Good electrical insulation performance and high dielectric strength.
High borosilicate glass (also known as
hard glass) is also known as "borosilicate glass 3.3" due to its linear
thermal expansion coefficient of (3.3 ± 0.1) X10-6/K. It is a special
glass material with low expansion rate, high temperature resistance,
high strength, high hardness, high light transmittance, and high
chemical stability. Due to its excellent performance, it is widely used
in industries such as solar energy, chemical industry, pharmaceutical
packaging, electric light sources, and craft accessories. Its excellent
performance has been widely recognized by various sectors of the world,
especially in the field of solar energy, which is more widely used.
Physical and chemical properties
The
linear expansion coefficient of high borosilicate glass is
3.3±0.1X10-6/K, which is a type of glass composed mainly of sodium oxide
(Na2O), boron oxide (B202), and silicon dioxide (SIO2). This type of
glass has a high content of boron and silicon, with boron content
ranging from 12.5% to 13.5% and silicon content ranging from 78% to 80%.
Therefore, it is called high boron silicon glass. PYREX glass belongs
to borosilicate glass. It is acid resistant, alkali resistant, and water
resistant, with superior corrosion resistance and good thermal
stability, chemical stability, and electrical performance. Therefore, it
has characteristics such as resistance to chemical erosion, thermal
shock, good mechanical properties, and high temperature resistance.
Borosilicate glass begins to soften at approximately 821℃ (1510℉).
Borosilicate glass is less dense than ordinary glass.
Although
borosilicate glass has better thermal vibration resistance than other
types of glass, it can still break due to rapid or uneven temperature
changes. When broken, the cracks in borosilicate glass are often larger
than crushed.
In terms of
optical performance, borosilicate glass has low dispersion (about 65
Abbe coefficient) and relatively low refractive index (the entire
visible light range is 1.51-1.54)