By Lisa Nadile
PALM SPRINGS, CA—Working with cleanroom tape and labels often includes removing what they've left behind. For many, the process of adhesive removal can create more problems than the products themselves solve. Fortunately, many suppliers of these products say they are happy to work with customers on this issue, because removal is part of these products' lifecycle.
According to Dennis Baldwin of Alma Inc. in Palm Springs, CA, the first step when removing adhesive is to determine if the residue would affect the user's product adversely. For example, “Cleanroom tape is not made to the same specifications as labels. It is often used during construction, so it is used some distance from the finished product,” he says.
A question submitted to CleanRooms.com Industry Chat points out the next step users should take. The reader, who wished to remain anonymous asks, “How do you quantify the amount of residue left by cleanroom tape and labels?”
To quantify the amount of residue either to set an in-house standard or to meet customer requirements, users of cleanroom tape or labels should determine which measurement to use, Baldwin says. Depending on the location and purpose of the product, users should choose whether the residue is best evaluated with a microscope using particles per cm2 or with a solvent using particles per milligram.
Baldwin explains that the choice of solvent depends on the material covered by the adhesive. In order to make an accurate evaluation when using it, users should take care not to pick up metal particles.
Many companies market instrumentation for conducting these measurements. However, having an outside source quantify the amount of residue is the practical choice for many companies. Cleanroom users can contract with one of the many laboratories that specialize in surface measurement. One such company is AST Products, Inc. in Billerica, MA.
Alma has turned to Surface Sciences Laboratories in Mountain View, CA, Baldwin says. To make accurate measurements, Surface Sciences uses electronic spectroscopy and scanning electron microscopy to perform these measurements.
Once users quantify the amount of adhesive left by cleanroom tape or labels, they can incorporate the use of this data into their contamination control strategy. The results can aid in the reassessment of tape or label choice, or to create a residue removal procedure.
For more information, contact the companies mentioned:
- Alma Inc. at (760) 323-2692
- AST Products, Inc. at 978-667-4500 or http://www.astp.com
- Surface Sciences Laboratories at (800) 321-4775 or visit http://www.surface-science.com/