🧩 PE-LLD – Linear Low-Density Polyethylene
(Weldable flexible and tear-resistant plastic, used in automotive parts, tanks, and deformable protections)
🔹 What is PE-LLD
PE-LLD (Linear Low-Density Polyethylene) is a linear low-density polyethylene obtained by copolymerizing ethylene with alpha-olefins (usually butene or hexene).
It has a more ordered molecular structure than PE-LD, which gives it superior mechanical strength, high elongation at break, and controlled elasticity. It is the ideal material for flexible yet durable parts that must withstand repeated deformations and impact at low temperatures.
🔧 Composition
- Ethylene + alpha-olefins – linear copolymer
- Additives – UV stabilizers, antioxidants, anti-static agents
- Density: 0.91–0.93 g/cm³
- Melting point: ≈ 120–125 °C
🚗 Where PE-LLD is used in the automotive industry
| Component | Example parts | Observations |
| Exterior | Flexible guards, lower covers, mudguards | High resistance to cracking and impact |
| Engine Compartment | Fluid tanks, pipes, thermal shields | Chemical and temperature resistant |
| Technical Interior | Gaskets, deformable panels | Smooth, soft surface, easy to clean |
| Aftermarket | Tanks, covers, flexible accessories | Lightweight, weldable, durable |
🔧 Welding temperatures and methods
| Method | Optimal temperature | Observations |
| Hot air | 250 – 270 °C | Fast melting, homogeneous weld |
| Heat plate (mirror) | 240 – 260 °C | Clean, controlled bonding |
| Manual extrusion | 230 – 250 °C | For long cracks or flexible corners |
| Electrofusion | — | Used for large tanks and pipes |
🔩 What to weld PE-LLD with (Material compatibility)
The question “what to weld PE-LLD with” often arises in repairs of tanks and flexible parts. The material is only compatible with polyethylenes of similar density, such as PE-LD and PE-MD.
✅ Compatible:
- PE-LLD ↔ PE-LLD – ideal combination
- PE-LLD ↔ PE-LD / PE-MD – very good compatibility
- PE-LLD ↔ PE-HD – partial compatibility, different melting points
❌ Incompatible:
- PP, ABS, ASA, PC, PA, PVC – will not bond, different melting points
💡 ReplastMD Recommendation:
Use original PE-LLD or PE-LD welding rods at a temperature of 260 °C. Maintain a constant flow of hot air and light pressure — PE-LLD becomes glossy and bonds without bubbles if correctly melted.
🏭 Manufacturers and trade names
| Manufacturer | Brand / Series | Country / Region |
| LyondellBasell | Lupolen® LLD | Germany / Netherlands |
| Borealis | Borstar® LLD | Austria |
| SABIC | LLDPE Compound | Netherlands / Global |
| ExxonMobil | Exceed™ / Enable™ | USA |
🧠 How to identify PE-LLD
- Engraved marking: >PE-LLD<, >LLDPE<, or >PE-LINEAR<
- Glossy surface, soft, but denser than PE-LD
- Yellow-blue flame, paraffin smell
- Floats completely in water (density < 1 g/cm³)
- Softens at 250–260 °C, without bubbles
🛠️ PE-LLD Welding at ReplastMD:
At our service center in Chisinau (Ciocana sector), ReplastMD performs professional PE-LLD welding for:
- tanks, protectors, and flexible covers
- crack, broken corner, and deformation repairs
- watertight restoration and reinforcement of affected areas
- smooth, uniform finish, ready for immediate use