| 摘要 |
1356675 Joining superimposed continuous webs MOLNLYCKE AB 12 Aug 1971 [21 Aug 1970] 37931/71 Headings B5N and B5K Superimposed continuous running webs or parts of a web folded in the longitudinal direction are joined transversely by inserting between the running webs or parts of-the folded web a continuous thermoplastic web at a speed lower than that of the webs or parts of the folded web, and subjecting the webs or parts of the folded web to local heat and pressure across the webs or parts of the folded web in a transverse direction. The additional thermoplastic web may be fed in between the webs or web parts to be united at one side of these webs or web parts and at an angle to the side edge, all the webs being subsequently moved in the same direction. In the drawing webs 1 and 2 to be joined, which may be separate webs or two parts of one web folded longitudinally, are fed forward by pairs of feed rollers 3, 4 and 5, 6, thermoplastic web 9 being fed by feed rollers 7, 8 at a lower rate than rollers 3, 4 and 5, 6 over web folder or sword 10 arranged between webs 1 and 2 so that the part of thermoplastic web 9 lying behind folder or sword 10 is in contact with webs 1 and 2 and is inclined to accompanying them to heat and pressure applying means comprising rollers 11 and 12 provided with longitudinally extending heatable compressing and/or stamping elements 13 and 14. The speed of rollers 7, 8 is co-ordinated with that of rollers 11, 12 so that for each rotation of rollers 11, 12 the rollers 7, 8 feed only that amount of web 9 which corresponds to the width A of the joint, and because of the lower feeding speed of rollers 7, 8 compared with rollers 11, 12, web 9 is secured at the moment of union and is then torn off along the line formed by the compressing and/or stamping elements 13, 14. Rollers 11, 12 may be provided with knives to perforate webs 1 and 2 which have been transversely sealed in the centre of the seams or cutting rollers may be placed downstream in the direction of movement of the webs which are synchronous with rollers 11 and 12. |
