Making of PVC
PVC is made from chlorine (derived from salt) and ethylene (the simplest unsaturated hydrocarbon obtained from crude oil). Reactions between chlorine and ethylene yield vinyl chloride monomer (VCM).
The polymerisation of vinyl chloride monomer in the presence of an initiator produces PVC, this can be done in several ways:
| suspension polymerisation | 85 % |
| mass polymerisation | 5 % |
| emulsion and micro-suspension polymerisation | 10 % |
From the outset LVM has focused on suspension PVC. In this method VCM is placed in suspension in a reactor vessel in a water environment and then polymerised into PVC at a relatively low pressure and temperature.
The VCM that is not converted, it is recovered and reused. Once the polymerisation process is completed and after centrifugation, drying and sieving, PVC is obtained in the form of a white inert powder.
PVC is never processed in a "pure" state. It has to be mixed with other materials to make processing easier and to provide the physical properties required in the final product. PVC differs from other commodity plastics by containing chlorine as well as carbon and hydrogen. It is the presence of chlorine in the molecule that makes PVC particularly compatible with a wide range of other materials.
PVC formulations can be designed to be rigid or flexible, opaque or transparent, insulating or conductive, and extra fire resistant.
PVC resins are widely used in an enormous variety of modern day applications such as building and construction materials, the automotive and packaging industry and last but not least the healthcare area: applications.
