Hello John,
Some determining criteria.
1. Examine what you are cleaning. Pastes, epoxies, inks, etc. Get the MSDS and samples ready and be prepared to forward them to the manufacturers for testing. They can respond with appropriate system and chemistry configurations. The epoxies may suggest a need for heat or more aggressive chemistry but you will want it tested by the manufacturer to prove the process. There are temperature limitations due to the stencil emulsions, yet heat is still a viable option for assisting your epoxy cleaning process.
2. Are you cleaning the paste and epoxy stencils in the same cleaner? If so, you may want filtration on the tanks. This can capture particulate in the wash and rinse tanks and decrease chemical consumption by as much as 80%. Given the expense of the cleaning chemicals, this is the option that will truely pay for itself.
3. Have your team review the local laws regarding waste water disposal. This may justify the purchase of an evaporator to cut disposal costs vs having the liquid hauled away. Note, this is where you will need to be careful of how you interpret the claims of manufacturers with "Environmentally safe" chemicals. A number of manufacturers are using environmentally friendly chemicals (review the MSDS), and you will want to stick with those chemicals wherever possible, some have even gone so far as to get certifications on them. Sure you can dump those chemicals down the drain out of the bottle, but once any cleaning chemical is used to clean solder pastes it is contaminated and cannot be dumped directly to drain.
Make the suppliers prove the process, then you can decide which one does it best for the least amount of money. Also, make sure the manufacturer is supplying you a good cleaner, not a cheap cleaner to tie it to their chemistry. For this you chould review the warranty clauses on chemical usage. Any intelligent manufacturer will want to approve the chemistry you are using in their system to sign off warranty approval but beware anyone who is only warranting their chemical to their machine. You may be left at the mercy of one chemical supplier.
Please feel free to email me if you have any questions or concerns.
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