What is the difference between fused quartz and fused silica?

Fused quartz is melted from purified natural quartz crystal, while fused silica is usually synthesized from silicon-containing chemicals such as SiCl4. Fused quartz offers excellent thermal performance at a lower cost and suits most furnace, lighting and laboratory uses; synthetic fused silica is chosen when the deepest UV transmission and lowest metallic impurities are required.

What temperature can your quartz glass tubes withstand?

Our transparent fused quartz tubes are typically used continuously up to about 1100 °C and for short periods up to about 1450 °C. The softening point is approximately 1683 °C. Because the thermal expansion coefficient is only about 5.5 × 10⁻⁷/°C, the tubes tolerate rapid heating and cooling far better than borosilicate glass.

Can you manufacture custom quartz parts from my drawing?

Yes. We have more than 11 years of OEM experience and offer OEM, ODM and buyer-label services. Send your drawing, material grade and quantity to info@kemzoquartz.com and our engineers will confirm feasibility, tolerances and lead time.

Which payment and delivery terms do you accept?

We accept T/T, L/C, PayPal and cash, in USD, EUR, AUD, HKD or CNY. Delivery terms include FOB, CFR, CIF, EXW, DDU, DAF and express door-to-door delivery.

How do you pack fragile quartz glass for export?

Each item is individually protected with foam or bubble cushioning, tubes are separated so they cannot touch, and cartons are secured inside export-grade wooden cases for sea and air freight. Packing can be adapted to your warehouse handling requirements.

Which countries do you export to?

Between 71% and 80% of our output is exported. Our main markets are North America, Eastern Asia including South Korea, Southeast Asia, Europe, South America and Oceania.

Top 10 Quartz Melting Crucible Manufacturer & Exporter for Gwangju

High-Purity Fused Quartz Components Engineered for Gwangju’s Advanced Semiconductor, Photonics, and High-Temperature Industrial Processing Networks.

Precision Quartz Components & Crucible Solutions

Direct factory supply of thermal-shock resistant, ultra-pure fused quartz vessels, plates, and tubes configured for vacuum melting, analytical pyrometry, and wafer fabrication in Gwangju's high-tech industrial complexes.

Fused-Quartz Combustion Sample Boats with Integrated Pull-Ring Handles

Designed for high-temperature tube furnace calcination, organic element analysis, and alloy sintering up to 1200°C. Features flame-polished edges and thermal stress relief.

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Optical Cobalt Blue Glass Disc Sight Window

Optical Cobalt Blue Glass Disc Circular Filter Furnace Sight Glass Window

Filters sodium flame interference during high-temp molten metal inspection. High thermal tolerance for optical observation ports in Gwangju metal foundries.

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Capillary Micro-Bore Fused-Quartz Tubes for GC and Microfluidics

Ultra-precise aperture tolerances (±0.005mm) for gas chromatography, microfluidic optical channels, and precise fluidic dosing in photonics R&D.

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Clear Fused-Quartz Petri Dishes with Lids for High-Temp Applications

Chemically inert, acid-resistant quartz vessels tailored for high-temperature cell culture, optical clarity imaging, and hot acid evaporation.

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Raw Rough-Ground Fused-Quartz Blank Plates for Wafer Substrates

Dimensionally uniform quartz blanks designed as lapping substrates, vacuum chuck bases, and precision semiconductor carrier plates.

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4-Inch US Quartz Sand Fused Crucibles for Ingot Melting

Engineered with fire-polished rims and ultra-pure raw quartz sand. Ideal for semiconductor crystal growth, silicon ingot melting, and rare earth synthesis.

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High Purity Optical Clear Fused Quartz Disc Window Substrate

Deep UV to Near-IR spectrum optical window substrate featuring >90% transmission rate, zero bubble structure, and bubble class 0 certification.

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High Purity Opaque Milky White Fused Quartz Plate

High Purity Opaque Milky White Fused Quartz Rectangular Plate

Excellent thermal insulation, light-scattering performance, and infrared heat shield properties. Widely used in furnace liners and semiconductor heat baffles.

