Specialty chemicals producer Lubrizol (Wickliffe, Ohio / USA; www.lubrizol.com) has introduced “Estane” soft plasticiser-free TPUs for athletic footwear applications. The new material offers high flexibility, softness, abrasion resistance and mouldability and is available in both polyester-based and polyether-based versions. They range between 60A to 77A in Shore hardness and offer high transparency and high UV stability compared with plasticiser-containing TPUs for shoe components. The materials also provide an alternative to rubber and PVC in a range of moulding applications, Lubrizol said.

Conventional soft TPUs contain a phthalate-type plasticiser that may be subject to regulation by environmental agencies. In addition, such plasticisers can migrate gradually to the surface of the moulded product, creating poor aesthetics and altering the bonding strength, the company added.