definition
strict definition
polyethylene foam
Thermal insulation made from polyethylene plastic foam containing gas-filled cavities.
Polyethylene foam is an insulating material made from one of the most common types of plastic. The foam is filled with air cavities to reduce heat conductivity. Polyethylene is a thermoplastic polymer, and is often used in packaging materials.
The cellular structure distinguishes the foam from a solid sheet of polyethylene. The cavities reduce heat transfer through the material.
Polyethylene is the polymer used here. Polyurethane and polyisocyanurate foams belong to separate material definitions despite their similar insulating purpose.