SU676573A1 - Glass frosting method - Google Patents

Description

I

The invention relates to methods for the ion-exchange treatment of glass and glass products and can be used, for example, to produce a ribbon of glass and glass products with a matt light-scattering surface.

Known glass matting when processing it with lutem ion exchange in molten lithium salt I.

Closest to the present invention is a method of matting glass by treating alkali and alkaline earth metals in molten salts, followed by washing the glassware in an intermediate bath with molten salts containing zeolite 2 granules.

A disadvantage of the known methods is the low quality of the surface, which does not always satisfy the requirements imposed on glasses, for example, for lighting purposes.

The purpose of the invention is to improve the surface quality.

The goal is achieved by the fact that in the method of glass grinding by treatment in the molten salt of alkali metals at a temperature below the glass softening temperature

heated to a temperature of 20-200 ° C above its melting point to remove more than 99.96 wt. of crystallization water. %

The processing time for glass in such a melt can vary from a few minutes to several hours; temperature — from 200 to 800 ° C, depending on the chemical composition of the matting glasses and the melt of salts, as well as on the degree of maturity (to be obtained for this type of product.

Example 1. Several batches of explosive glass

industrial composition size 40X40X

X2 mm process in the melt of nitrates

alkali metal consisting of 50 wt. %

LitNOs and 50 wt. % KNO, within 30 min

ori 300 ° C. The water content in the melt varies from 5 to 0.03 wt. %

The initial water content of the B races: melt was 5 wt. % With this water content, the first batch of glass (5 pcs.) Is treated. Then the same melt is heated to a temperature of 350 ° C and maintained at this temperature for 30 minutes. The water content in the melt is reduced in this way to 2.3 wt. % In this melt process the second batch of products. .

Then, such an operation is repeated several times with an obligatory analysis of the proclamation on the concentration of H2O before J processing the next batch of glass.

Data on the appearance of the glass, depending on the water content in the melt are given in Table. one.

Table 1

As can be seen from the table. 1, a decrease in the water content in the melt leads to an improvement in the appearance of glass products.

Example 2. Several batches of quartz tubes with a diameter of 200 mm and a length of 60, mm are treated in molten salts consisting of 80 Weight. % Li2SO4 and 20 wt. % K2SO4

with a melt water content of 1.5; 1.0; 0.5;

0.05; 0,001 weight. % iri 700 ° C for

.

Data on quality and product quality

after processing are given in table. 2

table 2