METHOD OF IMPARTING DIRECTIONAL PERMANENCY OF FOLDING TO SHEET, AND APPARATUS THEREFOR

摘要

A method of imparting directional permanency of folding to a sheet, and an apparatus therefor, which is suitable for manufacturing frame bodies, cushioning members and other block products for packaging, from a sheet of paper and other recyclable materials. The method comprises a third step of shifting respective folding working tools, disposed on one or both surfaces of a sheet, required amounts so as to permit the sheet to be folded along respective folding ruled lines, and a fourth step of shortening spacings between the respective folding working tools at a uniform ratio in accordance with an apparent amount of shortening in a longitudinal direction caused by the shifting while synchronizing with the third step. Directional permanency of folding can be accurately and industrially imparted to the sheet along the folding ruled lines.