Polyvinyl chloride (PVC) is really a versatile and resource efficient thermoplastic together with the widest variety of applications of the plastics family making it useful in virtually all areas of human activity.
Without additives pvc compound would not a particularly useful substance, nonetheless its compatibility with a variety of additives – to soften it, colour it, ensure it is more processable or longer lasting, results in a broad range of potential applications from car underbody seals and versatile roof membranes to pipes and window profiles. PVC products can be rigid or flexible, opaque or transparent, coloured and insulating or conducting. There is not just one PVC but a huge group of products tailor-created to suit the requirements each application. Unlike the majority of thermoplastics, the majority of PVC applications have got a lifetime which is between 10 and a century. This involves proven durability and stabilisers play an important part in achieving such performance. All polymers require stabilisers of one sort or another; PVC is not any different in this respect.
Before PVC can be created into products, it should be combined with a selection of special additives. The essential additives for those PVC materials are stabilisers and lubricants; in the matter of rigid pvc compound, plasticisers are also incorporated. Other additives which can be used include fillers, processing aids, impact modifiers and pigments. Additives pvcppellet influence or determine the mechanical properties, light and thermal stability, colour, clarity and electrical properties of the product. When the additives happen to be selected, these are together with the polymer within a process called compounding. One method uses an intensive high-speed mixer that intimately blends every one of the ingredients. The end result is actually a powder, known as the ‘dry blend’, which can be then fed to the processing equipment.
The 2nd strategy is to blend the components either in a minimal or high-speed mixer and after that transfer the powder to a melt compounder. This could either be a compounding extruder, or another special equipment to make pvc compound. These generate a melt which, when cool, is cut into granules ready for processing. Within a specialised process, liquid compounds referred to as plastisols, are produced as dispersions of very fine PVC polymer particles in liquid organic media. PVC compounds are created into products using many different processing methods including extrusion, injection moulding, blow moulding, calendering, spreading and coating.