Pyrex

Pyrex is a brand name for glassware, introduced by Corning Incorporated in 1915.

Originally, Pyrex was made from borosilicate glass. In the 1940s[1] the composition was changed for some products to tempered soda-lime glass,[2] which is the most common form of glass used in glass bakeware in the US[3] and has higher mechanical strength so is less vulnerable to breakage when dropped (the leading cause of breakage in glass bakeware).[4] In 1998, Corning divested its consumer products division which subsequently adopted the name World Kitchen.

In 1908, Eugene Sullivan, Director of Research at Corning Glass Works, developed Nonex, a borosilicate low-expansion glass, to reduce breakage in shock-resistant lantern globes and battery jars. (Borosilicate glass was originally developed at the Jena Glass works by Otto Schott, which Sullivan had learned about as a doctoral student in Leipzig, Germany.) Jesse Littleton of Corning discovered the cooking potential of borosilicate glass by giving his wife a casserole dish made from a cut-down Nonex battery jar. Corning removed the lead from Nonex, and developed Pyrex as a consumer product.[5] Pyrex glass bakeware products are to be found in an estimated 80% of American homes and approaching 400 million units have been sold since the divestiture in 1998 alone.[3]

Pyrex kitchen glassware manufactured for sale in the United States is made at the World Kitchen facility in Charleroi, Pennsylvania. Pyrex products for the European Union are made at a factory in France.

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History of the Pyrex Brand

Borosilicate glass was first made by the German chemist and glass technologist Otto Schott, founder of Schott AG in 1893, 22 years before Corning produced the Pyrex brand. Schott AG sold the product under the name "Duran." In the English-speaking world, however, in the midst of World War I, Corning's Pyrex brand of borosilicate glass offered a non-German alternative. Ever since, the name Pyrex has been widely used as a genericized trademark for borosilicate glass in the English-speaking world.

Corning sold off its Consumer Products division in 1998 as World Kitchen but retained the Pyrex brand name, licensing it to World Kitchen and other companies that produce Pyrex-branded cookware (e.g. Newell Rubbermaid's Newell Cookware Europe).[6] The brand in Europe, the Middle East and Africa is currently owned by Arc International who acquired the European business in early 2006 from Newell Rubbermaid, who had acquired it from Corning in the 1990s.[7]

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

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.[8]

Pyrex kitchen products in Europe made and sold by a subsidiary of Arc International tableware company are made from borosilicate glass.[9]

Design

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.

Composition

Older Pyrex (pre 1900s), European Pyrex, and Pyrex laboratory glassware, is made of borosilicate glass. According to the National Institute of Standards and Technology, borosilicate Pyrex is composed of (as percentage of weight): 14% boron, 51% oxygen, .3% sodium, 1% aluminium, 38% silicon, and less than 1% potassium.[10][11]

According to glass supplier Pulles and Hannique, borosilicate Pyrex is made of Corning 7740 glass, and is equivalent in formulation to Schott Glass 8830 glass sold under the "Duran" brand name.[12] The composition of both Corning 7740 and Schott 8830 is given as 80.6% SiO2, 12.6% B2O3, 4.2% Na2O, 2.2% Al2O3, 0.04% Fe2O3, 0.1% CaO, 0.05% MgO, and 0.1% Cl.

However, the Pyrex glass cookware made in Charleroi, Pennsylvania is made of tempered soda-lime glass.[13]

Use in laboratory ware

Because Pyrex borosilicate glass has a high thermal resistance, it is often used in the manufacture of laboratory ware. In Europe, SciLabware Limited manufactures more than 800 items under the Pyrex brand name including beakers, bottles, flasks, dishes and test tubes.

Usage in telescopes

Because of its low expansion characteristics, Pyrex is often the material of choice for reflective optics in astronomy applications. The California Institute of Technology's 200-inch (5.1 m) telescope mirror at Palomar Observatory was cast by Corning during 1934–1936 out of borosilicate glass.[14]

In 1932, George Ellery Hale approached Corning with the challenge of fabricating the required optic for his Palomar project. A previous effort to fabricate the optic from fused quartz had failed.

Corning's first attempt was a failure, the cast blank having voids. Using lessons learned, Corning was successful in the casting of the second blank. After a year of cooling, during which it was almost lost to a flood, in 1935 the blank was completed. The first blank now resides in Corning's Museum of Glass.

Footnotes

  1. ^ "Exploding Pyrex, Urban Legend reference". snopes.com. http://www.snopes.com/food/warnings/pyrex.asp. Retrieved 2011-01-08. 
  2. ^ "Have you heard rumors about Pyrex Glassware breaking?". Pyrex. http://www.pyrexware.com/index.asp?pageId=30&TruthId=2. Retrieved 2011-01-08. 
  3. ^ a b "Manufacturing History". Pyrex Products. http://www.pyrexware.com/thetruthaboutpyrex/manu.htm. Retrieved 2010-02-07. 
  4. ^ Exploding the "exploding pyrex" myth, stats.com
  5. ^ Corning Pyrex Bakeware, Carroll M. Gantz, Design Chronicles: Significant Mass-produced Designs of the 20th Century, Schiffer Publications, Ltd. 2005
  6. ^ "Arc International page". Hoover's. http://www.hoovers.com/arc-international/--ID__103296--/free-co-factsheet.xhtml. Retrieved 2007-08-01. 
  7. ^ Hibberd, Susan (2007). The Little Book of Collectable British Pyrex. Exposure Publishing. ISBN 184685556X. 
  8. ^ Mathews, MM (1957). "title unknown". American Speech 32 (4): 290. 
  9. ^ "Glass Ovenware". Arc International. 2005. Archived from the original on 2008-03-11. http://web.archive.org/web/20080311222706/http://www.arc-international-cookware.com/en_Glass_Ovenware.html. Retrieved 2008-03-17. 
  10. ^ "Composition of Pyrex Glass". National Institute of Standards and Technology. n.d.. http://physics.nist.gov/cgi-bin/Star/compos.pl?matno=169. Retrieved 2000-02-17. 
  11. ^ "How Pyrex is Made". MadeHow.com. n.d.. http://www.madehow.com/Volume-7/Pyrex.html. Retrieved n.d.. 
  12. ^ "Borosilicate glass". http://www.pulleshanique.com/02_borosilicate-glass.htm. Retrieved 2009-01-08. 
  13. ^ Aikins, Jim. "Setting the Record Straight: The Truth About PYREX". Pyrex Products. http://www.pyrexware.com/thetruthaboutpyrex/index.htm. Retrieved 2010-02-07. 
  14. ^ "Caltech Astronomy: History - 1908–1949". Caltech. nd. http://www.astro.caltech.edu/observatories/palomar/history/. Retrieved 2008-03-17. 

References

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