Apparatus for making thermoplastic carrier bags

Apparatus for making carrier bags of thermoplastic material starting from a continuous tubular strip of thermoplastic film, either side of which contains a gusset fold, said apparatus comprising a set of supply rollers, said supply rollers driven at a constant speed for advancing said strip to a cylindrical drum and a co-operating supporting belt, said drum being provided with heatsealing means mounted in the periphery of the drum housing and means for rotating said drum with a circumferential velocity exceeding the feeding speed of the supply rollers, said apparatus further comprising:

• a. cutting means co-operating with the supply rollers for sequentially providing the tubular strip of thermoplastic film with a U-shape cut at spaced locations corresponding to the length of the carrier bags desired;
• b. severing means for cutting off the strip transversely at a line, somewhat beyond the legs of the U-shape cut so as to obtain cut-off strip portions;
• c. heat sealing means on the periphery of said drum for sealing the ends of said cut-off strip portions, and means for urging the ends of the cut-off strip portions into operative sealing arrangement with said heatsealing means;
• d. folding means along a describing line of the drum circumference, being positioned substantially half way of the length of the cut-off strip portion, and arranged for cooperation with folding tongs in an adjacent auxiliary drum for folding the cut-off strip portions.