| 摘要 |
In a method of producing composite sheet material by forming longitudinal rows of stitches in a paper sheet material, the length of paper sheet material used per stitch is increased so that there is entrapped within each stitch in each longitudinal row of stitches a portion of paper sheet material having a length greater than the length of the completed stitch. In consequence there are formed in the composite sheet material a longitudinal series of laterally extending corrugations, ridges or ribs which, in the case of a crepe paper sheet material, constitute a gross crimp imposed without distortion of the crimps in the initial crepe paper sheet material. The increase in the length of the sheet material used per stitch may be effected either by the action of the needles of the stitching machine to withdraw a greater quantity of the sheet material from a feed roll or by positively overfeeding the sheet material to provide slack sheet material which is entrapped within the stitches as a result of the needle action. The method of the invention may be used when producing composite sheet material by stitching through a plurality of sheets of sheet material, in which case the increase in length may be confined to only one or some of the sheets or may be provided in all the sheets. The paper sheet material may be either plain or crepe paper, or any combination thereof when a plurality of sheet materials are used. |
