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Vandateb Vandateb Company, an importer of laboratory materials and equipment, research and education

Pyrex Info

Pyrex is a brand introduced by Corning Incorporated in 1915 for a line of clear, low-thermal-expansion borosilicate glass used for laboratory glassware and kitchenware. Pyrex sold in the United States is now made of tempered glass; outside of North America the costlier borosilicate is still used.

A Corning executive gave the following account of the etymology of the name "Pyrex":

The word PYREX is probably a purely arbitrary word which was devised in 1915 as a trade-mark for products manufactured and sold by Corning Glass Works. While some people have thought that it was made up from the Greek pyr and the Latin rex we have always taken the position that no graduate of Harvard would be guilty of such a classical hybrid. Actually, we had a number of prior trade-marks ending in the letters ex. One of the first commercial products to be sold under the new mark was a pie plate and in the interests of euphonism the letter r was inserted between pie and ex and the whole thing condensed to PYREX.

In the late 1930s and 1940s, Corning also introduced other products under the Pyrex brand, including opaque tempered soda-lime glass for bowls and bakeware, and a line of Pyrex Flameware for stovetop use; this borosilicate glass had a bluish tint caused by the addition of alumino-sulfate. In 1958 an internal design department was started by John B. Ward. He redesigned the Pyrex ovenware and Flameware. Over the years, designers such as Penny Sparke, Betty Baugh, Smart Design, TEAMS Design, and others have contributed to the design of the line.

Most PYREX glassware is made from Code 7740 PYREX borosilicate glass, the most widely known of Corning’s family of low expansion Type 1, Class A borosilicate glasses (ASTM E438 Standard Specification for Glasses in Laboratory Apparatus)

It comes closest to being the ideal glass for most laboratory applications. It will withstand nearly all temperatures used in normal laboratory use. It is highly resistant to chemical attack. Its low coefficient of expansion allows it to be manufactured with relatively heavy walls giving it mechanical strength, while retaining reasonable heat resistance. It is the best glass available for laboratory use (Tables 1, 2, 3 and 4) PYREX Low Actinic glassware is also made from Code 7740 glass by firing a red stain fired into the exterior surface. The resulting product is as durable as the base glass. PYREX Low Actinic Labware was originally developed for work in the vitamin field, but it has found other uses in applications with chemicals sensitive to light in the 300o to 500nm range. PYREXPLUS glassware is made from Code 7740 borosilicate glass to which is added a tough transparent polyvinylchloride coating. It is designed to resist exterior surface abrasion and also helps minimize loss of contents if the glass vessel is accidentally broken. Prolonged and/or repeated chemical exposure of the coating to aldehydes, ketones, chlorinated solvents and concentrated acids should be avoided.

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