Date of Defense

Fall 12-3-1996

First Advisor

Brian Scheller, Paper and Printing Science and Engineering

Second Advisor

John Cameron, Paper and Printing Science and Engineering

Third Advisor

Michael Schrieter, Menasha Corporation

Abstract

With a high focus on quality in today's production of paper and paperboard, coatings are used to enhance the paper's surface and optical properties for higher quality printing and overall appearance. A coating formulation consists of pigments, binders (latex and starches), solvents (water), and additives. Binder migration is the movement of binder particles within the coating and causes product inconsistencies in optical properties such as ink receptivity and mottle and strength properties such as picking and dusting. Until recently, attempts to explain the phenomenon could be be proven, much less controlled. This thesis will analyze the effect of varying coat weights and the roughness of a non-porous substrate on the amount of lateral binder migration in the system as well as the nature of the migration. Hopefully, accomplishment of this goal will bring the industry a step closer to controlling the complex topic of binder migration. A plastic film will be pressed with a sinusoidal surface which will then be coated. After drying, the latex concentrations at the surface of the coating will be studied and compared to the thickness of the consolidated coating at particular points within the grooves and outside of the grooves. The data collected from the experiment will be tabulated and graphically evaluated. The evaluations will be discussed as well as their relevance to the final product. The findings of the experiment were that some migration occurred at points of sharp variation in the roughness of the substrate. The latex concentration peaked in the opposite direction as the drastic change in the substrate. This is possibly due to the fact that the water from deep in the groove had to escape but at the top of the peak on the side of the sharp difference, consolidation had already occurred due to the drying intensity. Therefore, the solvent (and the binder with it) had to escape around this consolidation depositing the binder on the surface as it evaporated.

Access Setting

Honors Thesis-Campus Only

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