05
Sep
For decades Pyrex was made of borosilicate glass a special type of glass in which boron oxide is added to the mix. The Corning Glass Works business invented Pyrex glass which is borosilicate glass.
The added boron allows Pyrex to handle heat much better than typical glass so Pyrex is commonly found in kitchens laboratories and in use with aquarium heaters as the heaters are necessarily submerged in much cooler water.
Is pyrex made of borosilicate glass. Chances are you just asked Google how you can tell if PYREX is Borosilicate. So Im willing to bet you already know the difference between Soda-Lime and Borosilicate glass. Soda-lime is your standard glass type used in most household applications while borosilicate is used for more extreme situations such as laboratory tests due to its resistance to thermal shock.
The Corning Glass Works business invented Pyrex glass which is borosilicate glass. Its manufactured by repeatedly heating raw resources like silica sand and boric oxide to paramount temperatures. The molten glass is subsequently transformed into various sorts of glassware.
For decades Pyrex was made of borosilicate glass a special type of glass in which boron oxide is added to the mix. In most cases that does not matter much as tempered soda-lime glass is still pretty good at withstanding thermal shocks. But its not great.
When it comes to labware there is only one material to use. Pyrex no wait thats not right thats a brand name. The actual answer is Borosilicate glass.
Borosilicate glass has a lot of brand names. Pyrex is the most well known a product of Dow Corning but as the material itself is not subject to copyright there are more than a few other names. Bomex Pallex and a few others.
Pyrex is made by the low coefficient expansion of borosilicate glass whereas glass is blown and pressed to prepare it for the molding process. Why did Pyrex stop using borosilicate. These dates are important because Cornings patent on the borosilicate glass used to make Pyrex pans expired in 1936.
This is partly because the brand is so popular in the US but also partly because its bakeware used to be less prone to breaking from thermal shock. Pyrex pieces used to be made of borosilicate. They are not the same products.
In the past Corning made PYREX upper case out of Borosilicate Glass. In America pyrex lower case is now made of Soda-Lime Glass. In France PYREX is STILL made of Borosilicate Glass.
French Borosilicate PYREX has a much higher resistance to Thermal Shock. Pyrex is a trademarked brand name for a line of glass products. Borosilicate glass is a type of low-thermal-expansion glass.
It can withstand moderate temperature changes without fracturing. Not all Pyrex is made from borosilicate glass. In other words just buying pre-1998 Pyrex cookware doesnt guarantee that its made of borosilicate glass and shattering remains a risk.
In an email the CPSC specified that it has received 850. Pyrex is one particular blend of Borosilicate glass with a particularly high heating tolerance. Soda Lime glass is sometimes used for glassware which is not likely to be directly and strongly heated for example petri dishes or TLC chromatography tanks.
Pyrex products were made of borosilicate glass until about 60 years ago at which point they began switching to manufacturing products with tempered soda lime instead. Today every piece of bakeware made in the US. Uses tempered soda lime including the full line of Pyrex consumer glassware.
Pyrex glass used in chemistry experiments is made of borosilicate glass whereas the Pyrex used when baking is made of soda lime glass. To my mind this is a completely separate question as Pyrex to my knowledge does not manufacture any borosilicate glass cookware that it labels as safe for stovetop use anywhere in the world and it hasnt for about 40 years. Today not all Pyrex is made of borosilicate glass.
Some years ago Corning switched the material in their products from borosilicate glass to soda-lime glass because it was more cost-effective. So we cant really be sure what is actually borosilicate and what is not in Pyrexs. For decades Pyrex was made of borosilicate glass a special type of glass in which boron oxide is added to the mix.
The added boron allows Pyrex to handle heat much better than typical glass so Pyrex is commonly found in kitchens laboratories and in use with aquarium heaters as the heaters are necessarily submerged in much cooler water. After Corning Glass Works introduced Pyrex in 1915 the name became synonymous for borosilicate glass in the English-speaking world in reality a sizable portion of glass produced under the Pyrex brand has also been made of soda-lime glass since the 1940s.