We have seen many pump oils, Krytex, silicones layers be removed, even ink on glass. Please note that freeze fracture is more effective with a liquid CO2 source than a gas CO2 source. Polymer layers are not soluble in liquid CO2 and require a freeze fracture process. For adhesives, epoxies, and fluxes, these polymeric layer will remain after cleaning. Here, surface binding to the substrate, substrate properties, and size of the deposit may be determining factors that prevent removal.
Testing is required on each sample class and situation.
One topic that needs separate clarification is the removal of deposited films or coatings by carbon dioxide snow cleaning. Films that are deposited properly will remain on the substrate while those films that were deposited poorly onto dirty substrates may be removed. The reason for the inability to remove well-bonded films may be related to the combination of the nonabrasive action of CO2 snow and the inability of the cleaning process to overcome any chemisorbed, covalent, metallic, or ionic bond. A recent suggestion has been made that there may be another particle removal mechanism. The liquid CO2 phase when in contact briefly with the surface, can act to change the particle adhesion and may lead to particle removal.