Method And Apparatus For Making Reclosable Bags In A Form, Fill And Seal Machine

What is this patent about?

'533 is related to the field of form, fill, and seal machines used to create reclosable bags, particularly those with a tamper-evident seal. The background involves various methods of attaching reclosable zipper strips to plastic film, including co-extrusion, heat sealing, and adhesive bonding. A key concern is providing a tamper-proof seal to protect the contents and assure the consumer of the bag's integrity.

The underlying idea behind '533 is to simultaneously attach a reclosable zipper and create a tamper-evident seal on a bag during the form-fill-seal process. This is achieved by guiding the zipper between the film edges as they are brought together, then using uniquely shaped heated bars to seal the zipper to the film and simultaneously form an outer security seal.

The claims of '533 focus on an apparatus and method for forming a bag with a reclosable zipper and a security seal. The apparatus includes rollers to bring the film edges together, means for feeding the zipper between the film layers, and uniquely shaped heated bars to seal the zipper to the film and simultaneously form the outer security seal.

In practice, the film is fed downward around a forming tube, and rollers press the edges together. The zipper is fed between these edges. The key is the set of inner and outer bars. The inner bars guide the zipper, while the outer heated bars press against the film, sealing the zipper webs to the film and simultaneously creating the outer security seal. This ensures the zipper is close to the filling spout, allowing the bag to be filled almost to the zipper.

This design differs from prior approaches by combining the zipper attachment and security seal formation into a single, simultaneous operation. The unique configuration of the guiding and sealing bars allows for precise zipper placement and reliable sealing, while also creating the tamper-evident seal. This integrated approach streamlines the bag-making process and ensures both reclosability and product security.