This table lists the most common materials used for manufacturing custom orthotics in our lab.
Information on durometer measurement, open-cell foam and closed-cell foam can be found following the list.
|Aliplast||closed cell polyethylene foam, 23 durometer, thermoformable, white||cushioning|
|Bilaminate||P-Cell laminated to Poron: 1/16" Poron plus 1/8" P-Cell or 1/8" Poron plus 1/8" P-Cell||cushioning, covering, diabetic top covers|
|Bio-Foam||closed-cell low density foam||foot impressions|
|Carboplast||composite shell material; carbon and glass fibers in a unique polypropylene matrix||orthotic shells|
|Cushion cork||cork & rubber composition, stiff, not thermoformable||heel lifts|
|EVA||Ethylene Vinyl Acetate: can be either open-cell or closed-cell; wide range of durometers, thicknesses & colors||top & bottom covers, cushioning, accommodations, wedges, filler, shell material for soft orthotics|
|Korex||cork & rubber blend, flexible yet durable, not thermoformable||accommodations, extensions, Morton's & reverse Morton's, wedges|
|Leather||processed animal hide which is durable and flexible||top and bottom covers|
|Neolon with bamboo||closed cell neoprene with fabric cover containing nanoparticles of activated bamboo, 1/16" & 1/8" thickness||cushioning and covering|
|Nickelplast-S||closed cell polyethylene foam, does not bottom out, 48 durometer, thermoformable, tan||cushioning, accommodations|
|P-Cell||closed cell EVA foam, pink, 20-25 durometer, 1/8" thickness||cushioning and covering|
|Plastazote||lightweight, closed-cell, cross-linked polyethylene foam, medium, firm & rigid densities||cushioning|
|Polypropylene||thermoplastic polymer, softens when heated and hardens when cooled||orthotic shells|
|Poron||medical grade, open-cell polyurethane foam, 15 durometer, blue, 1/16", 1/8", 3/16", 1/4", 3/8"||cushioning, met pads, heel pads, sweet spots|
|SBR||styrene-butadiene rubber, synthetic rubber||a component of SolFlex|
|Silicone Gel||low durometer polyurethane gel for shear reduction and pressure relief||cushioning|
|Solflex||EVA/SBR blend, 65 durometer, thermoformable||orthotic posting|
|Spenco||closed cell neoprene with fabric cover, 1/16" & 1/8" thickness||cushioning and covering|
|ThermoCork Lite||EVA/cork blend, 65 durometer, thermoformable||orthotic posting, wedges|
|Thin Stiff EVA||65 durometer EVA, 1.5 mm thickness||bottom covers; can be used as top covers when extra durable material is needed|
|TL 2100||composite material of carbon fibers (graphite) impregnated with a specific type of acrylic resin||orthotic shells|
|TL Silver||composite material with all woven glass fibers laminated unidirectional in an acrylic matrix||orthotic shells|
|Ultrasuede||durable synthetic microfiber fabric||top and bottom covers|
|Vinyl||polyvinyl chloride (PVC) plastic with knit fabric backing||covering, tops and bottoms|
|X-Static||1/8" soft EVA with Silver impregnated fabric cover; anti-odor, anti-microbial & thermodynamic properties||cushioning and covering|
Durometer is one of several measures of the hardness of a material. Hardness may be defined as a material's resistance to permanent indentation. The durometer scale was defined by Albert F. Shore, who developed a measurement device called a durometer in the 1920s. The term durometer is often used to refer to the measurement, as well as the instrument itself. Durometer is typically used as a measure of hardness in polymers, elastomers, and rubbers. There are several scales of durometer, used for materials with different properties. The two most common scales, using slightly different measurement systems, are type A and type D scales. The A scale is for softer plastics, while the D scale is for harder ones.
All of the durometer measures of the materials in the above list are of the type A scale.
Open-cell-structured foams contain pores that are connected to each other and form an interconnected network that is relatively soft. Open-cell foams will fill with whatever they are surrounded with. If filled with air, a relatively good insulator is the result, but, if the open cells fill with water, insulation properties would be reduced. Foam rubber is a type of open-cell foam.
Closed-cell foams do not have interconnected pores. The closed-cell foams normally have higher compressive strength due to their structures. However, closed-cell foams are also in general denser, require more material, and as a consequence are more expensive to produce. The closed cells can be filled with a specialized gas to provide improved insulation. The closed-cell structure foams have higher dimensional stability, low moisture absorption coefficients, and higher strength compared to open-cell-structured foams.