The hollow glass tubes have a smooth, fine texture and excellent heat resistance to high-temperature torch flames, meeting Hard Glass standards. They are easy to shape during melting and are not prone to breaking. They are highly suitable for blowing functional glass, fashion glass jewelry, or decorative pieces that require soft yet distinctive colors contrasting with clear glass.
Main Chemical Composition
- SiO₂ (Silica): 80% ±0.5
- B₂O₃ (Boron Trioxide): 13% ±0.2
- Al₂O₃ (Aluminum Oxide): 2.4% ±0.2
- Na₂O + K₂O: 4.3% ±0.2