Pyrex

{{For-multi|the programming language|Pyrex (programming language)|the rapper|Pvrx}}

File:Measuring cup.jpg manufactured {{circa|1980}}, featuring graduations in both U.S. and metric units]]

Pyrex (trademarked as PYREX and pyrex) is a brand introduced by Corning Inc. in 1915, initially for a line of clear, low-thermal-expansion borosilicate glass used for laboratory glassware and kitchenware. It was later expanded in the 1930s to include kitchenware products made of soda–lime glass and other materials.{{Cite web |date=November 24, 2014 |title=A CENTURY OF PYREX |url=https://www.cmog.org/article/pyrex |website=Corning Museum of Glass}} Its name has become famous for making rectangular glass roasters.

In 1998, the kitchenware division of Corning Inc. responsible for the development of Pyrex spun off from its parent company as Corning Consumer Products Company, subsequently renamed Corelle Brands. Corning Inc. no longer manufactures or markets consumer products, only industrial ones.

History

File:Pyrex dish.jpg

File:Pyrex newspaper ad 1922.png

Borosilicate glass was first made by German chemist and glass technologist Otto Schott, founder of Schott AG in 1893, 22 years before Corning produced the Pyrex brand. Schott AG sells the product under the name "Duran".

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. Sullivan had learned about Schott's borosilicate glass as a doctoral student in Leipzig, Germany. Jesse Littleton of Corning discovered the cooking potential of borosilicate glass by giving his wife Bessie Littleton a casserole dish made from a cut-down Nonex battery jar. Corning removed the lead from Nonex and developed it as a consumer product.[http://www.industrialdesignhistory.com/node/137 Corning Pyrex Bakeware], Carroll M. Gantz, Design Chronicles: Significant Mass-produced Designs of the 20th Century, Schiffer Publications, Ltd. 2005 Pyrex made its public debut in 1915 during World War I, positioned as an American-produced alternative to Duran.

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

{{blockquote|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 wikt:πῦρ and the Latin {{lang|la|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.{{cite journal | journal = American Speech | volume = 32 | issue = 4 | year = 1957 | page = 290 | title = title unknown | last = Mathews | first = MM}}}}

Corning purchased the Macbeth-Evans Glass Company in 1936 and their Charleroi, PA plant was used to produce Pyrex opal ware bowls and bakeware made of tempered soda–lime glass.{{Cite web |title=Macbeth-Evans Glass Company {{!}} ArchivesSpace Public Interface |url=https://archivesspace.cmog.org/agents/corporate_entities/20 |access-date=2022-10-16 |website=archivesspace.cmog.org}} 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.

File:Pyrex3 (2).jpg

Corning divested itself of the Corning Consumer Products Company (now known as Corelle Brands) in 1998 and production of consumer Pyrex products went with it. Its previous licensing of the name to Newell Cookware Europe remained in effect.{{cite web |url=http://www.pyrexware.com/thetruthaboutpyrex/manu.htm |title=Manufacturing History |publisher=Pyrex Products

|access-date=5 June 2015|archive-url=https://web.archive.org/web/20111002090834/http://www.pyrexware.com/thetruthaboutpyrex/manu.htm|archive-date=2 October 2011}}

France-based cookware maker Arc International acquired Newell's European business in early 2006{{cite web | url = http://www.hoovers.com/arc-international/--ID__103296--/free-co-factsheet.xhtml | title = Arc International page |publisher = Hoover's | access-date = 5 June 2015|archive-url=https://web.archive.org/web/20070929140533/http://www.hoovers.com/arc-international/--ID__103296--/free-co-factsheet.xhtml|archive-date=29 September 2007}} to own rights to the brand in Europe, the Middle East and Africa.{{cite book | isbn = 978-1-84685-556-6 | title = The Little Book of Collectable British Pyrex | first = Susan | last = Hibberd | publisher = Exposure Publishing | year = 2007 }}{{cite web | url = http://www.arc-international-cookware.com/en_Glass_Ovenware.html | title = Glass Ovenware | publisher = Arc International | access-date = 2008-03-17 | year = 2005 |archive-url = https://web.archive.org/web/20080311222706/http://www.arc-international-cookware.com/en_Glass_Ovenware.html |archive-date = 2008-03-11}} In 2007, Arc closed the Pyrex soda–lime factory in Sunderland, UK moving all European production to France. The Sunderland factory had first started making Pyrex in 1922.{{Cite web|url=http://www.bbc.co.uk/insideout/northeast/series11/week7_pyrex.shtml|title=BBC Inside Out -|website=www.bbc.co.uk}}

