Question: We have a customer who wants to use an adhesive-backed expanded PTFE gasket strip on a steel substrate. However, the customer wants to be able to remove and reapply the strip without losing adhesion. We do not make ePTFE gasket strips, but we have imported some samples for the customer to test. They are not satisfied with the results. I must admit, I am not surprised. Is there such a thing as a PSA that can be removed and reapplied a number of times without losing adhesion?
Answer: As you probably know, bonding to a low-energy “non-stick” surface like PTFE is not easy. However, pressure-sensitive PTFE materials frequently use a silicone pressure-sensitive adhesive (PSA) because of good adhesion and the ability to use the material at high temperatures. I recently tested such a combination on an aluminum surface by applying it, leaving for 24 hrs to develop adhesion and then peeling it off the substrate. After re-applying and subsequent testing, the peel adhesion was still quite high. A few suppliers can help you with this application.