Cleanroom Wipers: State-of-the-Art Evaluation Techniques
What makes the difference in wiper products is the amount of surface contamination they leave behind after use.
What makes the difference in wiper products is the amount of surface contamination they leave behind after use. Particles and fibers, non-volatile residue, metals and metal ions, anions and ESD propensity must be properly evaluated and quantified using techniques such as Soxhlet extraction, scanning electron microscopy (SEM), capillary ion electrophoresis (CIE), surface resistivity testing, charge decay testing and energydispersive x-ray (EDX) analysis.
A wide choice of consumable products is offered for sale to the cleanroom marketplace.
Distinguishing among these products—wipers, swabs, stationery, face masks, gloves, etc.— to
determine their suitability for cleanroom use is difficult without in-depth testing and measurement of critical characteristics. Testing is often an area of controversy as scientific principles are balanced against intuition and ease of testing. In this article, I will attempt to provide a framework for evaluating consumable products, indicate which tests are most important, and detail the current state-of-the-art in the testing of cleanroom wipers.
Why test? Is there really a difference?