JPH0729300B2 - Mold and manufacturing method thereof - Google Patents

Description

TECHNICAL FIELD The present invention relates to a mold comprising a surface layer portion and a backing reinforcing portion, and a method for producing such a mold.

[Conventional technology]

As a mold for manufacturing a plastic product by injection molding, press molding, or the like, a mold including a surface layer portion and a backing reinforcing portion is known.

Explaining the molding method of this type of mold, generally, as shown in FIG. 5, a surface layer part 5 made of a metal coating layer is formed on a mother mold 7 subjected to a mold release process by electric plating or thermal spraying, A composite material made of epoxy resin 4 mixed with aggregates 3 such as aluminum particles, or a non-metal material such as cement, or a metal material is injected and solidified from thereover to line it.
Next, after smoothing the back surface 2a of the lining reinforcing portion with the cutting tool 8,
By removing the mother die 7, a molding die 1 including the surface layer portion 5 and the backing reinforcing portion 9 is obtained.

It is to be noted that, as is known in the art, a molding method by a so-called electroforming method in which a plating layer is formed on the molding surface as described above, and an aggregate is put therein in order to reduce the shrinkage of the matrix phase (matrix) of the reinforcing portion of the lining is also known. There is an application example thereof, for example, Japanese Patent Laid-Open No. Sho 60
-54819 and JP-A-61-63413.

Compared with general molds, the molds obtained as described above do not require shaving and finishing processes, and have the advantage that the larger the product shape or the more complicated the product shape, the greater the cost reduction effect. is doing.

[Problems to be solved by the invention]

However, the above-mentioned conventional mold and the method for manufacturing the mold have the following problems.

First, when the backing material is a resin-based composite material or a non-metal material, there is an additional advantage that no expensive equipment is required in the backing process and the work is simple, but there is a drawback that the backing portion has a low compressive strength. is there. This means that aggregates such as aluminum particles have the effect of reducing mold shrinkage, but do not contribute to the improvement of compressive strength. The reason is as shown in FIG. ., 3 ... are not in contact with each other, and are separated and dispersed in the matrix material 4. On the other hand, when a metal is used as the backing material, the backing portion has sufficient pressure resistance, but the backing step has a drawback that expensive equipment such as metal melting equipment is required and the work is complicated.

The present invention has been made to solve the above problems,
An object of the present invention is to provide a molding die having excellent pressure resistance strength that can be molded by a simple operation without requiring expensive equipment.

[Means for solving problems]

The mold of the present invention that can achieve the above object comprises a surface layer, a large number of aggregates that are in contact with the surface layer and are in contact with each other, and a matrix material that fills the voids between them. And

Further, the method of the present invention for producing a molding die as described above comprises forming a resin or metal coating layer on the mother die,
Next, an aggregate is laid in multiple stages on the coating layer, a matrix material is injected into the voids formed and cured to produce a mold member, and then the master mold is released from the mold member. .

In particular, when the surface layer portion is a resin layer, metal plating is preferably applied on it.

As the aggregate used here, aluminum, iron, copper,
Any material can be used as long as it can withstand the molding pressure, such as metals such as zinc, ceramics, stones, etc., and its shape is also a sphere, polyhedron, block, heteromorph mixture, etc. when it is laid in multiple stages. Any shape may be used as long as voids are generated, and the size may be non-uniform.

As the matrix material, various resins such as epoxy resin, tin,
Any material having low melting point such as bismuth or lead, cement, gypsum, starch or the like, which has fluidity or can be imparted in a certain state, can be solidified or hardened after transformation.

The mold release treatment on the mother die, the coating of the resin or metal, and the metal plating on the resin layer may be carried out by a conventional method.

[Action]

With the above configuration, the pressure received by the cavity surface of the mold during molding is propagated to the matrix material and the aggregate, but the aggregate in the matrix material is connected to other adjacent aggregates, especially the back side of the aggregate. It is supported by the existing aggregate. Therefore, since the aggregate having a high pressure resistance substantially receives the molding pressure, the pressure resistance of the entire mold is secured.

〔Example〕

Examples of the present invention will be described below with reference to the drawings, but the present invention is not limited thereto.

