STACK CONDITIONING APPARATUS AND METHOD FOR USE IN BOOKBINDING

摘要

Apparatus and method for conditioning an edge of a sheet to be bound so that the edge is conducive to accepting heat activated adhesives used in conventional binding. The sheet is first bent in one direction to form a folding line, with the fold line being a short distance from the edge of the sheet to be conditioned and with that distance being determined primarily by the thickness of the sheet. The bend in the sheet is typically 90 degrees, with the radii of curvature of the opposite sheet surfaces at the fold line being unequal so that a shear force is applied near the sheet end thereby tending to tear or fracture in interior of the sheet near the end. Typically the sheet is then bent in an opposite direction along the folding line so as to produce an opposite shear force that reinforces the creation of tears and fractured in the sheet. These tears and fractures in the sheet greatly enhance the adhesion of binding adhesives to the sheet, particularly sheets having coatings used in photographic applications and the like.