PVC plastics, also known as synthetic resins, are broadly classified into two categories: thermosetting resins and thermoplastic resins. PVC is sometimes referred to as "vinyl" in Europe, mainly in North America. In Europe, "vinyl" usually refers to some specific products, such as flooring, decorative panels and artificial leather. In China's packaging industry, PVC usually refers to the Blister products of such products, such as PVC blister plates, PVC folding boxes, PVC folding and blister, etc.
PVC is a thermoplastic derived from 57% chlorine (derived from industrial grade salt) and 43% carbon (mainly from ethylene / oil / gas). Compared with crude oil or natural gas, the dependence of other polymers is low, which is not renewable, so it is considered to be a natural resource saving plastics compared to plastics such as PE, PP, PET and PS, which are completely dependent on oil. Or gas. This chlorine gives PVC excellent fire resistance.
Thermosetting resins include phenolic resin and melamine resin, which are hardened by heat and no longer softened. Thermoplastic resins include PVC, polyethylene (PET), polystyrene (PS) and polypropylene (PP), which can be softened by heating and can then be produced in various types of plastic packaging.
In general, thermoplastics will be added to various types of additives (antioxidants, etc.), and then made into granular materials (compounds) in the form available to buyers. However, PVC resin is usually supplied in powder form and can be stored for a long time because the material is resistant to oxidation and degradation. In the PVC processing stage, various additives and pigments are added to PVC, and then processed into PVC blister packaging products.
The smallest molecule of PVC is called monomer, and these monomer molecules are joined together in the process of polymerization. Long molecular chains are called polymers (also known as macromolecules). Polymers polymerized by monomers, such as PVC, are solid, and their chemical composition is stable, so it does not harm human health. VCM, which is the raw material of PVC, is a gas at low temperature, but it is usually stored in liquid form under pressure. Ethylene and chlorine are the raw materials of PVC, which provide the upstream industry of this material, including the basic petroleum chemical (sometimes called raw material) and chlorine alkali (caustic soda) industry supplier for the supply of ethylene.
Through the pyrolysis of oil or natural gas, the petrochemical industry produces ethylene and propylene. In the first stage of the PVC production process, ethylene and chlorine are combined to produce a substance called two chloroethylene and then converted to vinyl chloride. PVC is the basic component of PVC. The "polymerization" process links vinyl chloride molecules together to form PVC chains. The PVC produced in this way is a form of white powder. The powder is not used alone, but is mixed with other ingredients. Each film factory has its own unique PVC sucking material formula. Therefore, the raw materials of blister are different because of the different suppliers. This is very important. Because in the production process of PVC plastic packaging, because the suppliers of raw materials are different, although the same machine is the same machine, the products produced by the same operator can not be exactly the same.
PVC blister is widely used. Besides food packaging, it covers most industries. PVC, because of its non degradable properties, makes the raw material better than PET at the same thickness. But in countries with more stringent environmental protection, they are very concerned about environmental protection. Therefore, if the PVC plastic box and PVC glue box are exported to these places, we should understand the current national environmental laws and regulations in detail, with relevant standards to avoid unnecessary trouble.
