Achim, Germany -- A 100% polyurethane trainer developed by shoe machinery maker Desma alongside Bayer MaterialScience (BMS) was unveiled at the Desma Housefair this week.
The QuadWrap Concept trainer is created in four steps from a BMS polyurethane system.
Karsten Muller, marketing manager at BMS, told UTECH.polyurethane.com that Desma approached the firm with the idea of creating a concept shoe two years ago.
First a stabilising layer is directly moulded onto a carrier fabric. At the same time, outsole pads are created by micro-pouring. The outsole is directly moulded on top of the pads. A fourth layer completes it while adding three-dimensionality.
The shoe’s cast elastomer production process uses Baytec PE for the more rigid elements of the shoe and Bayflex S for its sole and shaft elements. Muller said Bayflex S is a low density PU – of density 220g/l – which can be produced either through the use of a physical blowing agent – for smaller production schedules – or through CO2 lightweight technology.
The innovation also uses a newly designed last-mould combination, two sets of moulds and allows production on a single machine. The polyurethane was tailored to meet the requirements of each element’s function.
The tensile strength of the first layer allows for comfortable fastening, while the outsole pads are slip and abrasion resistant. This dual density system combines to make the trainer’s external structure extremely lightweight, flexible and shock absorbent.
The trainers can be made without additional adhesives and the process is highly automated.
Desma displayed a specially-customised machine to demonstrate the technologies used to create the concept shoe. The shoe is not yet commercially available.
The prototype’s carrier material – a thin inner lining – is not polyurethane.