JPH01126234A - Forming die for curved mirror - Google Patents

Abstract

PURPOSE:To reduce the heat capacity and to improve the wear resistance and uniformity of the material by bonding or welding the fibers of alumina.silicate to each other with various inorg. binders to form the porous forming die. CONSTITUTION:The alumina.silicate fibers as the essential material and the inorg. binder such as silica sol and alumina sol are dispersed in water, and the dispersion is vacuum-formed. The formed product is then dried, and sintered to obtain a ceramic-fiber porous formed product. The product is formed into the forming die of a specified shape for a curved mirror. By this method, the resistance to the spalling due to the rapid change in temp. in cooling and heating is improved. The forming die is appropriately used for the curved mirror such as a back mirror and a toilet mirror.

Description

[Detailed Description of the Invention] [Object of the Invention] Degrees! What has not yet been invented by the Retired Emperor's Office is a method of bending made of alumina silicate fibers as a main material, which can be used to form natural hanging mirrors, suction molding (forced bending), etc., for bending mirrors used as rearview mirrors or cosmetic products. This relates to molds for mirrors.

Bending mirrors, which are used as rearview mirrors or for cosmetic purposes, are made by placing glass on a shaped material with a certain curvature called a noshi-gata, and then heating it at high temperatures of 650 to 750 degrees Celsius. There are two methods: natural hanging molding, which is a process in which glass is manufactured using the deformation of glass, and is bent only by the weight of the glass under high temperatures, or suction molding (forced bending), which is a process that uses vacuum suction. In these glass bending processes, the performance of the shape material has a great impact on the quality of the final product.

Therefore, a number of materials have been tried as the shape material, but currently, diatomaceous earth bricks and low stone refractory bricks are the mainstream, and such diatomaceous earth bricks are widely used as the shape material for rearview mirrors. Its characteristics are that it is lightweight, has a small heat capacity, is sensitive to the ambient temperature of the furnace, makes it easy to create an accurate curvature on the glass, is a natural product, is inexpensive, and has good processability and can be curved (R-processed). )
However, since it is a natural product, there are variations in the product, and it is difficult to use because it contains impurities (also, there is a problem of resource depletion, and it lacks wear resistance and needs to be molded once every 3 to 4 days.) It has drawbacks such as the need for modification.

In addition, low stone refractory bricks are mainly used for cosmetic mirrors, and are characterized by their high wear resistance, which eliminates the need for long-term mold corrections, and by which there is relatively little variation in the product, preventing the contamination of foreign matter. However, since the heat capacity is large, a lot of heat is taken away by the mold itself, and it is difficult to create an accurate curvature in the glass unless the furnace atmosphere temperature is high and the rotation speed is slow, and the mold temperature cools at the exit. First, workers are exposed to adverse environments, and furthermore, it has disadvantages such as poor workability.

From the above, the current mold materials have advantages and disadvantages, and users are by no means satisfied with their use. (Currently, there is a desire to use mold materials with even better performance and manufacture high-quality products.) be.

A turtle whose sun is shining The invention of Sandai is to increase the heat capacity with a mold made of alumina-silicate fiber as the main material, which is used in the molding of bending mirrors used as rearview mirrors or makeup mirrors. In addition to making it smaller, it also improves wear resistance and makes the material uniform.
It is an object of the present invention to provide a mold for a bending mirror, which can prevent the generation of impurity gases and impurity gases, and has significantly improved spalling resistance due to heating and cooling compared to conventional products.

[Structure of the invention]

In view of this point, the invention of 1 Uran ``' Ta at the end of the year is a bending mirror made of a porous ceramic fiber molded body made of alumina silicate fibers, each of which is bonded or fused to each other with various inorganic binders. It is an object of the present invention to provide a mold for use in order to overcome the above-mentioned drawbacks.

In the first major invention, by firmly adhering or fusing each fiber of alumina silicate fiber to each other, the porosity can be increased to make it porous, the heat capacity can be reduced, and foreign matter can be reduced. This eliminates the mixture of

To explain one embodiment of the present invention as follows, AlzOs
Alumina silicate fibers having a chemical composition of 45χ, 5iOz 55% are dispersed in water with an inorganic binder such as silica sol or alumina sol, vacuum formed, then dried and fired to form a ceramic fiber molded body into a predetermined shape. Shape it and make it into a mold.

Tables 1 and 2 show the results of comparison tests with diatomaceous earth cut bricks and low stone refractory bricks.

First, a ceramic fiber molded product (product A) with a bulk specific gravity of approximately 0.60 g/csd, a diatomaceous earth cut brick,
Table 1 shows the comparison test with the low stone refractory brick (the operating conditions in the furnace are the same as the operating temperature and rotation speed of the diatomaceous brick), and then the bulk specific gravity, approximately 0.40 g.
/cnl ceramic fiber molded product (product B),
Comparison tests with diatomaceous earth cut bricks are shown in Table 2 (as operating conditions, the operating temperature was set 30°C lower and the operating speed was set 20% faster than the operating conditions of diatomaceous earth cut bricks).

Table 1 Table 2 [Effects of the Invention] In short, the present invention is made of a ceramic fiber porous molded body made of alumina silicate fibers as the main material and each fiber is bonded or fused together with various inorganic binders, so the heat capacity is By reducing the temperature in the furnace, the operating temperature inside the furnace can be lowered, and the operating speed can be increased, saving energy and improving production efficiency. It becomes more sensitive to temperature and more likely to produce a uniform glass curvature.

Furthermore, the working environment for the process of placing the glass in the mold and the process of taking it out from the mold is improved.

In addition, because the material is not a natural product and is highly uniform, it does not contain moisture or sulfur, so it can eliminate fogging of the glass, and it can be molded without causing damage such as scratches to the glass. It is possible to improve the quality of glass.

In addition, the fiber structure makes it difficult for internal cracks to propagate, resulting in significantly improved resistance to spalling caused by sudden changes in temperature due to heating and cooling compared to conventional products. .

In addition, as is clear from the comparison test, compared to conventional diatomaceous earth bricks and lowite refractory bricks, even when used at the same operating temperature and speed, the period during which mold correction is required (C) is extended. Since the wear resistance can be improved, the labor required for mold correction can be significantly reduced.

In addition, the grooves improve workability and create complex curvatures, and holes (Ar vent hole φ 1.0 to 1.5 m/
(m) In addition, in the case of forced curved molding, even if a hole is required for attaching a degassing attachment, it can be easily machined (5), and its practical effects are enormous.

Below

Claims (2)

[Claims] (1) A mold for a bending mirror, characterized in that it is made of a ceramic fiber porous molded body made of alumina silicate fibers as a main material, and each fiber is adhered or fused to each other with various inorganic binders. (2) A mold for a bending mirror according to claim 1, characterized in that various inorganic binders are made of alumina sol, silica sol, borosilicate glass, etc.