Have you ever considered how important proper control is to the chemical processes we depend on every day? When you’re designing or refining a cleaning process for your remanufacturing facility, control matters as much to your results as any other factor.
For example, your car is filled with a chemical (gasoline) that’s perfect for powering an engine, which in turn is engineered to use it efficiently. But if too much gas is injected into the cylinders, you’ll waste fuel. Too little, and you lose power. If we move too far in either direction, the engine won’t start at all, and if the cylinders receive the right amount at the wrong time, the engine misfires.
In the same way, layout, equipment and proper chemistry are important in industrial cleaning, but improper control of the process will lead to poor results.
A useful mnemonic for evaluating cleaning controls is T.A.C.T.—Time, Agitation, Concentration and Temperature. All need to be considered and controlled; all work together to govern chemical reactions and results.
Each chemical reaction requires a certain amount of time to occur. Like that car engine that needs gasoline, air and a spark to all meet at the right time, you may need your reaction to occur within a certain timeframe to be time-efficient and achieve optimal cleaning. Time and temperature determine when the chemical reaction will take place.
Anyone familiar with a washing machine will have a very clear mental picture of one form of agitation. However, the term includes any motion used to assist in removing soils, from passing bubbles through a soak tank to spray rinsing.
The most important consideration here is the rate of flow, derived from Pressure over Time. This determines the volume of solution on the substrate, and therefore the amount of reaction products that will reach the metal surface and interact with soils.
This is the amount of available reactive components per unit volume of bath. Just as too rich a gas mixture can waste gas, too much concentration can waste cleaning chemicals; just as a lean mixture robs an engine of power, too low a concentration can lead to poor cleaning results. In some cases, too high a concentration can also damage the substrate, requiring rework or scrapping of the part. Hitting the right balance is essential for timely and effective cleaning.
Concentration and agitation determine how much chemical is applied to the substrate.
Higher temperature is helpful in cleaning because it reduces the viscosity of soils and increases the chemical reaction rate. As noted above, temperature and time determine when the chemical reaction will take place. Consider carefully what the properties of the cleaners you’re using are at certain temperatures, and choose the optimal range for your application.
With time and temperature determining when and for how long the reaction takes place, and concentration and agitation determining how the chemicals reach the substrate, these factors act in concert to produce a predictable result you can optimize.
Control Beyond T.A.C.T.
Designing proper control into your cleaning process will require you to consider a number of other factors, such as how cleaners will be dispensed and metered. Will the system be automated? What sort of sensors and controls will be used?
Our white paper, Remanufacture Cleaning: Problems, Solutions and Control is an indispensable resource for these and other questions about aqueous cleaning for remanufacturers. Download it here, and get in touch with us anytime if you have questions.