Polyvinyl chloride (PVC) can be a versatile and resource efficient thermoplastic with all the widest range of applications of the plastics family which makes it valuable in almost all regions of human activity.
Without additives pvc granule would not really a particularly useful substance, however its compatibility with an array of additives – to soften it, colour it, allow it to be more processable or more durable, produces a broad range of potential applications from car underbody seals and flexible 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 whole group of products tailor-created to suit the needs of each application. Unlike the majority of thermoplastics, virtually all PVC applications have got a lifetime of between 10 and 100 years. This involves proven durability and stabilisers play a significant part in achieving such performance. All polymers require stabilisers of one sort or any other; PVC is not any different in this respect.
Before PVC can be done into products, it should be combined with an array of special additives. The fundamental additives for all those PVC materials are stabilisers and lubricants; in the case of upvc compound, plasticisers may also be 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 in the product. As soon as the additives are already selected, these are mixed with the polymer in the process called compounding. One strategy uses an intensive high-speed mixer that intimately blends all the ingredients. The effect is actually a powder, referred to as a ‘dry blend’, which is then fed in to the processing equipment.
The second technique is to blend the constituents either in the lowest or high-speed mixer after which transfer the powder to a melt compounder. This may either be a compounding extruder, or another special equipment to make clear pvc granule. These create a melt which, when cool, is cut into granules ready for processing. Within a specialised process, liquid compounds generally known as plastisols, are made as dispersions of very fine PVC polymer particles in liquid organic media. PVC compounds are produced into products using many different processing methods such as extrusion, injection moulding, blow moulding, calendering, spreading and coating.