Case Study: Kemsley Paper Mill Reject Processing Centre
DS Smith’s flagship paper mill innovates with an award-winning process for difficult to recycle materials.
Innovation is at the heart of what we do at DS Smith, and it ensures we are living our company Purpose: ‘Redefining Packaging for a Changing World’. By thinking differently and working closely with our customers, we have developed the right strategies that not only benefit us and our customers but also the environment too.
Leading the way is our flagship paper mill in Kemsley, Kent, which is the second biggest recovered fibre-based paper operation in Europe; with a production capacity of over 820,000 tonnes per year, it is constantly developing new opportunities to turn waste into quality usable materials once again.
Our focus on sustainability has enabled us to introduce innovative ways of closing the loop on waste materials with award-winning processes like the Reject Processing Centre (RPC). The RPC has resulted in over 12,000 tonnes of ragger being diverted from landfill annually and has won awards since its inception including - ‘Towards Zero Waste’ award from the Chartered Institution of Waste Management (CIWM) and a ‘Sustainability Leaders Award’ from Waste and Resource Management.
The Challenge
In an ideal world, only paper fibres would enter our paper recycling operations. The reality is that other materials, such as plastic and metals, often end up mixed in with paper fibres. These materials are contaminants and levels of contamination can vary, with the least amount coming from separately collected paper and card.
Contamination in the paper-making process can compromise the quality of the final product, and in extreme cases can cause machinery to break down.
Reducing and removing contamination is essential in ensuring that quality finished paper products can be made from recycled fibres. In the first stage of the paper-making process, contaminants are removed during pulping and screening. Ragger rope is used to capture and remove contaminants from the paper stream such as plastic and metal. As part of the process to extract contaminates some fibres are also captured which we were keen to recover and reuse in the paper-making process.
The rejected materials are hard to recycle and would typically be sent to landfill or incineration but DS Smith developed and launched Kemsley Mill’s first RPC to improve the way that the mill handles contaminated material.
The challenge was to divert as much of rejected materials from landfill and turn it back into something useful once more.
The Solution
The RPC handles the removed contaminants through additional shredding and screening processes.
All of the metals can be recovered via a magnet and sent for recycling. Once fibres are separated from other materials, they can go back into the paper process to be reused as good fibre. Currently plastics can’t be recycled because they are mixed with some of the non-recyclable paper fibres.
We’re actively seeking better outlets for our mixed plastics rejects. We’re in contact with technology providers and are running trials, with a target to divert all our plastic rejects from landfill within three years. Additionally, we are putting focus on quality control of our raw materials to drive minimisation of plastic contamination from our suppliers.
What are the benefits?
By developing the right sustainable strategy at our Kemsley Paper Mill, we were able to divert more materials from landfill.This resulted in less waste and more recycling – which in turn led to revenue opportunities from the materials captured. More importantly for our customers, it underpins our commitment to producing high-quality and sustainable recycled packaging papers.
By thinking differently and having a dynamic and flexible approach to how we do things at DS Smith, this project has helped make our recycling process at Kemsley Mill much more sustainable. For customers whose material goes through our mill, their waste can breathe life again as another useful material, helping to close the loop.
12,000 tonnes of ragger per year is being processed through the RPC each year, in addition to 6,000 tonnes of fibre recovery from pulper rejects. This also benefited the mill by hundreds of thousands of pounds in sales of recyclable material extracted from the pulper. Again, DS Smith is leading the way in innovating with suppliers and customers to ensure sustainability is at the heart of everything we do on our journey to redefine packaging.
Following and applying the principles of the waste hierarchy from the top down is integral to our closed-loop philosophy.
"DS Smith is passionate about identifying how to achieve the best environmental and economic solution to redefine packaging for a changing world. Through thinking differently to others, we have found ways to divert materials previously deemed too difficult to recycle and found new uses for them. What we have done with the Rejects Processing Centre here at Kemsley is a great example of that."