the 3 plastics

In terms of twin wall profile extrusion.
There are three plastics that relate to the production.

1. Polypropylene(abbr: PP)
PP is tough, flexible and solvent resistant, this allows polypropylene to be used as a packaging plastic, and a main resin for twin wall / triple-wall plastic sheet extrusion. Normally used to make sign boards, protection sheets and packaging boxes.

2. High Density Polyethylene(abbr: HDPE)
HDPE is known for its large strength-to-density ratio, compared to polypropylene, it is harder and more transparent, and can withstand long time exposure to sunlight. It’s mostly used to make tree shelters and vines guards which can endure both low & high temperature, in the meantime can promote plants growth due to its higher light transmittance.

3. Low-Density Polyethylene(abbr: LDPE)

LDPE is chemical resistant and very flexible with high impact strength, it’s often used to make buffer material and thermal insulation material, such as plastic covers for greenhouse and bucket coat. Because of its low density and low flow rate, productivity for twin wall LDPE extrusion is not high, this also reflects on the final production cost.