Production Machining

AUG 2017

Production Machining - Your access to the precision machining industrial buyer.

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36 PRODUCTION MACHINING :: AUGUST 2017 PARTS CLEANING Most of these units have an internal separation system that removes the soils from the solvent. is allows the same solvent to be reused for conservation of operational cost as well as reduction of waste disposal volume. Environmental Health and Safety Features During the vacuum degreasing cleaning process, all cleaning work is conducted inside a sealed unit, isolating any operator from potential chemistry contamination as well as reducing any fugitive emissions such as VOCs that could contribute to global warming. Ambient area personnel are not exposed to an open process tank subject to fugitive emissions migration created by wind drafts or improper system operation and lack of proper ventilation. Dirty metal parts enter the system, and clean parts exit only after all the proper cycles have been completed. e process chamber door is sealed before the cleaning cycle starts and only opened after the process chamber has been evacuated of residual cleaning solvent. Clean and dry parts can be removed and generally are immediately ready for the next stage because lower part temperature allows rapid handling. During processing, there isn't remaining chemistry to drain. Waste is separated for periodic disposal, but at a lower volume compared with discharging the entire tank bath, as was done in the past. ere is also no rinse water to recycle or dispose of. is feature is a strong point in the Clean Water Act compliance. Chemical Compatibility Modified alcohol is the typical cleaning agent used in most new degreasers. Chemistries such as Kyzen's Metalnox M6386 cleaning blend are designed to clean a range of oils and coolants as well as metal fines, and are safe on steel, brass, aluminum and other metals. Europe has led the way for this type of process to replace both solvent and aqueous systems in recent years. e modified alcohol solvents feature compatibility with a variety of metals, removal of both polar and non-polar soils, excellent solvency for a range of soils, low surface tension to penetrate and remove soils from blind holes and crevices and low odor on parts upon exiting the system. Other benefits include dry parts and those free of chemical residue, parts that can be recycled or reused, parts that meet regulatory and safety requirements, and these solvents are not listed as a hazardous air pollutant by the EPA. Hydrocarbon compound such as Kyzen Metalnox M6381 is another common solvent used in vacuum degreasing. is solvent is usually not recommended for polar soils. e process using hydrocarbons requires higher opera- tional temperature than modified alcohols. Hydrocarbon chemistry and its process is quickly growing worldwide, especially in the U.S. where small parts in large volumes create the need to clean and dry quickly and thoroughly inside a work basket filled with small parts. e benefits of modified alcohol and hydrocarbon compound solvents to match the new equipment process have led to the acceptance of these solvents by many users—those who cannot or will not use a water cleaning process, and those who require solvent cleaning for blind holes, cavities and passageways where the substrate requires cleaning, rinsing and drying. Sometimes water processes simply will not work. Why Switch to Vacuum Degreasing? Small metal parts, especially in high volume bulk, are sometimes difficult to clean and dry in the desired timeframe. ey can present material handling issues to prevent part damage during transfer from containers to the cleaning process or during the cleaning process itself. Various substrate materials or soils may require dedicated process equipment and/or application- specific chemistry. In addition, environmental health and safety concerns are front and center in any plant; the Occupational Health and Safety Administration, Environmental Protection Agency, American Conference of Governmental Industrial Hygienists and other organiza- tions are developing new guidelines that may affect current process methods. Cost of quality increases as a result of rejects/rework; overall operational costs for chemicals, utilities, labor, waste disposal; operational compliance and monitoring/process adjustments and other items. Environmental impact is driving equipment design toward enclosed systems when possible. Whether in an atmospheric shielded tank or hermetically sealed chamber, vacuum degreasing is easily becoming the preferred process of many companies. Lower solvent usage costs and emissive losses, combined with a controlled process that yields repeatable results with minimum operator interface are the advantages of these systems. Vacuum Degreasing's Future Vacuum degreasers are quickly becoming the future of solvent cleaning technologies for small parts/high volume cleaning, and they generally function equally well with most aqueous soils.

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