| 摘要 |
824,015. Multi-ply paper bags. BEMIS BROS. BAG CO. Feb. 21, 1957 [Sept. 28, 1956], No. 5947/57. Class 94(2). A multi-ply paper bag has transverse reinforeing bands interposed between the plies in the region of the closure folds to produce the effect of an additional ply in these areas. The bands may be of paper or of other material such as cloth. In making a three ply bag, a web 1 forming the inner ply is combined with the intermediate ply web 3 in passage round a roller 7, and the outer ply web 5 is combined with the other plies between rollers 9, 25. Each ply is slit and perforated in the usual manner to produce stepped end closures by elements 45, 53, 61. A web 65 of the reinforcing material is fed by rollers 67 to cutting elements 73 which cut off a band 63 as the web enters the point A of joining of the webs 1, 3. A band 63 is fed between webs 1, 3 at bag length intervals. In a similar manner a web 79 of reinforcing material supplies bands 77 which are fed between the webs 3 and 5 at bag length intervals. The bands 77 and 63 are arranged on opposite sides of the slits and perforations so as to form top and bottom reinforcements respectively. Adhesive applicators 97, 99, 107, 109 each apply transverse lines of glue spots to the webs so that each band is glued by two lines of spots 91a, 93a, 103a 105a and 91b, 93b, 103b 105b to both webs enclosing it, and the webs are glued to each other by lines of spots such as 95, 95a, 101, 101a, adjacent the slits and perforations. The bag lengths are torn from the multi-ply web and the end closures formed in the usual way. The bands preferably stop short of the longitudinal seam, as shown. |
