JPH1044168A - Foam molding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To carry out easily and accurately the setting of a resin material and a core material, shorten the mold setting time to shorten the molding cycle and reduce the precentage of rejects in foam molding. SOLUTION: In the foam molding method in which one mold 1 with a skin material 3 disposed thereon is mold registered with another mold 2 with a core material 4 disposed thereon, and a foaming material 5 is injected between the skin material 3 and the skin material 4, and a foam molded product composed integrally of the skin material 3, a foamed layer and the skin material 4, a catalyst is applied on a core material face of a clearance S on the end of the skin material on a bonding section of the skin material 3 and the core material 4 bonded together at the time of mold registering, and the chemical reaction of the foaming material is accelerated at the time of foaming the foaming material and curing is carried out, and also a recessed section 7 of a channel shape is formed on a core material side bonding face to store the leakage of the foaming material 5 in the recessed section, and skin material edges are clamped from both of inner and outer faces.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foam molding method, and more particularly to an instrument panel, a glove box, and the like.
The present invention relates to a method for molding a foamed material of a foamed synthetic resin molded article used for automobile interior parts such as a console box.

[0002]

2. Description of the Related Art Conventionally, in foam molding of automotive interior parts such as an instrument panel, for example, as shown in FIG. And the other mold 2
The core material (insert material) 4 is arranged in
After the mold 2 is molded, a foam synthetic resin material such as urethane is injected between the two to integrally mold the skin material 3, the foam layer 5 and the core material 4. In the foam molding, the vicinity of the edge of the skin material and the joint portion of the core material are brought into surface contact with each other at the time of the foam molding, and the upper and lower molds 1 and 2 are press-bonded. Therefore, the foam material is injected between the core material 4 and the skin material 3. The foamed material leaks from the joint near the edge and hardens to form burrs, or isocyanate and polyol are mixed, and the gas generated during the chemical reaction to become urethane moves to the weaker pressure, and this When the urethane finishes reacting during the movement due to leakage, the gas remains as fine particles, and after molding, it has to be removed in a trimming process, which is not only very troublesome but also preferable in appearance. No more Defective products, there is a problem that results in a scrap.

For this reason, as a technique for preventing the leakage of the foaming material at the joint portion of the skin material edge, a foaming material can be prevented from leaking by using a slide mold as a foaming material molding die (Japanese Patent Application Laid-Open No. 2-197443). When a skin material and a core material are arranged in a foaming mold, and a foam material is injected between them to form an integral foam, a ridge 10 is provided on the core material at the joint between the skin material and the core material as shown in FIG. Or a sealing material (JP-A-4-247
No. 915) or a liquid thermoplastic resin (Japanese Patent Publication No.
And the like.

[0004]

However, although each of the above-mentioned leak prevention structures is effective to some extent, it is necessary to set the skin material in advance to a seal shape or to set the shape of the core material other than the product surface. In addition to this, it takes a lot of time and labor, and at the time of foam molding, there is a problem that the edge of the skin material is pulled and opened between the core material joining surface and the dimensional accuracy is deteriorated.

[0005] The present invention addresses the above-mentioned actual situation, aims at the shapes of the skin material and the core material, facilitates the setting, shortens the mold setting time, and promotes the shortening of the molding cycle. The purpose is to achieve reduction.

[0006]

That is, according to the present invention, which meets the above-mentioned object, one mold in which a skin material is arranged and the other mold in which a core material is arranged are matched with each other, and the skin material and the core material are combined. In a foam molding method for injecting a foam material in between to form a foam molding method in which a skin material, a foam layer and a core material are integrated, a skin at a joint portion between the skin material and the core material to be joined to each other at the time of mold matching It is characterized in that a catalyst is applied to the gap core material surface at the tip of the material to promote the chemical reaction of the foamed material when the foamed material is foamed and to cure the material.

[0007] The invention according to claim 2 has the above features,
A groove-shaped recess is provided at the joint side of the core material at the joint between the skin material and the core material, so that leakage of the injected foam material is accumulated, and the skin material of the portion is sandwiched from both the inner and outer surfaces. The curling is eliminated, and the sealing effect is further improved.

[0008]

According to the foam molding method of the present invention, when the upper and lower molds are matched, the vicinity of the edge of the skin material is joined to the joint of the core material, and the foam material is injected. The joint is sealed, but further reacts with the catalyst applied to the core material at the gap at the top of the skin material, further sealing the sealing effect more reliably, and the generation of burrs that necessitates time and effort in the trimming process And the molding cycle is shortened.

[0009] In particular, when the leaked foam material accumulates in the groove-shaped recessed reservoir of the core material joining surface according to the second aspect of the present invention, the skin material is sandwiched from both the inner and outer surfaces, and the skin material is not turned up. Improve the appearance of the product.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings.

1 and 2 show one embodiment of the foam molding method of the present invention. In the drawings, reference numeral 1 denotes a lower mold, 2 denotes an upper mold, and a foam molding die comprises the pair of molds 1 and 2 described above. In carrying out the present invention, the skin material 3 is placed on the lower mold 1 while the upper mold 2 is placed on the lower mold 1.
A core material 4 is disposed on each of the upper and lower molds, and the upper and lower molds are matched with each other, and a foamed resin material is provided between the skin material 3 and the core material 4 in a state where the bent edges of the skin material 3 are joined to the core material 4. 5 is injected to perform foam molding.

