🧩 PE+PP – Polyethylene + Polypropylene
(Hybrid weldable plastic, used in flexible or mixed automotive parts, combining PE’s elasticity with PP’s rigidity)
🔹 What is PE+PP
PE+PP is a blend of polyethylene (PE) and polypropylene (PP), designed to combine the advantages of both materials:
- Elasticity and chemical resistance from PE.
- Rigidity and thermal stability from PP.The result is a semi-elastic, resistant, and lightweight plastic, used in the automotive industry for parts requiring durability and low weight without extreme structural demands.
🔧 Composition
- PE (Polyethylene) – 30–60 %
- PP (Polypropylene) – 40–70 %
- Compatibilizers (maleic anhydride grafted) – to bond the two phases.
- Density: 0.92–0.94 g/cm³.
- Melting Point: ≈ 140–160 °C (depending on the ratio).
🚗 Where PE+PP is used in the automotive industry
| Component | Example parts | Observations |
| Body / Exterior | Covers, mudguards, lower guards | Flexible and impact resistant material |
| Engine Compartment | Caps, housings, protectors | Chemically stable, moderately thermal |
| Technical Interior | Supports, panels, gaskets | Lightweight and partially weldable |
| Aftermarket | Boxes, protection elements | Hybrid, economic and recyclable material |
🔧 Welding Temperature and Methods
| Method | Optimal Temperature | Observations |
| Hot Air | 260 – 280 °C | Weldable only with compatible PE+PP rod |
| Heat Plate (Mirror) | 250 – 270 °C | Requires precise melting control |
| Manual Extrusion | 240 – 260 °C | Uniform melting if proportions are balanced |
🔩 What to Weld PE+PP With (Material Compatibility)
As a hybrid, the material does not fully bond with either pure PE or pure PP. The best result is achieved with PE+PP rod or compatible grafted rod (PP-g-MA).
✅ Compatible:
- PE+PP ↔ PE+PP – ideal combination.
- PE+PP ↔ PP / PP+EPDM / PP+TPO – good compatibility.
- PE+PP ↔ PE-HD / PE-MD – partially compatible (superficial bonding).
❌ Incompatible:
- ABS, ASA, PC, PA, PVC – different melting points and polarities.
💡 ReplastMD Recommendation:
Use PE+PP or PP-g-MA rods at a temperature of 270 °C with constant hot air flow. For minor repairs, PP-TPO rods can be used, as they adhere well to hybrid blends.
🏭 Manufacturers and Trade Names
- Borealis: Daplen® PP/PE
- LyondellBasell: Hostacom® PP/PE
- SABIC: PP-PE Compound
- TotalEnergies: Lumicene® PP/PE
🧠 How to Identify PE+PP
- Engraved marking: >PP-PE<, >PE-PP<, >PP/PE< or >PP+PE<.
- Semi-matte surface, elastic but resistant to folding.
- Yellow-blue flame, faint paraffin smell.
- Softens uniformly at 270 °C, without black smoke.
- Floats completely in water (density < 1 g/cm³).
🛠️ PE+PP Welding at ReplastMD:
At our service center in Chisinau (Ciocana sector), ReplastMD performs professional PE+PP welding for:
- OEM protective elements, covers, and mixed parts;
- crack and deformed zone repairs;
- reinforcement with compatible rods and aesthetic finishing.