摘要 |
An improved method is disclosed for forming a strata of overlapping sheets suitable for use in a pop-up dispensing system. The sheets are cut from ribbons which initially have edges essentially parallel to the longitudinal axis of the ribbon. At least one side edge of each ribbon is stretched to form a knee-like protrusion, with the opposing side edge being either, substantially parallel to the longitudinal axis of the ribbon, or also stretched to form one or more knee-like protrusions on the opposing edge. The ribbons are then aligned so that a knee-like protrusion on one edge aligns with either the essentially parallel edge of an adjacent ribbon or a knee-like protrusion on the side edge of an adjacent ribbon. After phasing, the ribbons are overlapped creating a series of predetermined areas of greatest overlap adjoining areas of least or no overlap, such that successive ribbons are bonded only by the interfacial interaction between each ribbon. By overlapping multiple ribbons in this manner a strata is formed which is then folded to interleave the ribbons. A resulting stack of interleaved ribbons is cut in a direction essentially normal to the longitudinal axis of the ribbons at predetermined intervals to form blocks of individual interleaved sheets. The process can be accomplished manually or in a continuous production process. |