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Polycarbonate is commonly used in eye protection, as well as in other projectile-resistant viewing and lighting applications that would normally indicate the use of glass, but require much higher impact-resistance. Polycarbonate lenses also protect the eye from UV light.
Sand casting involves the use of hot molten glass poured directly into a preformed mould. [5] It is a process similar to casting metal into a mould. The sand mould is typically prepared by using a mixture of clean sand and a small proportion of the water-absorbing clay bentonite. Bentonite acts as a binding material.
Apsley Pellatt in his book Curiosities of Glass Making was the first to use the term "millefiori", which appeared in the Oxford English Dictionary in 1849; prior to that, the beads were called mosaic beads. While the use of this technique long precedes the term "millefiori", it is now most frequently associated with Venetian glassware. [2] [3]
The glass transition temperature of basalt is about 700 °C (1,292 °F). [4] The mechanisms controlling formation of volcanic glass are further illustrated by the two forms of basaltic glass, tachylite and sideromelane. Tachylite is opaque to transmitted light because of the abundance of tiny oxide mineral crystals suspended in the glass ...
Lehr – a specialized, temperature-controlled kiln for annealing glass. [5] Mandrel – metal rod used to construct a glass bead around. When cooled and removed, the space occupied by the mandrel creates the hole through the bead. Marver – a tool used in glassblowing A marver is a large flat table. The glass piece is rolled across is surface.
Glass can be coloured by adding metal salts or painted and printed with vitreous enamels, leading to its use in stained glass windows and other glass art objects. The refractive, reflective and transmission properties of glass make glass suitable for manufacturing optical lenses, prisms, and optoelectronics materials.
English tin-glazed majolica. First shown at the 1851 Exhibition by Minton & Co., Exhibit Number 74. Potteries Museum, Stoke-on-Trent, UK. The notes in this article append tin-glazed to the word meaning 'opaque white tin-glaze, painted in enamels', and coloured glazes to the word meaning 'coloured lead glazes, applied direct to the biscuit'.
Glass-ceramic materials share many properties with both glasses and ceramics. Glass-ceramics have an amorphous phase and one or more crystalline phases and are produced by a so-called "controlled crystallization" in contrast to a spontaneous crystallization, which is usually not wanted in glass manufacturing. Glass-ceramics have the fabrication ...