Wins out over aqueous

DoverTech-Weldcraft manufactures welding equipment, which includes precision machining processes that produce contaminated subassemblies.

“Like many companies, we were faced with the challenge of replacing our conventional vapor degreaser,” stated Paul Lien of Dover Tech-Weldcraft Corporation (Burbank, CA).  “Initially we looked into water-based cleaning, thinking it was the obvious solution to our cleaning problems.  We tested several aqueous-base systems and found they did a good job.”

“There were three main concerns with aqueous cleaning systems.  The first concern was how to deal with the waste.  We operate in a city that demands strict adherence with the air and water municipality’s disposal guidelines.  The second concern was the increase in maintenance costs of both the water-based equipment and all the support equipment.  The third concern was bath life and bath maintenance.  We also realize that current wastewater disposal regulations are subject to change at any time.”

“We clean our parts in preparation for brazing and/or molding operations and, as such, cannot tolerate any residue/oil.  We require consistently clean parts all day, every day, without an on-board chemist checking pH and concentration of the aqueous solutions.  When we were introduced to a dry cleaning process that uses LCO₂, Our initial thought was ‘Even if it worked, could we afford it?’  Well, as it turned out, we could not afford to not have it.”
Lien explained that his company first tested an LCO₂ cleaning system four years ago.  “Our goal was to eliminate the use of pollution-generating cleaning processes,” he remarked.  “We found the LCO₂ cleaning process to be more effective, extremely consistent, and less costly to operate than our TCA solvent process and the alternate aqueous systems we initially considered.

“Our analysis involved a detailed comparison of both capital equipment and ongoing operational costs of the various systems being considered.  Our analysis confirmed that although the LCO₂ system was more capital-intensive than the water-based option, the operational cost difference between the two provided the necessary justification for the purchase of the LCO₂ equipment.  The operational cost difference between the LCO₂ and water-based process was significant at approximately $2500 per month.  After much testing and cost analysis, we purchased an LCO₂ system for our production operation.

“Four years ago we implemented the technology and, after some initial startup glitches, we have run successfully ever since.  Our production demand requires us to clean medium-size brass and copper components 17 hours a day, 6 days a week.  Our monthly operational cost to run the LCO₂ system is approximately $450.  To date, we have experienced no real down-time with the LCO₂ system.  Our concerns regarding bath maintenance were resolved since the LCO₂ process does not degrade over time.  And finally, we now generate no pollution related to cleaning processes and enjoy consistently clean product on a daily basis.”

Source:
“Liquid CO₂ Immersion Cleaning: The User’s Point of View”, Parts Cleaning, April 1999