GB1295618A - - Google Patents

Abstract

1295618 Filling sealing and separating strips of partially-formed bags H MEMBRINO 8 July 1971 32113/71 Heading B8C A method of filling, sealing and separating thermoplastic bags 12 from a strip of connected bags separated from each other by lines of seal and severance 24 having at least one unsevered interruption 28 therein which forms at least one connecting nip, and each being provided with a filling opening 20, the strip of bags is passed over a mandrel 38 which spreads the bags to receive filling material at 48, the bags being heat sealed adjacent the openings at 56, and then broken away from each other at their nip portions 28 to fall into a storage bin 72. As shown, a roll of partially-formed bags 12, formed from a longitudinally folded sheet of polyethylene, having nips of unsealed and uncut portions 26, 28 and small sealed but not severed portions 29 at the upper edge, is moved by a pair of endless belts 32, 32 to pass over a guide roller 36 and over the mandrel 38. The latter comprises an elongated tube bent to form two arms which are inclined laterally outwardly from an infeed elbow 40 towards a knife block 42, 44 to which they are secured at their rear ends. The block 42 may be provided with apertures for directing air, under pressure, into the bags to assist in spreading their sides during filling beneath a hopper 48. The latter is provided with a star-valve 50 which meters the articles 52 to be packed. The elbow end of the mandrel 38 is supported by a roller 46. As the belts 30 move the filled bags forward the unsevered portions 29 are cut by the knife 44 and are sealed along the top portion 60 by a pair of reciprocable, heated sealing bars 56, the excess, or selvedge, portion 62 being removed as another pair of endless belts 64 move the filled bags past a knife 70. The filled and sealed bags then break away at their nip portions 26, 28 to fall into the storage bin 72. The sheet stack can be pre-printed, Fig. 10, not shown, and a line of perforations 74 can be provided along the bottom of each bag for use as a pull-away strip. If tubular stock is used the filling openings may be made as the stock passes a vertically reciprocable knife (202), Fig. 11, not shown. In a modification, Figs. 12-16, not shown, employing tubular stock, with upper and lower lines of perforations (302, 303), the feed hopper (308) is provided with a cutting edge (310) to open the bags, the hopper otherwise being the same as the hopper 48.