Fluid situations

4 min read

Cutting fluid is an often-neglected component of a manufacturing facility, but with increasing cost of purchase and stricter environmental controls over its disposal, it is a vital element of any production strategy.

It is not just the choice of coolants and lubricants that counts, but how to manage their use and disposal. Two of the most popular options available for high-volume manufacturers are to enter into a service arrangement with one of the main suppliers or invest in a coolant recycling system.

One of the heaviest users of coolant is the automotive sector, so it is no surprise to see it leading the way. A cutting fluid reprocessing facility installed and managed by Castrol has reduced waste fluid disposal by more than 80 per cent at Perkins Engine plant in Peterborough. The two transfer systems on site have an annual output of 20,000 cylinder heads and cylinder blocks for Caterpillar engines. A cylinder head machining line produces 80,000 units and a bearing cap machining facility produces 150,000 sets for a variety of different engines.

Four years ago the company adopted Six Sigma methodology and applied the system to evaluate the potential for outsourcing fluid management. After the review, which included proposals from the existing cutting fluid suppliers, the company concluded that a total fluid management programme would not benefit the business.

However, some of the specific proposals put forward in Castrol's proposal were of interest, and the company decided to use them in a separate working partnership.

Initially the partnership focused on a specific project, and Castrol was awarded a contract to install and manage coolant reprocessing and laundering equipment in the main metal cutting facility responsible for producing cylinder blocks and heads.

The performance of the three-year contract exceeded expectations by making a substantial saving in costs and, more importantly, a significant reduction in the amount of waste cutting fluid that required disposal.

Commenting on the project, Perkins manufacturing manager Chris Baty-Symes explained that the waste fluid volume was reduced from 466,000 litres to 45,000 litres — a cut of over 90 per cent.

He added that while cost savings are important, meeting the demanding target of zero emissions to landfill by 2010 set by parent group Caterpillar's environmental policy was an even greater incentive.

'We expected the environmental benefits to be at least cost-neutral,' he said. 'But this was a major environmental improvement that was cost-beneficial and meant that the equipment paid for itself within the contract period.'

He added that the waste reduction improvements achieved in the first 12 months not only met Perkins' 2003 target, but also enabled the company to meet its 2006 targets two years ahead of schedule.

And, having demonstrated the effectiveness of the products and the technology that it brought to the partnership, Castrol is now working with Perkins to investigate other opportunities to improve the way its fluids are managed.

Increasing the performance of a coolant system does not necessarily mean handing the entire process over to a third party. Excellent savings can be achieved by installing a cutting fluid recycling system, as did Nissan UK. The car giant installed a Master Chemical fluid recycling system last year with an initial aim to reclaim between 60 and 80 per cent of its waste production cutting fluids.

The system soon substantially broke through this target and within months was achieving levels of 90 to 95 per cent. Now, less than a year on, the results continue to surprise with reclaim efficiency levels of 100 per cent being recorded in recent months, assisting Nissan's control of on-site waste and ISO 14000 environmental objective — in particular the on-site waste management volume.

Demand on the system has grown in line with the company's increased production of cylinder heads at its Sunderland plant.

This growth in manufacturing was resulting in its swarf-centrifuging system extracting upwards of 1,000 litres of machining fluids a day. Keen to conform to ISO 14000 environmental management standards, the company invested in a Master Chemical XYBEX 3000 Autodesludge Centrifuge Recycling System.

This water-miscible system is specifically configured to remove tramp oil and particulate matter from coolant, and wash fluids down to eight microns or less.

The unit is equipped for use on high temperature and high pH fluids and, being mobile, is able to process fluids in different locations within the group's engine parts manufacturing facility.

Since the launch of the system, Nissan UK reckons to have saved just over 160,000 litres of metalworking fluids

This presents the prospect of the company saving in excess of £20,000 a year in coolant oil alone. So a speedy return on investment is certainly assured. All in all, the system has far exceeded the initial expectations/ planning calculations.

At Ford's Dagenham plant, the high-volume car maker opted for a coolant recovery system from Clearwater Systems for its machining and process operations. It purchased a dedicated coolant recovery system after the company realised the vast potential for savings from its stamping operations. A year on Ford is enjoying the benefits of increased tooling life and a notable reduction in coolant disposal.

High-volume engineering, such as Ford's production of wheel rims, uses large amounts of coolant that had to be replaced frequently to ensure high-quality products and prevent tools from being damaged by contamination. This in turn meant higher coolant purchases and hazardous waste disposal costs.

Clearwater was brought in to design and install a system that would address these issues. The cost savings on coolant became apparent within the first quarter, and hazardous waste disposal costs were reduced dramatically.

Marc Horn, Clearwater's general manager, said: 'I am extremely pleased for Ford, but I am not surprised that this system has made such an impact. We have provided a high-quality, affordable solution that includes the use of vertical gravity separation to remove oil contaminations.'

A hydrocyclone system was also introduced to remove swarf particulate which links to Ford's existing band filter to remove large particulate. According to Horn, from machining workshops to large plants, everybody with the need for extending coolant life can benefit in the same way as Ford.

'We have developed a range of coolant recovery solutions that do so much more than just recovering coolants. The cleaning capabilities even enable customers to sell the condensed oil rather than tankering it away to landfill.'