Cleanliness & Cleaning Strategies for Great Adhesion

Mar 5, 2020 6:00:00 AM

Cleanliness in manufacturing gains avid devotees all the time. Once the importance of cleanliness is grasped, it’s nearly impossible to think about manufacturing processes without considering the pervasive impact cleanliness has on every aspect and feature of the process.

Cleaning as a means to create superior products has increased in importance over the last several decades as manufacturing across all industries has evolved. Precision machining of parts with lower tolerances for any aberrant particulate (even microns thick debris) has demanded higher precision cleaning. Lightweighting innovations and challenges in aerospace and automotive sectors have introduced advanced materials that are joined by adhesive bonding rather than mechanical fasteners, by and large. This means the surfaces of these materials need to be cleaned in such a way that they are adequately compatible with the glues and adhesives being applied to them.

Cleaning has been a topic of great interest in electronics manufacturing for some time (the history of which is outlined in greater detail here).  Various residues that are intentionally applied to circuit boards or that find their way onto the boards throughout the manufacturing process are known to be the cause of circuit failures and the best method of removing them is to clean them. Additionally, conformal coatings are increasingly needed to protect boards from harsh environments. In order to have confidence in the application of these coatings to the board and component surfaces – those surfaces have to be cleaned to very particular specifications.

Medical device manufacturing is much the same. Not only do they utilize electronic components within them, many are coated themselves. Medical devices also need to meet standards for cleanliness and sterilization that other industries don’t necessarily. For this reason, the medical device world has always been rather obsessed with cleaning. Cleanliness and sterilization are not exactly the same thing, although they can have similar processes to achieve their goals.

Cleaning for manufacturing means creating surfaces ready for bonding, coating, sealing, joining, printing, or painting through processes that alter the material surfaces in various ways. Sometimes that means the removal of substances. Other times it means making an already “clean” surface chemically reactive.

In order to control these changes to the surface, manufacturers need to be aware of the entire production process as a cleaning and adhesion process. Then, and only then, can you appreciate what actually is happening during an intentional part washing or surface treatment step, and adequately manage it.