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99.99%

SiO2 Ultra-Purity Grade

1450°C

Max Operating Thermal Limit

5.5×10⁻⁷

Coeff. of Thermal Expansion (/°C)

ISO 9001

Certified Quality System

1. Technical Intent & Strategic Procurement Needs in Gwangju (South Korea)

Gwangju Metropolitan City has firmly established itself as South Korea’s premier hub for advanced photonics, optical communication devices, compound semiconductor packaging, and next-generation battery research. Industrial ecosystems such as the Gwangju High-Tech Industrial Complex, Nambuk Industrial Complex, and nearby energy tech zones demand strict reliability from high-temperature processing consumables.

When processing compound semiconductor crystals (such as GaAs, GaN, and InP), melting precious metal alloys, or conducting vacuum induction melting (VIM), standard ceramic crucibles fail due to chemical leaching, structural thermal shock, and inadequate purity. High-purity fused quartz crucibles—manufactured from processed natural crystal sand or synthesized fused silica—serve as the indispensable containment medium due to their exceptional thermodynamic stability and near-zero metallic ion leaching.

Key technical criteria prioritized by Gwangju engineering leads include:

Ultra-Low Contamination: Total alkali metal impurities (Na, K, Li) kept strictly below 10-15 ppm to prevent crystalline defect migration during CZ (Czochralski) or Bridgman crystal growth.
Thermal Shock Resilience: Extremely low coefficient of thermal expansion (5.5 × 10⁻⁷ /°C) allowing rapid thermal cycling from ambient temperature up to 1100°C–1300°C without catastrophic fracture.
Devitrification Resistance: Optimized glass surface matrix designed to slow down phase transformation into cristobalite during long furnace soak times.

2. Material Grade Benchmarking: Fused Quartz vs. Standard Ceramics

An engineering comparison illustrating why high-purity fused quartz crucibles surpass alumina, graphite, and borosilicate vessels in Gwangju's cleanroom and high-temp environments.

Material Property / Parameter	High-Purity Fused Quartz	High-Purity Alumina (99.7% Al₂O₃)	Synthetic Borosilicate Glass
SiO₂ Purity Level	99.9% – 99.995%	N/A (Alumina based)	~80% SiO₂ (B, Na additives)
Continuous Operating Temp	1100°C (1450°C short-term)	1600°C	500°C
Coeff. of Thermal Expansion (20-300°C)	5.5 × 10⁻⁷ /°C	8.0 × 10⁻⁶ /°C	3.3 × 10⁻⁶ /°C
Thermal Shock Tolerance	Extreme (Instant quench tolerant)	Moderate to Poor	Moderate
Acid Resistance (except HF/H₃PO₄)	Outstanding (Inert to hot acids)	Good	Moderate
Dielectric Strength (20°C, 1MHz)	25 – 40 kV/mm	10 – 15 kV/mm	15 – 20 kV/mm

3. Localized Applications Across Gwangju Industrial Sectors

Precision quartz components exported by Donghai Kemzo Quartz Products Co., Ltd. directly align with the core technological thrusts of Gwangju Metropolitan City:

Semiconductor & Compound Ingot Growth

In silicon wafer pulling and III-V compound semiconductor processing (GaAs, InP), 4-inch to 18-inch quartz crucibles serve as zero-contaminant melt containers under vacuum or inert argon shields.

Photonics & Optical Component Sintering

Gwangju’s cluster of optical fiber cable and precision lens manufacturers utilizes custom quartz boats, disc plates, and sight glasses for high-temperature UV optical window fabrication and glass preform collapse.

Battery Materials & Precious Metal Assay

Advanced energy researchers in Gwangju rely on quartz combustion boats and petri dishes for calcination, acid digestion, and high-temp battery cathode material powder analysis.

