The two materials are made of the same material, but the proportions of the materials are different, the molded state is soft on one side and hard on the other.
PVC plastic bag
The natural color is yellowish translucent and shiny. Transparency is better than polyethylene and polypropylene, but less than polystyrene. Depending on the amount of additives, it can be divided into soft and hard polyvinyl chloride. Soft products have flexibility, toughness and stickiness. The hardness of hard products is that of low-density polyethylene, but if it is lower than polypropylene, whitening will occur at the bends. Common products: plates, pipes, soles, toys, doors and windows, wire sheaths, stationery, etc. It is a polymer material that uses chlorine atoms instead of hydrogen atoms in polyethylene.
Chemical and Physical Properties of PVC (Polyvinyl Chloride) Hard PVC is one of the most widely used plastic materials. PVC material is an amorphous material. In actual use of PVC materials, stabilizers, lubricants, auxiliary treatments, pigments, impactors and other additives are often added .
PVC material is nonflammable, strong, weather resistant and has excellent geometric stability. PVC is highly resistant to oxidizing agents, 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 or chlorinated hydrocarbons.
The melting temperature of PVC during processing is a very important process parameter. If this parameter is not appropriate, material decomposition problems will occur. The flow properties of PVC are very poor and its process range is very narrow. Low molecular weight PVC materials are usually used, especially because high molecular weight PVC materials are difficult to process (this type of material usually requires the addition of lubricants to improve flow properties). The shrinkage rate of PVC is very low, generally 0.2-0.6%.
Post time: Oct-20-2021