PE foam materials
On account of their closed cellular structure, PE foam materials are mainly used for absorbing, insulating, and sealing in the packaging sector.
PE foam materials have a closed cellular structure with excellent properties such as low density, outstanding resistance to ageing and weathering, good sound and heat insulation, and very good resistance to commercial acids, bases, and other chemicals.
PE foam materials are primarily used in the fields of packaging and transport protection, as well as industrial and technical sealing or sound and thermal insulation. In automotive engineering, for example, they are found in door interiors, engines, and headlining.
To produce PE foam materials, melted polyethylene is permeated with a foaming agent (e.g. pentane or CO2) in the extruder under high pressure. PE foam materials are classified as cross-linked or non-cross-linked.
In cross-linked PE foam materials, the polymer chains are chemically or physically linked to each other at certain points, forming a three-dimensional network. Cross-linked PE foam materials have a fine, uniform, and closed cellular structure. This means that gases and liquids cannot penetrate or exit the cells. PE foam materials are therefore only somewhat elastic and hydrophobic, i.e. water-repellent. Moreover, they exhibit low thermal conductivity values and good insulating properties.
In non-cross-linked PE foam materials, the polymer chains are not linked to each other. As a result, non-cross-linked foam materials have a limited melting point at which the polymer chains separate from each other. Plastification occurs at this temperature. All non-cross-linked PE foam materials can be granulated and recycled.
The macro images on this page are intended to provide an overview of the special features of different foam materials. For the sake of clarifying the differences in cell size and structure, the same image excerpt is used throughout. Of course, many other types are available than those highlighted.