Equipment maker ends solvent cleaning
18 Sep 2007
Measuring equipment manufacturer, Renishaw has responded to the situation by switching to the use of aqueous-based washing machines, which are designed to produce results as good as solvent cleaning systems.
The Gloucestershire-based company is using Mecwash Midi 400 washing machines in combination with an ultra pure water system from ELGA Process Water to remove cutting oils from its precision machined components.
Some of our parts, particularly satin chrome plated components, suffered staining even when they were rinsed in demineralised water, according to Neil Wood , development engineer at Renishaw. “We now use ELGA Process Water Aquaclean service exchange cylinders to improve the quality of our demineralised water by an order of magnitude, and that eliminates the staining.”
Renishaw uses two ELGA Aquaclean cylinders in series, the first containing activated carbon and the second containing a mixed bed of cation and anion exchange resins. The company recirculates water from the rinse tank, which used to be discharged to waste at a conductivity of about 100µS/cm.
Passing the water from the rinse through the Aquaclean exchange cylinders upgrades its quality to about 5µS/cm and allows recirculation, thus reducing mains water consumption and eliminating the need to discharge into the local sewerage system.
Renishaw has a duty of care to ensure that their wastes are disposed of safely. In the case of resin disposal, this means having a fully documented audit trail to trace their resin’s route from the process finishing areas to its ultimate fate.
ELGA operates a major regeneration centre at Stoke-on-Trent, where it handles ion exchange resins from many different industries. Every batch of resin that comes into the centre is identified and fully traceable back to its previous regeneration, and that includes a record of compliance of regeneration wastes with the discharge consent.
