"Sealing" of polyester textile strapping is done by metal buckles made of bent wire. Please note that for hot melt (WG) and composite polyester strapping, galvanized metal buckles are recommended whereas with woven polyester textile strapping phosphatized metal buckles should be used in order to guarantee optimized system strength. Due to the fact that the surface of woven strap is quite "smooth" compared to hot melt strapping which is kind of waxed due to the hot melt glue, roughened metal buckles (= phosphatized) are needed in order to prevent the woven strap from slipping off the buckles.