(57) Apparatus for making side-sealed bags (22.1, 22.2, 22.3) from a double-layer web
(22) of thin synthetic plastics film. The apparatus includes a rotatably mounted sealing
drum (14) having a plurality of circumferentially spaced axially extending slots (16)
in its periphery. In use, the web (22) moves belt-fashion over the slots (16) in contact
with the drum (14). A sealing rotor (18) running in synchronism with the drum (14)
has a heat cutter member (20, 21) which intersects the web (22) at circumferentially
spaced intervals by passing cyclically into the slots (16) of the drum (14). The heat cutter member (20, 21) has spaced interruptions (21.2)
along its length which result in spaced perforations (160.1) being made across the
width of the web (22). The two layers (22.11, 22.12) of film are welded together at such perforations (160.1), thus forming side-sealed
bags separated by zones of weakness (160). The web (22) is rolled up into a roll (26) of such side-sealed bags (22.1, 22.2. 22.3). The sealing rate and web speed can
be adjusted to match the rate of extrusion of an extruder (242).
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