it is made of 100% polyester yarn that has high tensile strength,high resistance to alkali ... salt,heat and abrasion SpecificationsBag closing thread is made of 100% polyester yarn that has high tensile strength,high resistance to alkali ... Resin, Geotextile, Charcoal, etc. - Binder (Reinforced Material) for making Filter Fabric, Canvas, Ropes, Webbing, Core Thread for Zipper, etc Standard Specification ...