In 2014, Arc International sold off its Arc International Cookware division which operated the Pyrex business to Aurora Capital for its Resurgence Fund II. The division was renamed the International Cookware group.{{Cite press release|url=https://www.prnewswire.com/news-releases/aurora-capital-group-completes-acquisition-of-arc-international-cookware-243487371.html|title=Aurora Capital Group Completes Acquisition of Arc International Cookware |website=PR Newswire}} London-based private equity firm Kartesia{{cite web |title=Jaime Prieto - Kartesia |url=https://informaconnect.com/superreturn-international/speakers/jaime-prieto/ |access-date=16 November 2021 |website=informaconnect.com |language=en}} purchased International Cookware in 2020.{{cite web |title=Aurora Resurgence has sold International Cookware to Kartesia |url=https://www.lincolninternational.com/transactions/aurora-resurgence-has-sold-international-cookware-to-kartesia/ |access-date=16 November 2021 |website=Lincoln International LLC |language=en}}

In 2021, Pyrex rival Duralex was acquired by International Cookware group for €3.5 million (US$4.2m).{{Cite web |last=AFP |date=2021-01-29 |title=French glassmaker Duralex purchased by rival |url=https://www.dawn.com/news/1604250 |access-date=2021-01-29 |website=DAWN.COM |language=en}}{{cite web |title=Pyrex completes acquisition of Duralex |url=https://www.glass-international.com/news/pyrex-completes-acquisition-of-duralex |access-date=16 November 2021 |website=Glass International |language=en}}{{cite web |last1=Whitten |first1=Zoe |date=31 January 2021 |title=International Cookware, Pyrex's parent company, takes over Duralex |url=https://www.glassonline.com/international-cookware-pyrexs-parent-company-takes-over-duralex/ |access-date=16 November 2021 |website=Glass Online}}

In March 2019, Corelle Brands, the makers of Pyrex in the United States, merged with Instant Brands, the makers of the Instant Pot.{{Cite news |last=Gottfried |first=Miriam |date=March 3, 2019 |title=Owners of Instant Pot, Corelle to Merge; Combined company would have enterprise value of more than $2 billion |work=The Wall Street Journal |url=https://www.wsj.com/articles/owners-of-instant-pot-corelle-to-merge-11551654000 |access-date=June 23, 2023}} On June 12, 2023, Instant Brands filed for Chapter 11 bankruptcy after high interest rates and waning access to credit hit its cash position and made its debts unsustainable.{{Cite web|url=https://finance.yahoo.com/news/instant-pot-pyrex-maker-instant-204114763.html|title=Instant Pot and Pyrex Maker Instant Brands Files for Bankruptcy|date=June 12, 2023|access-date=June 12, 2023|website=Yahoo Finance|language=en}} The company emerged from bankruptcy on February 27, 2024 under the previous Corelle Brands moniker, after having sold off its appliance business ("Instant" branded products).{{Cite web |last=Brands |first=Instant |title=Instant Brands Provides Update on Sale Process for its Appliance Business |url=https://www.prnewswire.com/news-releases/instant-brands-provides-update-on-sale-process-for-its-appliance-business-301982393.html |access-date=2024-03-21 |website=www.prnewswire.com |language=en}}{{Cite web |date=2024-03-01 |title=Instant Brands emerges from chapter 11 as Corelle Brands {{!}} Davis Polk |url=https://www.davispolk.com/experience/instant-brands-emerges-chapter-11-corelle-brands |access-date=2024-03-21 |website=www.davispolk.com |language=en}}

