectional view.
This automobile floor spacer is used by interposing it between the floor surface of the body frame and the floor mat laid on the floor surface, and has predetermined mechanical strength, soundproofing property, and sound absorbing property. Etc. are required.

Conventionally, it is known that different types of foam molded resin members having different foaming ratios are separately molded for the purpose of obtaining different characteristics, and these are joined and integrated using an adhesive. Further, as shown in Patent Document 2 and Patent Document 3, a method of molding two types of foam-molded resin members having no air permeability in one molding mold is also known. However, there has been no proposal for a product in which different types of foam-molded resin members having breathability and different types of foam-molded resin members having no breathability are integrally molded in one molding mold, and a method for manufacturing the same.
On the other hand, in the foam-molded body made of different types of foam-molded resin members of the present invention, the two resins are mixed at the joint end between the foam-molded resin member having breathability and the foam-molded resin member having no breathability. It is characterized by being integrated via a mixed layer that has been melted and solidified, and is a new product that has never existed before.

The breathable foam-molded resin member 31 is formed so that raw material beads made of foamed particles are point-fused together so as to have voids between the foamed particles. That is, it has three-dimensional fine pores formed by connecting spaces surrounded by at least three foam cells, and forms fine passages inside to have air permeability. It should be noted that these three-dimensional fine pores have a complicated spatial path in which they are branched into many branches and meander in a zigzag manner, and the inner diameter of the pores repeats expansion and contraction irregularly. It is possible to exert excellent soundproofing and sound absorbing properties by exerting an attenuation effect such as interference.

Further, the foam-molded resin member 32 having no air permeability is formed so that the raw material beads made of foam particles are fused to each other on substantially the entire surface, and does not have air permeability to circulate gas, vapor, or the like. It is a thing. The foam-molded resin member 32 having no breathability can exhibit excellent lightness and mechanical strength.

The breathable foam-molded resin member 31 and the non-breathable foam-molded resin member 32 are made of a thermoplastic resin. Specifically, it is made of a polystyrene-based resin, a polyethylene-based resin, a polypropylene-based resin, a polyolefin-based resin, or the like. Alternatively, the resin may consist of a mixture of two or more of these resins. Further, it is possible to select arbitrary beads having different foaming ratios, colors, bead diameters, etc. of the raw material beads. From the viewpoint of moldability, mechanical strength, fusion property and the like, polystyrene-based resin, polyethylene-based resin, or a mixed resin thereof is particularly preferable.
Further, the type, expansion ratio, particle size and the like of the raw material beads can be appropriately selected according to the type of the foamed molded product to be molded, the purpose of use, the place of use and the like.

The air permeability of the non-breathable foam molded resin member 32 (the ratio of the three-dimensional fine pores to the total volume of the foam molded body excluding the pores in the foam cell) is less than 5%, and the air permeability is low. The air permeability of the foam-molded resin member 31 having the above is preferably 10 to 40%. This is because if the air permeability of the foam molded resin member 32 having no air permeability is 5% or more, it cannot be said that the foam molded resin member 32 does not have air permeability. Further, if the air permeability of the foam molded resin member 31 having air permeability is less than 10%, it cannot be said that it has sufficient air permeability, while if it is more than 40%, the strength of the molded product is weakened.
As described above, by forming a molded body made of different types of foam molded resin members, the present invention can provide a complex that exhibits the characteristics of each foamed member and exerts a plurality of unprecedented effects. ..

The joint end between the breathable foam-molded resin member 31 and the non-breathable foam-molded resin member 32 has a structure integrated via a mixed layer in which both resins are mixed and melted / solidified. It has become. The term "mixed, melted and solidified" as used herein means a state in which the melt of the foam molding resin having air permeability and the melt of the foam molding resin having no air permeability are mixed and melted and solidified, and the air permeability. A state in which the melt of the foam-molded resin having the above and the raw beads of the foam-molded resin having no breathability are mixed and melted / solidified, and the raw beads of the foam-molded resin having the breathability and the breathability. It refers to a state in which melted foam molded resin that does not exist is mixed and melted / solidified.
As a result, the mixed layer 33 is formed by mixing a foam molding resin having breathability and a foam molding resin having no breathability to be melted and solidified, and only the surface is melted and bonded. The structure can be more firmly connected than the other.

Further, as shown in FIG. 2, the mixed layer 33 is preferably configured to have an uneven shape in a plan view. By increasing the distance between the adhesive surfaces, the foam-molded resin member 31 having breathability and the foam-molded resin member 32 having no breathability can be more firmly bonded and integrated.
In the figure, the uneven shape is a simple one with one concave portion and a convex portion, but it may be a plurality of uneven portions, or it may be an uneven shape such as a corrugated shape or a saw blade type, and the distance between the adhesive surfaces is long. Any shape can be adopted.

The mixed layer 33 is, for example, heated and melted in a chamber provided with a joint end portion after molding of the foam molding resin member 31 having breathability, and then heated after supplying foamable raw material beads having no breathability. By molding, both resins are mixed to form a melt-solidified mixed layer, and conversely, after molding of the foam-molded resin member 32 having no air permeability, the joint end portion is heated and melted in a chamber. Then, by feeding and then heat-molding the effervescent raw material beads having air permeability, both resins can be mixed to form a melt-solidified mixed layer.
Alternatively, after molding the foam-molded resin member 31 having breathability, the foamable raw material beads having no breathability are supplied, and then the mixed layer in which both resins are mixed and melt-solidified at the time of heat molding is formed. After forming the foam-molded resin member 32 having no air permeability, the foam-molded raw material beads having air permeability are supplied, and then both resins are mixed and melted during heat molding. A solidified mixed layer can be formed, and any method can be selected depending on the type, shape, application, etc. of the foam molded product to be molded.

