🧩 PBT+GF20 – Polybutylene Terephthalate + 20% Glass Fiber
(Rigid and thermostable technical material with superior mechanical and dimensional strength compared to standard PBT. Ideal for connector housings, sensor covers, headlight parts, and engine components exposed to heat and vibration.)
🔹 What is PBT+GF20
PBT+GF20 is a reinforced polyester made by adding 20% short glass fibers (GF) into the PBT matrix. These fibers significantly increase the elasticity modulus, rigidity, and warping resistance while maintaining PBT’s excellent chemical and thermal resistance. It is widely used in the automotive industry for electrical parts and structural components requiring high mechanical integrity.
🔧 Composition & Properties
- Base: 80% PBT, 20% Glass Fiber.
- Density: 1.45–1.55 g/cm³.
- Melting Point: ≈ 220–225 °C.
- Chemical Resistance: Excellent (oils, fuels, solvents).
- Continuous Heat Resistance: 130–150 °C.
🚗 Where PBT+GF20 is used in the automotive industry
| Component | Example parts | Observations |
| Electrical / Electronics | Connector housings, sensor mounts | Excellent insulation, dimensional stability |
| Engine / Tech Compartment | Covers, housings, clips | High mechanical and thermal resistance |
| Headlights / Lighting | Supports, frames, structural parts | UV resistant, does not warp |
| Technical Interior | Rigid parts, mounts | Smooth finish, zero visible shrinkage |
🔧 Welding Temperature and Methods
| Method | Optimal Temp | Observations |
| Hot Air | 260 – 280 °C | Fast melting, requires thermal control |
| Plastic Extrusion | 250 – 270 °C | Suitable for thick housings |
| Heat Plate (Mirror) | 250 – 270 °C | Clean bond, watch for glass edges |
🔩 Material Compatibility
- ✅ Compatible: PBT, PBT+GF, PC+PBT, PBT+PET, PA+PBT, POM+PBT.
- ⚠️ Good Compatibility: PBT+ASA, PBT+PC, PBT+PA66.
- ❌ Incompatible: PP, PE, PS, ABS, PVC (completely different melting points).
💡 ReplastMD Recommendation: Use PBT or PC+PBT rods at 270 °C. Heat the area uniformly and apply constant pressure. Avoid overheating—fibers may migrate to the surface, weakening the adhesion.
🧠 How to Identify PBT+GF20
- Engraved marking: >PBT+GF20<, >ULTRADUR<, >CRASTIN<, >VALOX<.
- Texture: Matte, rigid, feels slightly “rough” to the touch.
- ReplastMD practical test: If the part is very rigid with a slightly fibrous, matte look, it’s PBT+GF20. Burns with a yellow-blue flame and a sweet ester scent.
🛠️ PBT+GF20 Welding at ReplastMD:
At our ReplastMD service center (Chisinau, Ciocana sector), we perform professional PBT+GF20 welding for rigid housings and sensor mounts, ensuring a strong, heat-resistant, and factory-grade finish.