From optical photomask blanks and sight windows to heavy-wall reaction tubes and fused crucibles, explore our factory-direct product lines engineered to withstand thermal extremes up to 1450 °C.
In high-intensity discharge (HID) lamps, halogen lighting architectures, and thin-film vacuum evaporation apparatuses, quartz glass bell enclosures function as the primary atmospheric barrier. Donghai Kemzo Quartz Co., Ltd. formulates fused silica with an ultra-low linear thermal expansion coefficient of 5.5 × 10⁻⁷ /°C. This critical property virtually eliminates stress fracture propagation under abrupt thermal gradients (such as rapid water quenching from 1100 °C).
Our OEM manufacturing protocols adhere strictly to high-vacuum outgassing constraints. By reducing hydroxyl (OH⁻) content below 15 ppm or custom-doping cerium/titanium for target UV absorption envelopes, our engineered bell jars guarantee that gas discharge chambers maintain spectral efficiency without devitrification or solarization over thousands of duty hours.
| Critical Metric | Standard Grade | Kemzo High-Purity Spec |
|---|---|---|
| SiO₂ Purity | 99.90% | ≥ 99.99% |
| Softening Point | 1665 °C | 1683 °C |
| Continuous Service Temp | 1050 °C | 1100 °C – 1150 °C |
| Short-Term Peak Temp | 1350 °C | 1450 °C |
| Thermal Shock Index | 800 °C to H₂O | 1100 °C Drop Quench Safe |
| Hydroxyl (OH⁻) Control | < 40 ppm | < 15 ppm (Low-OH Option) |
From raw mineral crystal extraction in Donghai to advanced laser-guided quartz tube drawing and glass lathe bell blowing.
Specially blown fused silica bell chambers designed to seal corrosive metal halide vapors, xenon gas, and high-pressure iodine cycles without structural embrittlement.
Used as vacuum bells and process envelopes where uncompromised purity prevents metallic migration across silicon wafers during rapid thermal processing (RTP).
Inert bells for laboratory and industrial tube furnaces, sustaining pure nitrogen or argon containment while resisting blistering during continuous 1100 °C soak cycles.
Optically clean, bubble-free glass domes providing transparent real-time monitoring of plasma deposition with robust resistance to mechanical implosion stresses.
Strategic developments shaping fused quartz glass procurement among automotive lighting leaders, tier-1 optic specialists, and thermal process engineers.
As lighting fixtures push greater lumens per watt, high operating temperatures accelerate IR radiation loss via hydroxyl absorption bands. The supply chain is rapidly shifting toward pre-baked, vacuum-annealed quartz with OH content below 10 ppm, guaranteeing maximum radiant stability.
Manual lathe-working is being replaced by 4-axis diamond grinding and ultrasonic drilling. Modern automated assembly lines require bell jar flange flatness within ±0.05 mm and perpendicularity deviations under 0.1 mm to ensure airtight O-ring or viton gasket compression.
Global tariff fluctuations and transport lead times incentivize European and American purchasers to contract directly with vertically integrated Chinese manufacturers based in Donghai, securing competitive batch pricing from mineral refinement through hot glass finishing.
Located in China's crystal capital, we combine immediate access to the world's most concentrated natural quartz reserves with cutting-edge optical fabrication infrastructure.
Our plant operates in Donghai County, Lianyungang. Controlling the supply chain from raw rock crystals and silica sand directly translates to zero intermediate markups and verified raw purity.
From CAD blueprints (.DWG, .DXF, .STP) to physical production: our glass technicians perform custom lathe spinning, flame flanging, optical planar polishing, and precision hole boring.
Every hot-worked quartz bell jar undergoes controlled thermal annealing inside programmable muffle furnaces to completely dissipate hoop stress, verified via crossed-polarizer inspection.
Exporting over 70% of total capacity globally, our fragile freight packaging combines tailored EPE foam molds, vacuum shock insulation, and ISPM-15 compliant export plywood crates.
Answers to common inquiries regarding material equivalencies, dimensional tolerances, order MOQs, and global fulfillment terms.
Borosilicate glass 3.3 exhibits a maximum continuous thermal ceiling of approximately 450 °C to 500 °C with a thermal expansion coefficient around 3.3 × 10⁻⁶ /°C. In contrast, fused quartz consists of over 99.99% pure SiO₂, providing a linear expansion of 5.5 × 10⁻⁷ /°C (six times lower than borosilicate) and continuous thermal integrity at 1100 °C (short peaks up to 1450 °C). For halogen lamp envelopes and vacuum deposition systems, borosilicate will deform or shatter, while fused quartz maintains structural geometry.
Yes. We routinely fabricate OEM and replacement bell jars, envelopes, and quartz process housings designed to interface with equipment developed by Narva and international lighting and vacuum furnace manufacturers. Buyers can submit engineering sketches, 2D/3D CAD models, or physical samples; our engineers will verify wall thickness, flange profiles, and optical clarity tolerances prior to sample production.
On flame-formed diameters, standard dimensional tolerances are maintained within ±0.5 mm to ±1.0 mm depending on diameter size. For precision ground flanges, sealing rims, and flat optical viewing windows, our CNC grinding and double-sided polishing stations achieve flatness tolerances down to λ/4 (±0.005 mm) and edge perpendicularity within ±0.05 mm.
We accommodate custom prototyping and engineering R&D with sample runs as small as 1 to 5 pieces. Standard batch production orders typically ship within 12 to 18 business days. Emergency rapid tooling runs for high-priority production lines can be expedited upon engineering approval.
We support multiple delivery terms including FOB, CFR, CIF, EXW, DDU, DAF, and door-to-door express couriers (DHL, FedEx, UPS, TNT). Accepted transaction instruments include T/T, L/C, PayPal, and cash, with transactions settled in USD, EUR, AUD, HKD, or CNY.
Every quartz part is cleaned, wrapped with static-free barrier film, and suspended in multi-layer custom contoured polyurethane or high-density EPE shock absorption blocks. These boxes are then bolted into fumigated, reinforced export-grade plywood crates designed to absorb transit resonance and impact shocks during sea freight or air cargo handling.
Send us your technical drawings, operating parameters, and required delivery schedule. Our senior quartz processing engineers will review your geometry, advise on material grades, and return a competitive factory-direct quote within one hour.