Polyethylene Foam: Uses, Types, and Essential Properties

Polyethylene foam is a versatile foam that is known for its durability, light weight, and resiliency. It’s these properties that make the foam ideal for foam packaging, cushioning, gasketing, and a variety of other healthcare and marine foam applications. The material starts off as a thermoplastic that is then converted into a foam. It’s similar to rubber, but still maintains the soft and protective qualities of a foam material.

The Essential Properties and Benefits of Polyethylene Foam

Polyethylene is a closed-cell material that is easy to process and fabricate. It has some excellent natural qualities that manufacturers and fabricators find useful. These include:

High chemical and moisture resistance

Good tear resistance, shock absorption and strength to weight ratio
Non-abrasive and non-dusting
Vibration dampening
Resistance to mold and mildew
Odorless
Buoyant
Thermal insulation
Flexible and easy to work with
Variety of color options

There are many different polyethylene foam options. Choosing the right one for your application requires you to understand the individual properties and strengths of each type of foam.

Crosslinked Polyethylene Foam (XPE or XLPE Foam)

Crosslinked polyethylene foams have a strong and rigid structure that makes them more durable and resistant to gas and moisture penetration, making them great options for gasketing applications. They also have good resistances to shock and vibration, as well as strong insulating properties. XLPE foams can be made fire retardant and static-dissipative.

XLPE foams can either be chemically or physically crosslinked, the process by which the molecules are connected form chained connections. Chemical crosslinking involves adding chemical inflating and other agents during the molding and extruding process, creating dense cells that increase the durability of the foam. While the foam is durable, the surface often looks rough and may not be the most aesthetically pleasing.

Physical crosslinking creates a finer, larger cell structure that is more consistent. The links are weaker, making the foam more resilient. These types of XLPE have a smoother surface that looks better than chemically treated XLPEs.

Expanded Polyethylene (EPE) Foams

Expanded polyethylene foams have a high strength-to-weight ratio and good thermal resistance. This is because the foams are created using heat and pressure, which results in a beaded foam that can be molded and die cut. EPE foams are lightweight, non-abrasive, and can be recycled after use.

Extruded Polyethylene Foams

Extruded polyethylene foams are created using an extrusion process, which melts the polyethylene resin and feeds it through a mold after certain additives have been combined with the foam. EPE foams are known for their high insulation properties, light weight, and high durability.

Low-Density Polyethylene Foams

Low density polyethylene foams (LDPE) are created with gaps in their cellular structure, creating a foam that is less dense and therefore softer and more compressive. LDPE foams are ideal for packaging materials (for small, delicate items) as well as marine applications due to their buoyancy and resistance to moisture and water.