POLIURETHANE - COMPOSITE SANDWICH MOLDING:

Applying this patent to the construction of surf boards it is possible to speed up the very construction operations of objects made of composite materials, that is to say making the most of polyurethane's and composites' peculiarities.

For this prototype of 6 kg. the mould, divided in two shells, has been stratified with mats impregnated with resin or prepreg. Before this, of course, a gel coat was applied to the external side of the counter-proof.

When we closed the mould we injected polyurethane so that we got an aesthetically finished product with the inner part of the sandwich of polyurethane foam. On the external sides we will had carbon, kevlar or glass layers/coating automatically stuck on the polyurethane that is inside. The achieved results concerning rigidity and lightness were exceptional.
Let me explain that before making this mould, we carried out bending tests on a 1mt. long, 20 cm. large and 10 mm. thick plate, molded at 200 kg./m² with and without mats. The outcomes showed that the plate without mats on two bearings and with a 30 kg. weight in the middle bent 80 mm. The bending of the plate with mats was not measurable and we wanted to determine how much weight was necessary to bend it. We put 135 kg. when the first delamination signs appeared.

This already tested technology enables us to make objects not only specific for the nautical science but also for all those fields and branches where the weight-rigidity ratio is very important, such as for instance: aeronautics, material handling, sports competitions, furnishing, impact protection, orthopedic appliances, etc..