Effect of pu concentration on development of water based polyurethane coated polyester

The coating and lamination gives a powerful tool for the advancement of textile technology. It provides the opportunities to produce the special fabrics like water-proof resistant tarpaulins, coverings, large tents. Waterproof breathable fabrics are one of the harsh weather fabrics that protect the wearer without hampering their efficiency. Garments made from such fabrics keep away water from entering and wetting the body but allow the passage of air and moisture. The passage of water vapour from the garment makes it breathable and hence comfortable. One of the different methods of achieving waterproof breathable fabrics is application of polyurethane paste coating on the substrate. These coatings work on the principle of adsorption and diffusion and desorption of water vapour. Today waterproof breathable fabrics are largely manufactured by Paste coating with solvent based polyurethane emulsions. Solvent based emulsion coating causes adverse health hazards because of solvent evaporation during curing stage. Therefore the current study is an attempt to substitute current solvent based PU emulsion coating technology with water based PU emulsion. Here the performance of environmentally friendly water-based polyurethane dispersions (PUD) for waterproof breathable coating was studied and compared with commercial solvent based waterproof breathable fabric. Also the effect of variation in PU concentration in coating paste on the breathability of polyester was evaluated.