JPS61244508A - Manufacture of resin mold - Google Patents

Abstract

PURPOSE:To enable to use the titled mold over a long period of time by providing the surface of the same with excellent strength properties, wear resistance and heat resistance, by forming a surface layer of the resin mold constituted by curing synthetic fiber by making the same impregnated with heat-curable resin on a surface part of the resin mold to be molded. CONSTITUTION:A surface layer 3 of a resin mold is constituted by applying a thing obtained by loading a fiber to a heat-curable resin solution to the surface of a base mold 2 and an inner wall surface of a core box 1 manually or mechanically respectively. An intermediate paste layer 4 is formed on the surface of the surface layer 3 by laminating the intermediate paste layer 4. A thing obtained by mixing metallic powder and glass chop within a resin solution is either applied to the surface of the surface layer 3 of the resin mold or sprayed on the same by a sprayer. As for the manufactured resin mold, as a synthetic fiber which has been loaded to the surface layer of the resin mold is exposed close by the surface of the mold the surface of the resin mold is strengthened by mechanical strength properties, wear resistance, compression resistance and heat resistance and the resin mold is made into one provided with durability resembling to a metal mold.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is suitable for manufacturing resin molds that can be used in place of various molds such as press molds, injection molds, or vacuum molds. Regarding the method.

[Conventional technology]

Molding machines such as press molding machines and injection molding machines usually use molds made from various types of mold steel, but the cutting process of these molds is troublesome and they are very expensive. Therefore, as multi-product multiplex production is progressing, there are many problems such as the proportion of total mold cost in the total manufacturing price of a product becoming high and uneconomical, and the long manufacturing delivery time having a large impact on product manufacturing. There was a problem.

Therefore, manufacturing costs are lower than traditional metal molds,
In addition, the use of resin molds, which can be manufactured in a short period of time, was considered.

To explain the conventional manufacturing of resin molds using sheet metal press molds as an example, in manufacturing, first the base mold (model) is fixed in a wooden core box, and then the surface of the base mold and A mold release agent is applied to the inner surface of the core box, and a surface layer resin called gel coat, that is, a thermosetting resin (hereinafter simply referred to as gel coat) is applied to the surface of this mold release agent layer at a ratio of 1 to 2/nn. When this gel coat becomes semi-hardened (tack-free), an intermediate paste layer made of a mixture of resin, metal powder, and glass chop is formed on top of the gel coat. A laminate layer of, for example, glass fiber impregnated with a resin is laminated on top, and then a sand core, which is a mixture of silica sand, glass chop, and resin, is filled into the double-layered core box, and finally the top surface of the core box is laminated. After leveling and squeezing the resin and curing the resin, the core box was removed and released from the base mold to create a resin mold.

In addition, metal powders such as carborundum, carbon black, and electrolytic reduced iron have been mixed into the above-mentioned gel coat to reinforce the surface layer of the gel coat.

[Problem that the invention seeks to solve]

However, with the resin mold having the above structure, the thermosetting resin itself that constitutes the gel coat does not have sufficient mechanical strength, abrasion resistance, and heat resistance, and the glass fiber of the laminate layer does not have sufficient resistance. It does not have abrasion resistance or heat resistance, and the glass fiber does not directly appear on the surface of the mold.
There is a problem that the surface of the mold becomes deformed and worn when used repeatedly, and in addition, the structure between GELCO 1 and the intermediate paste layer is such that they are bonded when the thermosetting resin becomes gelled or semi-gelled. Because of this, the gel coat and intermediate paste layer are not completely integrated structurally, but are simply adhered to each other, and the thermosetting resin shrinks during curing and creates a gap between it and the intermediate paste layer. Due to the creation of gaps, peeling often occurs between the intermediate paste layer and gel coat during use. Therefore, the number of times the resin mold can be used is extremely small, and it can only be used for molding prototypes, etc. There was a problem that it could not be used as a main mold instead of a mold.

[Means for solving problems]

The present invention has been developed in view of the above points, and its purpose is to provide a resin that has excellent surface strength, abrasion resistance, and heat resistance, and can be used repeatedly over a long period of time. The purpose of the present invention is to provide a mold manufacturing method, and in order to achieve the object -1-, synthetic fibers are impregnated with a thermosetting resin in at least the surface portion of the resin mold to be molded, and This is configured to solidify to form a resin-type surface layer.

〔Example〕

Hereinafter, preferred embodiments of the resin mold manufacturing method according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows a resin mold surface layer 3 with respect to a base mold 2 fixed to a bottom plate 1 a l of a core box, generally indicated by reference numeral 1.
and an intermediate paste layer 4 are laminated, and the resin-type surface layer 3 is made of reinforcing synthetic fiber such as aramid fiber (for example, manufactured by DuPont, trade name: Kevlar). is impregnated with thermosetting resin (condensation resin) such as epoxy resin, polyester resin, or urethane resin (gel-in-the-fiber coating).
Use the one you made.

To explain the composition of the resin-type surface layer 3 in more detail, if the synthetic fibers used are aramid fibers woven into a cross, the above thermosetting resin solution is applied to the surface of the cloth using a brush or a spatula. Then, the impregnated cloth is applied manually or on the surface of the base mold 2 and the inner wall surface of the core box 1 as shown in FIG. The resin mold surface layer 3 is formed by mechanically pressing them together.

