Borosilicate
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| − | + | == '''Borosilicate''' == | |
| + | |||
| − | + | Borosilicate glass was first developed by German glassmaker Otto Schott in the late 19th century and sold under the brand name Schott "Duran" in 1893. After Corning Glass Works introduced "Pyrex" in 1915, it became a synonym for borosilicate glass in the English-speaking world. | |
| + | In addition to the quartz, sodium carbonate, and calcium carbonate traditionally used in glassmaking, boron is used in the manufacture of borosilicate glass. Typically, the resulting glass composition is about 70% silica, 10% boric oxide, 8% sodium oxide, 8% potassium oxide, and 1% calcium oxide. Though somewhat more difficult to make than soda lime glass, it's economical to produce because its superior durability, chemical and heat resistance. | ||
| − | + | == Manufacturing process == | |
| − | + | Borosilicate glass is created by adding boron to the traditional glassmaker's sand, sodium carbonate, and ground calcium oxide. Borrowing from the welding, new burners combining [[oxygen]] with [[natural gas]] were required to melt the glass. | |
| + | Although, there are electric ovens that are capable of this. | ||
| + | |||
| + | == Composition and physical characteristics == | ||
| + | |||
| + | Borosilicate glass has a very low [[COE]], about one-third that of soda lime glass. This reduces material stresses caused by temperature gradients, thus making it more resistant to breaking. This makes it ideal for use in telescopes and labware. | ||
| + | Borosilicate glass begins to soften around 821 °C (1510 °F). | ||
| + | Borosilicate glass is less dense than soda lime glass. | ||
| + | |||
| + | While more resistant to [[thermal shock]] than other types of glass, borosilicate glass can still crack or shatter when it is exposed to extreme temperature changes. Annealing can mitigate some of these properties, but it is an inherant property of glass, with quartz glass being the most shock resistant. When broken, borosilicate glass tends to crack into large pieces rather than shattering. | ||
| + | |||
| + | '''Fraction by weight''' | ||
| + | <table class="wikitable"> | ||
| + | <tr> | ||
| + | <th>Element</th> | ||
| + | <th>Fraction</th> | ||
| + | </tr> | ||
| + | <tr> | ||
| + | <td align=center>B</td> | ||
| + | |||
| + | <td>0.040064</td> | ||
| + | </tr> | ||
| + | <tr> | ||
| + | <td align=center>O</td> | ||
| + | |||
| + | <td>0.539562</td> | ||
| + | </tr> | ||
| + | <tr> | ||
| + | <td align=center>Na</td> | ||
| + | |||
| + | <td>0.028191</td> | ||
| + | </tr> | ||
| + | <tr> | ||
| + | <td align=center>Al</td> | ||
| + | |||
| + | <td>0.011644</td> | ||
| + | </tr> | ||
| + | <tr> | ||
| + | <td align=center>Si</td> | ||
| + | |||
| + | <td>0.377220</td> | ||
| + | </tr> | ||
| + | <tr> | ||
| + | <td align=center>K</td> | ||
| + | |||
| + | <td>0.003321</td> | ||
| + | </tr> | ||
| + | </table> | ||
| + | |||
| + | '''Physical characteristics'''<br> | ||
| + | Density = 2.23 g/cm<sup>3</sup><br> | ||
| + | |||
| + | == Usage == | ||
| + | |||
| + | Borosilicate is most often employed where a glass would be subject to swings in temperature, such as labware and glass pipes. | ||
| + | |||
| + | Artists and craftsman choose to use borosilicate due to the colors that are available, the working properties, thermal properties, and many more reasons. | ||
| + | |||
| + | [[Category:Materials]] | ||
Latest revision as of 19:22, 21 March 2012
Contents |
[edit] Borosilicate
Borosilicate glass was first developed by German glassmaker Otto Schott in the late 19th century and sold under the brand name Schott "Duran" in 1893. After Corning Glass Works introduced "Pyrex" in 1915, it became a synonym for borosilicate glass in the English-speaking world. In addition to the quartz, sodium carbonate, and calcium carbonate traditionally used in glassmaking, boron is used in the manufacture of borosilicate glass. Typically, the resulting glass composition is about 70% silica, 10% boric oxide, 8% sodium oxide, 8% potassium oxide, and 1% calcium oxide. Though somewhat more difficult to make than soda lime glass, it's economical to produce because its superior durability, chemical and heat resistance.
[edit] Manufacturing process
Borosilicate glass is created by adding boron to the traditional glassmaker's sand, sodium carbonate, and ground calcium oxide. Borrowing from the welding, new burners combining oxygen with natural gas were required to melt the glass. Although, there are electric ovens that are capable of this.
[edit] Composition and physical characteristics
Borosilicate glass has a very low COE, about one-third that of soda lime glass. This reduces material stresses caused by temperature gradients, thus making it more resistant to breaking. This makes it ideal for use in telescopes and labware. Borosilicate glass begins to soften around 821 °C (1510 °F). Borosilicate glass is less dense than soda lime glass.
While more resistant to thermal shock than other types of glass, borosilicate glass can still crack or shatter when it is exposed to extreme temperature changes. Annealing can mitigate some of these properties, but it is an inherant property of glass, with quartz glass being the most shock resistant. When broken, borosilicate glass tends to crack into large pieces rather than shattering.
Fraction by weight
| Element | Fraction |
|---|---|
| B | 0.040064 |
| O | 0.539562 |
| Na | 0.028191 |
| Al | 0.011644 |
| Si | 0.377220 |
| K | 0.003321 |
Physical characteristics
Density = 2.23 g/cm3
[edit] Usage
Borosilicate is most often employed where a glass would be subject to swings in temperature, such as labware and glass pipes.
Artists and craftsman choose to use borosilicate due to the colors that are available, the working properties, thermal properties, and many more reasons.
