As a result of a three-phase automation project, including the installation of a robust multi-head weigher from Dutch specialist manufacturer PIM, Caythorpe Farmers has doubled output and slashed giveaway on its potato packing line.
Home to the greatest proportion of Grade l land in the UK, Lincolnshire is prime potato growing country and the largest county to produce potatoes in the UK. Mill Farm in Grantham has been growing potatoes in its fertile limestone soils for years. More recently, the farm became a merchant for the local produce industry with Steve Dowse establishing Caythorpe Farmers, a produce packing and marketing operation, seven years ago.
“We buy locally grown potatoes, pack them into 10, 20 and 25kg bags and supply them to businesses – mainly wholesalers – in Southampton, Edinburgh and everywhere in between,” explains Steve.
For the first few years, the company made do with a basic, manual packing operation. However, as volumes grew, Steve made the decision to invest in automating the packing process. “The line required eight people to run it and we were finding it increasingly difficult to source the right calibre of operators,” says Steve.
Phased approach speeds up adoption
For a young company, taking a ‘big bang’ approach to automation can be prohibitively expensive. The solution for Caythorpe Farmers was to initially purchase a second-hand Pacepacker robotic palletiser for automating the palletising operation.
Upgrading its bagging line was the next priority, and a year later, in 2012, the company invested in a Total Bag Control (TBC) system and automatic sack placer from Pacepacker Services. The TBC is a fully automated system for stretching and transporting filled sacks into a stitcher or heat sealer. Because the system never lets go of the bags, it ensures consistent presentation and reliable sealing.
Following this second phase of investment, after being inspected and sized, washed and unwashed potatoes are weighed and conveyed to the bagging line or box packing area. Potatoes being bagged are dropped into 10, 20 or 25kg sacks supplied by the automatic sack placer, and are transported to the stitcher via the TBC system. Closed sacks are fed to the robotic palletiser on a conveyor.
Having got the packing and palletising functions running smoothly and delivering an output of 8-10 tonnes per hour, it became apparent that the two original mechanical ‘farm style’ weighers were causing a bottleneck. In addition, the inaccuracy of the weighers meant giveaway was reaching unacceptable levels. “We could be giving away 0.5 to 0.75kg away on some bags,” claims Steve. “This might not sound much, but can add up to an average loss of £45,000 annually. The weighers were also limiting our output to 10 tonnes per hour. It became clear that a more accurate weighing system was needed to match the output of the rest of the line.”
Steve knew that spending another £10,000 on a new farm weigher wasn’t going to achieve the improvements the business needed. Investment in a far more costly – but far more accurate – multi-head weigher was necessary.
Tackling the root cause of equipment damage
Although a significant financial investment, Caythorpe quickly recognised the business benefits of installing one of the fastest and most precise multi-head weighers currently available to the produce industry. Aside from its ‘Formula 1’ controls, the multi-head weigher from Dutch company PIM (Packaging International Machinery) tackles unwashed potato applications, something that few manufacturers have conquered. Knowing that the vibrating lanes are prone to damage from dirt, PIM has designed a multi-head weigher that uses self-learning dosing belts to feed the weighing buckets, making it more robust, accurate and particularly well suited to weighing root vegetables. In a split second the weigher calculates 500 possible combinations based on a faculty formula. “Traditional weighers are only as accurate as the last potato that falls into the weighing bucket. Ours can weigh sacks of potatoes within +/- 2g,” says PIM sales and project manager Jouke van der Meer.
In April 2014, Caythorpe Farmers placed an order for a 12-head multi-head weigher in a floor space-saving two-lane configuration. Pacepacker acted as PIM’s integrator, an arrangement that suited all parties – especially Steve who trusted the award-winning integrator to take ownership of the project and see it through on schedule. The weigher was delivered in July and within three days Pacepacker had it up and running. “Everything went very smoothly from our perspective” says Steve.
The new weigher may have cost approximately ten times more than a farm style weigher, but will quickly pay for itself in giveaway reduction. “Giveaway is down to 2-3g per bag, which is next to nothing,” says Steve.
Caythorpe Farmers road to automation has been a gradual process to suit their specific needs; now the line at Mill Farm has achieved its full potential, bagging up to 20 tonnes of Lincolnshire potatoes per hour, or 400 tonnes per week.
“We are getting maximum productivity out of the Pacepacker equipment and the robot. If we increased our output any more it would mean extra grading and forklift capacity,” says Steve. “Pacepacker have been instrumental in our growth journey. They appreciated that as a young company we couldn’t afford to fill our factory with new equipment at the outset and have worked with us to gradually build up our capacity until we were where we wanted to be.”