At cleaning solution provider Kumi Solutions, changes in the way hazardous chemicals are being legislated against and used are being met head on with its partners Safechem and Pero, working to ensure that its systems are safe and efficient now and into the future.
Highlighted at a recent customer event at Kumi's facility in Nuneaton, the use of chlorinated solvents, especially the popular trichloroethylene (TCE) has been under the legal spotlight for some time. Despite its classification as a carcinogenic, mutagenic and toxic for reproduction (CMR) substance, the fact remains that it is indispensable in certain applications. As such, cleaning technology has had to develop to ensure that it can be kept fully under control.
Following a European Union risk assessment led by the UK that identified high exposure levels for users of open systems for metal cleaning systems, the VOC Solvent Emissions Directive, which came into power in October 2007, placed strict controls over users consuming over one ton of CMR solvents, such as TCE or n-propyl bromide, essentially requiring a move to closed systems.
However, in anticipation of a future TCE ban, the VIC (Voluntary Industry Commitment) was also established with the help of UK authorities to enforce a similar level of regulation for companies using less than one ton. All European producers of TCE have signed up to the VIC, with the main point being that they will not supply the solvent to anyone using it in an open system from 31st December 2010.
The all encompassing REACH regulations have also been implemented against TCE since June 2009, for which companies must demonstrate adequate control measures to receive authorisation.
For those concerned about what this all means, both cleaning machine provider Pero and chemical service provider Safechem (part of the DOW chemical company) have been producing products that go beyond these requirements for some time now. Pero produced its first closed system in 1978 and now produces a range of cleaning machines with and without solvents. The most popular type is its universal vacuum series, accounting for 65% of its sales, which range from the V0, with 50kg basket capacity, to the V5 with 1,000kg capacity.
Accommodating change
As the name suggests, one of the major advantages of these machines is that they can function with almost any kind of chlorinated hydrocarbon solvent or A3 hydrocarbon (ie. any solvent with a flashpoint of over 55°C). The change can be made in one to three days onsite and requires no additional hardware. “You wouldn't expect to have to change your machine if you went from milling brass to aluminium,” explains Kumi's managing director Simon Graham, “so the same should apply to cleaning products.” The machines also operate well within the occupational exposure limit set by the Scientific Committee of the European Commission (SCOEL), with emissions of 5ppm over an eight hour time weighted average, exactly half the allowable limit. Thus, the machines are clean enough to emit to atmosphere and carbon regeneration equipment, although available, is not required.
While it is expected that there will remain an industry requirement for TCE for the foreseeable future, this universal ability also allows users to take advantage of new products or changes in the market. Mr Graham continues: “Actually, legislation is the least of our worries. What we have to do is fully defined and being 20 years in the making, I don't see that changing now.
“There are other more significant factors like end user demands. The goalposts can move at any time and future applications may require certain finishes and post-processes that don't work well with TCE, or companies might change their cutting or pressing oils or bring in new processes. There is also the fact that in the US and Japan, some companies are turning away from TCE because of their interpretation of legislation.”
Life in a vacuum
So although legislation often dominates discussion of solvent degreasers, there is still a competitive marketplace out there and such systems still need to perform. Thus, the event was also an opportunity for Kumi to extol the virtues of the vacuum system as a way of achieving cleaner parts in a lower carbon footprint.
The benefits were discussed in relation to a specific aerospace customer part – a 1m diameter honeycomb seal ring containing 45,000 blind holes 1.5mm across and 20mm deep. The main problem with the typical evaporation method for a component of this type is introducing a solvent to the part so that it covers all surfaces completely. In a typical atmospheric evaporation machine, air pockets can form in the recesses of the holes, preventing solvent/surface contact.
Another problem is drying. To be removed the solvent needs to be turned into a vapour. However, at atmosphere, oil doesn't evaporate at the same temperature as solvent, so a user would end up with a progressively higher concentration of oil in the recesses and only a moderately clean part. This process typically takes around 35 to 40 minutes to achieve and may need to be repeated to ensure it meets requirements.
In Pero's V series of machines, both the machine and the work chamber is under vacuum when the solvent is introduced, removing the first problem of trapped air. The chamber pressure is then rapidly dropped to 10 millibars (which on larger machines means pulling out 7,500 litres/minute of air). As that pressure drops the solvent starts to heat up and hits boiling point, expanding rapidly and bursting out, taking all the oil with it. Comparatively, on the same part, guaranteed cleaning can be achieved in 12 minutes in one hit. The vacuum machines also perform favourably from an economical point of view. Due to the more effective nature of vacuum machines, with 97-99% of the solvent removed from every cycle, the waste and thus solvent cost per distillation is vastly lower than an atmospheric machine. Comparing a Pero V1 with its atmospheric equivalent, both working on a 30kg load, Mr Graham claimed that the former would cost up to £1.19 per distillation, whereas the latter could cost up to £39.84. The machine's work rate is also more favourable, with the V1 capable of washing 10 baskets per hour at an electrical cost of £1.53 per hour, as opposed to six baskets at £2.88.
Full support
Complementing the Pero machines on the other side of Kumi's service offering is the support packages available from Safechem, who provide cleaning fluids and full chemical management services. At the heart of its business however is its Safe-Tainer system, which ensures a closed loop supply handling the safe storage, delivery and transfer of chemical products.
This includes a service alliance that encompasses manufacturers of closed cleaning equipment, waste management companies responsible for the whole supply chain of the product, and various authorities and institutes. It also offers a solvent maintenance service, providing consultancy test kits, stabilisers, additives and standard solvent analysis to ensure process optimisation. The latest addition to its business model is its Complease initiative, where the customer simply pays for a clean product, and Safechem manages the rest, effectively running a subcontract cleaning service at the customer's facility.
Add to this Kumi's UK demonstration facilities where customers can come and try out batches of their own parts, and its spares and service packages, and every aspect of the cleaning process is covered.
Kumi Solutions
www.kumi-solutions.com
