09/02/2010 - Dry ice cleaning cuts packing machine maintenance downtime by 60% at Turners PPL
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 nonmachine 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.