Innovation at our feet

The recent Micam footwear show (held in Milan from 15 to 18 September 2013), provided the Marche-based company Fainplast - a specialist in the production of compounds for use in the production, by means of injection technology, of cross-linked foam products - to unveil EVAtech, an innovative, lightweight, low-density and abrasion-resistant material. Suitable for making soles, midsoles and slippers, it is intended, above all, for the footwear sector.
During processing, the material is injection moulded, using a temperature-controlled screw at around 90-100 ° C; the screw temperature is kept "low" to prevent the material from starting reaction inside the screw itself. EVAtech is subsequently injected into temperature-controlled moulds at a temperature of between 170 and 190°C for a time ranging from 400 to 600 seconds. In this interval of time, thanks to the temperature of the moulds, the material expansion and cross-linking reactions occur simultaneously.
On opening the mould, the material undergoes a small "explosion". Then, as it cools, it shrinks slightly; by the time it is completely cold it has reached the desired size. Whereas the material  prior to expansion and cross-linking has the same properties as a thermoplastics, i.e. it can be melted and re-processed, after these processes it can no longer undergo any changes.
Furthermore, whereas the solid material has a density of around 1 g/cm3, after expansion it can have a density of 0.22, 0.35 or 0.45.
This process therefore makes it possible to obtain a very lightweight final product, available, for each type of expansion, in a range of hardnesses, densities and colours, to meet different requirements.
In addition to soles, midsoles and slippers, it can also be used for packaging, chairs and more besides.