When the skin material 3 is placed (set) on the lower mold 1, a suction mechanism (not shown) connected to a suction source is provided, and the skin material 3 is sucked into the lower mold 1 by this vacuum suction. Crimp. Here, a flexible material such as a resin sheet or leather is used as the skin material 3, and a resin panel, a metal panel, or the like is used as the core material 4.

As the foam material 5, polyurethane, P
Foam materials such as VC and polyethylene can be used,
Most commonly it is polyurethane. Polyurethane is produced by a chemical reaction between an isocyanate and a polyol, and a gas is generated during the chemical reaction. When the chemical reaction ends while the gas is moving, the gas remains as fine particles.

Therefore, in the present invention, in the above foam molding, a gap S is left between the tip of the skin material and the core material 4 particularly at the joint surface 6 between the core material 4 and the skin material 3, and the core in the gap S is formed. A catalyst (foaming accelerator) that promotes the chemical reaction of the foaming material such as urethane is applied to the material surface. Of course, core material 4
May be applied over most of the bonding surface of the bonding portion, but it is essential and effective to apply it to the core material surface of the gap. In this case, an amine catalyst such as a heterocyclic amine (such as triethylenediamine), an alkanolamine (such as dimethylethanolamine), or an aliphatic amine (such as tetramethyldiethylenetriamine) is used as a catalyst for the urethane foaming reaction. Morpholine-based catalysts can also be used as auxiliary amine catalysts. However, most commonly DETDA (diethyltriethylenediamine, Mitsubishi Dow) is used.

In addition to the above, as shown in FIG. 1, the invention according to claim 2 applies a catalyst as described above to the gap core material surface at the tip of the skin material 3 on the joint surface 6, accelerates the reaction, and cures. In addition, a groove-shaped concave portion 7 is set in the joint surface 6 of the core member 4 to create a pool of foamed material, thereby preventing leakage to the product design surface.

When the recess 7 is provided, FIG.
As shown in (1), a foamed resin material, for example, a urethane material is injected, and the foaming pressure causes the edge of the skin material 3 to abut against the joint surface of the core material 4 and is sealed, but the foamed material leaks in the direction of the arrow. Numerals 8 accumulate in the recesses 7, hold the edges of the skin material 3 from the outside, and sandwich the edges of the skin material 3 from both the upper and lower surfaces in the figure with a foamed material to prevent the edges of the skin material 3 from being turned up, thereby making the sealing of the portion more complete. Therefore, when the skin material 3 is set, it can be set in a state 3a in which the bent portion is slackened as shown in FIG.

[0017] Thus, the application of the catalyst to the core material joint surface on the front end side of the skin material, and furthermore, the accumulation of the concave portion provided on the core material joint surface completely seals the skin material edge, thereby minimizing the effect on the product surface. As a result, it has become possible to streamline the trimming process and shorten the molding time.

[0018]

As described above, according to the present invention, when the skin material and the core material arranged in a pair of molds are matched in a mold, the reaction of the foamed material to the joint surface of the core material at the front end of the skin material at the joint part joined to each other. Applying a catalyst that accelerates the reaction, the reaction in the part is accelerated and cured. By applying the catalyst, the chemical reaction of the foamed material near the joint surface is accelerated and cured to completely prevent liquid leakage from the joint. In addition, by forming a recess in the joint surface and forming a pool of leaked foam material, the skin material at the joint is sandwiched from both sides to prevent the edge from being turned up, and the conventional problem caused by liquid leakage In addition to greatly simplifying the trimming process such as removing burrs, the skin material can be set in the mold in which the skin material and the core material are slackened. Prevents requiring exact time as, has a very significant effect on reducing and improve appearance of the product of molding time.

[Brief description of the drawings]

FIG. 1 is a schematic partial sectional view showing one embodiment of the foam molding method of the present invention.

FIG. 2 is a schematic cross-sectional view of a main part showing a slack state when a skin material and a core material are arranged.

FIG. 3 is a sectional view showing an example of a known seal structure. DESCRIPTION OF SYMBOLS 1 Lower mold 2 Upper mold 3 Skin material 4 Core material 5 Foam material 6 Joining surface 7 Groove-shaped recess S S Gap between skin material tip and core material

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location B29L 9:00 31:58

Claims (2)

[Claims] 1. A mold in which one of the molds on which a skin material is arranged and the other mold on which a core material is arranged is molded, and a foam material is injected between the skin material and the core material. In a foam molding method for molding a foam molded product in which a core material is integrated, at the time of mold matching, a catalyst is applied to a gap core material surface at a skin material tip at a joint portion between the skin material and the core material to be joined to each other, A foam molding method characterized by promoting a chemical reaction of the foam material at the time of foaming, and curing the foamed material. 2. A method according to claim 1, wherein a groove-shaped concave portion is provided on a joint surface between the skin material and the core material on the core material side to collect leakage of the injected foam material, and the skin material of the portion is sandwiched from both the inner and outer surfaces. Item 4. The method for molding a foamed material according to Item 1.