Embodiment 1 FIG. 1 is a cutaway view showing a molding die 1 according to an embodiment of the present invention. The main mold 1 has a surface layer portion 5 including a resin layer 5a and a metal layer 5b.
And a lining reinforcing portion 9 made of aluminum spheres (aggregates) 3,3 ... and resin (matrix material) 4,
Each aluminum sphere 3,3 ... is another sphere around each other 3,3 ...
And are substantially in contact with each other (not all adjacent spheres must necessarily contact).

A method of manufacturing the main mold 1 will be described with reference to the process chart of FIG.

First, a mold release agent is applied to a mother die 7 made of resin, wood, stone or the like, and then an epoxy resin is applied with a brush to an appropriate thickness to form a resin layer 5a. Aluminum spheres 3, 3, ... Are laid in multiple stages on the semi-cured resin layer 5a. Then, the epoxy resin 4 is injected from above and the aluminum spheres 3, 3 ...
The mold member 12 is manufactured by infiltrating and curing the resin 4, which is a matrix material, into the non-contact voids between them and the non-contact voids between the aluminum spheres 3, 3, ... And the resin layer 5a. Then the mold member
The back surface 2a of 12 is cut with a cutting tool 8 to be parallel to the bottom surface 7a of the master mold. This cutting process may be omitted depending on the purpose of use of the molding die. Next, the mold member 12 is detached from the mother mold 7 and released from the mold, and a pretreatment is performed by a conventional method so that the metal plating easily adheres to the cavity surface (transferred surface of the mother mold) of the resin layer 5a. The metal mold layer 5b is formed, and the upper mold 2
To manufacture. In the same manner, the lower mold 6 is manufactured, and the upper mold 2 and the lower mold 6 are matched with each other to obtain the pair of molding dies 1 shown in FIG.

The mold 1 has excellent pressure resistance and its cavity 10
Even if the molding material is injected into the inside with high pressure, strain deformation does not occur.

Example 2 A metal was prepared by providing a thin silver film on the surface of the master mold and subjecting the master mold surface to electrodeposition plating such as N1, Co or by directly spraying molten Zn etc. onto the master mold surface with a pneumatic spray gun. Allow the layers to form.
Thereafter, the metal layer is subjected to a backing treatment in the same manner as the resin layer 5a of Example 1 (FIG. 2) to obtain a molding die.
However, when laying aggregate, pipes that allow temperature-controlled water to pass through are buried. Moreover, after removing from the mother mold, no plating is applied.

The mold thus obtained also has excellent pressure resistance,
When used under a higher molding pressure, the upper mold 2 and the lower mold 6 are fitted into the Omo molds 20 and 60, respectively, as shown in FIG. In the figure, 13 is a temperature control hole formed by burying the pipe.

〔The invention's effect〕

According to the present invention, a molding die manufactured by backing and reinforcing the surface layer is comparable to a general molding die that requires nitrification or finishing without the use of a refractory metal matrix material. It is now possible to provide a molding die with excellent pressure resistance.

In other words, expensive metal melting equipment and complicated work, special cutting equipment and advanced finishing skills can be eliminated,
It is possible to provide a molding die with high accuracy and durability at low cost and high productivity.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cutaway view showing a molding die according to an embodiment of the present invention, FIG. 2 is a process drawing showing a method for manufacturing a molding die according to one embodiment, and FIG. 3 is another embodiment. FIG. 4 is a schematic cross-sectional view showing a mode of using the molding die of the example, FIG. 4 is a cutaway view showing an example of a conventional molding die, and FIG. 5 is a process diagram showing a manufacturing method of the conventional molding die. In the figure, 1 ... Mold 3 ... Aluminum sphere 4 ... Matrix material 5 ... Surface layer 5a ... Resin layer 5b ... Metal layer 7 ... Mother mold 9 ... Backing reinforcement

Claims (3)

[Claims] 1. A molding die comprising a surface layer, a large number of aggregates which are in contact with the surface layer and are in contact with each other, and a matrix material which is filled in voids between them. 2. A mold member is manufactured by forming a resin or metal coating layer on a mother die, laying aggregate in multiple stages on the coating layer, and injecting and curing a matrix material into the resulting voids. After that, the molding die is released from the die member. 3. The manufacturing method according to claim 2, wherein metal mold is applied to the surface of the mold member after removing the mother mold.