PCR bucket and drum overcomes technical challenges

POLYOAK Packaging is one of the leading rigid plastic packaging suppliers in Southern Africa and its commitment to maximising post-consumer recyclate (PCR) in its high density polyethylene (HDPE) drums and polypropylene (PP) buckets, wherever possible, to help fight climate change and plastic pollution.

Contan’s Multilayer PCR Bucket

Polyoak invested in specialised multi-layer technology imported from abroad, to launch South Africa’s first multilayer bucket containing over 40% PCR!

Its specialist bucket division, Contan, based in Roodekop (Gauteng), launched its award-winning Multilayer PCR 20L Bucket with the paint and coatings market in July 2022.

The feedback has been extremely positive, with brand owners embracing the chance to include recycled polypropylene (rPP) in their buckets without having to compromise on critical technical performance or visual appearance and branding on-pack.

This necessitated a bucket design with multiple layers, where every layer is comprised of the same material (polypropylene) to enable maximum recycling.

Including PCR in single layer buckets is problematic, in that it weakens certain technical properties of the plastic and reduces the bucket’s technical performance including impact strength.

Another challenge with injection moulding PCR from an unknown source is the variability when it comes to melt flow rate and shrinkage. This is crucial when fitting a lid to a rim as there is no margin of error, or else the bucket will leak or allow gas exchange. Therefore, the lid and rim are also injection moulded using virgin PP.

Therefore, Contan’s technical team designed the bucket to utilise virgin PP for the inner and outer layers, so as not to compromise the critical technical performance of the container.

Isolating the PCR in the middle layer and using virgin PP for the outermost layer, overcomes the challenge of colour matching. Any colour PCR can be used for the middle layer, whilst brand owners can add any colour the outside layer of the bucket.

All the same decoration options available for a virgin bucket, are also available for the Multilayer PCR Bucket, including in-mould labelling, off set and digital print.

At the same time as commissioning its new Multilayer PCR Bucket, Contan added direct digital printing as a decoration option for all bucket sizes. This allows for efficient short print runs, zero origination fees, artwork flexibility and faster response times with no label stock holding. This is a major advantage given the trend towards product customization within the industry.

All this earned Contan’s Multilayer PCR Bucket the prestigious title of “Overall Packaging Winner” at the recent Gold Pack Awards, in addition to winning the overall Plastic Packaging and Industrial Packaging award categories. Internationally, Polyoak’s innovative multilayer PCR initiatives, its Contan bucket and Blowpack drum, both achieved World Star Awards, announced in January 2023.

Polyoak Packaging’s Managing Director, Karl Lambrecht adds, “We are extremely proud and thankful to our customers for partnering with us on these PCR projects. The fact that recycled polypropylene has 70% lower global warming potential than virgin polypropylene, and that this bucket contains 40% PCR, is a huge win for the environment. This project will create a demand for recycled polypropylene back into packaging which has not existed up until now. To top it off, our bucket manufacturing plant is powered by enough solar energy to reduce carbon emissions by 1,870 tons per annum!”

Blowpack’s Multilayer PCR Drum

Polyoak invested in multi-layer extrusion technology, imported from abroad to support its drive to grow PCR content in its packaging, wherever possible.

Its specialist industrial blow moulding division, Blowpack, initiated and launched its award-winning 20L Multilayer PCR Drum project in partnership with its customers in the chemical and agricultural space.

The middle layer of the drum comprises post-consumer, recycled, high density polyethylene (rHDPE) which has 70% lower global warming potential than virgin HDPE.

This significantly reduces the drum’s carbon footprint and drives demand for HDPE recyclate which, in turn, increases the collection and recycling of drums at end of life to advance Circular Economy. The end-result is less plastic pollution and landfilling, and more economic opportunities for South Africa’s recycling community.

The interior of the drum is moulded using virgin HDPE to mitigate the risk of contamination and chemical reaction, to protect the integrity of the contents and guarantee its safe containment. This is because PCR has somewhat diminished technical properties and greater variability in performance compared to virgin plastic.

Sealing the recycled plastic in the middle layer enables production of higher quality drums on a more consistent basis. The middle layer of PCR may be dark in colour to serve as a barrier to help protect light sensitive contents.

Blowpack’s Multilayer PCR Drum is UN Certified to retain its technical functionality with up to 30% rHDPE inclusion. This was a major achievement given that PCR reduces a drum’s top load capability.

The fact that recycled HDPE is not yet food grade, adds complexity to operations and requires additional control points be put in place to prevent contamination with any food grade material run in the same production plant. This was another important aspect of the project.