Sealing the strap ends is a very important and crucial step while strapping your goods. It can be done in many ways. These methods are described below. Friction Welding This method is used for sealing polypropylene straps and polyester straps. The principle behind this welding is that friction produces heat. In this process, the ends of the strap are rubbed against each other. Friction between the ends produces heat which causes the melting of the polypropylene or polyester at the ends and it ultimately results in the fusion of the free ends together. In this way, friction welding is done and the strap is applied.   Hot Blade Heat Sealing The hot blade heat sealing also works in the somewhat same way as the friction sealing. It also melts the free ends of the strapping tape and then fuses them but the method of heating is different from friction welding. The hot blade heat seal has a tongue that gets heated and is then inserted between the open ends of the strapping tape and in this way the ends get melted. The hot blade heat sealing is commonly used for sealing the PP (Polypropylene) strapping tape. The sealing of polyester strapping tape is very rare because it gives off a lot of smoke which is hazardous to the environment. Ultrasonic Sealing The ultrasonic heating uses an entirely different method to heat the free or open ends of the strapping tape. It uses vibrations of very low amplitude and very high frequency to melt the free ends of the strapping tape. The melted ends then get fused and get strongly sealed together. The ultrasonic sealing can be effectively used for polyester and polypropylene straps. The main advantage of the ultrasonic sealing is that this method is smoke-free.