🧩 PBT+PET – Polybutylene Terephthalate + Polyethylene Terephthalate
(A hybrid polyester blend with excellent chemical resistance and thermal stability, resulting from the combination of PBT (rigid and dimensionally stable) and PET (tough and tensile-resistant). PBT+PET offers hardness, gloss, and heat resistance.)
🔹 What is PBT+PET
PBT+PET is a compatibilized blend of two related aromatic polyesters. PBT provides ease of processing and oil resistance, while PET contributes higher mechanical and thermal strength. Their combination results in a material with low shrinkage, high rigidity, good surface gloss, and improved impact resistance. It is frequently used in automotive housings and lighting components.
🔧 Composition & Properties
- Base: 50–70% PBT, 30–50% PET.
- Density: 1.35–1.45 g/cm³.
- Melting Point: ≈ 225–235 °C.
- Chemical Resistance: Excellent (oils, solvents, fuels).
- Continuous Heat Resistance: 120–140 °C.
🚗 Where PBT+PET is used in the automotive industry
| Component | Example parts | Observations |
| Electrical / Sensors | Connectors, relay covers | Electrical insulation, thermal resistance |
| Engine Bay | Guides, frames, covers | Dimensional stability under heat |
| Headlights / Lighting | Frames, supports, reflectors | Good gloss, UV resistance |
| Technical Interior | Rigid parts, structural trim | Clean finish, high durability |
🔧 Welding Temperature and Methods
| Method | Optimal Temp | Observations |
| Hot Air | 260 – 280 °C | Fast and uniform melting |
| Plastic Extrusion | 250 – 270 °C | Suitable for thick technical parts |
| Heat Plate (Mirror) | 250 – 270 °C | Clean bonding, zero shrinkage |
🔩 Material Compatibility
- ✅ Compatible: PBT, PET, PC+PBT, PBT+GF, PBT+ASA, PBT+PC.
- ⚠️ Good Compatibility: POM+PBT, PBT+FR.
- ❌ Incompatible: PP, PE, PVC, ABS, PS (completely different melting points).
💡 ReplastMD Recommendation: Use PBT or PC+PBT rods at 270 °C. Clean the area thoroughly before welding—deposits significantly reduce adhesion. Maintain constant pressure for a uniform joint.
🧠 How to Identify PBT+PET
- Engraved marking: >PBT+PET<, >VALOX<, >ULTRADUR<.
- Texture: Semi-glossy, rigid, with a slight acrylic-like shine.
- ReplastMD practical test: If the part is rigid, heavy, and glossy with a PBT+PET mark, it is confirmed. Softens at ≈ 230 °C and releases a sweet ester scent when burned.
🛠️ PBT+PET Welding at ReplastMD:
At our ReplastMD service center (Chisinau, Ciocana sector), we perform professional PBT+PET welding for technical housings and headlight frames, ensuring a high-strength, glossy, and factory-grade finish.