There are two categories of plastics, which are also known as synthetic resins, and they are thermosetting resins and thermoplastic resins. The thermosetting resins include phenolic resin and melamine resin, which are thermally hardened, rigid, not-flexible, and can’t be softened again, even if they are exposed to a heat source. Thermoplastic resins include PVC, polyethylene (PE), polystyrene (PS), and polypropylene (PP), which is flexible, and can be re-softened by heating. Here comes an important question: What PVC means? – It is an abbreviation for “Polyvinyl Chloride”. With more than 45 million tons produced each year, PVC comes in the third place as the most widely produced synthetic plastic polymer.
In contrast to other thermoplastics, PVC resin is produced in powder form, while the rest of thermoplastics are supplied in a form of compounds as granular already mixed with additives (like the antioxidants, etc). That’s why long-term storage is possible since the material is resistant to oxidation and degradation. During the processing stage, various additives and pigments are added to PVC in order to manufacture multiple PVC products of different properties.