🧩 PE – Polyethylene
(Weldable soft and chemically resistant plastic, used in technical parts, tanks, and automotive protections)
🔹 What is PE
PE (Polyethylene) is one of the most widely used plastics, known for its elasticity, impact resistance, and high chemical stability. It is a semi-crystalline thermoplastic obtained from ethylene and exists in several forms:
- PE-LD – low-density polyethylene (flexible, soft)
- PE-HD – high-density polyethylene (rigid, hard)
- PE-MD / PE-LLD – intermediate variants with mixed properties.In the automotive industry, PE is valued for its resistance to acids, salts, water, and vibrations.
🔧 Composition
- Ethylene (CH2) – polymerized under pressure or with a catalyst
- Additives – antioxidants, UV stabilizers, colorants, anti-static agents
- Variants: PE-LD, PE-HD, PE-MD, PE-LLD, PE-X (cross-linked)
🚗 Where PE is used in the automotive industry
| Component | Example parts | Observations |
| Exterior | Mudguards, lower protections, fuel caps | Impact and corrosion resistance |
| Technical Interior | Covers, housings, fixing panels | Lightweight and durable |
| Engine Compartment | Fluid tanks, thermal shields | Chemical resistance |
| Aftermarket | Auxiliary tanks, tool boxes | Weldable, very lightweight |
🔧 Welding temperatures and methods
| Method | Optimal temperature | Observations |
| Hot air | 250 – 270 °C | Easy weld, homogeneous melting |
| Heat plate (mirror) | 240 – 260 °C | Recommended for thick parts |
| Manual extrusion | 230 – 250 °C | Ideal for cracks and corners |
| Electrofusion | — | Used for pipes and tanks |
🔩 What to weld PE with (Material compatibility)
PE only welds with polyethylene of the same type (HD, LD, MD), without mixing different polymers.
✅ Compatible:
- PE ↔ PE – ideal combination (same type: LD with LD, HD with HD)
- PE-HD ↔ PE-MD / PE-LD – partial compatibility (minor repairs only)
❌ Incompatible:
- PP, ABS, ASA, PC, PA, PVC – will not bond, different melting points
💡 ReplastMD Recommendation:
Use PE welding rods of the same type (HDPE or LDPE). The optimal temperature is 260–270 °C with uniform hot air. Clean the oxide layer and degrease with isopropyl alcohol for a clean joint.
🏭 Manufacturers and trade names
- LyondellBasell: Lupolen® PE
- Borealis: Borstar® PE
- SABIC: HDPE / LDPE Series
- ExxonMobil: Escorene® PE
🧠 How to identify PE
- Engraved marking: >PE-HD<, >PE-LD<, >HDPE<, >LDPE<
- Semi-glossy surface, soft, waxy to the touch
- Yellow-blue flame, typical paraffin / candle smell
- Floats completely in water (density < 1 g/cm³)
- Softens uniformly at 260 °C, no bubbles
🛠️ PE Welding at ReplastMD:
At our service center in Chisinau (Ciocana sector), ReplastMD performs professional PE welding for:
- tanks, covers, guards, and PE-HD / PE-LD housings
- crack repairs, broken mounts, and fixings
- clean, smooth, and watertight finishing