🧩 PPS – Polyphenylene Sulfide
(A high-performance thermoplastic with excellent resistance to heat, chemicals, and wear. PPS is used in technical engine components, electrical housings, and cooling systems where other materials like PA or PBT fail.)
🔹 What is PPS
PPS (Polyphenylene Sulfide) is a semi-crystalline aromatic polymer. Its $C_6H_4–S$ chemical bonds grant it exceptional thermal and chemical stability. It remains inert to most solvents, oils, and acids, maintaining its mechanical properties even at temperatures exceeding $200$°C. In the automotive industry, it is the primary choice for sensors, valves, thermostat housings, and parts in contact with boiling fluids or exhaust gases.
🔧 Composition & Properties
- Base: 100 % Polyphenylene Sulfide (often glass-reinforced).
- Density: 1.34–1.65 g/cm³.
- Melting Point: ≈ 285 °C.
- Chemical Resistance: Exceptional (oils, fuels, acids, bases).
- Continuous Heat Resistance: 200–240 °C.
🚗 Where PPS is used in the automotive industry
| Component | Example parts | Observations |
| Engine / Thermal | Pumps, valves, thermostats, EGR | Resistance up to 240 °C |
| Electrical Systems | Connectors, sensor mounts | Excellent insulation, inherently flame retardant |
| Fuel / Braking | Fluid contact parts | Exceptional chemical stability |
| Technical Structures | Covers, guides, clips | High hardness, dimensional stability |
🔧 Welding Temperature and Methods
| Method | Optimal Temp | Observations |
| Hot Air | 300 – 330 °C | Slow, controlled melting without charring |
| Plastic Extrusion | 290 – 310 °C | Requires PPS rod and precise control |
| Heat Plate (Mirror) | 290 – 320 °C | Clean bond, no porosity |
🔩 Material Compatibility
- ✅ Compatible: PPS, PPS+GF, PPS+CF, PBT+PPS, PEEK+PPS.
- ⚠️ Good Compatibility: PEI, PSU, PES, PPSU (high-temp family).
- ❌ Incompatible: PP, PE, PS, ABS, PET (completely different melting points).
💡 ReplastMD Recommendation: Use original PPS rods at 310 °C. Clean the area thoroughly and avoid overheating to prevent carbonization. A quick pass with hot air after welding can smooth the final finish.
🧠 How to Identify PPS
- Engraved marking: >PPS<, >RYTON<, >FORTRON<, >TORELINA<.
- Texture: Matte, rigid, slightly “sandy” or stony feel.
- ReplastMD practical test: Produces a clear, metallic-like sound when tapped. Burns with a blue flame and a faint sulfur scent (like a struck match).
🛠️ PPS Welding at ReplastMD:
At our ReplastMD service center (Chisinau, Ciocana sector), we perform professional PPS / Ryton welding for sensor housings and thermal components, ensuring a high-strength finish resistant up to 240 °C.