Effect of Inorganic Fillers in Paper on the Adhesion of Pressure-Sensitive Adhesives

Inorganic fillers are inexpensive materials used to increase the density, smoothness and other properties of paper that are important for printing. In the current study, the adhesion of pressure-sensitive adhesives (PSAs), a common type of adhesive used in labels and tapes, to papers containing varying amounts and types of fillers is investigated. Papers with three types of fillers, precipitated calcium carbonate (PCC), ground calcium carbonate (GCC) and kaolin clay, were investigated. The compositions of the papers were examined with SEM/EDX, while peel and double cantilever beam (DCB) tests were used to assess PSA paper adhesion. The results indicate that fillers enhance the adhesion between PSA and paper. In the case of the peel tests, a combination of inter-fiber bond strength and PSA-paper adhesion determines the peel strength. While in the DCB tests, failure is isolated to the PS A-paper interface, thus allowing measurements of pure interfacial failure