ICT
TECHNOLOGY OVERVIEW
Cleaning Technologies for Medical Engineering VALUE ADDED THROUGH HIGH LEVELS OF CLEANLINESS
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cycle breaks up the liquid – the cohesive forces are overcome. This causes the formation of millions of microscopically small bubbles. During the subsequent pushing phase, these cavitation bubbles are rendered unstable and collapse (implode), and they generate hydraulic impacts with very high energy densities, thus causing micro-currents in the liquid. When these strike a surface, they blast off contamination which has been partially dissolved by a suitable cleaning agent and rinse the “dirt” away. In addition to the cleaning agent, the frequency of the electrical signals generated by the ultrasonic generator which is transferred to the liquid bath by the vibration system in the form of sound waves is also decisive with regard to the cleaning effect. In general we can say that the llower the frequency of the electrical ssignals is, the more energy is released by the sound waves. b Ultrasonic cleaning is used in the U field of medical engineering for pre, intermediate and final cleaning of, in for fo example, implants and instrument components, cannulae and other co metallic parts. In particular machined m parts are frequently subjected to pa pre and intermediate cleaning pr with solvents such as chlorinated wi hydrocarbons, non-halogenated hy hydrocarbons and modified alcohols. hy The reason for this is the fact that Ultrasonic Cleaning – Th 1 machining media which have been Standard Procedure in ma Image source: Amsonic carried over into the solvent, for example Medical Engineering car 1 cutting oils, can be continuously distilled Wet chemical ultrasonic cut out, so that the cleaning agent delivers cleaning allows for economic, Various cleaning technologies are available in order to efficiently uniformly high cleaning performance gentle and ecological removal achieve high levels of cleanliness for medical products such as implants. over a long period of time. The current of particulate and film-like state-of-the-art for solvent cleaning contamination. Even parts involves closed systems. These minimise the emission of volatile with difficult to access hollow spaces, for example blind holes, organic compounds (VOCs), and thus comply with current can be quickly and effectively cleaned with this process. environmental protection and work safety standards. The cleaning effect is based on cavitation: When a liquid is In order to assure the required levels of biocompatibility subjected to ultrasonic sound, the high intensity of alternating for technical medical components, ultrasonic systems with sound pressure during the pulling phase of the oscillation
election of the ideal cleaning technology makes an important contribution to quality and efficiency in the production of technical medical products. Not only can both be enhanced with modern cleaning technologies, they frequently make it possible to realise new product ideas as well. Regardless of the fact that to date no legal requirements exist with regard to particulate and film-like residual contamination on technical medical products such as implants, instruments, cannulae and catheters, component cleanliness is becoming a more and more important quality and competitive criterion in the field of medical engineering. Various cleaning technologies are available in order to efficiently achieve high levels of cleanliness. Essential factors involved in selecting a suitable process include the material or material combination, type of contamination, component geometry and production throughput. The technically and economically most effective cleaning solution frequently consists of a combination of various processes.
20 AUGUST 2011