JPS62275718A - Resin molding tool - Google Patents

Abstract

PURPOSE:To make it unnecessary to pull a resin molded body itself and consequently make it possible to prevent the molded body from being damaged by a method wherein the resin molded body is released from a molding surface by means of a core at the separation of the body from a mold. CONSTITUTION:A molding tool is made of metallic material and consists of a molding tool vessel part 10, a molding tool cover part 11 and a core 12. In this case, the core 12 consists of a bottom plate having a large number of holes 14, through which a plurality of columnar parts 13 of the vessel part 10 are allowed to pass, and a cylindrical tube side wall part 17, at the upper part of which recesses 16 are provided so as to chuck the core easily, and is installed inside the vessel part 10. When the combined mold of the vessel part 10 and the core 12 is separated from the cover part 11 after the curing of liquid raw urethane foam material mixture during molding, urethane foam is left on the combined mold side. Next, the core 12 is separated form the vessel part 10 by pulling the core 12 out of the vessel part 10 by the recesses 16 of the core 12, and accordingly the urethane foam remains inside the core 12. The urethane foam left inside the core 12 can be pulled out of the core easier than in the case in which the contacting surfaces of the urethane foam with the columnar parts of the vessel part are much.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention (Field of Industrial Application) The present invention is a method of molding that is conveniently used when molding urethane foam, particularly urethane foam having a plurality of parallel bottle hole shapes. It's about type.

[Conventional technology]

Conventionally, a urethane foam body having a plurality of parallel hollow holes as shown in FIG.
As shown in Publication No. 2, it is manufactured as an intermediate product for manufacturing a porous ceramic structure.

As shown in the same publication, the container mold 21 shown in FIG. Inject while stirring, and cover the lid wall 2.
Close the mold 2, and after the urethane foam stock solution foams and pushes the air inside the mold 2, it overflows from the hole 21a, so plug it and add 100~
A method of obtaining a urethane foam molded body by heating and curing at 120°C for 20 to 60 minutes, separating the container mold 21 and the lid wall 22, and grabbing and pulling out the upper part 21 of the urethane foam molded body remaining on the container mold side. be.

[Problems to be solved by the invention] However, if the foaming ratio of the urethane foam is increased in order to reduce the weight, or if the isocyanate component of the urethane foam stock solution is changed to less toxic MDI (methylene diisocyanate), the urethane foam A problem arises in that the tear strength of the molded product decreases and the gripping portion 31 of the urethane foam molded product, where the frictional force generated between the molded product and the hollow bottle 23 concentrates when demolding the urethane foam molded product, is damaged.

[Means for solving problems]

In view of the above problems, the present invention has a core on the mold surface where the resin molded body remains when the molds are separated, and the resin molded body can be separated from the mold surface by the core. It is characterized by this.

[Effect]

According to the present invention, by pulling out the core from the mold, it is possible to easily demold the resin molded body.

〔Effect of the invention〕

Therefore, since there is no need to stretch the resin molded body itself, damage to the molded body can be prevented.

〔Example〕

A front sectional view of the urethane mold structure according to this embodiment is shown in FIG. 1, a plan view of a core which is a component thereof is shown in FIG. 2(a), and a front view is shown in FIG. 2(b).

This mold is made of metal material such as aluminum (S2017) or stainless steel (SUS303). Molding mold lid part 11. It is composed of a core 12.

Here, the core 12 is composed of a bottom plate 15 having a plurality of holes 14 through which the plurality of columnar parts 13 of the container part 10 can pass, and a cylindrical tube side wall part 17 having a recess 16 in the upper part for easy chuck. , are arranged inside the container part 10.

The container portion 10 has a bottom plate portion 18 in which a large number of columnar portions 13 are implanted.
and a cylindrical tube side wall portion 19, and the upper surface of the cylindrical tube side wall portion 19 is provided with screw holes 20 for assembly at four equal parts on the outer circumference. The mold lid 11 includes a lid plate 21 and a plurality of columnar parts 22 implanted on the lid plate 21. A through hole 21 a is bored in the cover plate 21 at a position that does not interfere with the columnar part 22 . The columnar portion 22 is provided in consideration of not interfering with the columnar portion 14 of the container portion 1o when the mold lid portion 11 is placed over the container portion 10 as described later. In addition, the lid part 11 is attached to the container part 10 at four equal parts on the outer circumference of the lid plate 21.
An assembly hole 21b for fixing is bored.

FIG. 1 shows that after the middle piece 12 is placed in the mold container part 1o, the mold cover part 11 is assembled to the mold container part 10, and the bolts 25 are attached.
The figure shows a fixed state.

