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All About Plastics: What is PVC?

What is PVC?

PVC is one of the most popular and oldest thermoplastic polymers in the world. It was discovered twice in the 1800s; first by Henry Regnault in 1838 and again by Eugen Baumann in 1872. PVC was first sold commercially by BFGoodrich in the 1920s. Most other polymers were only discovered in the 1940s and 1950s.

There are three forms of PVC; rigid, flexible and liquid. The rigid and flexible variants are by far the most common form, having various applications in a number of industries. Rigid PVC is most commonly used in the irrigation and construction sectors, whereas flexible PVC is widely used in the medical and clothing industries.

Rigid PVC is used to manufacture irrigation pipes, conduit, gutters, pharmaceutical bottles, and fridge magnets. Flexible PVC is used to produce drip bags, electrical insulation, vehicle dashboard skins, gumboots, safety gloves, garden hoses and packaging films. The polymer is highly durable and cost-efficient to produce, requiring minimal amounts of energy.

Benefits of PVC

PVC has numerous unique characteristics that make it a valuable packaging and plastic material. It is highly resistant to environmental degradation, including wear and tear, chemicals and alkaline substances. It is cheap to produce and requires little energy in the process, making it an economically-beneficial polymer.

PVC has a high density and good tensile strength, especially the rigid form. This makes it a popular polymer for the construction and irrigation sectors, where the plastic needs to be able to withstand impacts and hard use. Its high resistance to chemicals and heat also makes it a valuable polymer. PVC is inherently flame-resistant and impermeable to liquids.

All PVC pipes manufactured in South Africa have been lead-free since 2006 after local manufacturers belonging to the Southern African Plastic Pipe Manufacturers Association (SAPPMA) voluntarily, but at great cost to the industry, accepted a policy of heavy metal-free stabilizers for the manufacture of PVC pipes based on health and environmental considerations.

As a member of the Southern African Vinyls Association (SAVA), SAPPMA is also one of the signatories of the Association’s Product Stewardship Commitment (PSC) a voluntary programme aimed at ensuring that all heavy metal additives (primarily lead) are removed from their workplace environments

These characteristics of PVC make it a versatile and highly useful plastic material. It is easy to recycle and is readily available, making it a valuable polymer for the recycling industry. All PVC plastic should be reused, upcycled or sent to a recycling facility when no longer needed. It should never be sent to landfills or dumped in the environment.

For more information, visit SAVinyls.co.za

 

How PVC packaging is recycled in South Africa

Polyvinyl chloride (PVC) is one of the most common polymers used by plastics manufacturers in South Africa. It is used to manufacture irrigation pipes, medicine bottles, gumboots and so much more. However, PVC is more difficult to recycle than PET due to the chlorine content of the polymer.

Processing PVC plastics requires special machinery. Many small-scale recyclers in South Africa cannot process PVC, so plastics manufacturers have started to replace PVC products with PET. The one advantage of PVC is that it contains less carbon content than other thermoplastics.

PVC can be recycled up to eight times before becoming too brittle, depending on the application and the state of the plastic. It is also more energy-efficient to manufacture and process than other types of plastic. These characteristics make PVC a valuable polymer, especially when recycled properly.

Two methods of recycling PVC

There are two ways to recycle PVC; mechanical recycling by grinding it into small pellets which are then melted and remoulded into new products, or feedstock recycling where chemical processes break down the polymer into its basic chemical components. Both of these methods are used in South Africa but the mechanical recycling method is more common.

Unlike feedstock (chemical) recycling, mechanical recycling keeps the original composition of the PVC waste. This poses a problem because many PVC products contain additives and additional chemicals to make them rigid or flexible. For example, flexible PVC contains added plasticizers to increase the fluidity of the product. 

Even products used for similar applications may contain different amounts of additives, which makes mechanical recycling more difficult. PVC recyclate requires very specific compositions for different applications. In order to produce a high-quality recyclate, the PVC waste should be separated into uniform compositions before being mechanically processed.

This is where feedstock recycling has its advantages. By breaking down the recyclate into its basic chemical components, a mix of unsorted PVC products can be processed at the same time. However, feedstock recycling is more expensive than mechanical processing and the end-market for the recovered chemicals is not as big. This gives recyclers fewer incentives to use chemical methods to process PVC waste.

Post-consumer vs post-industrial PVC waste

The PVC waste that comes from post-consumer sources is often mixed in type and quality. On the other hand, PVC waste from post-industrial sources (factories) is often the same. This means that it is far easier to mechanically recycle the waste from post-industrial sources as it does not need to be sorted first. Post-consumer sources of waste require careful separation before being mechanically processed.

Post-industrial waste is relatively pure as it comes straight from the factories that produce one type of product (or products with similar chemical compositions). This waste is easy to collect and recycle since it comes directly from the source or the manufacturer and the quality is high. Post-consumer waste contains mixed materials that were used for various applications and the quality of the waste is often degraded.

PVC products are extremely durable – sometimes with a lifespan of over 50 years. The strength of this polymer lends itself to a lifetime of reuse, making PVC a valuable plastic. By reusing and recycling these products, we can maximise their usefulness while minimising their environmental impact.

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Plastics SA represents all sectors of the South African plastics industry. ​Together with our associations, we play an active role in the growth and development of the industry and strive to address plastics related issues, influence role-players and make plastics the material of choice.

​Plastics SA has been mandated to ensure a vibrant and sustainable plastics industry in South Africa. The plastics sector is uniquely placed to meet the needs of a sustainable society and to deliver solutions to many challenges such as recycling, climate change, water scarcity, resource usage and energy recovery.

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