RESEARCH ON ADHESIVE JOINT STRENGTH DEPENDENCY ON LOOSE LEAF POSITION IN A TEXT BLOCK
This paper deals with the binding ability of commercial high grade paper used in a perfect binding process. The adhesive binding strength changes happen as a consequence of adhesive rigid characteristics. Paperback bond strength evaluation is performed by pull-test measurement and visual assessment. Paperback contains a number of the loose leaves' binding edges that are bonded into assembly. The bonded assembly is discussed in terms of adhesion between hot-melt adhesive and paper (substrate). Adhesion strength within the inter phase includes the terms of adhesive joint strength. The research shows that a loose leaf position in a text block has a strong influence on adhesive joint strength changes, although other independent variables (paper and adhesive properties, binding process) have significant impact on the paperback mechanical durability. For this reason measurements of paper properties were included. The adhesive joint strength analysis results were obtained by the statistical regression method. The main goal of the paper is to determine the adhesive joint strenght dependency on a loose leaf position in the text block.