In addition, the synthetic fibers used are aramid fibers, for example 6 to
In the case of chopped fibers cut to a length of 12/I, or in the case of highly fibrillated pulp fibers with an average length of about 2/no, these fibers are subjected to the above-mentioned heat curing process. The resin mold surface layer 3 is formed by manually or mechanically applying a mixture of the resin solution to the surface of the base mold 2 and the inner wall surface of the core box 1, respectively, as shown in FIG.

In the resin-type surface layer 3 constructed in this way, the relative positions of the synthetic fibers are maintained as the thermosetting resin solidifies, especially when the synthetic fibers are short fibers such as chopped or pulp. 1. The fluidity of the resin is prevented by blending short fibers. At the same time, the relative position of the short fibers is maintained as the resin gels, resulting in excellent strength, abrasion resistance, and
Can exhibit heat resistance.

After the formation of the resin mold surface layer 3 described in 1- is completed, the intermediate paste I layer 4 described in 1- is laminated on this surface layer 3 as shown in FIG. Mix metal powder and glass chops etc. in a resin solution and apply it to the resin mold surface layer 3 1- using a brush or spatula, or spray it with a machine. This intermediate paste layer 4 that constitutes
The resin type surface layer 3 described in L and the sand core to be described later play the role of a medium [1], and the resin used is the resin type surface layer 3 described in G. A thermosetting resin similar to that used in the above is used, and a forming operation is continuously performed before the resin of the surface layer 3 is hardened (tack-free).

In FIG. 2) 1η and FIG. 3, 5 indicates a sand core that is continuously filled into the space in the core box 1 after the formation of the 1-] recording and recording layer 4. For example, this sand core 5 made by mixing silica sand, glass chop, and a resin solution is filled into the core box 1 by mechanical work instead of manual work, but in particular, the resin used is 1. In order to use thermosetting resins similar to those used in the resin-type surface layer 3 and the intermediate pastes 1 to 4, the affinity of these resin phases 7f and the affinity of the synthetic fibers can be improved.
1 synergistically, as each resin gels, the resin-type surface layer 3 containing reinforcing synthetic fibers is physically bonded to the surface of the sand core 5 using the intermediate paste layer 4 as a medium. and can be established.

In addition, in Fig. 2, 6 is 1 of the filled sand core 5.
．． In order to level the surface, there is a leveling resin layer formed by 4 people, and 7 indicates a presser plate that presses this resin layer (5) to release water.

After completing the following operations and solidifying each resin, remove the core box 1 and release it from the base mold 2 as shown in Figure 3, so that the surface is covered with a resin mold surface layer 3 containing synthetic fibers. , H, -7), and this synthetic fiber is near the surface <
Resin mold 10 exposed to (0,01~0.5/nwn)
is manufactured.

〔effect〕

The method for manufacturing a resin mold according to the present invention is as described in 1 below. Therefore, the resin mold manufactured according to the present invention has a relationship in which the synthetic fibers blended in the resin mold surface layer are exposed near the surface of the mold. The surface of the resin mold is strengthened by the mechanical strength, abrasion resistance, compression resistance, and heat resistance of this synthetic fiber. It has the advantage of being able to be manufactured in a short time and at a low cost, and also has the economical advantage of being able to significantly reduce the cost of manufactured products by being used in place of conventional molds. In addition, since the delivery time for mold production is significantly shortened, the number of days from product design to production of the finished product is shortened accordingly, making it possible to fully meet the ever-changing needs of society. It has the advantage of significantly reducing economic risks, lowering the production cost of small-volume products, and safely performing high-mix, low-volume production.

In addition, the resin mold manufactured according to the present invention not only has excellent durability, but also the relative position of the synthetic fibers blended into the resin mold surface layer is maintained by gelation of the thermosetting resin. Therefore, it is possible to maintain properties such as strength and wear resistance uniformly over the entire surface of the resin mold, and to provide a resin mold with good finishing effects. It also has the advantage of preventing peeling between the bag, the resin mold surface layer, and the intermediate paste layer, and improving mold accuracy.Coupled with the fact that it is simple in structure and easy to implement, Press mold, injection mold, vacuum mold, FRI
) It is useful for manufacturing various molds such as molds, RIM molds, textile models, etc.

[Brief explanation of drawings]

FIGS. 1, 2, and 73 are cross-sectional views sequentially illustrating the state in which a resin mold is manufactured by implementing the resin mold manufacturing method according to the present invention. 1 is a core box, 2 is a base mold; 3 is a resin mold surface layer blended with synthetic fibers, 4 is an intermediate paste layer, 5 is a sand core, and 10 is a resin mold manufactured according to the present invention. Patent applicant: Resin Machine Type U Co., Ltd.)

Claims (4)

[Claims] (1) Production of a resin mold, characterized in that a resin mold surface layer is formed by impregnating synthetic fiber with a thermosetting resin and solidifying it on at least the surface portion of the resin mold to be molded. Method. (2) The synthetic fiber is a reinforcing fiber such as an aramid fiber.
Method for manufacturing the resin mold described in Section 1. (3) The method for manufacturing a resin mold according to claims 1 and 2, wherein the synthetic fiber is a cloth-like cloth fiber. (4) The method for manufacturing a resin mold according to Claims 1 and 2, wherein the synthetic fibers are chopped or pulp-like short fibers.