PUR Formulations for Lightweight Footwear
Three new formulations from the Polyurethanes Business Unit of Bayer MaterialScience AG in Germany (U.S. headquarters in Pittsburgh) are designed for footwear that is both lighter in weight and more durable.
New Product: 6/1/2005
Three new formulations from the Polyurethanes Business Unit of Bayer MaterialScience AG in Germany (U.S. headquarters in Pittsburgh) are designed for footwear that is both lighter in weight and more durable. All three are suitable for either unit sole production or the more economical direct molding process, whereby the materials’ excellent adhesion properties allow for permanent bonding without adhesives to leather, TPU, or polyurethane at the initial foaming stage. Bayflex Safety Lightweight is a new “density-reduced” polyurethane ester system for the midsole of safety boots. It reportedly enables boots to weigh up to 30% less. Flexural strength and dimensional stability are reportedly retained over long periods of rough use. Midsoles of this foam are said to retain outstanding damping properties for high comfort. Bayflex Active Lightweight is a further development of Bayer’s density-reduced PUR for midsoles of sports and leisure shoes. This polyether foam is up to 30% lighter than standard PUR midsole foams. After 200,000 simulated steps in Bayer’s test lab, soles retained 68% of their compressibility (damping properties), reportedly a record in this weight category. Bayflex Longlast is a polyester PUR for shoe soles that are subjected to rough treatment (e.g., safety boots). Many other polyester urethanes react with water, which causes relatively quick aging in hot, moist climates. But hydrolysis reportedly occurs more slowly in the new Bayflex grade.