| 摘要 |
A plastics bag (1) includes a closure means (2) formed from a tape which has been folded into a U-shape about a medial part. The tape includes co-operating profiled strips (3) one of male and the other of female form which engage to form a resealable closure. The free sides (2a) of the tape are heat sealed to the top free edges (1a) of the bag (1). The bag is manufactured by feeding sheet material (1') to a mandrel (11) and simultaneously feeding the closure tape (2) after bending in a former (7) and engaging the closure parts (3) by rollers (8) between the overlapping free sides of the tape (2 ). The tape (2) is heat sealed to the bag material 1' by means of heat sealing bars (13) and the cylindrical assembly is then heat sealed laterally by means of further heat sealing bars (14). The bag is filled by passing contents down a chute (15) through the middle of the mandrel (11) and by this means forming, filling and closing of the bag may all be carried out as a stepwise automatic operation. The bags are separated by cutting through the central portion of the heat seal along X-X. |
