| 摘要 |
807,026. Multi-ply paper bags. BEMIS BROS. BAG CO. Oct. 21, 1955, No. 30227/55. Class 94(2). A patch 21 of reinforcing material is pasted in between the plies at one or both ends of a multiply bag with offset seams 45, 47 to form a reinforcement which does not extend into the seams. Two webs of paper 1, 3 drawn from rolls 5, 7 combine at a guide roller 9, forming a twoply web which is formed into tube, web 1, the inner ply, travelling from roll 5 over roll 11 to roll 9 and web 3, the outer ply, travelling from roll 17 around roll 13, to guide roll 15, forward to roll 17 and downward to roll 9. The bite of webs 1 and 3 is indicated at B. As webs 1 and 3 combine, reinforcing patches 21 are fed and pasted in between them at bag length intervals, being severed from a web 23 drawn from roll 25, at a speed less than the speed of webs 1 and 3, by a pair of draw rolls 27. The width of the patch web 23 is less than width of webs 1 and 3. The web 23 is fed by roll 27 through cutter 29 and between webs 1 and 3 into bite B, the distance between the cutter 29 and bite B being equal to the desired length of the patch, and the timing of the cutter is such that it severs web 23 at the instant that the end of the web 23 is caught in bite B. The patch is pulled away from the freshly cut end of web 23 and the speed of web 23 is such that the spacing of the patches corresponds to desired length of the bags. Paste is applied to web 3 at bag length intervals by means of a spot paster 35 adapted to apply a pair of rows of spots 37b and 37t across the width of the web 3. The timing of the paster is such that the rows of paste spots register with patch 21 as it is drawn between webs 1 and 3, the rows of spots lying near the transverse edges of the patch. The patches extend from near one side margin of the composite web 39 to near the other. The composite web travels around on guide roll 41 and thence to a tuber (not shown) where it is formed into a gusseted tube 43, which is severed into bag lengths 51 on line C-C, centrally through patch 21. Each bag length is bottomed by stitching together its front and back walls as indicated at 53 in Fig. 2, the stitches extending through the patch 21b and the gussets 49. The line of stitching is located outward from the row of paste spots 37b. Each bag is ultimately closed at its top by a line of stitching similar to the stitching 53. The patches may be pasted to both plies, in which case paste may be applied to web 1 by means of a paster similar to 35. The bags may be made with more than two plies by combining additional webs at roller 9. The patches may extend only between the plies of the unseamed side of the bag with the edges approximately coincident with the inner creases of the gusset. In another modification, the patches are adapted to reinforce a pasted self-opening square bottom and a pasted top closure. |
