Immersion General Information Immersion cleaning is effective for removal of soluble contaminants. Immersion cleaning may use any of the following chemistries: Water Neutral aqueous solutions Alkaline aqueous solutions Acidic aqueous solutions Ethyl lactate Alcohol Acetone N-methyl pyrollidone Terpenes Dibasic esters Glycol ethers Petroleum distillates The process depends primarily on the chemical solvency properties of the cleaning solution. Selection of proper cleaning solution is very important. Immersion cleaning is not recommended as a stand-alone process for higher cleanliness levels. Agitation of the part or process liquid improves cleaning. The following may be used to increase agitation: Ultrasonics Mechanical agitation of the part Spray under immersion Submerged spargers Stirring. Immersion cleaning can be used at room temperature or can be liquid heated in immersion tanks. Immersion cleaning may be used as a presoak for subsequent cleaning steps. An example process for difficult to remove soils is: Immersion soak (use a solvent matched to the contaminant) Ultrasonic cleaning in a different tank High-pressure spray (used to remove loosened contaminant) Low-pressure spray (used as a rinse) Dry (if required). Immersion cleaning may be manual or automated. A stand-alone dip tank can become loaded with soils rapidly. Recirculation/filtration/separation systems are recommended for heavily used tanks. Process optimization involves: Cleaning chemistry matched to the contaminants Soak time Bath temperature Control of soil loading in the tank Foaming may be a problem with some surfactants if agitation is used. Antifoaming agents may be needed. State Information | Glossary | Conversion Checklist | Comments Home | Process Advisor | Alternatives | Links | Search All SAGE material, Copyright© 1992, Research Triangle Institute Last Update: 15 March 1995 sage@rti.org http://clean.rti.org/alt.cfm?id=im&cat=gi