Ashland Performance Materials scientists developed a stress-relaxation method for calculating the cohesive strength of PSAs that offers significant advantages over other techniques. Lars Kilian, Ph.D., senior staff scientist, and Charles M. Lewis, Ph.D., technical director, investigated and developed a new process that uses a texture analyzer to measure stress relaxation over a specific time, enabling the force retention (FR) value to be calculated. This technique provides swift and reproducible measurements of cohesive strength directly from 1-mil PSA-coated stock.
Methods used prior to this discovery were often time-consuming, highly dependent on the operator’s skill and had poor repeatability on subsequent tests. The results from Kilian’s and Lewis’ findings show, in part, that the texture-analyzer method eliminates these problems and that FR could be a predictor for key performance attributes, such as PSA converting ability.
