SA’s mechanical recycling industry jeopardized by excessive filler use


THE South African Plastics Recycling Organisation (SAPRO) believes that South Africa’s mechanical recycling industry could be jeopardized by manufacturers of polyolefin plastic products adding increasing levels of calcium carbonate filler to HD shopping bags.

This follows the public outcry in April after it was revealed that many of South African plastic shopping bag manufacturers – who claimed their bags were recyclable – were adding high contents of filler to HD bags, making it difficult – and in some cases even impossible – to effectively recycle.

And recently SAPRO said it had come to its attention that convertors are also considering increasing the addition levels of CaCO3 filler to the material formulation of plastic furniture, buckets, pails and chemical drums.

Plastics/SA’s Anton Hanekom confirmed that a working group established to investigate the impact ‘fillers’ are having on the recyclability of plastic supermarket carrier bags is progressing well: it is researching possible solutions and is due to report back to the industry this month. The group includes convertors, recyclers, retailers and packaging specialists and has six months to investigate the impact and research possible solutions. The working group is being assisted by Bernard Reeksting, an independent external subject matter expert.

The main focus of the working group is threefold:

  • To provide clarification on the definition of recyclability versus not (currently) recycled. All polymers are by nature recyclable and can be recycled. However, there are factors that could affect certain processes when recycling plastics, making it less economically viable to recycle, e.g. high levels of fillers and dirt contamination can affect the washability of waste. Without an end-use market for the recycled material or an insufficient supply stream, this too will impact on the viability of recycling a particular material.
  • To consider the optimum level of filler in various plastics products before the specific gravity of the product will change to a density that does not allow efficient recycling and propose standardised methods and tests to assist recyclers.
  • To research technology and equipment available to deal with washing plastics with high levels of fillers.

“There are many challenges and differences in the approaches of the various working group members, but the group is united in achieving the common goal to find workable solutions to the recyclability of plastic products containing high levels of fillers. We are confident and optimistic that we will achieve the objectives that we have set,” said Hanekom.


Why excessive amounts of filler is a problem

Only mechanical recycling is currently commercially exercised in South Africa. There are two or three small private incineration and diesel-from-waste plants on trial. At 20.3%, the country's mechanical recycling rate is the highest in the world. By comparison, Europe's mechanical recycling rate is between 9-11% and Australia averages 9.2%.

Almost all mechanical recycling in South Africa that is performed on dirty, post-consumer polyolefins use ‘sink-float’ technology, as these facilities are reasonably accessible and facilitate economically viable recycling. Any threat to the ability of recyclers to recycle dirty plastics will therefore have an immediate detrimental effect on recycling in South Africa.

The majority of carrier bags manufactured in South Africa contain varying amounts from low to high percentages of fillers. The carrier bag industry alone is estimated at approximately 36 000 tons a year. This constitutes a massive source of raw materials for recycling and can significantly increase the sustainability of the industry. If 100% recycled, it could add a further 2.5% to the overall recycling rate.

In an attempt to reduce costs in the manufacturing of plastics products, convertors are adding increased amounts of fillers like CaCO3 (calcium carbonate) to material formulation. Unfortunately, the fillers have very high relative densities: CaCO3 has a density between 2.7 and 2.8 g/cm³. Even at low addition levels, the specific gravity of the mixture will exceed 1g/cc. This means that the average density of the product is more than water, effectively making conventional sink-float technology redundant.

According to a *White Paper published by SAPRO, fillers increase the specific gravity of the product to more than one and therefore makes it unfit for use in the sink-float processing equipment widely used by recyclers. SAPRO say that although these products are theoretically recyclable, with the current systems it is not possible to recycle dirty, post-consumer products where washing is an integral part of the recycling process.

Only polyolefins (HD, LD, linear and PP) can be separated and washed in this manner as their relative densities are between 0.92 and 0.98 g/cm³. The other plastics such as PET, PVC and polystyrene have specific gravities exceeding one and therefore sink with the dirt, also enabling the effective separation of these materials from the polyolefins during the washing process. Should the filled high HD also sink, it makes the process of separation more complex.


Effect on South African recycling industry

To SAPRO’s knowledge, there is no economically viable alternative to sink-float systems to be used in the mechanical recycling of dirty, post-consumer polyolefin plastics with a specific gravity greater than one. To further complicate matters, the products containing the fillers are indistinguishable from those without. Entire batches are therefore contaminated, reducing the yield from sink-float operations. The prices recyclers are then willing to pay for collected material become too low to cover the overheads of collection, forcing collectors to stop collecting the bags.

As more products start containing fillers, the recycling rate on these products will continue to drop, having a detrimental effect on the future of the complete recycling value chain in South Africa.

Internationally, a similar problem is experienced with many plastics products that contain fillers, but these are not mechanically recycled and the end-of-life products can still be used for energy recovery.

SAPRO believes that maintaining the status quo on filled material formulations will mean that products are incorrectly marked with the Mobius loop as well as claims of recyclability.


Compulsory specification for plastic bags?

Meanwhile, the Department of Environment Affairs said it would be liaising with the National Regulator for Compulsory Specifications (NRCS) and the South African Bureau of Standards (SABS) to ensure that manufacturers of plastic carrier bags comply with the regulatory requirements and standards of their products.

The DEA said that money collected from the plastic bag levy to support recycling initiatives through the establishment of necessary infrastructure for recycling in the country and the implementation of the Compulsory Specification for Plastic Bags (VC8087) through the National Regulator for Compulsory Specifications.

The DEA also claims that a contribution of R22.4-million will be allocated the NRCS for research on plastic bags over the next three financial years. As part of its mandate, the NRCS conducts compliance and enforcement of the specifications.

In 2003, South Africa introduced plastic bag regulations in a bold move to address the challenge of plastic bag litter. The regulations essentially made the provision of thicker, more durable plastic bags compulsory. The compulsory specification was subsequently developed prescribing that only plastic carrier bags and flat bags of the minimum thickness of 24 microns can be manufactured or imported into the country at a levy of 3 cents a bag (now 6c). In terms of the regulations, the plastic bags ought to be recyclable, thereby making them more ‘environmentally friendly’.  The new thickness also made them more reusable.

Since the inception of the levy in 2004, the National Treasury has been collecting the Plastic Bag Levy. The money collected goes into the National Revenue Fund and National Treasury allocates a portion of it to the DEA for regulation of the thickness of plastic bags. The collected levy is not ring-fenced and can only be allocated to recycling programmes following submission to the National Treasury of an approved and clear business plan on the implementation of such programmes.


DEA implementing initiatives to promote recycling

The DEA is implementing initiatives aimed at improving the regulation of the development and implementation of Industry Waste Management Plans in an effort to fast-track effective implementation of the National Waste Management Strategy, which promotes waste minimisation, re-use, recycling and recovery of waste. As part of the strategy, and in terms of section 34A (1) of the National Environmental Management: Waste Amendment Act, 2014 (Act No. 26 of 2014), the Department has established a Waste Bureau which monitors the implementation of Industry Waste Management Plans.

The Department has published a call for the development of among others Industry Waste Management Plans for recycling purposes and diverting waste from landfills. The Paper and Packaging Industry Waste Management Plan is one of these plans and comprises various waste streams, including plastic bags. The Paper and Packaging Industry Waste Management Plan provides effective and efficient ways through which plastic bags can be recycled.

The DEA said that tt is for this reason that they had allocated a budget of R155-million towards regulation of the thickness of plastic bags, and to support recycling initiatives for a period of three financial years. The funds are administered through the Waste Bureau.

* ‘The recyclability of filled polyolefins’ – a SAPRO White Paper, 2015