PVC film popular science pvc packaging film.

PVC film material is a non-crystalline material. In actual use, PVC materials often add stabilizers, lubricants, auxiliary processing agents, pigments, impact resistance agents and other additives. PVC material has non-flammability, high strength, weather resistance and excellent geometric stability. PVC has strong resistance to oxidants, reducing agents and strong acids. However, it can be corroded by concentrated oxidizing acids such as concentrated sulfuric acid and concentrated nitric acid and is not suitable for contact with aromatic hydrocarbons and chlorinated hydrocarbons. The melting temperature of PVC during processing is a very important process parameter. If this parameter is not appropriate, it will cause material decomposition. The flow characteristics of PVC are quite poor, and its process range is very narrow. In particular, PVC materials with high molecular weight are more difficult to process (this material usually needs to be added with lubricant to improve flow characteristics), so PVC materials with low molecular weight are usually used. The shrinkage rate of PVC is quite low, generally 0.2~0.6%.

Inorganic antibacterial agent is an antibacterial agent prepared by using silver, copper, zinc, titanium and other metals and their ions to sterilize and inhibit bacteria. In the early 1980s, Japanese scientists began to directly add silver compounds to the resin, and for the first time made an antibacterial plastic film with an inorganic antibacterial agent. Antibacterial mechanism: Since inorganic antibacterial agents belong to the dissolution contact type antibacterial agent, the antibacterial effect of the inorganic antibacterial agent film is passive. There are currently two explanations for the antibacterial action mechanism of metal ions.　One is the contact reaction mechanism. The metal ions in the inorganic antibacterial film come into contact with microorganisms, which destroys the structure of the microbial protein and causes the death of the microorganisms or dysfunction. One is the mechanism of active oxygen. The micro-metal ions distributed on the surface of the inorganic antibacterial film can absorb energy in the environment, activate the oxygen adsorbed on the surface of the packaging film, and generate hydroxyl radicals and active oxygen ions. They have strong redox ability and can Destroy the reproduction ability of bacterial cells, inhibit or kill bacteria, and produce antibacterial effects.