A day in a life at a paper mill - Valpak visits supplier DS Smith

At Valpak, we work with a number of reprocessors to meet our members’ packaging waste obligations and are very fortunate to enjoy some great relationships with suppliers across the country.

Last month, a team from Valpak were kindly invited to DS Smith Paper’s Kelmsley Mill, in Kent, to witness first hand their recycling process that sees a staggering 820,000 tonnes of card and paper recycled each year at this site alone.

DS Smith in summary

Before we even arrived at the mill, it was apparent how vast an area the site occupies; from a distance it really feels as if you are driving towards a small town! We navigated our way in and were warmly welcomed to DS Smith’s newly developed Visitors’ Centre, educating visitors and celebrating the mill’s 95-year history. At its inception, we were told, the mill’s four paper machines were the largest in the world and today the site is the second largest recovered fibre-based paper operation in Europe, which certainly explains the enormity needed of the site.

Quality control and quantities handles

We began our tour through the mill, getting a glimpse into the 14-day-turnaround life cycle of a cardboard box. This begins at the mill with lorries carrying loads of cardboard bales queuing up to deliver into the ‘cardboard graveyard’, before the material is reborn into new packaging. Six lorries an hour make these deliveries (50% of which comes from retail packaging and the rest is largely from local authority collections) and the quantity that arrives has led DS Smith to monitor the quality of the material by inserting probes into each bale, rather than doing it by sight, to keep standards high when time is tight. As you can imagine, delivery is a carefully orchestrated process to ensure efficiency and safety and is overseen from a control room overlooking the area. From up there, we really got a view of the quantities DS Smith are dealing with and the reason they are operational for 364 days a year – the 365th day being reserved for maintenance.

Paper recycling process

Next, we got to see the first stages of the recycling process itself, where the material is broken down in huge vats to what resembles a paper smoothie – not very pleasant, let me tell you! It was however fascinating to get a glimpse inside the machines, whirring away like giant blenders and cement mixers, preparing the remnants for the next stage. Luckily, we were provided with ear protection to let us get up close and personal with the machines safely! At this point we saw a couple of foreign objects among the mixture, emphasising the importance of quality testing, which we saw at the delivery area. If things like this aren’t removed swiftly, our guide explained how easily they can contaminate large quantities of material and damage machinery, leading to potential delays and added costs in what it already a highly complex process.

Once the material has been broken down, it needs to be formed and dried out. We moved through to the next stage and were immediately hit by a wall of intense heat and humidity – something we were struggling to tolerate for 10 minutes, so had great respect for the operatives who work in this section for hours a day! The heat and steam are both key components and natural by-products of the process in which the moisture level is gradually reduced in this stage, before the paper is run onto gigantic, perfectly-formed rolls. Once we got over the size of the rolls, we were invited into the quality test area where we got to see examples of the subtle differences that can be achieved by the varying techniques used in the production area.

Energy efficiency measures

Large scale operations like this require huge amounts of energy, so we were interested to hear about the measures DS Smith takes to make the mill as energy efficient as possible. The site has its own combined power station and AD plant. This produces methane that puts energy back into the grid to offset some of the energy they use. Energy from municipal waste is also utilised for steam that is required throughout the recycling process.

What I learnt from the visit

Our visit to Kelmsley Mill was a great opportunity to really see what happens to material once it has left customers such as ours and understand more about the different processes. Of course, it was fantastic to see first hand the continuous developments DS Smith are making to optimise their operations for the future and the challenges they face daily in a facility of this scale. A huge thank you to all at DS Smith Kelmsley Mill for their kind invitation to see and learn about their work.