Vertical Drawing – Turning Molten Glass into Medical Tubing — From Furnace to Precision-Formed Syringe Tube

Vertical Drawing – Turning Molten Glass into Medical Tubing

— From Furnace to Precision-Formed Syringe Tube

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After melting and refining, borosilicate glass must be transformed into precise, defect-free tubing — the foundation of high-quality prefilled syringes. At Sunrise Medical, this is achieved through vertical tube drawing, a process that combines gravity, geometry, and real-time feedback.

How It Works

The molten glass flows from the furnace into a platinum-lined feeder, where it is carefully funneled into a vertical stream. This stream is drawn downward, slowly cooled and stretched under tight dimensional control.

Laser-Guided Dimensional Accuracy

Two sets of laser triangulation sensors measure:

• Outer diameter (±0.05 mm tolerance)

• Wall thickness (±0.02 mm tolerance)

Data is fed into a control loop that dynamically adjusts drawing speed and temperature to ensure consistent concentricity across each tube.

Why Vertical Drawing Matters

Compared to horizontal methods, vertical drawing offers:

• Lower defect rates (fewer distortions or wall variations)

• Better control over tube straightness

• More stable internal pressure tolerance — critical for injection force control

✂️ Precision Cutting with CO₂ Laser

Once drawn and cooled, tubes are automatically cut to length using a CO₂ laser, creating burr-free edges that pass SEM inspection — essential for safe downstream processing.

✅ Key Takeaways

• Vertical drawing ensures uniform diameter and wall thickness

• Laser sensors provide ±0.05 mm control accuracy

• CO₂ laser cutting delivers clean, crack-free tube ends

• The result: pharmaceutical-grade glass tubing ready for syringe conversion

Interested in how vertical drawing can impact your syringe product quality?
Contact Sunrise Medical for OEM collaboration and production capabilities.