GB777342A - Method of and apparatus for applying valve sleeves to bag tubes - Google Patents

Abstract

777,342. Making paper &c. bags. ST. REGIS PAPER CO. April 14, 1954 [May 12, 1953], No. 11021/54. Class 94(2). In an apparatus for making multiwall valve bags from webs of paper &c., supplementary sheets, to form valve sleeves, are applied to the webs prior to the tubing operation. The apparatus also is applicable to the manufacture of singleply bags. As shown, paper webs 10 to 14, for making a 5-ply bag, are fed in transversely stepped relation from individually mounted rolls, Fig. 1 (not shown), the web 10 passing around a pulley 31, and through a perforator 35 providing perforations 36, Fig. 6, to a web assembly unit D. Webs 11 and 12 pass over guide rolls 39 and 40 respectively, and are superimposed at 43, and provided with perforations 45, Fig. 6, at 44. The web 11 is provided with a glue stripe 46 to secure the supplemental sheet 56, Fig. 6, at 47, and a similar glue stripe may be provided on the web 12 at 48. The dimension 49, Fig. 6, represents one bag length. The webs 13 and 14 are directed to a similar perforating and glueing unit C. The web 53 for the supplemental sheets 56 is supplied from a roll 51 and is provided at 57 with a cut 58, Fig. 9, and at 60 with a cut 61, which is angularly offset relative to a line perpendicular to the longitudinal axis of the strip 53. In this way a tuck-in valve sleeve is provided in which the outer edges are angularly offset relative to one another, but other types of valve sleeve of the inwardly protruding, or outwardly protruding tuck-in type may be used, Figs. 11 and 10 (not shown). The severed sheets 56 are brought up to the speed of the web 11 by rollers 63 and guided into position on the glue stripe 46 on the web 11. Glue is applied to the underside of the web 10 at 84, in register with the stripe 46, Fig. 6, and the now superposed webs 10 to 14 are provided with glue stripes 28b on their stepped longitudinal edges, at 84a, and formed into a gussetted tube 86, Fig. 12, by the unit E. The tube is then directed to a severing unit and discharge conveyer, Fig. 1b (not shown) where a portion 95 of the web is removed to provide a notched type of valve corner. If a notchless type of valve corner is required, Fig. 18 (not shown) the tuck-in sleeve, Fig. 10 (not shown) is made longer and folded over to take the place of the notch. The blank severed from the tube 86 is provided with a valve corner as shown in Fig. 17, the bag being finished by sewing across the top a closure tape, Fig. 19 (not shown). Specification 639,404 and 671,047 are referred to.