Recycling compatible adhesives: despite a huge push to develop greener adhesives, customers are hesitant to embrace these products.

Author:Diamond, Catherine

Adhesives have, historically, posed serious problems for recyclers. Adhesives themselves are not recyclable, but the papers to which they are affixed, are. By removing the adhesives--like the ones found on the back of a postage stamp--papers become recyclable commodities.

According to Carl Houtman of the Forest Products Laboratory in Madison, WI, USA, recycling compatible adhesives (RCAs)" were developed largely due to a push I from the United States Postal Service (USPS). Houtman says that it all started when a group of students in the early 1990s were doing research into problems in the recycling process. They contacted the USPS about the bottlenecks found in the recycling process, which were due, to a great extent, to postage stamps. The USPS, so the story goes, took the issue very seriously.

To facilitate the creation of recycling compatible adhesives, the USPS sponsored a conference during which the adhesive industry was invited to participate in its Environmentally Benign Pressure Sensitive Adhesives for Postage Stamp Applications program. Thirteen companies participated by submitting adhesive samples. To determine whether an adhesive was recycling compatible, a protocol needed to be developed. Houtman says that the results of this work led to a three-tier evaluation process with the development of laboratory, pilot-scale and mill-scale recycling protocols.

The USPS reached out to the Forests Products Laboratory and asked the organization to develop the testing protocols that would qualify adhesives as recycling compatible (then, they were known as environmentally benign adhesives, or EBAs). EBAs were tested and qualified by the USPS specifically for their usage on postage stamps.

Houtman worked alongside Richard Oldack and Fred Gustafson to research, develop, test and promote recycling compatible adhesives. Oldack, founder of Grafton, WV. USA-based adhesive manufacturer Dyna-Tech, served as the first chairman of the Tag & Label Manufacturers Institutes sub-committee on recycling compatible adhesives. Gustafson later assumed the role. The three worked together to educate the label industry on the importance of these adhesives, and to simplify the testing and qualifying process.

Previously, Oldack told L&NW that he wrote the testing protocols for RCAs with the label converter in mind. "Label construction differs from PS stamps in that stamps have a water-soluble barrier between the paper and the adhesive. We took the USPS EBA specification and tests from the Postal Services Specification USPS P-1238F and rewrote them to make them apply to labelstock," Oldack said. "Usually, when you...

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