Polyurethane fiberglass insulation sleeve is made of E-glass fiber yarn and polyurethane resin. Fiberglass yarn is woven finely by high-speed knitting machines to be blank tube, then it is coated with a specially formulated polyurethane resin under high temperature curing and then finally stereotypes. As the work temperature of the sleeve can often reach 155 degrees Celsius, it has very excellent electrical properties, and has good mechanical abrasion resistance and flexibility, it is widely used in F-class motor insulation.