Plastics are also known as synthetic resins and can be broadly divided into two broad categories: thermosetting resins and thermoplastic resins.

Thermosetting resins include phenolic resins and melamine resins, which never soften again by thermal hardening. Thermoplastic resins include polyvinyl chloride, polyethylene (PE), polystyrene (PS) and polypropylene (PP), which can be re-softened by heating.

Typically, thermoplastics are provided in the form of pelletized materials (compounds) using additives (antioxidants, etc.) that have been mixed in them. However, PVC resins are usually supplied in powder form and long-term storage is possible because the material is resistant to oxidation and degradation. Various additives and pigments are added to the PVC in the processing stage, and the blend is then converted into PVC products. Polyvinyl chloride is sometimes referred to in North America as "vinyl" in Europe, and mainly as such. In Europe, "vinyl" usually refers to certain specific flexible applications, such as flooring, decorative panels and artificial leather.

PVC is a thermoplastic made of 57% chlorine (obtained from industrial grade salt) and 43% carbon (mainly from oil/gas through ethylene). It is relatively less dependent on other polymers of crude oil or natural gas, which are non-renewable and can therefore be considered a natural resource saving plastic, in contrast to plastics such as PE,PP,PET and PS, which are totally dependent on oil or gas. This gives Chlorinated PVC excellent fire performance.

How is PVC formed?

Chemical process To prepare polyvinyl chloride, we must consider the simplest device, called a monomer, and during the polymerization process, these monomer molecules are linked together. Long molecular chains form so-called polymers (which are also referred to as macromolecules).

This is the case for PVC, which is made from vinyl chloride monomer by polymerization, which is generally known by its acronym Vinyl Chloride. Some monomers exist in the form of reactive gaseous chemicals, and some of them may cause health hazards when in direct contact with humans. In this case, they are manufactured and processed under strict control of hygiene, safety and environmental protection. On the other hand, such as PVC, which is a polymer produced by polymerization of monomers, is a solid and chemically stable substance, and therefore does not affect human health. VCM, whose raw material is polyvinyl chloride, is a gas at ambient temperature, but is usually stored in liquid form under pressure. Ethylene and chlorine are raw materials for polyvinyl chloride. Upstream industries are those that provide these materials, including the production of basic petrochemical products (sometimes referred to as feedstocks), which supply ethylene and chlor-alkali (caustic soda) industries, which provide chlorine.

By the thermal cracking of naphtha or natural gas, the basic petrochemical industry produces ethylene and propylene, naphtha, etc., mainly from the petroleum refining industry, which uses crude oil as the supply of raw materials. The chlor-alkali industry produces caustic soda, chlorine and hydrogen through electrolysis using industrial grade salt as the main raw material.

In the PVC production process the first stages of ethylene and chlorine are combined to produce an intermediate product called ethylene dichloride; this is then converted into vinyl chloride, the basic building block of polyvinyl chloride or PVC. 'Polymerization' is a process in which vinyl chloride molecules are linked together to form chains of PVC. The polyvinyl chloride produced by this method is in the form of a white powder. This is not used alone, but mixed with other ingredients to give dosage forms for a wide range of products.

Most commercial plastics have carbon and hydrogen as the main elements. Polyvinyl chloride differs from that by containing chlorine (about 57% by weight), as well as carbon and hydrogen. The presence of chlorine molecules makes polyvinyl chloride particularly versatile because it makes it compatible with a wide range of other materials. The chlorine content also contributes to making PVC flame retardant. It can also be used as a 'mark' to distinguish PVC in automatic sorting systems for plastic recycling. PVC formulations can be shaped by a variety of techniques and made into the final product form using very little energy. PVC polymers are chemically stable, neutral and non-toxic. PVC formulations have a wide range of applications, including the most sensitive, such as medical equipment, plus construction, automotive and electrical wiring.