🧩 PP-H – Polypropylene Homopolymer
(Rigid weldable plastic, used for technical parts and vehicle bodywork)
🔹 What is PP-H
PP-H (Polypropylene Homopolymer) is the pure form of polypropylene, without copolymer additives.
It features higher rigidity and temperature resistance than PP-C but is less flexible.
It is frequently used for structural parts, brackets, covers, and elements requiring dimensional stability.
🔧 Composition
- PP (Polypropylene) – pure homopolymer structure
- Additives – UV stabilizers, antioxidants, colorants
- Can be modified with fibers or minerals (e.g., PP-H+GF20)
🚗 Where PP-H is used in the automotive industry
| Component | Example parts | Observations |
| Bodywork | Covers, brackets, fasteners, lower liners | Rigid, lightweight, heat-resistant |
| Technical Interior | Panels, supports, consoles | Easy to weld, matte finish |
| Auxiliary Equipment | Sensor parts, radiator supports | Thermally and chemically stable |
| Tuning / DIY | Rigid bumpers, technical parts | Welds uniformly with PP-H rod |
🔧 Welding temperatures and methods
| Method | Optimal temperature | Observations |
| Hot air | 270 – 290 °C | Clean weld, no bubbles |
| Heat plate (mirror) | 260 – 280 °C | Recommended for flat joints |
| Manual extrusion | 250 – 270 °C | Good for cracks and corners |
| Electrofusion | — | Used for industrial PP applications |
🔩 What to weld PP-H with (Material compatibility)
The question “what to weld PP-H with” has a clear answer: only with materials from the same polypropylene family.
It is fully compatible with other PP types (PP-C, PP-TD, PP-GF) and partially compatible with PE.
✅ Compatible:
- PP-H ↔ PP-H – ideal combination, strong weld
- PP-H ↔ PP-C – fully compatible, similar thermal behavior
- PP-H ↔ PP-TD / PP-GF – partially compatible, for small areas only
- PP-H ↔ PE-HD – low compatibility, weak bonding
❌ Incompatible:
- ABS, ASA, PC, PA, PVC – different melting points, will not adhere
- PS, PMMA – carbonize at PP-H welding temperatures
💡 ReplastMD Recommendation:
Use original PP-H welding rods and maintain a constant temperature between 275–285 °C.
Clean the surface before welding for optimal adhesion and a clean joint.
🏭 Manufacturers and trade names
| Manufacturer | Brand / Series | Country / Region |
| LyondellBasell | Moplen® HP | Germany / Netherlands |
| Borealis | Daplen® H Series | Austria |
| SABIC | PP Homopolymer | Netherlands / Global |
| Repsol | Isplen® H | Spain |
| TotalEnergies | Polyfort® H | France |
| Hyundai EP | Polytron® PP-H | South Korea |
🧠 How to identify PP-H
- Engraved marking: >PP-H<
- Yellow-blue flame, smells like wax/paraffin
- Floats in water (density below 1 g/cm³)
- Melts uniformly at 270–280 °C
- Rigid, but not brittle
💡 ReplastMD Practical Test: If the part is rigid, lightweight, and softens uniformly at 280 °C without bubbles → it is PP-H.