Borosilicate Glass Tube Manufacturing: A Step-by-Step Look from Raw Material to Final Product

Borosilicate Glass Tube Manufacturing: A Step-by-Step Look from Raw Material to Final Product

Borosilicate glass tubes are widely used in laboratories, lighting, chemical processing, and medical devices due to their superior thermal resistance, low thermal expansion, and excellent chemical stability. But what does it take to produce these precision glass components? Here’s a step-by-step look into the manufacturing process—from raw ingredients to finished tubes.

1. Raw Material Selection and Batching

The primary components of borosilicate glass are silica (SiO₂), boron oxide (B₂O₃), sodium oxide, and aluminum oxide. These ingredients are carefully weighed and mixed into a uniform batch to ensure chemical consistency and performance in the final product.

2. Melting

The batch is then introduced into a high-temperature furnace—usually operating at around 1500°C to 1650°C. In this stage, the raw materials melt into a homogenous, molten glass. Advanced furnaces are designed to minimize contamination and bubbles, which are critical for applications requiring optical clarity.

3. Forming into Tubes

Once molten, the glass is shaped into tubes using either:

• Danner process (drawing the glass over a rotating mandrel), or

• Vello process (glass flows through a ring nozzle and is drawn into tubes).

Both methods allow precise control of inner/outer diameter and wall thickness.

4. Annealing

The formed tubes pass through an annealing lehr—a controlled cooling chamber—to relieve internal stresses. This step ensures mechanical stability and prevents cracking during later use.

5. Cutting, Finishing & Inspection

Tubes are cut to length, flame-polished if needed, and thoroughly inspected for dimensional accuracy, clarity, and surface quality. Only those meeting strict specifications proceed to packaging and shipping.

Conclusion

From raw materials to high-performance tubes, the production of borosilicate glass tubing is a precise and highly engineered process—ensuring the final product meets the demanding standards of modern science and industry.