PVC compounding process: how does it work?

In Brief

PVC, or polyvinyl chloride, is one of the most versatile and widely used materials in manufacturing a huge range of products. In this article, we will explore how PVC compound is made, the production process, and the material’s many applications.

Production and processing

What makes PVC so adaptable? Its adaptability is the result of a key process known as compounding. Compounding is a melting process that combines PVC with a variety of additives to create a material with distinctive properties. This targeted combination is what gives the PVC its various properties, making it suitable for a range of applications.

Let’s take a closer look at how this compound is made:

Raw materials:

PVC resin: the base of the compound is PVC resin, obtained through the polymerization of vinyl chloride. The PVC resin gives the material its basic structure and rigidity.
Additives: The additives are introduced to give the PVC the specific properties required for the end application. These can include:

heat stabilizers: to prevent thermal degradation during processing;
plasticizers: to make the material flexible;
fillers: such as kaolin or calcium carbonate to improve mechanical properties;
pigments: to give the PVC color;
lubricants: to make processing easier.

Dosing and mixing:

The raw materials are dosed accurately based on the specifics of the end product. These are then mixed in special mixing machines. This phase is fundamental to guaranteeing that the additives are distributed evenly through the PVC resin, ensuring consistency in the properties of the compound.

Fusion and extrusion:

The compound is then heated and melted through a process known as extrusion. During the extrusion, the molten material passes through a rotating screw inside a nut. This process helps further mix the compound and give it the desired shape.

Granulation:

The molten extruded material is then cooled and cut into granules or pellets of a specific size. These granules represent the finished PVC compound, ready to be used in the production of various products.

Quality control:

Throughout the compounding process, quality controls are carried out to guarantee that the compound satisfies the required standards. These controls can include checking the chemical composition, physical properties, and characteristics of the processing.

Applications:

The PVC compound obtained can be used in a variety of applications depending on the specific properties of the composite. For example, if the PVC has been plasticized during the compounding process, the result will be a more flexible material suited to products such as flexible pipes, floor coverings, or toys.

Reliability and applications

The versatility of PVC compound is made clear by the many applications in which it is used. Here are some of the main uses of PVC that we have chosen from countless others:

Pipework and plumbing: widely used for plumbing and sewage systems due to their resistance to corrosion and the formation of encrustations.
Construction: used in the production of windows, doors, fixtures, and sealing systems thanks to its durability, weather resistance, and ease of maintenance.
Electricity and telecommunications: insulating coatings for cables and electrical wires are made from PVC because the material offers excellent electrical resistance and is fireproof.
Automotive: internal and external components in the automotive industry, such as seat covers, interior coatings, seals, and hoses, which are often made from PVC for its lightness.
Medicine: it is used to produce flexible pipes, transfusion bags, medical devices, and sterile packaging.
Toys and baby items: many stuffed animals, dolls, and toys for kids are made from safe PVC because it is nontoxic.
Food and farming industry: PVC films and wraps are used for packaging food and in farming to cover tunnels and greenhouses.

These are just some of the examples of the uses of PVC. Its versatility continues to be exploited in many other sectors due to its unique characteristics and reliable performance.

Your best possible partner

We have looked at just some of the examples of the uses of PVC. Its versatility continues to be exploited in many other sectors thanks to its unique characteristics and reliable and long-lasting performance.

Find out how to improve your plastic production with Bausano’s cutting-edge pelletizing technology. Get effective and consistent results for your resins. Contact us today for a tailor-made consultation to suit your processing needs.

MD Nextmover Twin Screw Extruders

Up to 35% less power consumption thanks to the innovative I.E.4 motors, Smart Energy System and real-time energy analysis of the entire system with the Digital Extruder Control 4.0 system.

MD NEXTMOVER SERIES

High-quality customised extruders

With standard and customised extrusion lines to suit every need, we are a stategioc partner in plastic processing, pipe, profile, pellet and medical device production.

Our extruders