High-Density Polyethylene (HDPE)

Rigid thermoplastic polymer with high tensile strength.

Core Principles & Analysis

• It became practical in the early 1950s when Ziegler's organometallic and Phillips' chromium catalysts enabled linear chains at low pressure.
• Minimal chain branching lets crystallinity exceed 80%, making HDPE opaque and markedly stiffer than the LDPE of squeeze bottles.
• Carrying resin code 2, it is among the most recycled plastics, with milk jugs and detergent bottles reprocessed into pipe and plastic lumber.

Specifications & Metrics

• DENSITY: 0.95 g/cm³
• YIELD STRENGTH: 26 MPa
• HARDNESS: 60 Shore D