Milky quartz glass is an opaque form of quartz glass designed primarily for thermal insulation and infrared radiation management. Unlike clear quartz, which allows light and radiant energy to pass through, milky quartz uses its internal microstructure to scatter and reflect radiation.
This makes it particularly valuable in photovoltaic, semiconductor, furnace, and other high-temperature industrial equipment.
Why Is Milky Quartz White and Opaque?
The characteristic milky-white appearance of opaque quartz is mainly caused by a large number of uniformly distributed micron-sized bubbles inside the silica matrix.
When light enters the material, it encounters interfaces between the bubbles and the surrounding silica. These interfaces strongly scatter and reflect light, interrupting the direct transmission path and creating the characteristic opaque appearance.
The bubble size, density, and distribution are therefore important factors in determining the final optical and thermal performance of milky quartz.
Thermal-Management Mechanism
The primary function of milky quartz is not simply to block visible light.
Its internal microbubbles scatter and reflect infrared radiation, reducing radiative heat transfer. As a result, milky quartz can act as a thermal barrier in high-temperature equipment.
Typical applications include:
- Semiconductor reaction-chamber insulation panels
- Photovoltaic furnace insulation
- Furnace plugs
- Quartz flanges
- Insulation rings
- Infrared-reflective components
- Selected heating and heat-exchange structures
In these applications, milky quartz helps shield surrounding components from intense thermal radiation.
Manufacturing Milky Quartz
Milky quartz is generally manufactured from high-purity quartz sand combined with a controlled amount of foaming agent.
Common manufacturing methods include:
- Slip casting followed by solid-state sintering
- Electric fusion
During production, manufacturers need to precisely control the size, quantity, and distribution of internal bubbles. These parameters influence opacity, infrared reflectivity, thermal insulation, and mechanical reliability.
Temperature Resistance and Thermal Shock
The silica matrix of milky quartz is similar to that of clear quartz. However, its numerous internal microbubbles can create localized thermal stress during rapid heating and cooling.
As a result, milky quartz generally has lower long-term temperature resistance and thermal-shock performance than high-quality clear quartz and black quartz.
Its value in semiconductor and photovoltaic equipment therefore comes primarily from its ability to reflect infrared radiation and function as a physical thermal shield.
Milky Quartz for Semiconductor and Photovoltaic Equipment
Milky quartz products are widely used in thermal insulation structures for semiconductor and photovoltaic equipment.
Depending on the application, products may be evaluated according to GB/T 42800—2023, which covers milky quartz applications in the semiconductor and photovoltaic industries and distinguishes between semiconductor-grade and photovoltaic-grade materials.
When Should You Choose Milky Quartz?
Milky quartz is particularly suitable when an application requires:
- Infrared radiation reflection
- Thermal insulation
- Light scattering
- Radiation shielding
- High-temperature insulation structures
Compared with clear quartz, milky quartz is not intended primarily for optical transmission. Its main advantage is its ability to manage radiant heat through scattering and reflection.
Post time: Aug-18-2026