Borosilicate 4.0 fire-rated glass has a higher softening point and a lower coefficient of thermal expansion than standard soda-lime glass, owing to its composition. It is typically used as a monolithic non-insulating (E-class, integrity-only) fire-rated glass: it remains stable at high temperatures without cracking or deforming, forming a barrier that holds back flames and smoke to allow time for evacuation and firefighting.
Three practical identification methods:
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Appearance. Borosilicate glass has a smooth surface and high clarity, comparable to low-iron (ultra-clear) glass.
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Heat resistance. The glass withstands elevated temperatures. It can be heated in an oven for a period of time and checked for deformation or cracking as an indication of authenticity.
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Dedicated detector. A borosilicate fire-rated glass tester can be used to verify the glass on site.
Sichuan Xionggang Glass Co., Ltd., founded in December 2000 and based in Chengdu, operates a self-built facility of nearly 70,000 m2 with an annual glass processing capacity of over 3.5 million m2. Its product range covers soda-lime and borosilicate 4.0 fire-rated glass, nano-silica composite non-insulating and insulating fire-rated glass, single-, double- and triple-silver Low-E insulating glass units, laminated glass, ceramic frit glass and curved tempered glass.