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Quartz Window Custom Fabrication

 At Pacific Quartz Incorporated we specialize in the custom fabrication of Quartz Windows for Optical, Military and Aerospace applications.

The production method of fused quartz glass can be electrically fused, flame fused, plasma fused and electric-arc fused. The raw material can be natural quartz sand SiO2 and synthetic chemical-silicon tetrachloride (SiC14). The combination of production methods and raw material composes the main types of our quartz glass: electrically fused natural quartz, flame fused natural quartz, plasma fused natural quartz, flame fused synthetic quartz, plasma fused synthetic quartz and electric-arc fused natural quartz.

Clear Fused Quartz

Clear Fused Quartz

One of the most important properties of fused quartz is its extremely low coefficient of expansion: 5.5 x 10-7 mm ºC (20-320oC). Its coefficient is 1/34 that of copper and only 1/7 of borosilicate glass. This makes the material particularly useful for optical flats, mirrors, furnace windows and critical optical applications which require minimum sensitivity to thermal changes.

Mechanical properties of fused quartz are much the same as those of other glasses. THe material is extremely strong in compression, with design compressive strength of better than 1.1 x 109 Pa (160,000 psi).

Typical electrical property values for clear fused quartz include:

Electrical Resistance: 0.7 x 109 ohm-cm at 350oC

Dielectric Loss Factor: less than 0.0004 at 20oC, 1 MHz

Dielectric Constant: 3.75 at 20oC, 1 MHz

Specific Resistivity: I018 ohm/cm3 at 20oC

Dissipation Factor: Less than 0.0001 at 20oC. 1 MHz

 Electrically Fused Quartz Glass

Electrically Fused Quartz Glass

Electric fusion is the most commonly used melting process for manufacturing quartz glass.This process uses resistance Heaters to melt natural quartz sand into quartz glass tube, rod, blocks etc. There are two methods of electric fusion, continuous fusion and batch fusion. In the continuous process, quartz sand is continuously poured into the upper part of tungsten crucible surrounded by electric heaters elements. The inside crucible is maintained in a neutral or slightly reduced atmosphere that keeps silica from reacting with the refractory metal while the silica is melted inside. The melted quartz exits at the forming part at the bottom of crucible which is shaped into tube, rod and so on. The OH can be reduced by annealing. In the batch fusion process, several tons of raw material are placed inside a refractory vacuum chamber containing graphite Heaters elements to produce tube, rod and so on. THe OH is usually below 2ppm. The low OH makes electrically fused quartz glass have high infrared transmission. The electrically fused quartz glass usually has certain bubble and drawing lin on glass surface.

Flame Fused Quartz Glass

Flame fusion is a 2-step process. The first process is the natural quartz sand or synthetic SiC14 is melted in hydrogen/oxygen (H2/O2) flame into a solid round ingot. The second process is to further shape the ingot into various shapes and dimensions. Flame fused quartz glass contains an abundant amount of hydroxyl (OH) as a result of the direct contact between the H2/O2 and the silica raw material. This OH content cannot be reduced by annealing and its presence lowers the viscosity and infrared transmission. The flame fused quartz has no drawing line and very low bubble content.

Plasma Fused Quartz Glass 

Plasma Fused Quartz Glass

Plasma fusion is a 2-step process. The first process is the natural quartz sand or synthetic SiC14 is melted in plasma flame into a solid round ingot. The second process is to further shape the ingot into various shape and dimensions. Plasma fused quartz has low OH usually below 5 ppm, so it has good infrared transmission. The plasma fused quartz has very low bubble content and has no drawing line.


Electric-arc Fused Opaque Crucible

Electric-arc fusion is the commonly used process for manufacturing crucible which is used to grow monocrystalline silicon ingots.

Opaque Quartz

  • Opaque Quartz

When quartz sand of a high purity is brought to a molten state at a temperature of approximately 2000 ºC the opaque quality is created. Bringing the quartz sand to such a high temperature creates a multitude of gaseous micro-bubbles giving the materials its opacity along with some other exceptional properties.

Opaque silica glass offers a number of exceptional properties:


Extreme Hardness
Low Expansion
Excellent High Temperature Resistance
Maximum Continuous Temperature 1100(degree) C
Extreme Chemical Purity
Excellent Corrosion Resistance
Excellent Electrical Insulation Properties
Remarkable Stability Under Atomic Bombardment


Fine Quartz Diamond Finish

  • Pacific Quartz offers a quality superior diamond finish of your fine quartz window product that is processed managed by less pressure (diamond, bond, speed, coolant, etc.) during cutting.

  • Lapped (Ground) Finish

  • We also offer a Lapped (ground) finish, No subsurface damage.  This operation is grounded with a free abrasive compound that eliminates all fracturing and stress. This operation is used for Viewports, IR, UV windows.

  • Quartz Window Coatings

  • Different types of coatings are available.

  • Call Or Email Today: 714-546-8133

  • Our team of specialists have decades of experience taking projects from prototype to finished product. Send us your specifications and our technical team will provide you with a customized competitive quote.

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