Understanding plastic regrinds

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What exactly is a plastic regrind? As the world wakes up to the importance of plastic recycling, new terms are creeping into the dictionary which describes innovative new solutions to previously entrenched problems. Let’s take a closer look at plastic regrinding which is a specific form of handling plastic waste and preventing it from ending up in landfill for decades to come.

What is plastic regrinding?

The process stands for Post Industrial Regrind, or PIR. This essentially describes the process of recapturing scrap plastics and resins from any manufacturing process. These processes happen, for example, when lids are being made for bottles and plastic containers. It can include tails, moils, runners and flashings that result from the plastic moulding and extruding processes and which naturally produce waste.

Imagine this kind of waste being produced in plastic factories across the world and you can instantly see the extent of the problem. But with plastic regrinds, this wasted product is simply ground up and added back into the process.

Because the plastic regrinds have already been heated and moulded once, they aren’t virgin materials. This means that their properties differ slightly at a physical, flow and chemical level and, consequently, they can’t be used entirely to make new parts or bottles. But their value is significant, not least in reducing tonnes of plastic waste that would otherwise end up languishing in landfill for generations to come.

Where does this plastic regrind come from?

There tend to be two primary sources of material. The first is from rejected parts, such as those which have been rejected by QC for failing to live up to manufacturing needs. An example could be a bottle lid that leaked. These parts are considered defective and would typically be thrown out as waste from the manufacturing process. Now, they enter into the plastic regrind closed manufacturing loop. They will be returned to the grinder, ground and added back into the material feed where they can ‘try again’.

Another source of regrind material comes from the extrusion process, where moulded projects such as plastic tails and moils are left behind from the blow moulding processes. These are removed when the mould is released and then trimmed to be collected and – again – sent on to the grinder to be used once more.

A manufacturing green win

So, PIR isn’t something that your local council offers, but it is increasingly being used by manufacturing businesses. PCR recycled plastics – post-consumer regrinds – are something slightly different and are collected from recycling plants for further cleaning and processing, before being added back into manufacturing.

The good news is that manufacturers are committing to this kind of plastic reuse on a grand scale as they bid to make their operations greener and to introduce recycled products into their product lines in the process. This can save factories money as well as boost their eco-friendly credentials, as there are no longer extra costs required for virgin material purchases, nor costs required to dispose of excess waste products.

This means that everyone can become a winner when such innovative techniques are applied to better manage industrial processes and to reduce plastic waste insofar as possible.

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