Something you need to know about XPE and IXPE

Polyethylene (PE) has excellent physical and chemical properties. With its high production volume, low cost, and easy availability, it is widely used in various fields. Several derivative products can be prepared using polyethylene as the base material, such as flame-retardant polyethylene materials, foamed polyethylene materials, and anti-aging polyethylene materials. Among these, foamed polyethylene materials, due to their unique porous structure and excellent properties such as electrical and thermal insulation, strength and toughness, energy absorption, and corrosion resistance, have become one of the earliest industrialized foamed materials. They are widely used in infrastructure, construction, agriculture, home life, and other fields.

The traditional non-pressure foaming process mainly involves foaming polyethylene materials under heating or radiation conditions. This preparation method has the advantages of low equipment investment and simple preparation. However, it also has problems such as poor uniformity of foam cells, difficulty in controlling cell size, and low foaming ratio. Additionally, because polyethylene is a highly crystalline polymer, the resin tends to experience cell collapse, closure, or gas escape under the action of the foaming agent, leading to foaming failure.

To solve issues such as low gas retention and high gas permeability in polyethylene resin, a new direction in polyethylene foamed materials has emerged by using crosslinking methods to form a three-dimensional network structure of ethylene molecules (i.e., Cross-Linked Polyethylene). Currently, according to the crosslinking method, cross-linked polyethylene foamed materials can be divided into chemically cross-linked polyethylene and electron-beam cross-linked polyethylene (IXPE).

XPE (chemically cross-linked polyethylene foamed material) is made by continuously foaming low-density polyethylene resin with a cross-linking agent and a foaming agent at high temperatures. It has stable chemical properties, no odor, and good elasticity. However, its surface is relatively rough, and it tends to have a yellowish color. This material is commonly used to manufacture products such as crawling mats, sound insulation layers, thermal insulation layers, and car floor mats.

IXPE (electron radiation cross-linked polyethylene foamed material), also known as electron radiation cross-linked polyethylene foamed material, uses LDPE or modified LDPE resin as the base, with added foaming agents and other additives. After mixing and extrusion molding, the molecular structure of LDPE is altered using high-energy electron beams generated by an electron accelerator, forming a tight three-dimensional network structure. Finally, it is foamed at high temperatures. IXPE has a delicate closed-cell structure, smooth surface, excellent resilience, mechanical strength, thermal insulation, and aging resistance. Therefore, it is widely used in fields such as precision instrument packaging, semiconductor packaging, and sports protective gear.