Protective clothing including cooling effect
Swiss Empa (materials, science & technology) developed with industrial partners a new “smart” protective vest with an integrated cooling system
Up to now the functionality of working and protection clothing was reserved against fire, shap objects, chemicals, etc. and mostly in disregard to the wearer’s comfort because protection has top priority. But policemen have different requirements when they have to wear a bullet-proof vest made of Kevlar and these are impenetrable for water vapour also thus the policemen wearing this gear under his uniform is sweating profusely when there is warm weather and thus he is feeling uncomfortable.
Empa has now found the solution based on Coolpad technology, originally designed for us in cooling garments for medical applications. The Coolpads built into the vest are filled with water that will evaporate through the membrane and in consequence is cooling down its surroundings. A special mini fan – specially developed by Empa (and two units are needed including batteries and control electronics in each vest) because there was no such size available in the market – blows air through a newly developed fabric spacer (stable under pressure but flexible and soft to touch and developed by Swiss Eschler) behind the pad and providing further cooling. The cool pads proved to be an unsatisfactory solution because they became mechanically stressed and leaked water. Therefore a new technique (diode lasers) for welding the ultra-thin pad membranes was developed replacing the conventional method and providing in contrast also soft and flexible seams. Additionally evaporation rate and cooling ability have been enhanced. When water refill of the cooling pads is needed, a new portable filling station can be attached to the vest with a quick release fastener and at such moment also exhausted mini-fans can be equipped with freshly charged batteries and the vest is again fit for use for another three to four hours. The newly developed vest with built in air conditioner is lighter and with more effective cooling than other systems currently on the market. Zurich city police tested the vests and the reception of the new product was excellent. Project partner Unico swiss tex GmbH will manufacture the first small series of this new protective vest for use under and over normal clothing, uniform jackets, camouflage suits and even for rucksacks and the developments for these lines has already started.