Using MEK Solvent to Clean Inkjet Print Head Parts

July 1st, 2015

MEK LabelVolatile solvents such as MEK (methyl ethyl ketone) are often preferred to clean precision and intricate parts in an ultrasonic cleaner because solvents provide efficient cleaning and evaporate quickly leaving virtually no residues. An example is removing dry ink residues and contaminants from inkjet print head parts and nozzles in the coding and labeling division at Samuel Packaging Group in New Westminster, B.C.

Special care must be taken, however, to avoid MEK solvent and its vapors from contact with ignition sources originating in ultrasonic cleaners or from other sources in what is defined as a hazardous area.  That is from being ignited by nearby extraneous sources such as electrical equipment and associated wiring.

Using an Explosion-Proof Ultrasonic Cleaner for Print Head Cleaning

At Samuel Packaging inkjet print head parts and nozzles are cleaned in a 4-gallon Electrowave EW-12 EXP explosion proof ultrasonic cleaner from Tovatech.  These cleaners qualify for an Explosion-Proof Apparatus label and conform to NFPA and NEC guidelines for such apparatus.  That’s because all Electrowave EXP ultrasonic cleaner electronics are sealed in high density foam to be completely isolated from solvent and solvent vapors.

To avoid creating a hazardous area the cleaner is located in a high volume fume exhausted benchtop hood assembly equipped with a fume-proof light.  After the cleaner is filled with MEK solvent it is covered with the supplied lid to minimize evaporation and operated without a load for approximately 15 minutes to degas the solvent.  Degassing removes trapped air that reduces ultrasonic cleaning efficiency.

Parts to be cleaned are placed in the supplied stainless steel basket and lowered into the solvent.  The lid is replaced and the ultrasonic cleaning cycle begins.  Electrowave EXP explosion proof cleaners are equipped with a “sweep” mode that provides uniform distribution of cavitation cleaning action throughout the solvent.   The timer is set for 30 minutes after which parts are examined.  If further cleaning is required the cycle is repeated.  Parts are allowed to dry before reassembly.

When the MEK solvent loses its efficiency it is disposed of according to local regulations.

For more information on operating explosion proof ultrasonic cleaners in hazardous areas please check our post on safety guidelines.

Feel free to contact our scientists for answers to your questions on explosion-proof ultrasonic cleaners or for information on ultrasonic cleaning systems designed for water-based cleaning solutions.