Quartz can be manufactured into quartz glass tube, which is valued for its exceptional purity and serves a wide range of applications. Quartz glass does not contain additives. It is sometimes referred to as fused quartz or fused silica; the difference between the two is that fused quartz is made from pure silicon dioxide (SiO2) while fused silica is made from synthetic precursor. Natural quartz is rarely used in the industry since it may contain several impurities; the most commonly used raw material is "cultured quartz", which is quartz crystals that are grown in controlled conditions.
Quartz glass is valued due to its distinct and high value characteristics. Among these are because of its low coefficient of thermal expansion, high gas permeability, and extensive optical transmission.
Chapter Two - Production of Quartz Glass
This chapter presents the steps in transforming the raw quartz into a formed, fused quartz glass plate.
Washing and Drying
Dirt, moisture and contaminants present in the natural quartz are removed in the early stages of processing which may affect the quality and performance of the quartz glass rod to be produced. This is only applicable for mined quartz.In this method, a natural quartz or a synthetic precursor can be a starting material. Natural quartz passes through a chamber with a high temperature hydrogen/oxygen (H2/O2) flame until the starting material is fused. If silicon tetrachloride (SiCl4), a gaseous synthetic precursor, is to be used, it is made to react with the H2/O2 flame. The viscous melt is deposited in a refractory-lined vacuum chamber, collected slowly by a die at the bottom of the container, and shaped to its final form. Due to its direct contact with H2/O2 flame, this method produces quartz crucible with 150-200 ppm OH content from natural quartz and up to 1000 ppm for synthetic silica.Cutting: Band and wire saws, chop saws, CO2 lasers, and water jet cutters are used to cut the quartz glass instrument. Using a laser cutter can leave a glazed and smooth cut, while those quartz glass which used saw cutting can leave a rough cut. Thick quartz glass slabs may require multiple consecutive cuts if a single cut would not suffice. Annealing may be required to relieve the thermally-induced stress and to keep it from shattering.Purity is one of the most important aspects in quartz boat manufacturing. Contaminants, even in very low levels, influence the thermal, electrical and optical properties of the resulting quartz glass and material in contact in their final application. Strict handling precautions must be taken at the starting material source and all stages of production to ensure high purity. The most common impurities are metal oxides (Al2O3, Fe2O3, MgO, etc.), water, and chlorine.A majority of the applications of quartz pyramid utilize its optical properties due to its wide transparency range and superior light transmittance, ranging from the ultraviolet to infrared regions. Quartz glass is not easily damaged by ultra-violet and high energy radiation. Light can pass through a quartz glass in a functionalized optical path with minimal distortions. Examples of products with optical applications are: prisms, lenses, beam splitters, polarizers, mirrors and windows.