Trademark

In Europe, Africa, and the Middle East, a variation of the PYREX (all uppercase) trademark is licensed by International Cookware{{Cite web |title=Kartesia participates in the {{as written|aqu|isition [sic]}} of International Cookware, the leading kitchenware manufacturer under the Pyrex® brand in EMEA |url=https://www.kartesia.com/newsroom/new_deal_international_cookware |access-date=2023-06-23 |website=www.kartesia.com |language=en}} for bakeware that has been made of numerous materials including borosilicate and soda–lime glass, stoneware, metal, plus vitroceramic cookware.{{Cite web |last=EU |first=Pyrex® Webshop |title=Pyrex® Webshop EU |url=https://www.pyrex.eu/ |access-date=2023-06-23 |website=Pyrex® Webshop EU |language=en}} The pyrex (all lowercase, introduced in 1975{{Cite web |title=Pyrex 1975 Dealer Catalog. Corning, N.Y: Corning Glass Works |url=https://cmog.primo.exlibrisgroup.com/discovery/fulldisplay?&context=L&vid=01CORNING_INST:01CORNING_INST&search_scope=MyInstitution&tab=ALWAYS_DISPLAY&docid=alma991233953504126 |access-date=2022-11-20 |website=cmog.primo.exlibrisgroup.com |language=en}}) trademark is now used for kitchenware sold in the United States, South America, and Asia.{{Cite web |title=Shop Pyrex Kitchenware {{!}} Official Website {{!}} Pyrex |url=https://www.pyrexhome.com/ |access-date=2023-06-23 |website=www.pyrexhome.com}} In the past, the brand name has also been used for kitchen utensils and bakeware by other companies in regions such as Japan and Australia.

It is a common misconception that the logo style alone indicates the type of glass used to manufacture the bakeware.{{Cite web |date=2015-02-18 |title=How are MacBeth-Evans and Monax related to Opal Pyrex and Corelle? - Dates & Details for Collectors of Corelle, Pyrex, Corning Ware & Centura |url=http://www.corellecorner.com/company-history/114-macbeth-evans-monax-opal-pyrex-corelle.html |access-date=2023-08-30 |archive-url=https://web.archive.org/web/20150218040546/http://www.corellecorner.com/company-history/114-macbeth-evans-monax-opal-pyrex-corelle.html |archive-date=2015-02-18 }} Additionally, Corning's introduction of soda-lime-glass-based Pyrex in the 1940s predates the introduction of the all lowercase logo by nearly 30 years.{{Cite web |date=2023-02-27 |title=That Viral 'PYREX' Brand Hack Is Horseshit, Folks |url=https://lifehacker.com/that-viral-pyrex-brand-hack-is-horseshit-folks-1850157381 |access-date=2023-08-26 |website=Lifehacker |language=en}} Nevertheless, all "pyrex" manufactured since 1998 in the United States is soda-lime glass,https://www.smithsonianmag.com/innovation/how-pyrex-reinvented-glass-new-age-180955513/ while all French-made "PYREX" glassware is borosilicate.https://www.pyrex.eu/en-eu/pages/history

Composition

File:Pyrex and PYREX.jpg

Older clear-glass Pyrex manufactured by Corning, Arc International's Pyrex products, and Pyrex laboratory glassware are made of borosilicate glass. According to the National Institute of Standards and Technology, borosilicate Pyrex is composed of (as percentage of weight): 4.0% boron, 54.0% oxygen, 2.8% sodium, 1.1% aluminium, 37.7% silicon, and 0.3% potassium.{{cite web | publisher = National Institute of Standards and Technology | title = Composition of Pyrex Glass |access-date = September 8, 2016 | url = http://physics.nist.gov/cgi-bin/Star/compos.pl?matno=169}}{{cite web | publisher = MadeHow.com | title = How Pyrex is Made | date = n.d. | url = http://www.madehow.com/Volume-7/Pyrex.html}}

According to glass supplier Pulles and Hannique, borosilicate Pyrex is made of Corning 7740 glass and is equivalent in formulation to Schott Glass 8330 glass sold under the "Duran" brand name.{{cite web | url = http://www.pulleshanique.com/02_borosilicate-glass.htm | title = Borosilicate glass | access-date = 5 June 2015|archive-url=https://web.archive.org/web/20120315092729/http://www.pulleshanique.com/02_borosilicate-glass.htm|archive-date=15 March 2012}} The composition of both Corning 7740 and Schott 8330 is given as 80.6% {{chem2|SiO2|link=silicon dioxide}}, 12.6% {{chem2|B2O3|link=boron trioxide}}, 4.2% {{chem2|Na2O|link=sodium oxide}}, 2.2% {{chem2|Al2O3|link=aluminium oxide}}, 0.1% {{chem2|CaO|link=calcium oxide}}, 0.1% {{chem2|Cl|link=chlorine}}, 0.05% {{chem2|MgO|link=magnesium oxide}}, and 0.04% {{chem2|Fe2O3|link=iron(III) oxide}}.

