Structure induced effectiveness of shear thickening fluid for modulating impact resistance of UHMWPE fabrics

The structural parameters of woven fabrics play a crucial role in determining its impact resistance performance. Conventionally, treatment with shear thickening fluid (STF) has been found to increase the impact energy absorption capacity of fabrics. However, the findings of the current study present a new perspective, and suggest that the effect of STF treatment is favorable based on the structural integrity of woven fabrics. Plain woven fabrics with different fabric sett (threads per inch) were produced using ultra-high molecular weight polyethylene (UHMWPE) yarns of 400 denier and 1350 denier linear density. These fabrics were then treated with STF (65% w/w) made from silica particles (100 nm) dispersed in polyethylene glycol i.e. PEG (200 M-w) and subsequently evaluated for yarn pull-out force and impact energy absorption. The increased yarn pull-out force, at all levels of yarn linear density and fabric sett, implies that STF treatment considerably increases the inter-yarn friction. However, increased yarn to yarn friction is not necessarily beneficial in terms of impact energy absorption and rather becomes detrimental for fabrics made from finer yarns (400 denier) beyond a particular fabric sett.