Opting for solvent-free cleaning processes
Heaton, C., Helminger, A. G., & Northeim, C. M. (2004). Pollution prevention: Opting for solvent-free cleaning processes. Chemical Engineering, 111(1), 42-48.
As a result of sweeping regulations that were promulgated in the late 1990s in the US and abroad, most chemical process plants and industrial manufacturers have been encouraged to evaluate and select more environmentally friendly cleaning processes, and to reduce their dependence on traditional cleaning processes that rely on chemical solvents. The goal is to select more-benign cleaning processes that can both meet the process' technical requirements and ensure compliance with environmental and occupational health and safety regulations without being cost-prohibitive. A variety of pollution prevention opportunities can help a facility to reduce its dependence on hazardous, regulated chemical solvents. Ultrasonic cleaning uses acoustic energy to create cavitation bubbles in a liquid. These bubbles vibrate and collapse, creating a scrubbing action that removes contaminants from many surfaces. The cleaning efficiency of ultrasonic systems depends on cleaning time, part shape, chemical additives and temperature.