In the late 1930s and 1940s, Corning also introduced new product lines under the Pyrex brand using different types of glass. Opaque tempered soda–lime glass was used to create decorated opal ware bowls and bakeware, and aluminosilicate glass was used for Pyrex Flameware stovetop cookware. The latter product had a bluish tint caused by the addition of alumino-sulfate.{{cite web |title=PYREX Flameware |url=http://www.nettally.com/attic/Pyrexflameware.htm |archive-url=https://web.archive.org/web/20110104125655/http://www.nettally.com/attic/Pyrexflameware.htm |archive-date=January 4, 2011 |access-date=5 June 2015 |website=The Antique Attic}}{{cite web |title=Exploding Pyrex, Urban Legend reference |date=18 September 2009 |url=http://www.snopes.com/food/warnings/pyrex.asp |access-date=2011-01-08 |publisher=Snopes.com}}

Beginning in the 1980s, production of clear Pyrex glass products manufactured in the USA by Corning was also shifted to tempered soda–lime glass, like their popular opal bakeware.{{cite web |url=http://www.pyrexware.com/thetruthaboutpyrex/index.htm |first=Jim |last=Aikins |title=Setting the Record Straight: The Truth About PYREX |publisher=Pyrex Products |access-date=5 June 2015|archive-url=https://web.archive.org/web/20111026114654/http://www.pyrexware.com/index.asp?pageId=30|archive-date=26 October 2011}} This change was justified by stating that soda–lime glass has higher mechanical strength than borosilicate{{emdash}}making it more resistant to physical damage when dropped, which is believed to be the most common cause of breakage in glass bakeware. The glass is also cheaper to produce and more environmentally friendly. Its thermal shock resistance is lower than borosilicate's, leading to potential breakage from heat stress if used contrary to recommendations. Since the closure of the soda–lime plant in England in 2007, European Pyrex has been made solely from borosilicate.{{cite web|last1=Butterworth|first1=Trevor|title=Exploding the exploding Pyrex rumor| url=http://stats.org/stories/2009/exploding_pyrex_oct14_09.html |website=STATS |publisher=Statistical Assessment Service |access-date=5 June 2015 |archive-url=https://web.archive.org/web/20141120095647/http://stats.org/stories/2009/exploding_pyrex_oct14_09.html|archive-date=20 November 2014 |date=14 October 2009}}[http://consumerist.com/2010/12/consumer-reports-breaks-a-lot-of-glass-investigating-shattering-pyrex.html Consumer Reports Breaks A Lot Of Glass Investigating Shattering Pyrex Bakeware] {{Webarchive|url=https://web.archive.org/web/20120514061947/http://consumerist.com/2010/12/consumer-reports-breaks-a-lot-of-glass-investigating-shattering-pyrex.html |date=2012-05-14 }}, The Consumerist

