| 摘要 |
A pair of heat seal jaws (31, 32) for heat sealing together two heat sealable polymeric surfaces (33, 33'), the jaws (31, 32) including first sealing surfaces (36) which in use cooperate to produce at least one relatively strong heat seal between the said polymeric surfaces (33, 33') and second heat sealing surfaces (37, 38) which in use cooperate to produce at least one relatively weak but substantially hermetic heat seal between the polymeric surfaces, said first and second heat sealing surfaces being disposed relative to each other so that during heat sealing of the polymeric surfaces, polymer in the vicinity of the second heat sealing surfaces can flow away from the relatively weak seal to produce a substantially hermetic seal as the relatively weak seal is being formed.
|
