Laboratory and Pilot-Scale Evaluations of Environmentally Benign PSA Stamps, 2000 Recycling Symposium Proceedings

Nancy Ross Sutherland, Donald Donermeyer--Since the introduction of pressure-sensitive adhesive (PSA) postage stamps in 1989, their popularity with the stamp-buying public has grown each year. Currently, more than 93% of the total volume of stamps produced is PSA stamps. With the increased use of pressure-sensitive adhesives in a variety of products ranging from labels to envelopes and stamps, concerns about their environmental impact have emerged, especially with respect to recycling. To address these concerns, the U.S. Postal Service initiated an environmentally benign PSA program to develop PSA stamps that do not adversely affect the recovered paper recycling. As part of this program, experimental adhesives were evaluated for stamp performance specifications, laboratory recycling, and pilot-scale recycling. Phase IV of this program involved printed commercial postal stamp production with benign PSA adhesives. Three printing methods were used: intaglio, offset, and gravure. These stamps were processed through the USPS test mail program and provided the feedstock for post-consumer recycling trials using the USPS Laboratory and Pilot Recycling Protocols. Results of the laboratory and pilot recycling trials of the new benign PSA adhesives show PSAs that are effectively removed in the recycling process can be developed.