JPH0788855A - Integrated molding method for foamed synthetic resin molded products - Google Patents

Abstract

(57) [Summary] [Purpose] A sealant for surely preventing leakage of the foamed synthetic resin material from the joint between the insert material and the skin material,
(EN) Provided is a method for integrally molding a foamed synthetic resin molded article which can be provided in the foaming molding step of a production line and does not complicate the molding article manufacturing step. [Structure] The insert material 18 and the skin material 17 are attached to the molding die 10.
When the foamed synthetic resin material 30 is injected and integrally molded, the sealing agent 20 having viscoelasticity is provided at the portion 19 to be joined with the insert material in the skin material arranged in the molding die.
Is applied in a string or strip shape, an insert material is overlaid on the skin material via the sealant, and a foamed synthetic resin material is foamed between the skin material and the insert.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for integrally molding a foamed synthetic resin molded article.

[0002]

2. Description of the Related Art Foamed synthetic resin moldings often used for automobile interior parts such as automobile instrument panels and door trims are generally composed of a skin material, a foamed body and a core material. In such a foamed synthetic resin molded article, an insert material is arranged on the mold surface of the upper mold and a skin material is arranged on the mold surface of the lower mold, and a urethane foam raw material or the like is foamed between the insert material and the skin material. It is manufactured by foaming a synthetic resin material and integrally forming a foam with the insert material and the skin material.

Incidentally, in the production of the foamed synthetic resin molded article, the foamed synthetic resin material leaks out from the joint portion between the skin material and the core material, causing unnecessary burrs outside the product, or the leaked foamed synthetic resin material. The material may adhere to the surface of the skin material and spoil the appearance of the product. Further, due to the leakage of the foamed synthetic resin material, the resin material may be insufficient between the skin material and the insert material, and a cavity may be generated in the foam. Therefore, there is known a method in which a breathable foam such as soft urethane foam or a hot melt adhesive is attached in a string shape in advance at a predetermined position of the insert material as a sealing material.

However, according to this method, it is difficult to perform the process of sticking the sealing material on the insert material in the foam molding process of the production line, so that the pretreatment process outside the production line must be performed. The manufacturing process of the molded product was complicated. Therefore, there is a problem that not only the productivity of such a foamed synthetic resin molded article cannot be improved, but also the personnel, equipment and working space for this pretreatment step must be secured. Further, in some cases, the pretreatment process and the manufacturing process of the foamed synthetic resin molded product may be located at a distance from each other, and a space for storing the sealant-coated or untreated product of the insert material, etc. In addition, the transportation means for them was required.

[0005]

SUMMARY OF THE INVENTION Therefore, according to the present invention, a sealing agent for surely preventing the leakage of the foam synthetic resin material from the joint portion between the insert material and the skin material is provided in the foam molding step of the manufacturing line. It is an object of the present invention to provide a method for integrally molding a foamed synthetic resin molded product which can be manufactured without complicating the manufacturing process of the molded product.

[0006]

That is, the present invention is
When the insert material and the skin material are arranged in the molding die and the synthetic resin material is injected and integrally molded, a viscoelastic sealant is attached to the portion of the skin material arranged in the molding die at a portion to be joined with the insert material. Alternatively, a method for integrally molding a foamed synthetic resin molded article, characterized in that the foamed synthetic resin material is applied in a strip shape, an insert material is overlaid on the skin material via the sealant, and a foamed synthetic resin material is foamed between the skin material and the insert. Pertain to.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a cross-sectional view showing an example of a molding die for carrying out the method of the present invention, FIG. 2 is a cross-sectional view of a main portion of the molding die showing a state in which a skin is arranged on the molding die, and FIG. FIG. 4 is a cross-sectional view of the main part of the molding die showing a state in which a sealing agent is applied to a predetermined joining portion, FIG. 4 is a cross-sectional view of the main part of the molding die showing a state in which a foam synthetic resin material is injected into a skin material. FIG. 6 is a cross-sectional view of a main part of the molding die showing a state where the insert material is superposed on the surface material, and FIG. 6 is a cross-sectional view showing another state of the molding die shown in FIG.

FIG. 1 shows an example of a molding die for carrying out the method of the present invention. Reference numeral 10 is a foaming mold, 11 is a lower mold, 12 is an upper mold, and has a predetermined molded product cavity 13, and the hinge 1
4 is formed so as to be openable and closable. In this example, the lower mold 11 is provided with a split mold 15 for the undercut portion of the product, and this split mold 15 portion is the hinge 1
The lower mold 11 can be opened and closed via 6 through. As shown in FIG. 2, the skin material 17 is arranged on the mold surface of the lower mold 11. The skin material 17 is made of soft vinyl chloride or the like, and is formed in advance into a predetermined skin shape by known slush molding or the like. On the other hand, the insert material 18 is arranged on the mold surface of the upper mold 12. The insert material 18 is made of a hard synthetic resin molded product or a metal molded product formed in a predetermined shape. At this time, a mold release agent or the like may be applied to the mold surfaces of the lower mold 11 and the upper mold 12.

Next, as shown in FIG. 3, the lower mold 1
The insert material 1 at the periphery of the skin material 17 arranged in No. 1
A sealant 20 is applied to a portion 19 to be joined with 8.
A liquid substance having viscoelasticity such as a known sealant agent, a thermoplastic hot melt agent, or a thermosetting hot melt agent is used as the sealing agent 20, and the nozzle 22 of the discharge gun 21 is used.
Is applied to the predetermined portion 19 in the form of a string or a strip.
It is preferable that the sealing agent 20 is appropriately heated and softened before use. This heating temperature is set slightly lower than the temperature at which the sealant 20 is usually used as an adhesive,
It is preferable to keep the sealing agent 20 in a state having a higher viscosity than the adhesive. Thereby, the sealing agent 2
0 can be applied in a string or strip. At this time,
If the heating temperature is too high, the viscosity of the sealant 20 becomes low, which may cause dripping from the coated portion. Also,
If the viscosity is too high, it becomes difficult to discharge from the discharge gun 21.

