JP2593895Y2 - Mold for molding thermosetting resin products - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding die used for molding a resin product from a thermosetting resin material.

[0002]

2. Description of the Related Art A molding die used for manufacturing a product using a thermosetting resin is easily worn due to high temperature. Therefore, conventionally, a steel material having a large structural strength and abrasion resistance is used, and after machining such as cutting is performed on the steel material to form a mold material having a desired shape, usually, the mold material is quenched to form a mold. Has formed. Then, this mold is inserted into, for example, FIG.
As shown in (1), the surface of the mold 1 is heated by the panel heater 3 attached to the rear surface of the mold 1 to heat the contact portion 2 with the thermosetting resin.

However, in the conventional mold 1, the entire mold is made of metal, and heat is transmitted from the panel heater 3 on the rear surface of the mold 1 to the entire mold, and a contact portion between the panel heater 3 and the resin on the opposite side. 2 is heated so that heat is easily radiated on the way to release heat, and a large amount of heat is required until the contact portion 2 reaches a required temperature, which is uneconomical.

[0004] Further, since the mold is made of wear-resistant steel material, it is expensive and it is necessary to form it by machining such as cutting. There is a disadvantage that the processing cost is high. Furthermore, the number of times the mold is used is usually several thousand to tens of thousands of times, but the number of products molded by the same mold is often relatively small, and it is difficult to expect cost reduction by mass production. However, there is a problem that the cost is high even in other mold methods.

As a solution to such a problem,
Japanese Patent Application Laid-Open No. 1-288412 discloses a mold for molding a resin product in which a ceramic or metal sprayed layer is provided on a backup layer made of concrete.
This solves the above-mentioned problems, but since the backup layer made of concrete has low hardness, the surface layer portion gradually collapses when used continuously. as a result,
The sprayed layer formed on the backup layer may also be damaged at the collapsed portion, or the sprayed layer may be separated from the collapsed portion, and the concrete backup layer is heated due to its relatively high thermal conductivity. There are various problems that the heat of the sprayed layer easily escapes and is uneconomical.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems of the concrete backup layer. The present invention uses a concrete material having high hardness and small thermal conductivity. The purpose is to provide a material having improved durability and thermal efficiency by forming, and the gist of the purpose is to roughen and heat a concrete mold formed by mixing silica fume into cement. A thermosetting layer characterized by providing a sprayed layer of ceramics or metal on the entire surface or a part of the surface from which water is removed, and providing a current-carrying electrode at a desired portion of the sprayed layer. In the mold for molding resin products.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the embodiments of FIGS. 1 to 7. In the drawings, reference numeral 1 denotes a mold for molding a thermosetting resin product according to the present invention, and its base ( The mold member 2 is made of concrete in which fine silica fume is mixed into cement. Reference numeral 3 denotes a plurality of arc-shaped ridges formed in parallel with the surface 2a of the silica-fume-concrete concrete mold member 2 and has a shape opposite to that of a molded product. Alternatively, a metal sprayed layer 4 is formed.

The ceramic or metal spray layer 4 is
In the illustrated embodiment, the surface 2 of the concrete mold 2 is
a, but as shown in FIG. 2A,
A plurality of concave grooves 2b may be formed in parallel at intervals of, for example, 2 to 3 cm, and the thermal spray layer 4 may be formed only in the concave grooves 2b. In this case, it is possible to save thermal spray material. Various effects can be expected, such as that it can be performed, that the thickness of the thermal sprayed layer 4 can be easily formed to be constant, and that the energizing electrode described later can be easily installed at an arbitrary position. In the drawing, reference numeral 5 denotes an electrode for heating the molding die 1, more specifically, heating the molding die 1 by supplying a current to the sprayed layer 4.

As shown in FIGS. 3 and 4, a method of manufacturing the molding die 1 is as follows. First, in a master model manufacturing process A, a plurality of arc-shaped protrusions 6 are formed on the upper surface of the same shape as the die 2.
A master model 6 having a is manufactured from a desired material such as wood. Then, in the next reverse mold manufacturing process B, the master model 6 is placed in the box-shaped mold 7 with its arc-shaped convex 6a facing upward, and the surface of the master model 6 and the After applying a release agent to the surface of each of the four side walls 7a, for example, plaster S is put into the gap 8, and after the plaster S is hardened, the mold 7 is turned upside down and removed. A gypsum mold 9 is formed in the shape opposite to that of the master model 6.

Next, as shown in FIG. 5, the reversing mold 11 is formed by placing the plaster mold 9 in the mold 10. Then, in the next concrete casting step C, a mold release agent is applied to the surfaces of the arc-shaped concave 9a of the plaster mold 9 and the four side walls 10a of the mold 10, respectively. The concrete K is cast, and the concrete K is hardened, so that the concrete mold 2 is formed.

Here, as an example of the mixing of the concrete K mixed with silica fume, as shown in Table 1 below,
The mixing ratio of silica fume to cement was about 8%. In this case, since the fine particles of silica fume are finely and uniformly filled in the cement to be dense, the mold material 2 having high strength and high wear resistance can be obtained.

