The Insulating tape of thermal contraction is made from a special compound fiber of thermal contraction. After binding and dried at 105 degree for 10 minutes, it will be shrunk to 70 percent,which is good at a solid binding and at a compatibility with transformers. In this way, it will be utilized in the transformer oil at 105 degree for a long time. Fiberglass tape is made of the non-alkali glass fiber yarns. The main component is E-glass,oxidation potassium,oxidation sodium,fo which the content of oxidation of alkli metals is no more than 0.5 percent. Cotton tape of electrician is made from pure cotton fiber and can be used for electric motor, appliance, etc. As binding materials because of good mechanical strength and insulating quality.