Solvent Degreasing One Million Cold Formed Parts Monthly
East London-based Cold Formed Products Ltd (CFP) has installed a Pero V1 universal degreasing machine from exclusive UK distributor Kumi Solutions Ltd. Installed in October 2007 – at the end of the production line at CFP’s Plaistow manufacturing facility – the new Pero is already cleaning approximately 1 million aluminium ‘impact’ extruded parts a month for several automotive and aerospace industry customers.
With over 45 years of history, CFP has grown to become a thriving, 40-employee second-tier automotive supplier to some of the biggest names. Until recently, however, the company had relied on an ageing open-top solvent degreasing tank to clean the vast number and range of components it produces, something that clearly needed to change in light of the EU’s Solvent Emissions Directive (SED), which came into force at the end of October 07.
“We first heard about the impending SED legislation three years ago,” states the company’s technical director David Binks. “At first we thought the best approach would be to try and replace solvents altogether, so we looked at aqueous-based degreasing solutions. But to be honest, the trials we conducted were far from convincing.”
Undeterred, the company refocused its attention on solvent degreasing, but this time Mr Binks and his team examined hermetically sealed systems.
“We visited four or five suppliers of solvent-based sealed machines, but again the results were not impressive. It was only when we spoke to our supplier of solvents that I heard about Pero machines. We subsequently contacted Simon Graham at Kumi, and he recommended the Pero V1 machine. After trials in Germany, we were relieved to find that it did the job very well.”
CFP has developed its own in-house methods for measuring part cleanliness that replicate the procedures used by its customers, to determine whether or not components are sufficiently clean.
According to Mr Binks, one of the differentiating factors favouring the Pero V1 was its vacuum system, which is used to evacuate the chamber of residue. Many competitor systems use a ‘regenerative carbon stack’, which can be a time-consuming alternative. CFP also claims that the V1 was priced more competitively.
Pero machines represent a significant step forward in cleaning technology as the machines are “universal”. They employ almost any type of solvent, from chlorinated hydrocarbons – such as trichloroethylene and perchloroethylene – through to methylene chloride, modified alcohols. A great example is Safechem’s, Dowclene 1601 – and any standard hydrocarbons – for example, A3 category products with a flashpoint above 55°C. A V-Series system can be changed from one solvent type to another in as little as one day.
The V-Series machines are hermetically sealed to provide “near-zero” emissions and comply with the new SED. The machines are run under partial vacuum conditions, thus lowering the solvent’s boiling point. This has many advantages such as improved energy efficiency, reduced solvent consumption and the ability to clean more delicate materials such as thermoplastics and coated parts.
Solvent condition is monitored automatically with solids, oil and water separated as part of the process. Sophisticated drying using two or three vacuum pumps is also fully integrated. The V-Series machines come in five sizes ranging from a basket-type system with 380 x 220 x 200mm capacity, up to a Euro pallet size capable of handling a 1500kg payload.
Installed in October 2007, the CFP Pero V1 was commissioned (using perchloroethylene) within two days without any interruption to the company’s production.
“So far it has performed very, very well,” says Mr Binks. “We manufacture around 1 million parts a month here, and they all go through the Pero. Cycle times are typically 6 minutes, but because of the machine’s automatic basket loading system, which accommodates four baskets on the conveyor, the machine looks after itself for 24 minutes at a time. It’s a feature we really like.”
Depending on the size of the component, CFP places between 150 and 2000 units in each basket. The machine runs for 10 hours a day, five days a week.
“In total, the Pero machines cleaned 2.5 tonnes of aluminium a day, which is 25% more than we could do previously,” says Mr Binks, “Furthermore, the V1 solvent degreasing machine only requires cleaning once every three weeks, whereas we had to clean our previous open top tank every week without fail – and the process was much more labour intensive.”
CFP operates in what it describes as an intensely competitive automotive industry. Its customers’ advantage lies in its impact extrusion process, which can deliver up to 3000 parts per hour. The company also offers subsequent CNC machining to supply finished parts.