Abstract: An insole (10) for athletic shoes and the like. A first layer (12) of the insole is suitable for disposition toward a user's foot. A second molded layer (14) is comprised of a visco-elastic material. The visco-elastic material typically comprises a plasticizer, and, in minor portion, a resin material, and has the ability to flow, upon exertion of a force thereon, with sufficient elasticity to resume its original shape upon removal of the force. The second layer comprises a lower surface comprising recesses which make up less than 20% of the exterior surface in the absence of deforming forces. The recessed areas function to receive adjacent material of the second layer upon application of pressure representative of the presssure applied by the human foot. A third optional layer (16) of a foamed plastic material may be interposed between the first and second layers.

Abstract: A process is disclosed for inhibiting thermal oxidative degradation of polypropylene webs results from rinsing the polypropylene webs after washing in an aqueous solution of either dilaurylthiodipropionate (DLTOP) or distearylthiodipropionate (DSTDP). The aqueous solution has a concentration of DLTDP or DSTDP of 5 ppm. The aqueous solution is maintained about 150.degree. F., and the polypropylene web is rinsed or dipped in the aqueous solution until saturated. A polypropylene web is also disclosed which has been treated to inhibit thermal oxidative degradation by the above process.