Analysis of key problems in crystal glass manufacturing

Top

Categories:news
Author:
Origin:
Time of issue:2019-11-22 09:47
Views:

(Summary description)Only when we always put quality and design first, rather than blindly pursue profits and customer numbers, can we become a international famous brand.

Analysis of key problems in crystal glass manufacturing





Analysis of key problems in crystal glass manufacturing

Top

(Summary description)Only when we always put quality and design first, rather than blindly pursue profits and customer numbers, can we become a international famous brand.

Categories:news
Author:
Origin:
Time of issue:2019-11-22 09:47
Views:

Information

There are many manufacturers of crystal glass in the world, but only a few have become international famous brands. Some enterprises in our country export lead crystal, which has a big gap compared with international famous brands. The whiteness and brightness are not as good as foreign famous brands. There are often bubbles and stripes in the glass. More importantly, after being placed in the air, the surface will be hazy and lose the unique brilliance of lead crystal, which makes lead crystal in our country unable to become one of the top-grade crystals. The key problem of crystal glass manufacturing lies in the following aspects.

Use appropriate glass composition

The volatilization of PBO must be considered in the design of glass composition. There are two grades of all lead crystal, one is 30% PbO, the other is 33% PbO. For 30% PbO, the content of PBO in the design composition should be 31% ~ 31.7%, and for 33% PbO, the content of PBO in the design composition should be 34.5% ~ 35.1%, so as to ensure that the content of PBO required by the analysis and test can be reached. Similarly, the design PbO of medium lead crystal should be about 25%. However, it is not that the more PbO is added, the higher PbO is, the greater the volatilization is, and the volatilization is in direct proportion to the amount of introduction. At the same time, the increase of PBO will increase the stratification of glass and the erosion of refractories, and the more easily stripes and stones are formed in glass.

In order to ensure the whiteness and brightness of glass, Fe2O3 content must be strictly controlled below 0.01%, and other colored ions such as TiO2 and MnO must also be strictly controlled. In addition to K2O, some Na2O can be properly introduced into the high lead glass. The double alkali effect can be used to melt, reduce the expansion coefficient and improve the chemical stability. Lead glass is generally not acid resistant. It is weathered by SO2 in the atmosphere, forming weathering film, and the surface loses luster. When the composition of lead glass conforms to the following formula, it has good acid resistance:

PR = 0.36(79.4-PPbO)

(1) PR in the formula - alkali metal oxide content in glass (mass fraction);

Ppbo -- PbO content in glass (mass fraction).

For sio2-pbo-k2o-na2o, sio2-b2o3-pbo-na2o, sio2-pbo-cao-na2o component system glass, the ratio (mole fraction) of network regulator and SiO2 is obtained by etching with 1% acetic acid (HAC) at room temperature, which plays an important role in acid resistance, namely: < 0.7

(2) at this time, the dissolution rate of network regulator ion in acetic acid is slow, and the acid resistance of glass is good. When the ratio is more than 0.7, with the increase of network regulator ion, the acid resistance of glass is poor. The composition of lead glass can be designed according to formula (2).

As the density of glass is easy to measure and calculate, the empirical formula of glass density and refractive index proposed by told is as follows:

(3) where ρ - glass density.

The relationship between dispersion coefficient and PbO content of lead crystal can be calculated according to meess formula:

υ= 0.003307x2 – 0.7862x +65.58

(4) where, τ - dispersion coefficient;

X -- PbO content in glass.

Keyword:

Scan the QR code to read on your phone

Previous: None

Next: None

Previous: None

Next: None