4. Localized Supply Chain & Market Trends in South Korea

South Korea’s high-tech manufacturing sector has undergone significant structural supply-chain optimization. High-tech enterprises in Gwangju increasingly emphasize supplier diversification, compliance with ISO 9001 quality audits, and rapid customs transit protocols.

Donghai Kemzo Quartz Products Co., Ltd., situated in Donghai County (Lianyungang, Jiangsu, China)—the world-renowned crystal hub—offers direct regional advantages for South Korean importers:

Geographic Proximity & Shipping Logistics: Fast sea-freight routes from Lianyungang / Qingdao port directly to Incheon, Busan, or Gwangyang ports, enabling delivery lead times under 5–7 days for standard stock orders.
China-Korea FTA Utilization: Preferential tariff processing with complete Certificate of Origin documentation (Form K), ensuring lower landed costs for Gwangju procurement officers.
Custom OEM Drawing Fabrication: Rapid prototype turnaround from CAD files (STEP, DWG, PDF) to finished annealed quartz components within 10–14 business days.

5. Corporate Capability & Quality Management

Backed by over a decade of dedicated production, Donghai Kemzo Quartz combines source-mine raw material advantages with international quality management standards.

ISO 9001 & High-Tech Certification

Certified quality management system covering raw sand purification, electric/arc melting, stress annealing, and spectrographic trace analysis.

Comprehensive Processing Fleet

Operating over 10 production lines equipped with CNC quartz glass lathes, automatic tube drawing towers, fire-polishing stations, and double-side optical polishing tools.

Export Packing Safeguards

Custom shock-absorbing EPE foam matrices, vacuum sealing, and plywood crate packaging engineered specifically to eliminate shock damage during cross-border transit.

6. Frequently Asked Questions for Gwangju Procurement Engineers

Addressing key engineering, purity, and logisitcal considerations commonly queried by South Korean buyers.

Q1: What is the primary difference between fused quartz and synthetic fused silica crucibles?

Fused quartz is produced by melting natural high-purity quartz crystal sand (SiO₂ ≥ 99.99%). It offers exceptional cost-performance, high mechanical strength, and excellent thermal stability up to 1100°C–1450°C, making it ideal for solar and standard semiconductor ingot melting. Synthetic fused silica is produced via chemical vapor deposition (SiCl₄ gas), offering deep UV transmission and lower metallic content, but at a significantly higher cost.

Q2: How does Donghai Kemzo prevent devitrification (cristobalite formation) at high temperatures?

Devitrification is accelerated by surface alkali metal impurities (Na, K, Li) and surface scratches. Kemzo crucibles undergo hot acid washing (HF/HNO₃ balance), deionized water rinsing in cleanroom environments, and precise flame annealing to ensure a ultra-clean, micro-smooth glass surface that delays crystallization onset during long thermal holds above 1150°C.

Q3: What dimensional tolerances can be achieved for custom OEM quartz components?

For standard tubes and crucibles, outer diameter (OD) tolerance is maintained within ±0.15mm to ±0.3mm. For precision CNC ground plates, optics, or capillary tubes, dimensional tolerances can be tightened to ±0.01mm – ±0.05mm according to customer CAD specifications.

Q4: What are the recommended heating and cooling ramp rates for quartz melting crucibles?

While quartz possesses extreme resistance to thermal shock, ramping rates between 5°C/min to 15°C/min are recommended for heavy-walled crucibles to ensure uniform internal heat distribution and prevent localized stress points, especially when heavily loaded with dense metal or silicon charge.

Q5: How can Gwangju companies request custom quotation and sample delivery?

Enginering teams can submit technical drawings (PDF, STEP, DWG) directly via our live chat window or sales contact email. Engineering feasibility assessments, formal proforma quotes, and sample production schedules are generated within 1 hour during active business operating times.

Need Customized Quartz Crucibles or Components for Your Gwangju Facility?

Speak directly with our technical glass engineers today. Obtain custom drawing reviews, material purity certificates, and localized delivery timelines within 1 hour.

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