Vycor glass boasts a low coefficient of thermal expansion that equates to one fourth that of Pyrex. The majority of products sold by Macalaster Bicknell Company of New Jersey are made from Pyrex borosilicate glass. But Mac Bic also stocks Vycor glass for customers that are working with a high heat.
Vycor is Corning’s answer to glass products that must accommodate high temperatures, like evaporating dishes. Vycor glass shares similar compounds with borosilicate glass, which also has a high threshold for heat. But Vycor is comprised of 96% silica, and just 4% boron trioxide. This high-silica percentage gives the glass its extremely low coefficient of thermal expansion.
During a multi-step process, a soft borosilicate glass is melted into a desired shape. Heat is added, causing the glass to separate into distinct chemical compounds. One composition can be easily dissolved in acid. The other is made of mostly silica, which is insoluble. The glass is soaked in a hot acid solution which removes the soluble compounds, leaving behind the high-silica material.
At this stage, the Vycor glass is porous. After it is heated to 1200 degrees Celsius, the glass shrinks and becomes non-porous. The finished product is considered reconstructed glass.
For some applications, the final heating step is skipped, and the porous glass is left. Because of its affinity for absorbing water, it is often used in science and engineering labs to absorb water vapor. Submersing the porous glass into certain chemical solutions results in a colored glass. The added pigment can withstand high temperatures without breaking down, and can be used as a filter for various applications.
The reconstructed Vycor glass is ideal for applications that require a very high level of dimensional stability. Metrology instruments are often made from Vycor glass because it can withstand high thermal-shock loads.
Contact The Experts
Mac Bic offers a variety of clear Vycor glass tubes for a number of applications. The non-porous standard wall glass tubing ranges in size from 6 mm to 51 mm thick. Contact the glass experts at Macalaster Bicknell Company of New Jersey today for all your Vycor glass needs.