Properties of Ethafoam

A good package design should provide sufficient protection to prevent or minimize the effects of physical abuse, corrosion, temperature extremes, chemical attack, aging, and other adverse conditions that may occur in shipping or storage. The properties of polyethylene foam make it an ideal material for designing protective packaging.

Ethafoam polyethylene foam is supplied in a variety of densities ranging from 30 to 150 kg/m³:

The flexible, closed-cell structure of Ethafoam polyethylene foam contributes both to its excellent cushioning characteristics and to its light weight. Since many commonly used cushioning materials are bulkier and/or heavier, packaging with Ethafoam can often yield significant savings in transportation costs.

Ethafoam has excellent chemical stability. It is exceptionally resistant to most solvents and other chemicals at room temperature. Acids and alkalis normally have no effect on this material, although strong oxidizing agents may cause some degradation, especially at high temperatures. Products coated with preservatives, or which contain oils, greases, or animal fats will have little or no effect upon Ethafoam packaging.

Shipments that may be subject to adverse environmental conditions in transit or in storage have a better chance of being received in good condition when they are packaged in Ethafoam. Water absorption and water vapor transmission rates of the foam are low to negligible.

Ethafoam packaging will perform effectively in most climates and at most temperatures, and its closed-cell structure has thermal insulation value. Stability depends upon the load imposed upon the foam, on exposure time, and the temperature involved. Therefore, no specific maximum use temperature can be given for Ethafoam. Without load, Ethafoam can be used successfully in many applications exposed to intermittent temperatures as high as 74°C and as low as -40°C. Like other thermoplastic materials, polyethylene foam becomes more flexible at high temperatures and more rigid at low temperatures. This must be considered in determining optimum cushioning for demanding applications (e.g., military) in which the package may be exposed to temperature extremes.

Storage cases for fine instruments and precision tools are often provided with recessed inserts fabricated from Ethafoam. Either the standard natural (white) or black foam provides an attractive setting for any article packaged in or displayed upon it. Its texture and appearance connote quality, tending to enhance the perceived value of the packaged product.

Ethafoam is a stable material. It resists shattering, breakage, or crumbling in normal use when flexed, cut, or struck. It displays excellent recovery from shock or strain, returning to shape quickly after impact. Its flexibility contributes to fast packing operations. It also facilitates close fitting of cushion blocks and recessed inserts.

Over an extended period of exposure, ultraviolet rays in sunlight will cause some degradation of Ethafoam. It is first noted as a yellowing of the foam's surface. Some degradation of physical properties will be experienced after long periods of exposure. For applications requiring long-term performance under direct sunlight, a protective coating should be applied to the foam.

Many of the hazards, inconveniences, and housekeeping problems often associated with other cushioning materials and dunnage can be avoided by using Ethafoam.

When heat is used to cut or form Ethafoam, adequate ventilation must be provided to carry smoke or fumes away from personnel. When large quantities of Ethafoam are stored or fabricated, small quantities of the blowing agent released from the foam may tend to accelerate corrosion of heaters and boilers. Corrosion may eventually create holes in a combustion chamber, leading to the release of combustion gases and carbon monoxide, which would endanger the health of persons in the area. Heating equipment should be inspected regularly during every heating season and checked for pinholes or larger defects.

Ethafoam can be reused repeatedly, generally with minimal loss of effectiveness. If the material becomes soiled, it can usually be cleaned without adverse effect on its properties and performance.