Next, to explain the method for molding urethane foam, a wax-based mold release agent is heated in advance to a temperature higher than the melting point of the mold release agent, and then applied by spraying or brushing to the inner surface of the mold. Next, the temperature of the mold is adjusted to 30°C to 50°C, and organic isocyanate, polyol, and foam stabilizer are placed in the mold container part 10.

A urethane foam raw material mixture containing a blowing agent and a catalyst is injected while stirring, and the mold lid 11 is closed. Here, the organic isocyanate is tolylene diisocyanate, methylene diisocyanate, or a mixture of both, and the polyol is a polymer polyol consisting of a polyether polyol and/or a polyester polyol, or a combination of this and a polyether polyol. A mixture, the foaming agent is water or a halogen-substituted aliphatic hydrocarbon foaming agent (Freon M such as trichloromonofluoromethane), or a mixture of both; the foam stabilizer is an alcohol-modified silicone foam stabilizer; The catalysts include tertiary amines and organic acid salts thereof, which are effectively used as catalysts for the reaction between polyols and isocyanates, and catalysts for the reaction between water and isocyanates as catalysts for promoting the foaming reaction. Monophorin, ethanolamine, etc., which are effectively used as The urethane foam raw material mixture is
After pushing the air in the mold which has foamed in this mold, it overflows from the flame 21a, so it is plugged. After foaming, the foam is cured by heating at 100°C to 120°C for 20 to 60 minutes.

After curing, the combined shape of the container part 10 and the core part 11 and the lid part 1 are formed.
When separated from 1, the urethane foam remains on the combined mold side. Next, when the core 12 is pulled out from the container part 10 by grasping its recessed part 16, the core 12 is separated from the container part 10,
The urethane foam remains inside the core 12.

The urethane foam remaining inside the core 12 can be easily removed by the core, unlike the case where there are many contact surfaces with the container-shaped columnar part.

Next, the present invention will be explained in detail using experimental data.

When expanded 10 times using TDI (tolylene diisocyanate), which is a relatively strong isocyanate type, the tear strength was 1.3 kg as shown in the upper column of Table 1.
/ crn, 240% elongation strength urethane foam, even if it fell off using the conventional demolding method, there was no damage during demolding as shown in the demolding damage evaluation section in the same column. However, when the expansion ratio is increased to 20 times or when MDI is used as the isocyanate species, the strength of the urethane foam decreases and breakage occurs during demolding, as shown in the strength section of Table 1.

However, in the present invention, no breakage occurred during demolding, as shown in the right column of demolding damage evaluation items in Table 1, indicating that the present invention is effective.

Table 1 The present invention can be modified in various ways as described below.

(1) When the urethane foam molded product remains on the lid side instead of the container side, only the bottom plate 61 of the core is left as shown in FIG.
In addition, the core 12 may be attached so as to be in contact with the lid portion 11.

(2) As shown in FIG. 4, the upper lid part 11. In a mold that can be divided into three parts with a side wall part 18, the core 12 has no side wall part (it may have a bottom plate structure).

(3) The material of the mold and core is aluminum (A207)
Or other metal materials such as stainless steel (SUS303),
Other aluminum materials, SUS materials, iron materials such as carbon steel and general rolled steel, P and D containing Teflon, epoxy resin, and talc.
A resin material that can withstand temperatures of 150° C. or higher, such as heat-resistant arrylic resin, or silicone or fluorine-based heat-resistant rubber may be used.

(4) Although the shape of the mold in this embodiment has a large number of columnar parts, it may have a shape having a single columnar part.

(5) As shown in FIG. 5, the core 12 is connected to the lid part 11. Container part IO
A model that can be installed on both sides of the board is also acceptable.

(6) In this embodiment, each columnar portion corresponds to one hole 14 through which the columnar portion of the bottom plate 15 of the core 12 passes, but one hole may correspond to several columnar portions. good.

(7) In addition to urethane foam, the resin molded body can also be composed of styrene foam or vinyl chloride foam.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing one embodiment of the mold of the present invention, FIGS. The figures are a sectional view showing an embodiment of the present invention, FIG. 6 is a sectional view showing a conventional example, and FIGS. 7(a) and 7(b) are a plan view and a sectional view showing a resin molded body. 10...Mold container part 211...Mold lid part, 12
... Core 231 ... Resin molded body.

Claims (1)

[Claims] A resin molding die having a core on a mold surface where a resin molded body remains when the molds are separated, and the resin molded body can be removed from the mold surface by the core.