Start up Projekt
Herstellung von Bleifreie leichte Röntgenschürzen
Manufacturing lead-free x-Ray protection gown
A new manufacturing method for lead free x-ray protection gown which reduces the surface density of protection layer less than 5 kg/m2 (equivalent to 0.5mm Pb) has been proposed and tested. This method is based on deceasing net polymer as much as possible and also minimizing the size of metal particles. The optimized combination of metal powders has been chosen accurately in order to maximize the attenuation coefficient. This mixture consists of Tin, Barium, Tungsten, Bismuth in certain percentages and very small amount of gold powder. To decrease net polymer, which here is silicon, we have used polydimethylsiloxane as polymer solvent to lessen the viscosity of combined fluid. Lower viscosity leads to better distribution of fluid in the mold and the final layer will be more homogenous. Using polydimethylsiloxane decreases viscosity without adding more silicon, which causes lower final density. In this method, mass fraction of net polymer is less than 25% in the final product.
The mixed polymer and solvent and metal powders insert into the molds after adding hardener to transfer into solid layer. To prevent the residual part of layer a new design of casting machinery is proposed. By using this machinery, the layers will produce exactly in the desired shapes and material waste decreases down to zero. The pattern of clothes in the molds are carved in the desired depth (1 mm equivalent to 0.25mm Pb and 2 mm equivalent to 0.5mm Pb). The nozzle of the device is designed to be as wide as the mold and the fluid insert into the mold through a 4 mm groove from nozzle. The nozzle is pressed to the surface of the mold by holding springs therefore the fluid only will pour into the deep part of mold which are exactly shaped in clothes pattern. Each round, the nozzle will pour 1 mm of material into the mold. Therefore, for thicker layer (2mm) an additional backward movement of nozzle will complete the layer. During the movement of nozzle, the hardener will spray to the layer.
The proposed method both in material combination and manufacturing process, causes very light and cheap x-Ray protection aprons.