In this embodiment, the discharge gun 21
Is provided at the tip of a discharge robot 23 provided in the molding die 10 via arms 24 and 25, and the lower die 11
The skin material 17 is arranged on the mold surface, and the skin material 1
7, the sealant 20 is automatically applied along the shape of the planned joining portion 19 of the skin material 17 arranged. Therefore, the application of the sealing agent 20 can be continuously performed by incorporating it into the foam molding process of the foam molded article without performing the previous process.

Further, as shown in FIGS. 4 and 5, the foam synthetic resin material 30 is injected inside the skin material 17 of the molded product cavity 13, and the upper die 12 is closed to insert into the skin material 17. Overlaid on the material 18. And
The foaming reaction of the foamed synthetic resin material 30 is performed between the skin material 17 and the insert material 18 to form a foamed body. The sealing agent 20 is pressure-bonded to the insert material 18 by the pressing force of the upper mold 12, and flows to the end of the planned joining portion to seal the skin material 17 and the insert material 18. In particular, in the hot-melt type sealant, since it is further softened by the reaction heat of the foamed synthetic resin material, it easily fits into the gap of the insert material 18 and is easily peeled off. Prevent leaks.

By the way, the angle of the surface to which the sealant is applied is at least 45 with respect to the discharge direction of the sealant from the nozzle.
It has been confirmed by experiments that the sealant 20 can be applied most accurately and reliably when applied at an angle of more than 90 °, preferably close to 90 °.

However, when the portion to be joined 19 of the skin material 17 to be joined to the insert material 18 is an inclined portion such as an undercut portion of the product as shown in FIG. 1, its inclination angle and application are performed. Depending on the viscoelasticity of the sealing agent 20,
In some cases, it may run off and the reliable application may not be achieved. In addition, depending on the shape of the molding die 10 and the installation position of the ejection robot, it may be difficult to maintain the above-described preferable angle in all the planned joining portions 19 of the skin material 17.

Therefore, as shown in FIG. 1, it is preferable to provide the mold 10 with a tilting device 26. The tilting device 26 includes a hinge device 27 and a cylinder device 28. The hinge device 27 is attached to one end of the bottom portion of the molding die 10 and appropriately rotates the molding die 10 up and down with respect to the floor surface. Can be made. In addition, the cylinder device 2
8 is provided at the opposite end of the hinge device 27,
The bottom of the mold 10 can be moved up and down. By operating the cylinder device 28, one end of the mold 10 is hinged by the hinge device 27.
The mold is tilted at an appropriate angle by rotating through. As will be understood from FIG. 6, according to this structure, the joining scheduled portion 19 does not have a preferable inclination angle with respect to the discharge direction of the sealing agent 20 or the viscoelasticity of the sealing agent 20 is insufficient. Even when there is a possibility that the joining portion 19 will flow down due to the inclination, the molding die 10 is appropriately rotated to make the inclination angle of the joining portion 19 as close as possible to 90 ° with respect to the discharge direction of the sealing agent. 20 can be applied accurately and reliably. Furthermore, by using a well-known ball joint or the like for the hinge device 27, the molding die 10 can be rotated not only up and down but also back and forth. In addition, the hinge device 2
By providing 7 near the center of the bottom of the mold 10,
The rotation width of the mold 10 can be made larger.

In the above embodiment, the robot is used to apply the sealant, but the operator may manually apply the sealant instead of the robot. Further, a raw material injection port may be provided in the upper mold, and the foamed synthetic resin material may be injected from the raw material injection port after the mold is closed.

[0016]

As shown and described above, according to the method of the present invention, not only the leak of the foamed synthetic resin material from the portion where the skin material and the insert material are to be joined is reliably prevented, but also the joining portion is to be joined. The operation of applying the sealing agent can be performed within the foam molding process of the molded product manufacturing line. Therefore, not only can the manufacturing process of such a foamed synthetic resin molded product be simplified to shorten the production cycle, but also space saving and manpower saving can be achieved, the production cost can be reduced, and the productivity can be remarkably improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of a molding die for carrying out the method of the present invention.

FIG. 2 is a cross-sectional view of a main part of a molding die showing a state in which a skin is arranged on the molding die.

FIG. 3 is a cross-sectional view of a main part of a molding die showing a state in which a sealing agent is applied to a portion of a skin material to be joined with an insert material.

FIG. 4 is a cross-sectional view of a main part of a molding die showing a state in which a foam synthetic resin material is injected into a skin material.

FIG. 5 is a cross-sectional view of a main part of a molding die showing a state in which an insert material is superposed on a skin material.

FIG. 6 is a cross-sectional view showing another state of the molding die shown in FIG.

[Explanation of reference numerals] 10 molding die 11 lower die 12 upper die 17 skin material 18 insert material 19 planned joining portion 20 sealing agent 30 foam synthetic resin material

Claims (1)

[Claims] 1. When arranging an insert material and a skin material in a molding die and injecting a synthetic resin foam material to integrally mold the molding material, viscoelasticity is applied to a portion to be joined with the insert material in the skin material arranged in the molding die. A foamed synthetic resin molding characterized in that a certain sealing agent is applied in a string or band shape, an insert material is overlaid on the skin material via the sealing agent, and a foamed synthetic resin material is foamed between the skin material and the insert. One-piece molding method.