Common cleaning agent for Water soluble, No-Clean and RMA paste| 9 October, 2001
Can I use one common cleaning agent to clean the stencils from a lines which are using RMA, No-clean and clean paste ( b'cos we onlyhv one stencil cleaner ). What about those misprinted board ? Can all of them use the same chemical or cleaned in the same tank/machine?
How to determine the right time for changing the solvent in the tank other than measuring the specific Gravity ?
Although the chemicals listed above are capable of removing all paste types, they may not all be compatible with your cleaning system. Some of the chemicals are designed for ultrasonic applications while others are suitable for both ultrasonic and spray-in-air technologies. As for chemical life, some chemicals have a relatively low loading capacity and must be changed out every week or two. That may present an environmental issue. Some chemicals on this list have very high loading capacities. A chemical with a high loading capacity, depending on the cleaning equipment, may never need to be changed. If your cleaning system is equipped with a filtration system that will remove solids from the wash solution, then the periodic addition of chemistry to make up for chemical dragout and normal evaporation will create a chemical attrition rate that will prevent the need to �throw out� spent chemicals.
Loading of chemicals are not usually determined by specific gravity, titration, or pH tests. These tests indicate the concentration factors of the chemical. They are helpful in determining if the chemical is at the correct concentration.