Soda Glass

Soda-lime glass, most common form of glass produced. It is composed of about 70 percent silica (silicon dioxide), 15 percent soda (sodium oxide), and 9 percent lime (calcium oxide), with much smaller amounts of various other compounds. The soda serves as a flux to lower the temperature at which the silica melts, and the lime acts as a stabilizer for the silica. Soda-lime glass is inexpensive, chemically stable, reasonably hard, and extremely workable, because it is capable of being softened a number of times if necessary to finish an article. These qualities make it suitable for manufacturing a wide array of glass products, including light bulbs, windowpanes, bottles, and scientific glassware objects.

What is the difference between DURAN® and soda-lime glass?

DURAN® is a borosilicate glass 3.3. The coefficient of linear expansion,  

α= 3.3 x 10–6 K–1. This means that the glass expands by some 3.3 x 10-6 Length units per Kelvin, over a temperature range of +20°C to +300°C. The smaller the linear expansion coefficient, the more resistant the glass is to temperature variations. 

At larger expansion coefficients (compare the linear coefficient of expansion for soda lime glass, α= 9.1 x 10–6 K–1), the temperature difference during heating causes stresses in the glass and thus possible breaking.

How high is the chemical and thermal resistance of soda-lime glass?

Soda-lime glass is a clear glass belonging to the third water resistance class (compare DURAN® resistance class 1). 

Due to its high heat expansion (coefficient of linear expansion, α= 9.1 x 10–6 K–1), the resistance of soda lime glass to temperature changes is small (ΔT = 30 K). 

A maximum usage temperature of +100°C is recommended.