Seat belts function as a safety harnesses which secure the passengers in a vehicle against harmful movements during collision or similar incidents. Seat belts minimise injuries during accidents. Seat belts are woven narrow fabric made from nylon filament yarns or high tensile polyester filament yarn. The load specification is an important criterion for usage in vehicles. At present, the seat belts, which are used in the cars, are called three-point which has single continuous length of webbing. They are called three-point because these belts help spread out energy of the moving body in a collision over the chest, pelvis and shoulders. The seat belts are made from nylon filament yarn or polyester filament yarn which is woven to produce the webbing pattern. The linear density of synthetic yarns should be between 100dtex and 3000dtex, preferably 550-1800dtex. The filament linear density should be between 5dtex and 30dtex, preferably 8-20dtex. A typical seat belt is made of 320 ends of 1,100 dtex polyester each. Most weft yarns made from polyester are 550dtex.The critical characteristics of the webbing are abrasion resistance, resistance to light and heat, capable of being removed and put back in place easily and good retraction behaviour.