1）PVC热收缩膜制品有软质、硬质的不同。一般情况下，配方中增塑剂的用量在10PHR（PerHundredResin，表示每100质量份树脂所需配方料的质量份数）以下的PVC制品称为硬质制品；增塑剂的用量在10～40PHR的PVC制品称为半硬质制品；增塑剂的用量超过40PHR的PVC制品称为软质制品。 1) PVC heat shrinkable film products have soft, hard and different. In general, the amount of plasticizer in the formula in 10 PHR (PerHundredResin, every 100 quality needed the formula of resin quality copies) of the following PVC products called hard products; The amount of plasticizer used in PVC products of 10 ~ 40PHR is called semi-rigid products. More than 40PHR of PVC products are called soft products. 2）由于PVC是热敏性塑料，因此配方中不能没有热稳定剂。一般PVC配方中，热稳定剂的用量为5～8PHR。如果热稳定剂少了，则不足以阻止PVC在热熔融成型的温度下分解；如果热稳定剂多了，则会提高热熔融流动的温度。 2) since PVC is a heat-sensitive plastic, there can be no heat stabilizer in the formula. In general PVC formula, the dosage of heat stabilizer is 5 ~ 8PHR. If the thermal stabilizer is small, it is not enough to prevent PVC from decomposing under the thermal melting temperature; If the heat stabilizer is much, it will increase the temperature of the hot melt flow.