A common reaction to the excessive use of disposable coffee cups is: “Why don’t we just recycle them all?”
To meet the demands of liquid portability, the simple paper cup is not just made out of paper; the paper is coated with plastic to make it waterproof. Disposable paper cups are made of about 95% high quality paper fibre and 5% plastic coating. Although the paper fibre is recyclable, contamination caused by food and drinks can limit the recyclability of the paper, and the small amount of plastic which coats the paper deters most paper mills from accepting plastic coated cups for recycling.
For many paper mills, plastics (even the smallest amounts) can wreak havoc with paper reclamation equipment and contaminate downstream processes. For those few paper mills willing to take on the challenge, a consistent supply of used cups is often nowhere to be found. According to a press release issued in the UK, for a paper mill to begin recycling paper cups, at least 10 tons of used paper cups are needed monthly. If a cup weighs about 5 grams, that’s almost 2 million cups a month. For disposable cup recycling to become a reality, the used cups need to be collected systematically in bulk. Since consumers often take their beverages with them when they leave the coffee bar or fast food chain, disposable cups end up everywhere but in proper collection systems. Even if consumers end up taking the paper cups home, the cups most likely end up in landfills, since most municipalities do not recycle paper cups.
In order for hot drink cups to be compatible with the existing recycling program, an end-market must exist for this material, either segregated or in combination with other collected materials.
The closest material source to plastic lined paper cups that is currently recycled in Australia is liquid paper board packaging (e.g. gable top milk cartons).
The Australian recovery rate for liquid paper board is estimated to be around 10%. (Recycling How Does Australia Compare 2000 – Nolan-ITU.) Assuming annual cup consumption of 1 billion cups and with a similar recovery rate of 10%, Australia could expect to collect about 3,000 tonnes per year of post consumer plastic lined paper coffee cups.
Extract from Stage 2 report for life cycle assessment for paper and packaging waste management scenarios in Victoria, January 2001.
Currently, collected liquid paper board from kerbside can undergo several types of reprocessing into different end products. In Australia, there are three main routes that collected liquid paper board cartons go:
Office paper products at Paperlinx Shoalhaven Paper Mill: only accepting gable top cartons, where they are converted into office paper products.
Cardboard at Visy and Amcor cardboard paper mills: post consumer aseptic cartons are reprocessed together with collected cardboard into new cardboard boxes.
Tissue production in Korea: Liquid Paper Board is exported overseas and reprocessed into tissues.
A study of the treatment of coffee cups in paper recycling was conducted under the direction of the City of Toronto in 2009.
While some plastic lined paper cups are labelled recyclable, if they enter the paper waste stream, they are not recycled. Instead, they are considered contaminants that will be removed from the mixed paper batch before being recycled. As a contaminant of the process, cups are considered a waste product and would be sent to landfill from the paper-processing site.
If the level of ‘contaminants’ was low enough, then the recycled product could still be sold as a low contaminated batch.
End markets for post consumer poly coated paper products:
Field interviews were conducted in North America, where end markets were investigated for potential consumption of post-consumer polycoated cup packed as:
1. a stand-alone grade;
2. mixed with aseptic and gable top containers;
3. mixed with other fibres (paper items).
Material composition and economics determine the grades best suited for each paper mill’s process. Recovered paper grades are selected based on the finished product’s fibre requirements and the mill’s recovered fibre processing capabilities.
Recovered paper must be compatible with the mill’s fibre preparation systems, emphasizing:
• Fibre length/strength
• Coatings and contaminants
• Colour (bleached or unbleached)
• Ink component
Containerboard and newsprint mills are not interested in any form of plastic coated paper. Containerboard mills see this as a grade that will come with challenges.
Many different types of fibres that would be present in a batch of paper cups, including brown kraft from the sleeves.
Newsprint mills do not have the pulping time to deal with this plastic coated paper.
What should happen with post consumer poly-coated cups?
Because hot drink paper cups are comprised of a high quality fibre, there is interest in finding a way to use this recovered fibre. However, currently it is not economically feasible to collect, separate and prepare this grade for the market.
Disposing this in the Mixed Paper is not the most lucrative idea – especially for a grade with such good fibre.
These items need to be kept separate when collected, or the Material Recycling Facilities need to invest in significantly lengthening the sorting line, and paper and mills similarly need to invest in updating equipment to deal with this waste stream.
Along with government legislation and incentives for diverting organic waste from landfill, in future I hope that we do find a way to recover at least some of the estimated 210,000 tons of paper resulting from the more than 1 billion paper cups disposed of annually in Australia.
STORY BY RICHARD FINE