Substitute Technology for CFC-113 in Clock Production

Abstract

Since around 1986, restriction on consumption of CFC (chloro fluoro carbon) has been continued in a global scale in order to protect ozone layer. Under such circumstances, we made a project to phase out the CFC consumption by December 1991. Till then, we had consumed CFC-113 for the cleaning of plastic and/or metallic parts, the elimination of refuse and/or oil on electronic parts, and the drying the surface of processed parts in clock production. First, we decided the order of priority for our phase-out project of CFC consumption as the following: (1)non-cleaning, (2) air cleaning, (3) aqueous cleaning and (4) organic solvent cleaning. We developed the substitute cleaning technology which we considered most suitable for each item, and then switched over the processing used so far to the renewed one.Some of the developed processing are, for example, air cleaning of plastic parts before paint application, and 2-stage drying of plated parts both by jet air and by hot air after cleaning by demineralized water. As the results of the development as above, we accomplished the phase-out of CFC consump-tion in November 1991. Among the new processing introduced for the phase-out project, 25% is non-cleaning and air cleaning, 21% is aqueous cleaning, 35% is organic solvent cleaning, and the rest of 19% is production control such as countermeasure for leakage.