JPH0280209A - Manufacture of resin mold - Google Patents

Abstract

PURPOSE:To manufacture a resin mold without protruding reinforcing fibres in a mustache manner from the surface layer and transferring texture of fibres on its surface which is smooth by molding the surface of a resin mold, impregnating the surface of a reinforcing fibre layer with a prompt curing type adhesive agent, upon manufacturing a resin mold whose surface is reinforced by filling a sand core in a base mold over which reinforcing fibres are spread. CONSTITUTION:Shown is a state wherein a reinforcing fibre layer 3 infiltrated with a prompt curing type adhesive agent and an intermediate paste layer 4 are lamination-formed with respect to a base mold 2 fixed on the bottom plate 1a of a molding mold. The reinforcing fibre layer 3 infiltrated with a prompt curing type adhesive agent is prevented in its rise due to the repulsive force of the reinforcing fibres, and the adhesive agent may be able to block the texture of fibres. After completing the formation of the reinforcing fibre layer 3, subsequently, an intermediate layer 4 is lamination-molded on the surface of the fibre layer 3. In subsequence to the formation of the intermediate layer 4, a sand core 5 is filled continuously within the space of a molding mold 1. Each resin and the adhesive agent are cured, after that, the molding mold 1 is removed and separated from the base mold 2.

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 high-mix, low-volume production is progressing these days, the proportion of total mold costs in the total manufacturing price of a product has increased, making it uneconomical, and manufacturing delivery times are long, which has a large impact on product manufacturing. There was a problem.

Therefore, as an alternative to the conventional metal mold, one surface is covered with a thermosetting resin (gel coat), and the inside is covered with an intermediate paste layer that is a mixture of resin, metal powder, glass chop, etc. The idea was to use a resin mold whose inside was covered with a laminate layer of glass fiber impregnated with resin.

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 the gel coat and the intermediate paste layer is such that they are bonded when the thermosetting resin becomes gelled or semi-gelled. As a result, the gel coat and intermediate paste layer are not completely integrated structurally, but are merely adhered to each other, and the thermosetting resin shrinks during curing, creating a gap between it and the intermediate paste layer. Due to the manufacturing process, 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 at best it can only be used for molding prototypes, and there is a problem that it cannot be used as a regular mold instead of a metal mold.

Therefore, the present applicant has applied for the previous Japanese Patent Application No. 60-86053 (Japanese Unexamined Patent Publication No. 61-244508),
As seen in each application of No. 28342, reinforcing fibers such as synthetic fibers such as aramid fibers and metal fibers formed from various metals into a cross shape, thread shape, or wave shape are applied to the surface of the resin mold. By impregnating and solidifying a thermosetting resin with a thermosetting resin to form a surface layer, or by bonding these reinforcing fibers with double-sided adhesive tape, one surface can have excellent strength and durability. Equipped with wear and heat resistance.

We have developed a resin mold that can be used repeatedly as a wooden mold over a long period of time.

[Problem to be solved by the invention]

However, in the case of reinforcing fibers with strength such as the synthetic fibers and metal fibers mentioned above, each fiber has an extremely strong repulsive force, so they are impregnated with thermosetting resin and solidified. When bonding with double-sided adhesive tape, a large number of fibers will cause a bridging phenomenon on the surface of the surface layer and protrude like whiskers. Since flaws are left on the surface of the molded product, there is a problem in that the surface treatment requires a great deal of time and effort.

In addition, as mentioned above, in the case of resin molds in which various reinforcing fibers are directly exposed on the surface, when used in press molds, there is a problem that the frictional resistance of the fibers deteriorates the slipperiness during pressing. Furthermore, when this resin mold is used in an injection mold or a vacuum mold, there is a problem that the texture of the fibers is transferred to the surface of the molded product.

Therefore, the technical problem of the present invention is that reinforcing fibers do not protrude in one surface layer in a straight line, and the surface can be molded to be smooth and exhibit excellent sliding properties. The object of the present invention is to provide a method for manufacturing a resin mold that is devised so that the texture of the resin mold is not transferred.

[Means to solve the problem]

The measures taken in the present invention to solve the above technical problems are as follows.

A resin mold in which reinforcing fibers such as synthetic fibers or metal fibers are stretched over the surface of a base mold coated with a mold release agent, and the surface is reinforced with a reinforcing fiber layer by filling this base mold with sand core or cement. In the method of manufacturing, the surface of the reinforcing fiber layer is impregnated with a fast-curing adhesive to form the surface of a resin mold.

However, the term "sand core" as used herein means a mixture of silica sand, glass chop, and resin. Furthermore.

Synthetic fibers refer to carbon fibers, aramid fibers, glass fibers, etc., and metal fibers refer to various metals such as stainless steel, copper, and iron in the form of crosses, threads, waves (cotton, etc.). means a product that has been molded into a shape).

[Effect]

The above means works as follows.

■ The surface layer that covers the surface of the resin mold is reinforced with a reinforcing fiber layer such as synthetic fibers or metal fibers, so this fiber layer exhibits excellent strength and abrasion resistance and strengthens the surface of the resin mold. This allows the resin mold to be used repeatedly as a main mold over a long period of time.

■ Fast-curing adhesive impregnated on the surface of the reinforcing fiber layer (
The instant adhesive (instant adhesive) penetrates and diffuses between each fiber, flows, and impregnates each fiber itself, making it possible to close the weave of the fibers.Furthermore, the adhesive force of the fast-curing adhesive allows each fiber to Since bridging can be prevented, the surface of the resin mold can be made smooth to improve slippage during press molding, and it is also possible to produce clean molded products with no bridging marks or texture transfer marks on the surface. .

