Application of oxidized polyethylene wax in PVC heat shrinkable film

Application of oxidized polyethylene wax in PVC heat shrinkable film

Plasticizer is one of the important additives in the processing of PVC heat shrinkable materials. It can reduce the force between polymer molecules, increase the plasticity of polymer, and improve the moldability of PVC. The amount of plasticizer should not be too much, otherwise it will reduce the mechanical properties of the film, reduce the shrinkage stress of the film and affect the shrinkage rate.

PVC has good characteristics, but it also has disadvantages, and poor thermal stability is one of them. The role of stabilizer is to inhibit or prevent PVC from being degraded by heat during processing, and to prolong its service life. Thermal stabilizer should not affect the color and transparency of products, have good compatibility with resins, plasticizers, etc., and be non-toxic, cheap and small in dosage.

In the production of PVC heat shrinkable film, the amount of plasticizer is small, so it is difficult to plasticize. Increasing the plasticizing temperature will increase the possibility of thermal decomposition of PVC. Adding proper amount of ACR processing modifier in the formula can improve the processing performance. The solubility parameters of ACR and PVC resin are similar, and they have good compatibility. The adhesive force between ACR and PVC resin is large, and the hardness of ACR is larger than that of PVC. Under certain stress, it produces larger friction force, which makes PVC particles more easily broken and melted, improves the gelation speed and melting quality of materials, and has high melt strength.

Lubricant is also very important in polymer processing. In the production of pvc heat shrinkable film, a proper amount of lubricant should be added to reduce harmful friction and interfacial adhesion. According to the mechanism of lubricant, the matching amount of internal and external lubricants should be properly adjusted to reduce the matching cost. And stearic acid oxidized polyethylene wax has carboxyl and hydroxyl polar groups on its molecular chain, which can significantly improve the compatibility of PVC and has unique internal and external lubrication effect.