Home     Contact     Projects     Experiments     Circuits     Theory     BLOG     PIC Tutorials     Time for Science     RSS     Terms of services     Privacy policy  
   
 Home      Projects     Experiments     Circuits     Theory     BLOG     PIC Tutorials     Time for Science   


<< Back to INDEX

They sure don't make Pyrex like they used to
posted April 27 2011 20:23.26 by Giorgos Lazaridis




Pyrex became known worldwide mainly for the high temperature glass. Originally, Pyrex was borosilicate glass with added boron to the silica (quartz), the main ingredient in all glass. But today, high-temperature glasses may not follow this successful recipe. Instead, prestressed soda-lime glass is used. The difference is that in the original glass, boron changes the atomic structure of glass so it stays roughly the same size regardless of its temperature. Little thermal expansion means little stress. Thus borosilicate glass withstands heat not because itís stronger, but because it doesnít need to be stronger. With pre-stressed, or tempered, glass, the surface is under compression from forces inside the glass. It is stronger than borosilicate glass, but when itís heated, it still expands as much as ordinary glass does. It doesnít shatter immediately, because the expansion first acts only to release some of the built-in stress. But only up to a point.

Watch this video to see what happens when this size change happens rapidly!!!

[Link: popsci]
Tags: discovery   temperature   crazy photo/video   science   chemistry   fire   
Share



You might also like...


Franklin's Bells Demonstration [Electricity]

Lego robot programmed to play Clash of Clans [Project]

Kinetics: Chemistry's Demolition Derby [Chemistry]

How to capture, analyze and crack GSM [Hack]

Is 666 the number of the beast? [Skepticism]

How Many Batteries Would It Take to Cook a Turkey? [Science]

Secret Knock Lock [Project]

10-terawatt laser fits on a desktop [News]


<< Back to INDEX



Comments

  Name

  Email (shall not be published)

  Website

Notify me of new posts via email


Write your comments below:
BEFORE you post a comment:You are welcome to comment for corrections and suggestions on this page. But if you have questions please use the forum instead to post it. Thank you.


      

No comment yet...

Be the first to comment on this page!












 Contact     Forum     Projects     Experiments     Circuits     Theory     BLOG     PIC Tutorials     Time for Science     RSS   

Site design: Giorgos Lazaridis
© Copyright 2008
Please read the Terms of services and the Privacy policy