Polyurethane Foam for Footwear Soles

The preparation of molded PU soles using the nanofiller cum blowing agents has been optimized using industrial-scale reaction injection molding (RIM) and pouring machines. Technology to prepare PU soles for footwear based on biodegradable polyol and environment-friendly nanofiller, as well as commercial polyol/isocyanate systems and the nanofiller, by direct reaction injection molding process, has been developed.

• The technology involves the use of an environment-friendly nanofiller cum blowing agent in making polyurethane (PU) foam (free/molded).
• The technology also has potential application in making other footwear components such as midsole and in-sock.

• The nanofiller cum blowing agent used in making the PU-composite sole is environment-friendly, halogen-free, cost-effective and compatible with the commercial polyol systems used in making footwear soles
• The developed PU-nanofiller composite shoe soles show improved flexibility, improved cell stability, and a reduction in bulk density. High flexibility makes the sole suitable for applications where repeated flexing is required (outsole, midsole and in-sock).
• Increased PU foam formation because the nanofiller acts as a chemical blowing agent. Use of 1-3% of the nanofiller leads to a 20-40% increase in foam volume.