AliPlast™ — Pads, Supports, Protects, Positions, and Immobilizes!
AliPlast is a family of cross-linked, polyethylene foam. The five types of AliPlast vary in firmness and stiffness to satisfy a broad range of orthotic applications.
AliPlast can be used by itself to fabricate soft splints and other orthotic devices and can also be used in combination with other materials such as Plastazote®, polyethylene sheets, etc., to achieve varying degrees of stiffness.
As a general guideline, when the primary splint function is for cushioning, use the softer version of AliPlast. Use a firmer AliPlast when support and motion restriction is desired. Common properties of the AliPlast family include: thermoplastic moldability, closed-cell structure, smooth skin, auto-adhesiveness, isotropic sheet properties, impermeableness to liquids and gasses, good energy absorption on impact, and inertness.
- Soft, adhesive-backed padding
- Use for splint and strap padding as well as tool and utensil build-ups
- Medium-soft grade
- Use for splint and cast padding and resting splint liners
- Medium grade
- Use for foot orthotic top coats, non-rigid splints and body jacket liners
- Firm grade, resilient
- Use for semi-rigid foot orthotics and splint shells
- Firmest grade, abrasion-resistant, lightweight
- Use for custom insoles, posting orthoses, and rigid splints
Molding is Simple
AliPlast softens when heated for a few minutes in an oven temperature of 250°-300°F. Heating time depends on material thickness. It is limp and flaccid when ready to mold. Experience is the best guide.
The softened material forms around any shape. When cool, the original cushioning feel and physical properties are regained. Generally, 2E and 4E can be molded directly to the body. 6A and 10 should be molded to a plaster cast to avoid any danger of a burn. AliPlast can be vacuum formed.
CAUTION: Use a convection oven for heating AliPlast to minimize the risk of overheating. A toaster or radiant-type heater can overheat the surface. The overheated surface is actually a melted layer of polyethylene. Touching can cause severe burns.
AliPlast is Auto-Adhesive
When the surfaces of two heated pieces are brought together, they weld. The strength of a well-made bond will exceed the foam itself. If peeled apart, the foam will tear, not the bond.
The unique polyolefin base creates a unique bond with polyethylene or polypropylene. AliPlast will heat-bond to either of these difficult-to-bond materials. A thin layer of AliPlast is often used to bond sheets of either of them together.
AliPlast Stays Clean
AliPlast has a closed-cell structure with a smooth skin that provides an impervious barrier to penetration by liquid, gas or bacteria. Since it is a closed-cell foam, it cleans and disinfects easily.
Watch the Grain!
AliPlast is isotropic. The sheet materials have different properties, depending on direction. Sheets bend easily in one direction and are stiffer in the other. Careful orientation of the sheet in a particular construction will often improve the performance of the orthotic. For example, when used as an insole, orient the AliPlast so that the easy bend direction is parallel to the flex axis of the metatarsal heads.
AliPlast will shrink along the grain when heated and the thickness increases. Heating time will vary with moldability requirements. You can compensate for shrinkage by stretching the material during the molding process.
Which AliPlast is right for me?
The major criteria for selecting a particular grade of AliPlast in any given application are compression set (bottoming out) and firmness (durometer).
The degree of recovery or permanent compression of a closed-cell foam, after a sustained load (or compression) depends on the magnitude of the load, the duration of loading, and the foam itself. Generally, if the selected foam is too soft and the load and subsequent compression are too high, the foam will suffer too great a permanent compression (bottoming out) and probably not cushion properly for the intended life of the orthotic. The softest grade of AliPlast is 2E. The hardest is XPE.
Permanent compression can be useful in certain clinical applications. For example, a 1⁄8" thick AliPlast 6A insole will mold to the plantar aspect of the foot and eventually be compressed to zero thickness at the points of highest loading, the metatarsal head and apex of the heel. However, other parts of the insole maintain thickness. The resultant shape is a useful diagnostic tool. The metatarsal head and heel are still protected as the pressures are not as great as without the insole. The same self-molding behavior in an orthotic actually reduces pressure on any bony prominences or high pressure areas.
There are AliPlast imitations available. Insist on safety-proven, hypoallergenic AliPlast.
|Table of Durometer/Hardness (Shore A)
|Dr. Scholl's Latex / 9
||AliPlast 4E / 23
||NickelPlast XF / 54
|PE LITE (Soft) / 14
||AliPlast 6A / 34
||Neoprene Crepe / 56
|Poron / 15
||Plastazote #2 / 35
||AliPlast 10 / 60
|AliPlast 2E / 15
||PE LITE (Medium) / 37
||AliPlast XPE / 68
|Plastazote #1 / 20
||PE LITE (Firm) / 45
||Plastazote #3 / 69
|Human Soft Tissue / 20-25
||NickelPlast / 48
||Leather Soling / 80
|Microcellular Rubber / 22
||Human Scar Tissue / 50
||Neolite / 92
|Physical Properties of AliPlast™
|Oven temperature (ºF)
|Density (pounds per cubic foot)
20 in. per min. (PSI)
|Permanent set (%)
50% compression for 24 hours,
|Service temperature (ºF)
||-110 to +160
||-110 to +190
||-110 to +200
||-110 to +200
||-110 to +200
AliPlast is chemically inert and safe. In the most demanding daily practice, it has been demonstrated to be safe and reliable for virtually all orthotic and prosthetic applications, which include body jacket liners, arch supports, temporary BK and AK liners, hand and ankle splints, protective athletic pads and cervical collars.