| 摘要 |
Packages having improved openable and resealable interlocking closures a nd methods and apparatus for making the same from a continuous web of film, the closure having male and female portions and being formed either in line with or transversely to the direction of film flow during package formation at line speed. A converter device adjunct to standard packaging apparatus forms a small amoun t of the running packaging film into a multilayer strip as an integral part of th e film. The converter functions with both horizontal and vertical form/fill/seal wrappin g machines and with overwrap packagers, and uses diverse packaging films and film laminations of which the substrates may be non-plastic. The packaging film i s fed into the converter where the film is fanfolded to form a stack, the layers o f which are heat sealed together forming a multilayered strip in plane with the film. Th e number of stack folds varies depending on the thermoforming properties and thicknes s of the particular film being used. The strip is abraded on one surface to selective ly remove the thermoplastic coating, the film then passing into the package former whe re product wrapping takes place in packages having single or double overlap longitudinal package seals, and which places portions of the strip in stacked apposed position. The package ends are sealed and the package resealable locking closure is formed in the strip. The female portion of the locking closure is formed in the packag e face that includes the overlapped longitudinal package seal which includes multiples o f the strip and optional additional layers. In another embodiment the strip is not abraded and the inner and outer parts of the resealable closure are separately forme d before package formation takes place. Alternatively to form the strip, layering oth er than by fanfolding to form a stack may be utilized, as for example heat sealing a strip of heat sealable material to the packaging film, Also optionally formed in the resealable closure are hinges and reinforcing V-notches. |
