🧩 PE-LD – Low-Density Polyethylene
(Weldable soft and flexible plastic, used for automotive parts, protectors, tanks, and deformable elements)
🔹 What is PE-LD
PE-LD (Low-Density Polyethylene) is a polyethylene with a branched molecular structure, which provides it with high elasticity, transparency, and good resistance to impact and stress-cracking. It is one of the easiest plastics to weld, used in the automotive industry as well as in technical and industrial applications. Compared to PE-HD, the PE-LD variant is softer, easier to shape, and has a lower melting point.
🔧 Composition
- Ethylene (CH2) – polymerized at high pressure
- Additives – antioxidants, UV stabilizers, anti-static agents, colorants
- Density: 0.91–0.93 g/cm³
- Melting point: ≈ 110–120 °C
🚗 Where PE-LD is used in the automotive industry
| Component | Example parts | Observations |
| Exterior | Mudguards, flaps, flexible housings | High resistance to shock and folding |
| Engine Compartment | Reservoirs, caps, auxiliary tubes | Good chemical resistance |
| Technical Interior | Plugs, gaskets, deformable parts | Soft, smooth texture |
| Aftermarket | Water tanks, flexible boxes | Weldable and easy to mold |
🔧 Welding temperatures and methods
| Method | Optimal temperature | Observations |
| Hot air | 240 – 260 °C | Fast melting, simple control |
| Heat plate (mirror) | 230 – 250 °C | Clean and watertight joint |
| Manual extrusion | 220 – 250 °C | For thick or long parts |
| Electrofusion | — | Used for tanks and pipes |
🔩 What to weld PE-LD with (Material compatibility)
“What to weld PE-LD with” is a frequent question in repairs of flexible parts. The material only welds with polyethylene of the same type or similar density.
✅ Compatible:
- PE-LD ↔ PE-LD – ideal combination
- PE-LD ↔ PE-MD / PE-HD – partial compatibility, different melting points
- PE-LD ↔ PE-LD + additives – fully compatible
❌ Incompatible:
- PP, ABS, ASA, PC, PA, PVC – different structures, will not bond
💡 ReplastMD Recommendation: Use original PE-LD welding rods at a temperature of 250–260 °C. Clean the weld zone, degrease, and work slowly to avoid bubble formation. PE-LD welds best with constant pressure and slow cooling.
🏭 Manufacturers and trade names
- LyondellBasell: Lupolen® LD
- Borealis: Borstar® LD
- SABIC: LDPE Compound
- ExxonMobil: Escorene® LD
🧠 How to identify PE-LD
- Engraved marking: >PE-LD<, >LDPE<
- Glossy surface, soft, waxy to the touch
- Yellow-blue flame, paraffin / candle smell
- Floats completely in water (density < 1 g/cm³)
- Softens at 240–250 °C, without smoke or bubbles
🛠️ PE-LD Welding at ReplastMD: At our service center in Chisinau (Ciocana sector), ReplastMD performs professional PE-LD welding for:
- guards, covers, tanks, and flexible parts
- crack, fissure, and deformation repairs
- structural reinforcement with own PE-LD rods
- smooth, watertight, and original-strength finishing