Properties and application of quartz glass

      Quartz glass sheet, usually cut from quartz glass and made of grinding, its silica content can reach more than 99.99%. Hardness for Mo-type seven, with high temperature resistance, low thermal expansion coefficient, thermal shock resistance and good electrical insulation performance, etc.

      Quartz glass is usually colorless and transparent, and the transmittance of visible light is above 85%. Quartz glass from the large production range can be divided into fused quartz glass and synthetic quartz glass two categories. Heat resistance, light transmittance, electrical insulation, chemical stability are very good.


      Optical performance

      Quartz glass has its unique optical properties, it can not only through the far ultraviolet, is the best of all ultraviolet materials, but also through visible light can be near infrared spectrum. Because of its high temperature resistance, minimal thermal expansion coefficient, good chemical stability, bubble, fringe, uniformity and birefringence, quartz glass is an essential optical material with high stability optical coefficient in all kinds of harsh situations.

      According to its optical properties can be divided into three categories:

      Far ultraviolet type JGS1

      Transparent in the ultraviolet and visible spectrum range; There is no absorption band in the band range of 185-250nm; There is a strong absorption band in the band range of 2600-2800nm. Non-luminous, stable light radiation.

      Uv class JGS2

      Transparent in the ultraviolet and visible spectrum range; There is no absorption band in the band range of 200-250nm; There is a strong absorption band in the band range of 2600-2800nm. Non-luminous, stable light radiation.

      Infrared class JGS3

      Transparent in visible and infrared spectral range; There is no obvious absorption band in the band range of 2600-2800nm.

      Compared with ordinary silicate glass, transparent quartz glass has excellent transmissibility over the whole wavelength. In the infrared region the spectral transmission is larger than that of ordinary glass; In the visible region, the transmittance of quartz glass is also relatively high. In the ultraviolet region, especially in the short-wave ultraviolet region, the spectral transmission is much better than other glasses

      The spectral transmittance is influenced by three factors: reflection, scattering and absorption. The reflection of quartz glass is generally 8%, the ultraviolet region is larger, the infrared region is smaller. Therefore, the transmittance of quartz glass is generally not greater than 92%. The scattering of quartz glass is relatively small, generally can be ignored. Spectral absorption is closely related to the impurity content of quartz glass and its production process. The transmittance in the band below 200 sodium meters represents the amount of metal impurity content; The absorption of 240 sodium meters indicates the amount of anoxic structure; The absorption of the visible band is caused by the presence of transition metal ions. The absorption of 2730 sodium meters is the absorption peak of hydroxyl group, which can be used to calculate the hydroxyl group content.

      Spectral transmittance using spectral absorption hydroxyl group calculation method:

      AgE’s calculation formula: C=910/T * LOG10 (Ta/Tb) mm-1 C: hydroxyl content (C, PPM) T: thickness (mm) Ta: transmittance of 2600 sodium meter wavelength Tb: transmittance of 2730 sodium meter wavelength

      B: China’s national standard calculation formula: C=96.5/ D * LG10 (IA /I) mm-1 C: hydroxyl content (PPM) D: thickness (cm) IA :2730 Naomi base line to the zero line distance (mm) I :2730 Naomi absorption peak to the zero line distance (mm)

      Spectral transmittance: thickness 1mm) Spectral transmittance of other thickness can be derived from the formula: T = (1-r)2 E-at T: transmittance R: SLR reflection loss. E: Natural logarithmic base. T: Thickness (cm) Spectral transmittance wavelength nm


      Physical properties of

      Quartz glass sheet is a kind of special industrial technology glass made of silicon dioxide. It is a very good basic material. Quartz glass has a series of excellent physical and chemical properties, such as:

      1, high temperature resistance. The softening point temperature of quartz glass is about 1730℃. It can be used at 1100℃ for a long time, and the highest temperature can reach 1450℃ for a short time.

      2, corrosion resistance. In addition to hydrofluoric acid, quartz glass almost does not react with other acid substances, and its acid resistance is 30 times that of ceramics and 150 times that of stainless steel. Especially, its chemical stability at high temperature is incomparable to any other engineering materials.

      3, good thermal stability. The thermal expansion coefficient of the glass is extremely small, and it can withstand drastic temperature changes. When the quartz glass is heated to about 1100℃, it will not burst when put into room temperature water.

      4, good light transmission performance. Quartz glass has good transmittance in the whole spectrum from ultraviolet to infrared, and the transmittance of visible light is above 93%, especially in the ultraviolet spectrum, and the maximum transmittance can reach above 80.

      5, quartz glass has good electrical insulation performance. The resistance value of quartz glass is equivalent to ten thousand times that of ordinary glass. It is an excellent electrical insulating material and has good electrical properties even at normal temperature.



      The formation of quartz glass sheet is caused by the high viscosity of its melt at high temperature. It is widely used in manufacturing semiconductor, electric light source device, semi-conductor communication device, laser, optical instrument, laboratory instrument, electrical equipment, medical equipment and high temperature and corrosion resistant chemical instrument, chemical industry, electronics, metallurgy, building materials and national defense and other industries.