Below is a list of Polyethylene Foam manufacturers from Boothbay, Maine. Polyethylene foam, also referred to as PE, is a type of foam that is very rigid and made primarily through an extrusion process. Polyethylene foam is a strong, resilient, closed-cell type of foam. Polyethylene foam, unlike polyurethane foam, has the capability of being reheated in order to change its shape.