JPH0767699B2 - Soluble medium size for molding - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention is intended to improve a medium-sized mold used for molding a hollow member when the hollow member is molded and manufactured from a thermosetting material or a composite material containing a thermosetting material as a base material. Pertain.

(Problems to be Solved with Prior Art) Thermosetting materials or composite materials based on thermosetting materials (hereinafter referred to as "thermosetting materials") as equipment parts for aircraft, automobiles, etc., or centrifugal separators, etc. The hollow member manufactured in 1) has been widely used because it is lightweight and has high strength.

For example, in the case of a hollow member as shown in FIG. 3, as a conventional molding method, generally, a split mold as shown in FIGS. 4 to 6 is used, and a thermosetting material is applied onto the split mold for molding. Has been done. That is, the molding medium mold 11 is divided into five parts, a central split mold 12, left and right split molds 13 and 14, and upper and lower split molds 15 and 16, and these are combined to fix the left and right end parts as shown in FIG. 1
Cover with 7 and 17, and tighten the bolts to make the split mold integral.

After applying the product material to this and heating and curing, remove the left and right fasteners, pull out the central split mold 12 in the horizontal direction in the figure, and move the upper split mold 15 (or lower split mold) to that space. After the convex part of the mold is removed from the concave part of the product, remove it horizontally, then similarly remove the lower (or upper) split mold 16, then remove the center split mold 12 and the upper and lower split molds 15, 16. The left (or right) split mold 13 is moved to the vacant space and removed laterally, and the right (or left) split mold 14 is similarly removed to form a hollow product.

By the way, curing of the thermosetting material attached to the middle mold, the resin of the thermosetting material whose viscosity is temporarily reduced during heating enters the gap between the upper and lower split molds and the left and right split molds to cure,
Since it adheres to the mating surface of the split mold, it requires a considerable number of man-hours for its removal work, and the disassembling or assembling of the mold during molding is a manual work, and unmanned operation cannot be performed. Or, as each split mold becomes slender, the rigidity of the medium size is reduced, making it unsuitable for long objects. Moreover, under high temperature, each split mold deforms and the gap between joints becomes large, resulting in a short life. There is a problem
Further, there is an inconvenience such as the occurrence of burrs at the joint of the mold on the inner surface of the product.

It is an object of the present invention to provide a molding medium mold that solves the above problems.

(Means for Solving Problems) In order to solve the above problems, the present invention provides a molding medium-sized mold having an inner surface shape of a product formed on the surface thereof, in which at least the surface layer portion or all is soluble in a solvent. It consists of solid calcium carbonate powder collected in a predetermined shape and solidified,
In addition, a large number of fine pores for facilitating the penetration of the solvent are continuously present in the inside thereof.

In the present invention, an acid or salt such as dilute sulfuric acid, a solution containing caustic soda, or water is used as the solvent.
As the medium-sized material that dissolves in these solvents, for example, a material powder such as calcium carbonate that dissolves in an acid is used,
It is desirable that the particle size distribution be uniform in order to make it easier to dissolve in the solvent, and it is preferable that the powder particles have a large number of pores and facilitate penetration of the solvent.

A small amount of, for example, a thermosetting silicone resin is added as a binder to such a material powder and mixed, and then molded and cured into a desired shape.

(Example) Next, an example will be described. Calcium carbonate powder was used as a medium-sized material, and a small amount of thermosetting silicone resin was added as a binder to the mixture, which was mixed with a mixer. An outer shell 2 having a required shape was formed around the outer shell 2 and heated and cured in an electric furnace. The center through mold 3 may be inserted into the central portion after forming the outer shell 2.

A glass fiber-impregnated FRP prepreg sheet as a medium-sized material was wound around the outer shell 2 to a required thickness and molded into a predetermined size.

After heating and hardening this, the central penetrating mold 3 was taken out and immersed in diluted sulfuric acid as a solvent, and the molding mold 1 melted and disintegrated, and could be easily removed and separated from the product 4. We were able to. The product was removed from the liquid, washed and dried.

There are no defects such as casting and cracks on the inner surface of the obtained product,
It had the required shape.

(Effect) As described above, when the melt-molding medium die for hollow products of the present invention is used, since the medium die is an integral type, the work of assembling the mold or the separate take-out work or the work of removing the adhering material becomes unnecessary. In addition, since the medium-sized product can be removed simply by immersing it in a solvent solution, automation of manufacturing hollow products becomes easy.

In addition, the inner surface shape of the hollow product can be obtained with a desired shape and size, or the central penetrating type can be made thicker and the rigidity can be increased, so that it can be used for manufacturing long products, etc., and improvement of product quality is expected, In addition, the soluble middle mold can be easily molded by a cold isostatic press and an automatic grinder, the precision can be obtained, and the whole system can be automated and labor-saving, so it is also suitable for mass production. The practical effect is extremely large. Further, since many fine pores are continuously formed in the mold, the solvent easily penetrates into the mold, the melting time of the middle mold is shortened, and the manufacturing time can be shortened. Moreover, since the calcium carbonate, which is relatively easy to obtain and inexpensive, is used as the material, the manufacturing unit price can be reduced.

[Brief description of drawings]

FIG. 1 is a partially crushed front view showing an example of the molding medium die of the present invention, FIG. 2 is a side view of the same, and FIG. 3 is a partially crushed front view showing an example of a product manufactured by using the molding medium die. Fig. 4 is a vertical sectional view showing an example of a conventional split mold for molding, Fig. 5 is a sectional view taken along line VV of Fig. 4, and Fig. 6 is a side view showing a state in which a stopper 17 is removed. is there. 1 ... Molding medium size, 2 ... Outer shell, 3 ... Center penetration type, 4
... Hollow products

Claims (1)

[Claims] 1. A molding medium die having an inner surface shape of a product formed on the surface thereof, wherein at least the surface layer portion or the whole thereof is formed by assembling and solidifying a solvent-soluble calcium carbonate powder into a predetermined shape. And a soluble medium mold for molding, characterized in that a large number of fine pores for facilitating the penetration of the solvent are continuously present therein.