By utilising cryogenic (dry ice) cleaning technology from Polar Intelligent Cleaning Solutions (Polar ICS) on its weighing and packing machines, fresh produce pre-packer Turners PPL Ltd has reduced the overall time it takes to strip down, clean, refurbish and reassemble machines by 60 per cent, from five days down to two days, maximising machine availability and minimising production downtime costs.
Based in Newmarket, Turners PPL is part of Turners (Soham) Ltd, a UK-based privately owned transport company with a fleet of more than 800 vehicles, around 1,800 employees and 13 depots around the country. The company specialises in temperature-controlled distribution and bulk tanker operations. The Turners PPL division was originally set up to complement the existing distribution business, offering third party pre-packing solutions to the fresh produce sector. These services include produce packing, grading, box end labeling, storage and picking.
For more than six years, Turners PPL has acted as a supply hub for Tesco, providing pre-pack solutions on a range of citrus fruit products imported worldwide. The site now supplies around 85 per cent of all Tesco citrus fruit. In total, the Turners PPL site pre packs around 50 million citrus units per year in either ‘wine glass’ or ‘giro’ packaging. This means that the 11 weighing and packing machines are absolutely critical to site operations and profitability.
Antony Taylor, Head of Operations at Turners PPL, comments: "As you can imagine, citrus fruit is a very messy product for machines to deal with. For example, in just a matter of hours, the wax coating applied to the fruit can come off during the packing process and is deposited on parts of the machine and ancillary equipment, including mechanical and electrical components. Similarly, sticky labels applied to the fruit also add to this problem. We operate the 11 machines on a 24/7 basis and so cleaning and maintaining the machines is critical to what we do here. In terms of food hygiene and safety, cleaning the machines on a regular basis is just as important."
Moving parts of the machines can fail or wear more quickly if they are not thoroughly cleaned on a regular basis. These include belt drives and conveyors, electric motors, PCBs, operator displays, weighing instruments and sensors. As Taylor puts it, "If these machine components were left uncleaned, eventually the machine would simply grind to a halt."
Because the machines operate 24/7, preventive maintenance is key says Taylor: "Finding the time to take machines offline for routine maintenance is very difficult. In an ideal world, we would schedule in the removal of a machine for a five-day period for a complete strip down, clean, refurbish and assemble. However, because of the wax build up, within a typical six-month period we would have a huge number of operational and engineering issues to deal with on the machines due to increasing number of faults and general breakdowns, that it is inevitable that certain machines would be lost at critical, busy packing periods."
After reading an article on Polar ICS’ new cleaning technology, Taylor invited Polar ICS to the Newmarket site to demonstrate the technology. "What really grabbed my attention on reading the article was the fact that you can clean machines in situ without having to remove them from the production line and then strip them down before cleaning can take place."
At the time, Turners PPL used high-pressure washers to clean the machines. However, according to Taylor, this process was time consuming and involved disassembling the machine first, then removing the parts from the packing line to a designated cleaning area outside. The pressure washing was then carried out, after which the various machine parts were moved to the maintenance workshop where the machine would be refurbished and re-assembled. The final stage involved moving the machine back to the packing facility. "This whole process required two engineers working for five days. Obviously, if an unexpected breakdown occurred on a second machine whilst we were servicing the first one, could result in a failure to meet the delivery schedule. Before using Polar ICS, with the best will in the world, you could say we were being reactive rather than proactive in terms of how we maintained the machines," concedes Taylor.
In June 2009, Polar ICS demonstrated its cleaning technology at the Turners PPL site, by cleaning one of the weighing and packing machines in situ. This took four hours to complete and did not require the engineers to strip down or remove the machine from the line, saving two to three days of labour time.
"Within 30 minutes of the demonstration, I knew we could benefit from using the technology," enthuses Taylor. "After being dry ice blasted, the machine parts and weighing systems looked like brand new stainless steel parts supplied straight from the factory. The operator from Polar ICS was able to clean all parts of the machine by switching to different shaped nozzles when required. I was so impressed that we are currently considering whether we can use Polar ICS to clean other non-machine assets at our site, including cold storage racking, walls and ceilings."
How does it work?
Polar ICS’ cleaning technology is based on dry ice (or cryogenic) blasting, which enables production machines to be cleaned whilst in situ. Compared to traditional, labour intensive methods that food producers use to clean their machinery, including steam cleaning, solvents, chemicals and jet washing, Polar ICS’ dry ice cleaning solution typically reduces cleaning time by 90 per cent. The cleaning process itself is also non-toxic, non-conductive and non-abrasive.
Dry ice blasting uses small compact dry ice pellets that are accelerated in a jet of compressed air. These pellets strike the surface at the speed of sound, whereupon they crack and loosen the coating on the surface that is being treated. The low temperature (-79 deg C) of the dry ice pellets makes the coating brittle, which cracks and loosens the surface, allowing the dry ice to permeate the coating. The dry ice then passes from a solid state to vapour, which leads to a 700-fold increase in volume, an explosive effect that lifts the coating off the surface. Dry ice vapourises immediately on contact with treated surfaces, which offers unique advantages compared to traditional blasting methods. First, there is no secondary waste material such as sand, plastic or glass. The only waste from the process is the coating that has been dislodged by the treatment, which can be swept or vacuumed. This also means the technology can be used to clean difficult-to-reach surfaces. If traditional blasting methods were used, residual-blasting materials would collect in these inaccessible corners.
"By collaborating closely with Polar ICS, we’ve now set up a revised maintenance and cleaning plan. This is based on a joint agreement of what both parties believe can be achieved in a certain time period. Once a fortnight, a Polar ICS service engineer comes to site to clean two machines in situ, which takes one day to complete. This means that our preventive maintenance on any one machine now takes just one to two days maximum, a significant reduction. In addition, we only ever have one out of 11 machines out of operation," adds Taylor.
And despite the fact that Turners PPL has only been working with Polar ICS for five months and so there is little historic data to work with, Taylor already has a "gut feeling" that the new cleaning methods "have reduced the number of machine breakdowns dramatically", including unexpected breakdowns.
In addition, Taylor says that by reducing the time it takes to strip down/remove/clean/refurbish and reassemble a machine from five days to two days, staff that used to carry out the cleaning duties can be deployed elsewhere in the factory.