Parts washing and coating pretreatment is an integral part of many manufacturing operations across the U.S. today. Typically if the part is going to be welded, coated, assembled, or shipped “as is,” the greases, lubricants, coolants, and oils from the previous step must be removed to ensure effective future process success. Sometimes the pretreatment step is an afterthought, or an effective full assessment has never been performed to determine what is the best pretreatment chemistry for your process. How do you choose the best pretreatment chemistry?
Many times the existing cleaning process was recommended by the spray washer equipment manufacturer, or adopted from a process used at another location, not specifically designed for the present application, soils, or process. Changes from increased corrosion protection demands for the shipping or different end use locations mean that the pretreatment that worked before may not be able to provide the current corrosion protection expectations. Cost savings projects on much higher costing areas upstream, like coolants or stamping fluids, may have created a negative effect downstream and have not yet been addressed.
Maybe the changes either postwashing or prewashing have been addressed, but rigged in a way that is not the most ideal fit, either due to lack of industry knowledge or trusting the wrong source of advice. Instances in which the washing process is rigged with poor rinsing, double cycles (sending parts through the line twice), or post dipping in buckets of R.P. all may be acceptable solutions but ones just settled for because of not knowing there may be a better way. Possibly the process is just getting by, causing costly rework, rejects, and returns.
It is best to work with a trusted adviser in the pretreatment field who knows the most effective pretreatment building blocks of a cleaning system, to assess the entire process and work with you on deciding if there is a better or more efficient way to meet your specifications. When approaching the existing pretreatment process systematically, with the correct knowledge, while keeping in mind the quality requirements required from beginning to end, a cleaner manufacturer can effectively select a cleaner to meet your needs. Many times we find that when the time is taken to properly assess all the external factors of the parts needing pretreatment and the equipment already being used, there is a one-step cleaner that can meet these needs. Reducing costs, rejects, and saving customer relationships with their end users are all results of choosing the correct pretreatment chemistry. I’ve personally worked with companies and reduced operational costs up to 75% just with a change in pretreatment chemistries.
Here are some helpful baseline information sources when assessing your current pretreatment system:
- Time, temperature, concentration, and impingement data
- Corrosion requirements – parts that used to be shipped across town are not required to remain corrosion free for weeks
- Existing soils – recent changes in either product, application, or concentration
- Equipment maintenance and performance – assess rinses, nozzles, filters, oil collection units, pipe diameters, P.M. schedules
Assess your system using the above list. A correct change in pretreatment chemistry can reduce rejects, reduce waste treatment chemistry and discharge, shorten production cycles, extend corrosion protection, and reduce overall cleaner costs.