The differences between Pyrex-branded glass products has also led to controversy regarding safety issues{{emdash}}in 2008, the U.S. Consumer Product Safety Commission reported it had received 66 complaints by users reporting that their Pyrex glassware had shattered over the prior ten years yet concluded that Pyrex glass bakeware does not present a safety concern. The consumer affairs magazine Consumer Reports investigated the issue and released test results, in January 2011, confirming that borosilicate glass bakeware was less susceptible to thermal shock breakage than tempered soda lime bakeware.{{Cite web|url=https://gizmodo.com/the-pyrex-glass-controversy-that-just-wont-die-1833040962|title=The Pyrex Glass Controversy That Just Won't Die|last=Estes|first=Adam Clark|date=March 16, 2019|website=Gizmodo|language=en-US|access-date=2019-03-22}} They admitted their testing conditions were "contrary to instructions" provided by the manufacturer.{{cite web|title=FOIA requests examine glass bakeware that shatters|url=http://news.consumerreports.org/safety/2010/12/foia-requests-examine-glass-bakeware-that-shatters-.html?EXTKEY=I91CONL&CMP=OTC-ConsumeristLinks|publisher=Consumer Reports|access-date=7 February 2012|archive-url=https://web.archive.org/web/20111206025207/http://news.consumerreports.org/safety/2010/12/foia-requests-examine-glass-bakeware-that-shatters-.html?EXTKEY=I91CONL&CMP=OTC-ConsumeristLinks|archive-date=6 December 2011}} STATS analyzed the data available and found that the most common way that users were injured by glassware was via mechanical breakage, being hit or dropped, and that "the change to soda lime represents a greater net safety benefit."

Use in telescopes

File:Hale telescope mirror during grinding 1945.jpg]]

Because of its low expansion characteristics, borosilicate glass is often the material of choice for reflective optics in astronomy applications.

In 1932, George Ellery Hale approached Corning with the challenge of fabricating the {{convert|200|in|m|adj=on}} telescope mirror for the California Institute of Technology's Palomar Observatory project.{{cite web|title=The Glass Giant|url=http://www.cmog.org/article/glass-giant|website=Corning Museum of Glass|access-date=30 January 2015}} A previous effort to fabricate the optic from fused quartz had failed, with the cast blank having voids. The mirror was cast by Corning during 1934–1936 out of borosilicate glass.{{cite web|title=A History of Palomar Observatory|url=http://www.astro.caltech.edu/palomar/about/history.html|website=Palomar Observatory|publisher=California Institute of Technology|access-date=5 June 2015|date=28 May 2015}} After a year of cooling, during which it was almost lost to a flood, the blank was completed in 1935. The first blank now resides in the Corning Museum of Glass.{{cite web|title=200-inch Disk|url=http://www.cmog.org/artwork/200-inch-disk |publisher=Corning Museum of Glass|access-date=30 January 2015}}

Citations

General and cited references

{{Cite journal |last1=Bradt |first1=R. C. |last2=Martens |first2=R. L. |date=September 2012 |title=Shattering Glass Cookware |url=https://bulletin-archive.ceramics.org/is-cacheable/1605850352249/ucuifj.pdf |url-access=subscription |format=PDF |journal=American Ceramic Society Bulletin |volume=91 |issue=7 |pages=35–41 |issn=0002-7812 |oclc=302290362 |access-date=15 March 2024}}
{{Cite press release |last=DeGuire |first=Ellen |date=September 11, 2012 |title=New Paper Addresses Causes of Shattering Glass Cookware; Margin of Safety Described as 'Borderline' |url=http://ceramics.org/uncategorized/new-paper-addresses-causes-of-shattering-glass-cookware |publisher=American Ceramic Society |access-date=2012-09-17 |quote=Their investigation confirmed the borosilicate glass would withstand a much larger rapid temperature change. According to their calculation and those of others, soda lime glass cookware shatters more frequently because, in theory, it can only resist fracture stress for temperature differentials less than about 55 °C (99 °F). In contrast, they estimate that the borosilicate glassware could tolerate a temperature differential of about 183 °C (330 °F), a three-fold difference.}}
{{Cite book |last=Gantz |first=Carroll |year=2001 |title=Design Chronicles: Significant Mass-produced Products of the 20th Century |location=Atglen, PA |publisher=Schiffer Publishing |isbn=978-0-7643-2223-5 |oclc=58729534}}
{{Cite book |last1=Rogove |first1=Susan Tobier |first2=Marcia B.|last2=Steinhauer |year=1993 |title=Pyrex by Corning: A Collector's Guide |location=Marietta, Ohio |publisher=Antique Publications |isbn=0-915410-94-X |oclc=28440879}}
{{Cite book |last1=Rogove |first=Susan Tobier |year=2016 |title=More Pyrex by Corning: A Collector's Guide |others=Photography: Jay Kogut Photography |location=Pennsauken, NJ |publisher=BookBaby |isbn=978-1-4835-8646-5 |oclc=963732418}}