Future Designs of Pressure Sensitive AdhesivesSteven J. Severtson, University of Minnesota, Saint Paul, MN, Carl Houtman, USDA, Forest Products Laboratory, Madison, WI, and Larry Gwin, Franklin International, Columbus, OH.
Over the past ten years there has been considerable progress in the development of pressure sensitive (PS) products such as labels, stamps and notes that are recycling compatible. These are paper products containing pressure-sensitive adhesive (PSA) that can be incorporated into post-consumer waste without interfering with the paper recycling process. The most promising designs appear to be those that limit the fragmentation of PSA films during the processing of secondary fiber. This results in residual PSA particles that are removed with high efficiency from the process with conventional mill contaminant control equipment. The modifications required to achieve these environmentally friendly designs are relatively minor and can be accomplished by adhesive producers and converters without raising costs or sacrificing performance. In this presentation, our research, development and commercialization efforts on recycling compatible PS products are reviewed. Results for both hot-melt and water-based acrylic PSA will be summarized as well as the roles additives and laminate design play in determining the impact of adhesive films on recycling operations. Characteristics of recycling compatible PS laminates will be outlined as well as methods for incorporating these into products while maintaining performance properties. Also discussed will be future trends in PS products and our progress in identifying structural requirements for compostability.