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Author: Subject: Fuck "Pyrex"
gutter_ca
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[*] posted on 10-5-2012 at 09:45


From Pyrexware.com :

"Pyrex glass bakeware is, and has always been, durable, reliable and safe.
The U.S. Consumer Products Safety Commission conducted an investigation in 2008 and concluded that Pyrex glass bakeware does not present a safety concern.
While both borosilicate and soda lime are appropriate compositions for glass bakeware, heat strengthened soda lime is more resistant to impact breakage - the far more likely cause of consumer injury according to national emergency room data.
World Kitchen did not change the product composition for Pyrex glass bakeware.
Pyrex glass bakeware has been made – first by Corning Incorporated and now by World Kitchen – using the same soda lime composition and heat-strengthening process for more than 60 years.
World Kitchen has always manufactured Pyrex glass bakeware in the U.S. and our packaging proudly displays the American flag and the “made in the USA” label.
World Kitchen, which purchased the Pyrex consumer products business from Corning Incorporated in 1998, is a U.S. company based in Rosemont, Illinois"




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Dr.Bob
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[*] posted on 10-5-2012 at 11:42


That is partly correct, Corning had made SOME of its bakeware out of soda lime glass for the past 60 years, but now ALL of it made in the US is soda lime glass. But much of the Pyrex bakeware was borosilicate glass up until around 1988, when Corning started cheapening it, and then they sold it to World Kitchen, who may or may not have appreciated what the difference is. Either way, household bakeware is not useful for lab work now.

Most Pyrex labware is now made in Germany or England, as they don't manufacture much borosilicate glass in the US now, due to environmental issues and such. I don't know if Ace, Chemglass or other companies now make their own, buy the raw glass in the US, or import it all now.
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watson.fawkes
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[*] posted on 10-5-2012 at 14:11


Quote: Originally posted by Dr.Bob  
Most Pyrex labware is now made in Germany or England, as they don't manufacture much borosilicate glass in the US now, due to environmental issues and such. I don't know if Ace, Chemglass or other companies now make their own, buy the raw glass in the US, or import it all now.
Insofar as I am aware, there are only four major primary producers of raw borosilicate glass, with their associated brand names: Schott (Duran), Corning (Pyrex), Kimble (Kimax), and Kavalier (Simax). Kimble Chase evidently also owns Bomex, as I found out on their company location page; it was news to me. I don't know where the factories are now, but the companies are German, US, US, and Czech, respectively. The compositions of the various glasses aren't identical, but they're close, and they have closely matching coefficients of thermal expansion, so they can be worked interchangeably. Disclaimer: There are likely other producers outside of North America and Europe that I'm not aware of.

Ace and Chemglass are fabricators; they buy their glass from other producers. I don't know who their suppliers are.
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S.C. Wack
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[*] posted on 10-5-2012 at 15:53


Quote: Originally posted by Dr.Bob  
Most Pyrex labware is now made in Germany or England, as they don't manufacture much borosilicate glass in the US now, due to environmental issues and such.


Dubious statement is dubious; reference?

The usual over and over
http://www.sciencemadness.org/talk/viewthread.php?tid=3384




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Arthur Dent
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[*] posted on 11-5-2012 at 04:38


I've had "pyrex" brand glass shatter, but it was entirely my fault.

I was preparing basic Copper Carbonate, my resulting mixture was put in a glass baking pan (8X8) directly on a hotplate element, and upon dessication of the mixture, I did kind of a nitwit thing without thinking...

I took the pan away and deposited it on the concrete floor. Then 30 seconds later, I hear a little noise... crik TCHING! The damn thing just split cleanly in half. That was my favorite drying pan! :( The temperature difference was simply too much and the thermal shock did its dirty deed.

I replaced the pan since, opting for a used pan that I bought at a thrift store for a buck, and it looked very old but not scratched. I feel more confortable with a pan that saw a lot of usage than a brand new pan that might not be up to specs.

So far the old pan has performed its duties without a problem, but I don't remove it from the heat without proper thermal isolation. Usually, I just deposit it on an old newspaper, which prevents the excessive surface temperature differences.

But I have to admit that I do not "bake" the glassware at extreme temperatures, I mostly use this to boil away water from solutions outdoors on my porch, and never at the max temperature of the hotplate.

Robert




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Dr.Bob
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[*] posted on 11-5-2012 at 06:11


Quote: Originally posted by S.C. Wack  
Quote: Originally posted by Dr.Bob  
Most Pyrex labware is now made in Germany or England, as they don't manufacture much borosilicate glass in the US now, due to environmental issues and such.


Dubious statement is dubious; reference?

The usual over and over http://www.sciencemadness.org/talk/viewthread.php?tid=3384


The main reason for changing to soda lime glass is cost of materials, higher working temps (thus higher energy costs), and shorter life of equipment, but for some examples of the environmental issues of borosilicate glass production see:

http://thestatsblog.wordpress.com/2008/02/29/pyrex-soda-lime...

http://www1.ifc.org/wps/wcm/connect/384e20804885574ebc0cfe6a...
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[*] posted on 12-5-2012 at 04:29


Quote: Originally posted by Dr.Bob  
That is partly correct, Corning had made SOME of its bakeware out of soda lime glass for the past 60 years, but now ALL of it made in the US is soda lime glass. But much of the Pyrex bakeware was borosilicate glass up until around 1988, when Corning started cheapening it, and then they sold it to World Kitchen, who may or may not have appreciated what the difference is. Either way, household bakeware is not useful for lab work now.


Ah, then the stuff I've got might be OK. I discovered it abandoned in my deceased mother's outhouse, and, from vague memories of it, it must be about 20-30 years old. Not a scratch or chip on any of it. Just a 10+ year thick layer of dust and grease. Saucepans, and even a frying pan in a heavy brown glass. If I recall correctly they were intended for use directly on a cooker ring: (a frying pan??!) and decades old vague memories associate them with a brand name of "Vision".

Ah, I've just googled it, and it's Corning borosilicate from before the change to soda glass. A treasure trove!
This will be very handy.
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[*] posted on 12-5-2012 at 14:48


Quote: Originally posted by tryptamine  
Well what would you expect when you are using the dish outside of the manufacturers stated uses....



You did something foolish and have no right to be pissed off, but you did learn something...

In my line of work in a research/industrial setting I've seen engineers buy perhaps 30 pyrex baking dishes to store 100 degree calcine as it exited a furnace. After the first one blew up in the hands of an operator the rest of the dishes ended up in the trash bin...


It would seem the 'engineers' "in your line of work".. "did something foolish"...hopefully they learned something as well!My wish was that the engineer that selected the dishes was the the one who held the dish that exploded ratether than a min wage operator.:D

The definition of smug comes to mind.I dont wish anyone ill but when that accident happens!LOL

[Edited on 12-5-2012 by grndpndr]

[Edited on 12-5-2012 by grndpndr]
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