Heat resistance customize clear quartz Petri dish

Manufacturing Process and Workflow of clear quartz Petri dish

This method involves the secondary thermoforming of a pre-fabricated quartz tube into a crucible shape using gas pressure and a mold.

Stage 1: Preparation Phase

1. Raw Material Preparation
   · Material: High-purity, defect-free transparent quartz tubing. This tube is typically produced via an electrical or flame fusion process, and its quality dictates the final crucible's performance.
   · Mold Preparation: A high-precision, heat-resistant graphite or refractory alloy mold is used. The mold's cavity defines the external shape of the crucible (e.g., spherical, cylindrical, custom shapes).


2. Quartz Tube Pre-processing
   · Cutting: The quartz tube is cut to the required length.
   · Cleaning: The tube undergoes high-purity cleaning (e.g., with ultra-pure water, acid etching, ultrasonic cleaning) to remove all contaminants from the inner and outer walls.
   · Sealing One End: One end of the tube is heated using a hydrogen-oxygen torch until it melts and fuses shut, forming a smooth, hemispherical dome that becomes the bottom of the crucible.

Stage 2: Thermoforming Phase - The Core Process

This is the most critical step, performed on a specialized glassblowing lathe or automated forming machine.

1. Heating and Softening
   · The pre-processed quartz tube (sealed end first) is mounted on the lathe and positioned inside the pre-heated mold.
   · The target area (the future body of the crucible) is rotated and evenly heated using a hydrogen-oxygen flame or plasma torch. Rotation is crucial for uniform heating.
   · The quartz is heated to its softening point (approximately 1650-1800°C), where it becomes pliable but not fully molten.

2. Gas Pressurization and Forming
   · While the quartz is soft, high-purity inert gas (e.g., Nitrogen, Argon) is introduced into the tube through the open end, with its pressure precisely controlled.
   · The internal gas pressure forces the softened quartz wall to expand uniformly outward until it fully conforms to the shape of the mold's inner surface.
   · The mold defines the final external geometry, while the gas pressure ensures dimensional accuracy and a smooth surface finish.

3. Annealing and Cooling
   · After forming, the quartz Petri dish is immediately annealed while still in or near the mold. A broad, soft flame is used to relieve thermal stresses induced by rapid heating and cooling.
   · The formed quartz Petri dish is then cooled under controlled conditions to room temperature before being removed from the mold.

Stage 3: Post-Processing and Finishing

1. Cutting and Opening
   · The open end of the formed quartz Petri dish is cut to the exact specified height and squareness using a diamond wheel saw or laser cutter.
   · The sharp, cut edge is then fire-polished or mechanically ground to a smooth, rounded finish to prevent chipping and stress concentration.

2. High-Intensity Cleaning & Inspection
   · Cleaning: The quartz Petri dish undergoes a multi-step, high-purity cleaning process (acid cleaning, ultrasonic cleaning, rinsing with ultra-pure water) to remove all contaminants from processing.
   · Inspection:
     · Dimensional Check: Verifying diameter, height, and wall thickness.
     · Visual Inspection: Inspecting for bubbles, scratches, pits, or any irregularities on the inner and outer surfaces under controlled lighting.

Stage 4: Special High-End Treatment - Inner Surface Fire Polishing

For high-end crucibles used in semiconductor or premium photovoltaic applications, an additional critical step is performed:
· Inner Surface Fire Polishing
  · Purpose: To create a perfectly dense, smooth, mirror-like transparent layer on the clear quartz Petri dish inner surface.
  · Method: The quartz Petri dish is rotated while a hydrogen-oxygen flame or plasma torch is inserted and scanned across the entire interior surface.
  · Effects:
    · Seals Micro-Pores: Clear quartz Petri dish eliminates micro-cracks and tiny pores.
    · Reduces Roughness: Clear quartz Petri dish creates an atomically smooth surface, preventing material adherence and facilitating easy cleaning.
    · Enhances Devitrification Resistance: Significantly improves the clear quartz Petri dish resistance to crystallization at high temperatures, thereby extending the crucible's service life.

Summary Workflow Diagram of clear quartz Petri dish:
High-Purity Quartz Tube → Cutting → Cleaning → One-End Sealing → Mounting in Mold → Rotational Heating & Softening → Gas Pressure Forming → Annealing → Demolding → Cutting/Opening → Edge Polishing → (Inner Surface Fire Polishing) → High-Intensity Cleaning → Final Inspection → Clean Packaging

Advantages of clear quartz Petri dish:
· High Purity: Clear quartz Petri dish uses high-purity quartz tubing, minimizing contamination.
· High Precision: Clear quartz Petri dish mold-forming ensures excellent dimensional consistency.
· Shape Flexibility: Capable of producing complex and custom geometries.
· Superior Surface Quality: Fire polishing the clear quartz Petri dish achieves an exceptional inner surface finish.

Primary Applications:
· Semiconductor Industry: For high-temperature diffusion, oxidation processes, and epitaxy.
· Laboratory & R&D: For material synthesis, crystal growth, and high-temperature chemical reactions.
· Photovoltaics R&D: For experimental silicon growth and processing.
· Optoelectronics: For sintering phosphors, laser crystals, and other specialty materials.

  
Technical Parameters