The main differences between soda-lime glass and borosilicate glass lie in chemical composition, thermal performance, chemical stability, mechanical strength, cost and application scenarios. Detailed comparisons are as follows:
1. Chemical Composition (Core Difference)
| Index | Soda-lime Glass | Borosilicate Glass |
|---|---|---|
| Main Components | SiO₂ (70%–75%) + Na₂O + CaO | SiO₂ (70%–80%) + B₂O₃ (10%–15%) + Al₂O₃ |
| Alkali Metal Content | High Na₂O content (12%–15%), no B₂O₃ | Almost no Na₂O, B₂O₃ as core modifier |
| Characteristic Root | Alkali oxides reduce melting temperature, lowering production cost | B₂O₃ forms a stable network structure with SiO₂, enhancing heat resistance and chemical stability |
2. Key Performance Differences
(1) Thermal Expansion Coefficient & Thermal Shock Resistance
- Soda-lime glass: High linear expansion coefficient (about 90×10⁻⁷/℃). It is prone to cracking when subjected to rapid temperature changes, and can only withstand a temperature difference of less than 50℃.
- Borosilicate glass: Extremely low linear expansion coefficient (about 3.3×10⁻⁷/℃, known as “low-expansion glass”). It has excellent thermal shock resistance and can withstand a temperature difference of over 200℃ (e.g., directly pouring ice water into boiling water-containing containers without cracking).
(2) Temperature Resistance
- Soda-lime glass: Softening temperature ranges from 500–600℃, with a long-term service temperature ≤ 150℃. It deforms easily when overheated.
- Borosilicate glass: Softening temperature ranges from 800–900℃, with a long-term service temperature up to 450℃ and short-term resistance to 600℃ high temperature.
(3) Chemical Stability
- Soda-lime glass: Moderate acid resistance, poor alkali resistance. Long-term contact with water or humid environments may lead to alkali ion precipitation (e.g., fogging on the inner wall of glass cups).
- Borosilicate glass: High chemical stability, resistant to acid, alkali and water erosion, with almost no ion precipitation. It is suitable for storing chemical reagents or food.
(4) Mechanical Strength
- Soda-lime glass: Brittle texture, weak impact resistance, and easy to break.
- Borosilicate glass: Higher mechanical strength and impact resistance than soda-lime glass; broken fragments are relatively round, with lower danger.
3. Cost & Application Scenarios
| Index | Soda-lime Glass | Borosilicate Glass |
|---|---|---|
| Production Cost | Low (easy-to-obtain raw materials, low melting temperature) | High (expensive B₂O₃ raw materials, high melting temperature) |
| Typical Applications | Daily glassware (cups, bowls), beverage bottles, window glass, glass beads, ordinary tableware | Laboratory glassware (beakers, test tubes), microwave-safe tableware, coffee pots, optical instruments, high-temperature-resistant glass tubes |
4. Summary
- Choose soda-lime glass for scenarios where low cost, daily use and no strict temperature resistance requirements are needed.
- Choose borosilicate glass for scenarios where high temperature resistance, thermal shock resistance and chemical stability are required.