1. The influence of material properties on vacuum forming
Softening temperature
PC: The softening temperature is about 140-150°C, and it needs to be heated in a high-temperature oven (160-180°C). Due to the high heating temperature, it is more suitable for thermoforming with large vacuum forming equipment.
ABS: The softening temperature is about 105-115°C, and it can be processed in a conventional oven (120-140°C), and the operation tolerance is high.
Melt fluidity and molding complexity
PC: The melt viscosity is high, and a larger vacuum pressure (≥0.1MPa) is required to promote molding. Complex molds are prone to uneven filling (such as thin walls or deep drawing structures).
ABS: Good melt fluidity, low vacuum pressure requirement (0.05-0.08MPa), suitable for fine textures, sharp angles or deep cavity designs.
Thermal expansion and dimensional stability
PC: The shrinkage rate is large after cooling, and the mold needs to reserve compensation.
ABS: It has low shrinkage and is the most suitable material for vacuum forming among all plastic sheets, but it is easily affected by residual stress and causes warping.
Performance Comparison: Polycarbonate Sheet (PC) vs ABS Sheet
| Property | Polycarbonate Sheet (PC) | ABS Sheet |
|---|---|---|
| Density | 1.2 g/cm³ (Lightweight yet rigid) | 1.06 g/cm³ (Lighter but more brittle) |
| Impact Strength | 60–80 kJ/m² (20x higher than ABS) | 2–4 kJ/m² (Prone to brittle fracture) |
| Light Transmission | 90–92% (Optical grade up to 92%) | 85–90% (Transparent grade) |
| Long-Term Use Temperature | -40°C to 120°C | -20°C to 80°C |
| Heat Deflection Temperature | 135–145°C (at 1.82 MPa) | 85–105°C (at 1.82 MPa) |
| Chemical Resistance | Resists oils, weak acids; poor against strong alkalis, chlorinated hydrocarbons | Resists acids, alkalis; soluble in ketones, esters |
| Flame Retardancy | Self-extinguishing (UL94 V-2; modifiable to V-0) | Flammable (UL94 HB; requires flame retardants) |
| Weather Resistance | UV-resistant (10+ years without yellowing with UV stabilizers) | Prone to aging (yellows/brittles after 1–2 years outdoors) |
| Surface Hardness | Rockwell M70–80 | Rockwell R110–120 |
Price difference range
| Material type | Ordinary grade price (USD/kg) | High-end grade price (USD/kg) | Price multiple |
| 1.9-2.3 | 2.3-3.2(flame retardant, electroplating grade) | Baseline | |
| PC sheet | 2.5-3.4 | 3.1-5(bulletproof, optical grade) | 1.5 |
| ABS/PC sheet | 2.3-3.1 | 2.6-3.5(high temperature resistant, high impact resistant) | 2 |
When is it more appropriate to choose PC:
- The product needs long-term outdoor exposure (UV stability is required).
- The transparency and impact resistance are extremely high (such as bulletproof masks).
- High temperature resistance is key (such as kitchen appliance parts).
When is it more appropriate to choose ABS:
- The pursuit of low-cost, short-cycle production (such as promotional gifts).
- The design is complex and requires surface decoration (such as game console shell).
- Equipment limitations cannot achieve high-temperature processing (such as small processing plants).
A compromise between PC/ABS alloys
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Balancing performance and cost: e.g. automotive interiors (need to be scratch-resistant and cost-effective).
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Complex structures: alloys flow better than PC and can be molded into deep cavities or sharp-edged designs.