Polyurethane Shoe Soles

This study is concerned with the development of polyurethane foam shoe soles, by Clarks. It is an example of intuitive design skill allied to technical development of a high order. The will to succeed was perhaps the most important factor of all. The study also provides an excellent example of a polyurethane application, with a comparison with competitive types of material. In the development described here market forces are particularly dominant. 

---

The footwear industry uses polyurethane as microcellular elastomer for shoe soles thermoplastic elastomers for ski boots, coatings for shoe uppers, and adhesives. The microcellular elastomer shoe soles have been used for over 10 years. The polyurethane shoe sole offers lightweight and flexibility in styling. Fine detail simulating wood, cork, leather, and handstitching can be readily reproduced. New style sport shoes have been developed to incorporate multi-colors and multi-density soles. As a result, these shoe soles are used in women s high-fashion shoes, work shoes, and a variety of leisure and sport shoes. The current demand for polyurethane shoe soles is for continued steady growth and demand. There has been a continued shift of the shoe sole market to the Middle East and Eastern European areas. 

Of the many other end uses for polyurethane products, shoe soles and synthetic leather should be mentioned. The polyurethane shoe sole usage reached a peak demand in 1973 before styling trends and competition from other synthetic materials resulted in market erosion. The expected demand will be centered in women s fashion, sports, and recreational shoes for both domestic and export markets. 

Based on the numbers in Figures 1 and 2, by 1985 RIM and RRIM will require approximately 50 M lbs. of monomeric MDI, which is about one-third of the monomeric MDI supply in 1985 (Table IX based on 20-25% of 85% nameplate capacity, excluding ARCO capacity, = 137-171 M lbs. monomeric MDI). This will leave about 100 M lbs. of monomeric MDI for cast elastomers, thermoplastic polyurethanes, shoe soles, semi-rigid foams, and some adhesives and sealants, a monomeric MDI supply which should be more than sufficient for these applications. As RRIM grows, a need for capacity expansion can be seen in the late 1980 s. No effects on the market will be seen from PUR-SMC until after 1985, and at the present time meaningful projections are impossible. 

MAJOR USES Used in the production of epoxy resins, polyurethane, shoe soles, rolls for postage stamp machines, plywood, computers and pulleys for escalators and elevators. 

---