Next, an example of a method for manufacturing a foam molded product made of different types of foam molded resin members of the present invention will be briefly described.
3 to 5 are explanatory views showing an example of a method for manufacturing a foam molded product according to the present invention. In the figure, 1 is a convex mold which is a mobile molding mold, 2 is a concave mold which is a fixed molding mold, 3 is a moving die plate, 4 is a fixed die plate, and 5 and 6 are chambers formed on the back surface of the uneven mold. .. In the illustrated molding die, the molding cavity formed by the concave-convex mold is separated by a pair of movable chambers 7a and 7b that are movable in the direction perpendicular to the mold and are separable, and one of them has air permeability. The molding cavity 8a of the foam-molded resin member and the other are the molding cavities 8b of the foam-molded resin member having no air permeability.
9a and 9b are cylinders for moving the movable chambers 7a and 7b, and 10a and 10b are fillers for supplying effervescent raw material beads into the molding cavities 8a and 8b.

As shown in FIG. 3, the movable chambers 7a and 7b are closed and the cavity is divided into left and right. After filling the raw material beads, the cavity 8a is heat-treated to form a foam molding resin member having air permeability.
Next, as shown in FIG. 4, a heating fluid is supplied into the movable chamber 7a, and the heating fluid is ejected from a hole provided on the surface of the movable chamber 7a to eject an end portion of the foam-molded resin member to be joined. Is locally heated and melted.

Next, as shown in FIG. 5, the movable chambers 7a and 7b are retracted from the inside of the cavity so as to be flush with the cavity surface. After that, the foamable raw material beads are filled in the molding cavity 8b of the non-breathable foam-molded resin member with the filler 10b, and then the cavity 8b is heat-treated to obtain the non-breathable foam-molded resin member. Mold. At this time, the raw material beads are mixed with the heat-melted molten layer to form a mixed layer 33 in which both are melted and solidified. As a result, the foam-molded resin member 31 having breathability and the foam-molded resin member 32 having no breathability are connected by the mixed layer 3 to form a strongly integrated molded product.

In the figure, 21a is a service supply pipe for supplying a heating fluid to the chamber 5, 21b is a service discharge pipe for discharging drain and air from the chamber 5, and 22a is a service supply pipe for supplying the heating fluid to the chamber 6. The pipe 22b is a utility discharge pipe for discharging drain and air from the chamber 6.
Further, 23a is a service supply pipe for supplying a heating fluid to the movable chamber 7a, 23b is a service discharge pipe for discharging drain and air from the movable chamber 7a, and 24a is a service for supplying the heating fluid to the movable chamber 7b. The supply pipe and 24b are utility discharge pipes for discharging drain and air from the movable chamber 7b.
Further, 25a is a service supply pipe for supplying a heating fluid to the cavity 8b, and 25b is a service discharge pipe for discharging air and drain generated through the cavity 8b.

The foam-molded body obtained by this manufacturing method is continuously molded in one molding mold, and the foam-molded resin member 31 having breathability and the foam-molded resin member 32 having no breathability are formed. The joint end has a structure in which both resins are mixed and integrated via a mixed layer 33 that is melted and solidified. Further, the mixed layer 33 is formed by heating and melting with the heating steam supplied to the movable chamber 7a for molding the joint surface after molding the foam molding resin member 31 having air permeability, and is formed in one molding mold. The mixed layer 33 can be molded in a series with the above, and it is made of different types of foam molded resin members efficiently and with high quality, unlike the conventional case where separately molded ones are joined and integrated using an adhesive. It becomes possible to manufacture a foam molded product.

As is clear from the above description, the present invention molds a foam-molded body made of different types of foam-molded resin members, which are a foam-molded resin member having a temper and a foam-molded resin member having no air permeability. It is intended to provide a foam molded article having a new structure that can be continuously molded in a mold and can exhibit excellent soundproofing property, sound absorbing property, moisture absorbing property, heat retaining property and the like. As a result, it becomes possible to provide a foam molded product having a new structure as a building material such as an automobile part such as a bumper core material or a floor material.

1 Convex 2 Concave 3 Moving die plate 4 Fixed die plate 5 Chamber 6 Chamber 7a Movable chamber 7b Movable chamber 8a Molding cavity 8b Molding cavity 9a Cylinder 9b Cylinder
10a Filler
10b Filler
21a service supply pipe
21b Utility discharge pipe
22a Service supply pipe
22b Utility discharge pipe
23a Service supply pipe
23b Utility discharge pipe
24a service supply pipe
24b Utility discharge pipe
25a service supply pipe
25b Utility discharge pipe 31 Breathable foam molded resin member 32 Non-breathable foam molded resin member 33 Mixed layer

Claims (1)

It is a manufacturing method in which a foam molded body made of different types of foam molded resin members is molded in one molding mold, and the inside of one molding mold is a molding cavity of one foam molding resin member and the other foam molding resin member. After molding one foam molding resin member in one molding cavity, the end portion of the one foam molding resin member in contact with the boundary between the two molding cavities is heated and melted. Then, the other effervescent raw material beads are supplied to the other molding cavity and heat-molded, so that the other effervescent raw material beads are mixed with the molten layer and both are melted and solidified. A method for producing a foam-molded article made of different types of foam-molded resin members, which comprises forming a mixed layer.

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