As described above, the above-mentioned technical problem can be solved by the above-mentioned means, and the problems of the conventional technology can be solved.

〔Example〕

Hereinafter, a preferred embodiment 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 reinforcing fiber layer 3 impregnated with a fast-curing adhesive and an intermediate paste layer 4 on a base mold 2 fixed on a bottom hole 1a of a mold, generally indicated by reference numeral 1. is a cross-sectional view showing a state in which the reinforcing fiber layer 3 is made of a synthetic fiber such as aramid fiber, or a metal fiber made of stainless steel or the like. To impregnate mold 3 with a fast-curing adhesive (not shown), apply the fast-curing adhesive to the surface of the base mold 2 coated with a release agent (not shown), and remove the applied adhesive. A method of pasting reinforcing fibers on the adhesive, or applying the above-mentioned quick-curing adhesive to the surface of the reinforcing fibers, and then pasting the reinforcing fibers on the base mold 2 coated with a release agent. There is, and the selection is optional.

In addition, instant adhesives of various compositions such as emulsion type, prepolymer type, heat-melting type, and pressure-sensitive type can be used as fast-curing adhesives, but in the experiment, we used a product manufactured by Konishi Co., Ltd. I used the famous Bond Quick Set.

Reinforcing fiber layer 3 impregnated with fast-curing adhesive as described above
Because the properties of fast-curing adhesives, such as flow, leakage, penetration, diffusion, adsorption, and solidification, work strongly and quickly between molecules, it prevents the adhesive from rising due to the repulsive force of the reinforcing fibers. In addition, since the adhesive can fill the texture of the fibers, it is possible to form a smooth surface and exhibit excellent strength, abrasion resistance, and heat resistance as described below.

After the above-mentioned reinforcing fiber layer 3 has been formed, the above-mentioned intermediate paste layer 4 is subsequently laminated on the surface of this fiber layer 3 as shown in FIG. A mixture of metal powder, glass chop, etc. in a resin solution is applied onto the reinforcing fiber layer 3 using a brush or spatula, or sprayed with a machine. This intermediate paste layer 4 serves as a medium for integrally bonding the reinforcing fiber layer 3 and the sand core or cement described later, and the resin used is epoxy resin, unsaturated polyester, etc. Condensation resins such as resins and urethane resins are used.
The fiber layer 3 is continuously formed before the fast-curing adhesive impregnated into the fiber layer 3 is cured.

In FIGS. 2 and 3, 5 indicates a sand core that is continuously filled into the space in the mold 1 after the intermediate paste layer 4 is formed. This mixed sand core 5 is filled into the mold 1 by manual or mechanical work, and in particular, the resin used is one of the same type as the thermosetting resin used in the intermediate paste layer 4. In order to use the sand core 5, reinforcing fibers 3 impregnated with a fast-curing adhesive are applied to the surface of the sand core 5 using the intermediate paste layer 4 as a medium, depending on the mutual affinity of these resins and the gelation of each resin. It can be integrally bonded and fixed.

Further, in Fig. 2, 6 is a leveling resin layer injected to level the upper surface of the filled sand core 5, and 7 is a presser plate that presses this resin layer 6 to create a horizontal surface. .

Once each of the above steps has been completed and each resin and adhesive has solidified,
By removing the mold 1 and releasing it from the base mold 2 as shown in FIG. 3, the surface is covered with a reinforcing fiber layer 3 impregnated with a fast-curing adhesive and molded smoothly. Reinforcing fibers near the surface < (0,01-0,5/mm)
A resin mold 10 exposed to the outside is manufactured.

It is also possible to use cement instead of the sand core 5 described above, and it is also possible to use cement for reinforcement by directly impregnating the surface of the sand core 5 or cement with a fast-curing adhesive without forming the intermediate paste layer 4. It is also possible to form the fiber layer 3, and these selections are arbitrary.

〔effect〕

Since the method for manufacturing a resin mold according to the present invention is as described above, the resin mold manufactured according to the present invention has a structure in which the synthetic fibers or metal fibers constituting the reinforcing fiber layer are exposed near the surface of the mold. In this connection, the surface of the resin mold is strengthened by the mechanical strength, abrasion resistance, compression resistance, and heat resistance of these fibers, making it possible to create a resin mold with durability close to that of conventional molds.
Although it is extremely easy to manufacture, the present invention particularly allows the reinforcing fiber layer to be impregnated with a fast-curing adhesive and the surface to be molded to be smooth, resulting in excellent sliding properties. Moreover, it is possible to manufacture beautiful molded products without bridge marks or texture marks on the surface, and it is simple in structure and easy to implement, and it is suitable for press molding or injection molding. .

It is useful for manufacturing various molds such as vacuum molds, FRP molds, and RIM molds, or casting models.

[Brief explanation of the drawing]

FIGS. 1, 2, and 3 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 mold, 2 is a base mold, 3 is a reinforcing fiber layer impregnated with a fast-curing adhesive, 4 is an intermediate paste layer, 5 is a sand core or cement, and 10 is a resin mold manufactured according to the present invention. Resin Machine Mold Co., Ltd.

Claims (1)

[Claims] A resin mold in which reinforcing fibers such as synthetic fibers or metal fibers are stretched over the surface of a base mold coated with a mold release agent, and the surface is reinforced with a reinforcing fiber layer by filling this base mold with sand core or cement. A method for manufacturing a resin mold, characterized in that the surface of the reinforcing fiber layer is impregnated with a fast-curing adhesive to form the surface of the resin mold.