Polyvinyl chloride (PVC) is a versatile and resource efficient thermoplastic together with the widest selection of applications of the plastics family which makes it valuable in nearly all aspects of human activity.
Without additives pvc granule would stop being a particularly useful substance, but its compatibility with a variety of additives – to soften it, colour it, allow it to be more processable or longer lasting, generates a wide range of potential applications from car underbody seals and flexible roof membranes to pipes and window profiles. PVC products may be rigid or flexible, opaque or transparent, coloured and insulating or conducting. There is not only one PVC but a huge family of products tailor-designed to suit the requirements of each application. Unlike other thermoplastics, the vast majority of PVC applications have a lifetime of between 10 and a century. This requires proven durability and stabilisers play a significant part in achieving such performance. All polymers require stabilisers of merely one sort or another; PVC is not any different in this way.
Before PVC can be created into products, it needs to be coupled with a variety of special additives. The essential additives for all PVC materials are stabilisers and lubricants; with regards to soft pvc granule, plasticisers can also be incorporated. Other additives which might 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 from the product. As soon as the additives happen to be selected, they can be mixed with the polymer inside a process called compounding. One strategy uses an intensive high-speed mixer that intimately blends all the ingredients. The effect is a powder, known as the ‘dry blend’, which can be then fed in to the processing equipment.
The 2nd way is to blend the constituents either in a small or high-speed mixer then transfer the powder to a melt compounder. This can either be a compounding extruder, or another special equipment for producing clear pvc granule. These generate a melt which, when cool, is cut into granules ready for processing. Inside a specialised process, liquid compounds generally known as plastisols, are designed as dispersions of very fine PVC polymer particles in liquid organic media. PVC compounds are manufactured into products using a number of processing methods including extrusion, injection moulding, blow moulding, calendering, spreading and coating.