The first steps have been taken towards rainwear which repairs itself.
In cooperation with research scientists and industry colleagues in eight countries, Susie Jahren and her project team are developing the clothing of the future for professional fishermen. Midway in the EU project “[email protected]”, the SINTEF team has high hopes of ending up with a world first: at textile coating which automatically seals small holes and tears in the surface layer of waterproof work-wear.
“We have shown that the principle works. Holes and tears we have made in test pieces in the lab close up all on their own,” says Jahren enthusiastically.
The team has worked with the plastic material polyurethane, which is applied in liquid form to the surface of the under-lying textile in modern rainwear and then hard-
ens. To achieve a self-repairing effect, the SINTEF researchers have added microcapsules containing a glue-like substance to the coating.
“If the coating tears, the capsules burst in the damaged area. Here the sealant content is released and hardens when it comes in contact with water and air, so the coating seals itself,” Jahren explains.
From structures to textiles
Jahren explains that the adhesion in the joins produced in laboratory tests is still mechanically weak, but that its strength can probably be improved significantly by using different types of “glue” and increasing the number of capsules.
“However, there are other challenges and a lot of research work ahead before we can say anything about how effective the method will be. We still don’t know what will happen if the tears are more than a couple of millimetres long, or whether rain will wash away the glue,” she points out.
At the limit
The EU “[email protected]” project will continue until the end of 2012. The work is being coordinated by SINTEF and managed by the Norwegian company Helly Hansen. Hilde Færevik, coordinating the work at SINTEF, says the ambition of self-repair has been included because the project team wants to test ideas which lie at the limit of what is technologically possible today.