PEAD

PEAD, or high-density polyethylene (HDPE) in English, is a polyethylene variant with higher density and crystallinity than low-density polyethylene. It typically has a density of 0.941–0.965 g/cm3 and a relatively linear molecular structure with limited branching, which gives it stiffness, strength, and chemical resistance. It melts around 120–130 °C and exhibits good impact resistance, especially when stabilized.

Production and processing: HDPE is produced by polymerizing ethylene using catalysts such as Ziegler–Natta or metallocene catalysts. Industrial methods include slurry and gas-phase processes. The resulting polymer is extruded, blown, or injection-molded into a wide range of rigid components, bottles, piping, and geomembranes. Additives can tailor UV resistance, color, and compatibility with food contact.

Applications: HDPE is used for rigid packaging (milk and juice bottles, detergent containers), piping systems for water and gas, geomembranes, plastic lumber, crates, and many consumer goods requiring stiffness and chemical resistance.

Recycling and environment: HDPE is widely recycled and commonly assigned resin code #2. Recycled HDPE can be reprocessed into pellets for new containers or other products. It is not biodegradable, so proper collection and recycling are important to reduce waste.

History and safety: HDPE was first synthesized in 1933 by Eric Fawcett and Reginald Gibson at ICI. Commercial production began in the 1950s after catalyst advances. It is generally considered safe for many food-contact applications, subject to additives and regulatory approvals.