Research Projects

At present, liners of helium gas bottles are fabricated using titanium alloy. Titanium alloy based liners attract large production delay, high cost and fabrication difficulties. In order to save time and cost in realizing such liners, it is proposed that the liners can be fabricated using suitable thermoplastic materials. Two important criteria for selecting the thermoplastic polymer for such applications are the helium gas barrier property and linear elasticity in the range of 10-20%. The thermoplastic polymers of choice are high density polyethylene, polyetherether ketone, nylon etc. In order increase the gas barrier properties, the polymer needs to be reinforced with platelet type fillers (nanoclay, graphene etc) in such a way that the helium leak rate of 10 E-8 mbar lit/sec/cm2 or better is achieved. The processing of layered material incorporated thermopolastic liners can be optimized using twin screw extrusion followed by injection molding of the two halves to get spherical liners. The plastic welding process also needs to be optimized so that there is no leakage of helium gas through the weld area and only maximum 5% drop in strength due to welding.