In this type of molding die 1, it is necessary to concentrate and heat only the surface of the die, which is a portion that comes into contact with the thermosetting resin as a molding material, in order to efficiently use a heat source. preferable. Therefore, it is better to select a material having as low a thermal conductivity as possible as a backup layer for the ceramic or metal sprayed layer 4. However, in the case of ordinary concrete, its thermal conductivity is 1.6 to 2.0 Kcal. /
In contrast to m · h · ° C., in the case of concrete made of silica fume mixed, it is as small as about 1.5 Kcal / m · h · ° C., so that the heat of the ceramic or metal sprayed layer 4 does not easily escape. Therefore, power consumption for heating the thermal sprayed layer 4 is small and economical.

[0013]

[Table 1]

Then, in the next curing step D, the concrete mold 2 is kept in the mold 10 in a state where it is naturally cured at 20 ° C. for one day, and then steam cured at 65 ° C. for 3 hours. After the curing step D is completed, the mold 10 is turned upside down and removed from the mold, thereby obtaining a concrete mold 2 containing silica fume.

Further, in the thermal spraying step E, first, the mold 2
Pre-polishing is performed on the entire surface 2a of the arc-shaped ridge 3 or in the groove 2b, and then the abrasive is polished to the surface 2a or
After spraying into b to roughen the surface, it is heated to about 50 ° C. to 90 ° C. to remove water immediately before thermal spraying. In the thermal spraying, for example, the heat of high-speed, high-temperature plasma injected from a plasma generator is used to heat the ceramic or metal powder added thereto to a state of melting or a state close thereto, and the molten powder is roughened. Surface 2a of the molded member 2
Alternatively, the sprayed ceramic or metal layer 4 is formed by spraying at high speed into the groove 2b.

Here, powder of titanium oxide, nickel chromium, manganese oxide, cobalt oxide chromium oxide or nickel oxide is used as the metal which is a thermal spray material. The components 1 such as the terminals 5 are attached to complete the resin product molding die 1. The electrode 5 may be embedded at the time of placing concrete.

Next, a method of molding a product using a thermosetting resin material by using the molding die 1 will be described. As shown in FIG. The conducting wire 13 is connected to each of the two electrodes 5 and 5. When a power supply of 200 V is applied to the conductive wire 13, about 10
Since the temperature of the ceramic or metal sprayed layer 4 of the mold 1 or the surface 2a of the mold 2 in the vicinity of the sprayed layer 4 reaches about 100 ° C. in one minute, the sprayed layer 4 and the mold 12
The thermosetting resin R is injected into the space 14 surrounded by the four side walls 12a. As a result, the resin R cures in about 10 minutes. It should be noted that after the temperature at the surface 2a of the mold 1 reaches 100 ° C.
The thermosetting resin can be cured even when the electric current of V is applied.

After the thermosetting resin R is cured, it is released from the mold 12 and has a shape opposite to that of the resin product forming die 1 shown in FIG. A molded article made of a thermosetting resin is obtained. Here, the relationship between the energizing time and the temperature of the mold in the above molding example is shown in FIG. Note that the shape of the molding die 1 is not limited to the above-described shape, and it goes without saying that molds of various shapes can be manufactured.

[0019]

[Effects of the Invention] The molding die for a thermosetting resin product according to the present invention is, as described above, a concrete mold formed by mixing silica fume into cement to roughen the surface and remove moisture by heating. A ceramic or metal sprayed layer is provided on the entire surface or a part of the surface.
Since the current-carrying electrode is provided at a desired portion of the sprayed layer, the ceramic or metal sprayed layer is formed on the surface of a mold having high strength, high abrasion resistance, and small thermal conductivity. ing. Therefore, the thermal sprayed layer is not damaged or peeled off from the surface of the mold material, and the durability is improved. In addition, since the heat of the heated thermal sprayed layer is hard to escape, the surface portion of the mold can be efficiently heated. There are various effects such as economical.

[Brief description of the drawings]

FIG. 1 is a perspective view of a mold for molding a thermosetting resin product according to the present invention.

FIG. 2 is an enlarged cross-sectional view of the same type.

FIG. 3 is a block diagram showing a manufacturing process of the same mold.

FIG. 4 is an explanatory view of the production of an inversion type.

FIG. 5 is an explanatory diagram of the production of a mold material by the reverse type.

FIG. 6 is an explanatory view showing an example of resin product molding using a mold.

FIG. 7 is a diagram showing a relationship between the energization and the temperature of a metal layer.

FIG. 8 is an enlarged cross-sectional view of a conventional resin product molding die.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 Mold for resin product molding 2 Concrete mold material mixed with silica fume 2a Surface 2b Recessed groove 4 Sprayed layer of ceramic or metal 5 Electrode 6 Master model 7 Mold 8 Air gap 9 Gypsum mold 10 Mold 11 Invert mold 12 Mold 13 Lead wire 14 void S gypsum

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B29C 33 / 38,45 / 26,39 / 26

Claims (1)

(57) [Scope of request for utility model registration] A ceramic or metal sprayed layer is provided on the entire surface or a part of the surface of a concrete mold formed by mixing silica fume into cement and removing water by heating. A mold for molding a thermosetting resin product, characterized in that a current-carrying electrode is provided at a desired portion of the sprayed layer.