Why are pressure-sensitive adhesives a problem for recycling?
Most paper recycling systems today use water as the medium to transform recovered paper into “pulp,” which is then transformed back into paper. PSAs do not dissolve in water, but rather fragment into smaller particles during the repulping process. These particles known as “stickies” deform under heat and pressure, making them difficult to screen or filter out of the pulp. Stickies can become lodged on papermaking equipment or even in the paper itself, often causing serious damage to both. PSAs exact a considerable cost on the paper recycling industry an estimated $700 million per year. (Tom Friberg, “Cost Impacts of Stickies,” Progress in Paper Recycling, November 1996.) This estimate includes the direct costs to paper mills and the reduction in prices received by recovered paper collectors and processors due to PSA contamination. Stickies that become lodged in paper also cause problems beyond the paper mill. By creating holes or weak spots in paper, stickies can cause paper rolls to t
