Characteristics of PVC heat shrinkable film

 Characteristics of PVC heat shrinkable film;

For rigid PVC heat shrinkable film, the suspended type 5 or 7 resin is used. Although the type 7 resin has good formability in heat shrinkable film for wire and cable connection, the production practice proves that it is difficult to form when the type 2 or 3 resin is used, and the produced rigid PVC heat shrinkable film is hard and brittle, so it cannot be folded and rolled.

When using plasticizer to plasticize, the thermal shrinkage temperature will decrease with the increase of plasticizer content. For example, when using suspended PVC resin powder and adding 30 ~ 50 phr DOP plasticizer, it can be stretched in two directions at about 70℃, and its products can shrink at about 40℃, which can't be stored in hot days.

 Moreover, with the increase of plasticizer content, the volume resistivity of heat shrinkable sleeve for wire and cable decreases. Therefore, when we produce PVC heat shrinkable sleeve for wire and cable connector, we still use type 6 or type 7 resin which is easy to process. In order to improve the insulation, we use a heat stabilizer combining three salts and two salts and appropriately increase the film thickness to ensure the insulation. P83 NBR not only has good processability, elasticity and cold resistance, but also can improve strength and stress cracking resistance of PVC products. Active CaCO3 mainly improves the insulation and flame retardancy of products and reduces the cost.