Apr 22 2005
Safety boots have protected many a foot from injury, but towards the end of a long working day, the weight of the boots tends to affect the well-being of the wearer. With the aim of making safety boots lighter, Bayer MaterialScience AG has now developed a new density-reduced polyurethane ester system called Bayflex® Safety Lightweight, which, depending on the construction of the sole, enables shoe manufacturers to produce safety boots that weigh up to 30 percent less than before.
The material and technology concept for the lightweight polyurethane is based on a foaming technique optimized jointly by Bayer MaterialScience and Klöckner Desma Schuhmaschinen GmbH, Achim, Germany. Not only does the system reduce the density of the rugged sole material to 350 kg/m³, manufacturers also benefit from all the advantages that polyurethanes have to offer in the production of midsoles. For example, the lightweight safety boots can also be manufactured by the economical direct molding method.
"Despite its lightness, the innovative material naturally has all the qualities you would expect of materials used to make safety boots," says Dr. Erhard Michels, a shoe expert in the Polyurethanes Business Unit at Bayer MaterialScience. With its high mechanical strength and excellent resistance to tear propagation and swelling in aggressive media, Bayflex® Safety Lightweight protects the midsole from damage under tough environmental conditions and gives the foot permanent protection. The sole can also be given an antistatic treatment for work in electromagnetically sensitive rooms.
The new lightweight material also performs impressively in terms of its durability: "Flexural strength and high dimensional stability are retained over long periods of constant, rough use," says Dr. Michels. To ensure the necessary abrasion resistance, shoe producers combine the light polyurethane midsole with a rugged outer sole.
Wearers of safety boots with soles made of Bayflex® Safety Lightweight appreciate not only the lightness of the material but also its outstanding wear comfort. Midsoles made of this foam have outstanding damping properties and, because of its high resilience, retain them over a long period. The material's balanced energy absorption and transfer characteristics support the natural flexing action of the foot and ensure fatigue-free walking.
The comfort and lightness of safety boots produced with Bayer's innovative product can significantly improve the overall performance of the workforce. For manufacturers of these shoes, this is an important sales argument in a highly competitive market.
Further information on polyurethane shoe applications can be found on the Internet at www.bayflex-footwear.com.