| 摘要 |
The invention concerns a procedure for manufacturing paper bags. The paper bags (10) have been provided at both ends with a sewn seam (15) and the paper bag (10) has in its corner a valve aperture fitted with a collar. With a view to avoiding the cutting of separate collar blanks which has to be done manually, and their fitting, the valve aperture and the repeated running of the paper bag blanks through the production line, the procedure of the invention teaches to affix collar blanks to a full width paper web with a given spacing. Hereafter, the full width paper web is run to assume tubular form and cut in fixed lengths whereby the paper bag in tubular form comprises a shell with both ends open and carrying in its corner a collar blank. Finally on the paper bags in tubular form is performed folding of the corner and sewing of both open ends, whereby a finished paper bag (10) is obtained. It is advantageous for collar blank to use a collar blank, furnished with an incision, a collar blank from which a substantially segment-shaped piece has been removed or a collar blank from which a substantially triangular piece has been removed. On the edge of the collar blanks preferably an oblique cut has been made. |
