Quantification of pressure sensitive adhesive, residual ink, and other colored process contaminants using dye and color image analysis

Abstract

The USPS Image Analysis (IA) protocol recommends the use of hydrophobic dyes to develop contrast between pressure sensitive adhesive (PSA) particles and cellulosic fibers before using a dirt counter to detect all contaminants that have contrast with the handsheet background. Unless the sample contains no contaminants other than those of interest, two measurement steps are required: before dying to detect dirt and after dying to detect both dirt and dyed contaminants. The difference between these two measurements can be used to estimate the level of dyed contaminants present. To complement the efforts of the USPS, a new computer image analysis system that measures in full color was developed that is able to measure and classify on the basis of color, residual ink, colored contaminants, and dyed particles in a single analysis step. The theoretical foundations and the practical details of the IA system are discussed. Results obtained for mill stock samples containing PSA’s using both the USPS protocol with standard dirt counting and an abbreviated protocol using color image. analysis are compared. The data suggest that the two methods give very similar results.

Citation

Rosenberger, Roy R.; Houtman, Carl J. 2000. Quantification of pressure sensitive adhesive, residual ink, and other colored process contaminants using dye and color image analysis. 2000 proceedings, TAPPI Recycling Symposium : Mar. 5-8, 2000, Washington, D.C. Volume two. Atlanta, GA : TAPPI Press, 2000: Pages 713-724