The torsion-resistant insert is a reinforcing element, positioned between the inner sole and the heel of a shoe, which preserves its shape and makes it more comfortable. Rigidity is the main property of the materials used for these inserts, which is why they are often made of polyamide, reinforced with glass fibres.
BASF has developed a new solution involving the use of thermoplastic polyurethane (TPU), also reinforced with glass fibre: BASF’s new Elastollan® R series has the stiffness of other materials, almost without absorbing moisture. The excellent adherence to the polyurethane sole (PUR), and the uselessness of a long and expensive treatment of the surface are among the advantages.
Furthermore, the application of BASF’s Ultrasim® simulation technology allows the production of an even lighter TPU torsion-resistant insert, as it is efficiently designed, using less material, with consequent cost savings.
The further results of the virtuous multi-year collaboration between BASF and the Spanish Analco for the production of sustainable footwear components are also among the innovations presented at Simac. In this case we are talking about soles in Elastopan® Green (PUR) and Elastollan® N (TPU), by means of which can be made products up to 50% using renewable raw materials, certified by ASTM D 6866-12.
It should also be taken into account that these materials were not obtained from agricultural products, and therefore do not reduce the cultivation surface used for food production.
Both products have exceptional mechanical properties such as abrasion resistance, design flexibility – in the case of TPU, lightness and comfort, in the case of PUR the same properties as similar standard products.