HDPE (High-Density Polyethylene)
hdpe high density polyethylene
🔹 HDPE (High-Density Polyethylene) — Comprehensive Definition
Full Name: High-Density Polyethylene
Abbreviation: HDPE
Recycling Code: ♴ (2)
🧪 Chemical Composition
HDPE is a thermoplastic polymer made from ethylene monomers (C₂H₄) through polymerization.
It has a linear structure with minimal branching, resulting in high density and strong intermolecular forces.
Chemical formula: (C₂H₄)ₙ
⚙️ Technical Properties
| Property | Description / Value |
|---|---|
| Density | 0.94 – 0.97 g/cm³ |
| Melting Point | 130–137°C |
| Tensile Strength | 20–37 MPa |
| Impact Resistance | Excellent |
| Chemical Resistance | Excellent against acids, bases, and solvents |
| Water Absorption | Negligible |
| Recyclability | Very good (widely recycled worldwide) |
🧴 Main Applications
Bottles for milk, detergents, and chemicals
Water and gas pipes
Plastic tanks and containers
Crates, bins, and caps
Thick shopping bags and industrial films
♻️ Recycling Process
Recycled HDPE (rHDPE) is obtained through:
Collection and sorting
Washing and shredding
Melting and pelletizing
Uses of rHDPE:
Pipes and construction materials
Recycled containers and drums
Outdoor furniture and plastic lumber
🌍 Environmental Considerations
Non-toxic and chemically stable
Highly durable and reusable
Recycling reduces landfill waste and environmental pollution
