Question: The parts we test are of high value, and we need to re-introduce them into our manufacturing operation for continued processing. How do we clean off the test solution?
Answer: In general, the dyne test is not intended to be used on material which will continue through the manufacturing process. When necessary, our best suggestion is to wipe the test area clean with 99% isopropyl alcohol. In some cases, this will still leave a stain on the surface, and other solvents, including acetone or MEK, can be investigated. Be sure that the cleaning agent is not soluble with the substrate − any melting or swelling of the surface indicates solubility, which will permanently and significantly alter the surface.
Once an appropriate cleaning agent has been determined, the next consideration is whether the dyne testing or cleaning has altered the surface in any way that will be detrimental to downstream operations. Short chain polymer molecules, volatiles, etc. will be removed to some degree by the dyne test, and even more actively during the cleaning process.
To determine whether there is any deleterious effect, comparisons should be made of those pieces which have been tested and cleaned vs. those that have not. All downstream and end-use quality control tests should be checked to make sure that performance has not been affected.
Finally, please keep in mind that if your products are either medical or food grade, you will need to research any relevant restrictions regarding contact with the constituents of surface tension test fluids.