Chemical attack

4 mins read

How many production engineers can genuinely claim to know exactly which solvents are legal or the potential risks associated with each? Steed Webzell reports

To help combat the problems around solvent risk, Safechem Europe, a wholly owned subsidiary of the Dow Chemical Company, has launched the CHEMAWARE knowledge platform (www.chemaware.org). CHEMAWARE is aimed at providing know-how and raising awareness on the responsible and sustainable use of solvents for industrial surface cleaning. The platform helps guide customers through the ever-changing industry market requirements, providing answers and best practices. "The driving philosophy behind CHEMAWARE is to support companies in decision-making processes by providing professional advice," says Karl Stuetzle, Safechem's general manager. "It helps ensure that solvents are used safely and responsibly throughout their life cycle, helping the cleaning industry in protecting their employees and the environment." CHEMAWARE also explains the new concept of chemical leasing. Through this system, companies can increase their efficiency (up to 80 per cent reduction in solvent use), while seeing emissions decrease. This is possible, because customers are charged per square metre of product cleaned or time used to clean the parts. Therefore, the supplier 'leases' the product and also sells a service, providing a win-win situation for all parties. Safechem continues to develope chlorinated solvents. The latest result of its efforts is Mecthene MC, a stabilised, pure and virgin methylene chloride formulation that represents a viable alternative for cleaning applications where the use of trichloroethylene is not essential. It is biodegradable and does not deplete the ozone layer, while its impact on smog formation, greenhouse effect and acid rain is considered to be negligible. NEW SOLVENT EQUIPMENT In terms of new solvent degreasing machinery, among the most recent entrants to the market is the Pero V1R from UK agent, Kumi Solutions. Like other Pero models, the V1R is a universal unit suitable for use with virtually any type of solvent. It complies with all current and forthcoming regulations, including the EU Solvent Emissions Directive (SED) and more stringent German 31 BImSchV and 2 BImSchV standards. The V1R will process up to 700 kg of work/hour: double its predecessor. Furthermore, it has a cleaning, degreasing and drying cycle of just three minutes for a standard 35 kg load. With optimum competitiveness demanded of all modern manufacturing processes, it's not just the speed of the degreasing cycle that contributes to the bottom line. GK Enviro now offers solvent recovery systems and waste management systems that, it claims, can increase component cleaning efficiency at reduced costs. In view of legislation such as the SED, GK Enviro says that the goal is to reduce total use of product to 2 tonnes, or below. The ideal solution to arrive at this mass balance and avoid greater enforcement costs is to control and handle solvents 'in house' in effective ways. GK Enviro's solvent recovery systems are said to be capable of recovering a 90 per cent yield in batches of 800 litres. One sure-fire way of negating any concern or ambiguity about the use of solvents for cleaning is to use aqueous-based processes instead. Among the latest models on the market is the Duo from MecWash, which features twin wash and rinse tanks, allowing it to deliver both a high volume, flood/immersion wash cycle and a spray rinse stage. A single chamber format, which houses no less than 100 jetting nozzles, receives parts and components in plastic or metal baskets, or in purpose-designed fixtures. This then either gently rotates or oscillates, depending upon component design and which of the six pre-loaded programs is selected. The washing and rinsing process is followed by a high velocity, heated drying cycle. The result is dry parts within a cycle time of typically no more than 10 minutes. Among the first takers of Duo technology is Eastbourne-based sub-contractor Picross Precision Engineering. "Previously, we focused on solvent-based systems but now, with the MecWash Duo 400, we are not only producing excellent results, but also reducing operating costs and enhancing our environmental performance," says managing director of Picross, David Patfield. Picross also specified an Aqua-Save Junior (also from MecWash) as part of the installation. This is a mobile unit that connects directly to the Duo and continually recycles the wash and rinse water. This leaves only 5 per cent of the original volume as concentrated waste for off-site disposal. CLEAN TAX BENEFITS In a recent development, Aqua-Save technology may now qualify for the Government's Enhanced Capital Allowance (ECA) scheme, which provides financial incentives to businesses investing in products and technologies that encourage sustainable water use. If it meets the criteria, for every £100 invested – including installation – companies can reduce their Corporation Tax by up to £28. Image: Aquasave may now benefit from the Government's Enhanced Capital Allowance (ECA) scheme Another new aqueous system on the market is the EcoCMax from Dürr, available from UK agent, Geo Kingsbury Machine Tools. It is a three-stage cleaning and degreasing process, including hot air drying that takes place under vacuum in a single stainless steel work chamber. Baskets of components weighing up to 150 kg are loaded manually or automatically from the front. Programmable ultrasonics, together with jet turbulation is the latest equipment proving effective at helping to clean newly manufactured seal components, particularly in blind holes that tend to harbour swarf and cutting oil. This is the case at Slough-based stainless steel seal component manufacturer John Crane UK, which has installed a four-stage, aqueous cleaning line from Turbex that can process components to 500 mm in diameter. The company also finds that combining the two methods of agitation is equally efficient at removing heavy hydrocarbon soil from the rotating faces of seals that are returned periodically for refurbishment. Image: John Crane is using Finnsonic's latest aqueous technology in its operations, supplied by Turbex Cleaning of both new and used seal components is carried out in the Turbex line. Called Crystal CRX, it is one of the first in the UK of a new design of modular washing machine built by Finnish manufacturer FinnSonic, for which Turbex is the UK agent. A mix of new components and refurbished parts can be processed in successive loads, to a maximum weight of 60 kg per basket, in a cycle time of 15-30 minutes. Another specialist in the provision of ultrasonic cleaning systems, Guyson, has just upgraded its entire range of Kerry branded KS ultrasonic cleaning tanks. Kerry KS systems have been designed to achieve results using aqueous solutions. Ultrasonic transducers bonded to the tank base offer frequency that is factory tuned to the individual tank/transducer combination and then optimised under normal usage conditions with frequency sweep and fully automatic tuning. Guyson has also recently announced the delivery of a range of standard size configurations of Kerry KST submersible box type transducers. These products are designed to deliver the processing power of ultrasonic cleaning to existing industrial cleaning or degreasing tanks on a retrofit basis, or to be incorporated into new cleaning lines on an OEM basis. Box Item Dissolving oil Dürr has launched its EcoCO2, the first process that uses carbon dioxide in its supercritical state to treat small parts of complex geometry. Used at the appropriate temperature and pressure, CO2 exhibits oil-dissolving properties. Foreign matter removed from the component is separated from the CO2, while no residue of the cleaning agent remains on the processed part, which emerges from the machine at room temperature. The system is available from UK agent Geo Kingsbury Machine Tools. First published in Machinery, December 2009