DMSO can be evaluated as a cleaning solvent, or as a solvent component in a formulated cleaner, for certain resin residues on equipment and parts. The first question is whether it dissolves the residue, softens it enough for removal, or only swells it without producing a clean surface.
Studies have demonstrated swelling of particular epoxy materials in DMSO. That is a reason to test a resin system, not evidence that neat DMSO will dissolve every cured resin.
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Start with the residue that production actually leaves
Identify the resin chemistry, hardener or catalyst, cure history, fillers and approximate residue thickness. An uncured spill, a partially cured film and a fully crosslinked deposit can respond very differently.
Use production residues or representative coupons made with the same cure conditions. Include aged deposits if cleaning is delayed in practice. A test on fresh liquid resin cannot establish removal of a heat-aged deposit.
Compare DMSO against the current cleaning method under defined conditions. Record temperature, contact time, agitation and mechanical assistance. Judge whether softened material can be lifted away from corners and recesses, not just an exposed flat coupon.
Measure removal after rinsing and drying
A swollen layer may look easier to remove while still leaving a film. Inspect the surface after the full cleaning, rinsing and drying sequence. Where useful, combine visual inspection with microscopy, gravimetric measurements or a suitable surface-residue test.
For a weighed coupon, solvent uptake can temporarily increase mass. Weighing before it reaches a defined dry condition can confuse swelling with removal. State the drying and weighing conditions when comparing results.
Set acceptance criteria from the next operation. A mould may need to release parts consistently; a surface intended for bonding may need to meet an adhesion requirement. Include that downstream check rather than accepting appearance alone.
Check the parts and cleaning equipment
Test the actual substrate, coatings, seals, hoses and adhesives exposed to the cleaner. Check dimensional change, softening, cracking and surface damage during repeated exposure, including the proposed rinse. Compatibility with the metal body alone does not qualify the complete assembly.
If additives are required, evaluate the finished cleaner as a separate formulation. Results from a DMSO-containing blend cannot be attributed to DMSO alone. Do not add strong acids, bases or oxidizing agents to improve removal without a specific compatibility and process-safety assessment.
DMSO may increase skin absorption of contaminants in the cleaning liquid. Select gloves using permeation data relevant to the mixture and contact time, and control splashes and manual handling of wet parts.
Test the bath after it has been used
Repeat cleaning with representative resin loading and water content. Track removal time, suspended solids, redeposition and rinse demand. Filtration can remove detached particles, but it does not remove resin that remains dissolved.
Define a bath-change criterion from cleaning performance and relevant analytical checks. Fresh-solvent performance alone does not establish how long a bath can be used.
Include a validated rinse and dry step. DMSO remaining on the surface can interfere with the next operation; apparent cleanliness immediately after immersion is not the final endpoint. Compare the complete cycle: cleaning, rinsing, drying, bath maintenance and acceptance of the finished part.
For an initial DMSO supply discussion with YUJI, describe the resin residue, substrate and planned evaluation quantity. These details help define the purchasing request without assuming a proven cleaning result.
Further reading: DMSO in Photoresist-Removal Formulations.