Abstract: Methods and apparatus for feeding continuous zipper material with sliders to a thermoforming packaging machine that advances the packaging film N package lengths each advance, where N is a positive integer greater than unity. In the packaging machine, pockets are thermoformed in a central zone of the web, while the zipper material is sealed to the web along a lateral zone that is parallel to the machine direction and does not intersect the pockets. A trailing portion of the zipper material in a zipper processing machine is advanced N times every work cycle, one package length per advance. A slider is inserted during each dwell time between advances of the trailing zipper portion. In the zone between the slider insertion device and the zipper sealing station, the zipper material is accumulated each time the zipper material is advanced without concurrent advancement of the packaging material.

Abstract: A tamper-evident reclosable package having a header that is tack sealed to the zipper. A light tack, in the form of a light weld, is made at the end of the package header. The header is the top portion of the package and is designed to shroud the zipper. The header serves as a tamper-evident feature, and also serves to maintain cleanliness and aesthetics of the package. The header must be tom before a person can gain access to the contents of the package. Typically, means for preferential tearing are provided for easy removal of the header. The tack seal contributes to the maintenance of the cleanliness and aesthetics of the package, while still allowing easy removal of the header. The tack is light (i.e., low bond strength or pull-off force) in order to not make it significantly more difficult to open the package.

Abstract: A tamper-evident reclosable bag having a pull tab feature that facilitates opening of a header by a consumer. The pull tab feature is provided by an offset between the top and bottom webs (or front and rear walls) of the package. One web has a cutout while the other web has a portion that overlaps the cutout. The offset provides a simple means for the consumer to grasp only one of the webs of the package and then pull the webs apart or peel the offset web away from the cutout web. The peeled-away layer can be provided with a line of weakened tear resistance, allowing a section of the header to, at the same time, be torn off the package. After the tamper-evident seal provided by the header is broken, the consumer can open the zipper, gaining access to the contents of the package.

Abstract: Methods and apparatus for controlling the registration of one elongated continuous structure (e.g., plastic zipper) with attachments or formed features (e.g., sliders or pre-seals) as it is fed to a sealing station, where it is joined to another elongated continuous structure (e.g., packaging film) with formed features (e.g., thermoformed pockets). The latter elongated continuous structure will be intermittently advanced through the machine, pulling the former elongated continuous structure joined thereto forward. Registration is accomplished by tacking the respective elongated continuous structures together while the respective features on the elongated continuous structures are in proper registration. After tacking, the respective portions of the elongated continuous structures immediately downstream of the tack zone are advanced to the sealing station in proper registration.

Abstract: Methods and apparatus for controlling the tension of one continuous material (e.g., plastic zipper) with attachments or formed features (e.g., sliders or formed slider end stops) as it is fed to a sealing station, where it is joined to and later pulled by another continuous material (e.g., packaging film). The tension control scheme can be applied in cases wherein the packaging film advances a single package length per advancement as well as cases wherein the packaging film advances a distance equal to multiple package lengths per advancement. A tension control zone is created between a pair of nip rollers disposed in zipper processing equipment and a zipper sealing station inside a thermoforming packaging machine by applying a predetermined torque to one of the nip rollers using a torque control device. The zipper processing equipment may comprise a zipper shaping station and a slider insertion station.

Abstract: A method of manufacture involves the following steps: extruding a first zipper strip comprising a first zipper flange and a first closure profile; extruding a second zipper strip comprising a second zipper flange and a second closure profile that is interlockable with the first closure profile; interlocking the first and second closure profiles; and welding the first and second zipper flanges together in a first zone and welding the first and second closure profiles together in a second zone by applying energy to both zones in one operation or in separate operations. A generally T-shaped zone of fusion is formed. The second zone forms the top of the T shape, while the first zone forms the stem of the T shape. The first zone forms respective flange seals, while the second zone forms either back-to-back preseals or back-to-back slider end stops when the zipper is cut, depending on whether the zipper is sliderless or slider-actuated.

Abstract: Methods and apparatus for automated insertion of sliders on continuous zipper material. The method involves the following steps: (a) advancing a section of zipper material past a leading edge of a splitter plate that pries the zipper strips of the zipper material apart; (b) clamping a first portion of one zipper strip against one side of the splitter plate, while clamping a first portion of the other zipper strip against an opposite side of the splitter plate, the first portions of the zipper strips being disposed on an upstream side of a slider insertion zone; (c) closing a portion of the zipper comprising respective second portions of the zipper strips disposed on a downstream side of the slider insertion zone; and (d) inserting a slider onto the zipper in the slider insertion zone. A plow of the slider is disposed between respective third portions of the zipper strips.

Abstract: Methods and apparatus for feeding continuous zipper material with sliders to a thermoforming packaging machine that advances the packaging film N package lengths each advance, where N is a positive integer greater than unity. In the packaging machine, pockets are thermoformed in a central zone of the web, while the zipper material is sealed to the web along a lateral zone that is parallel to the machine direction and does not intersect the pockets. A trailing portion of the zipper material in a zipper processing machine is advanced N times every work cycle, one package length per advance. A slider is inserted during each dwell time between advances of the trailing zipper portion. In the zone between the slider insertion device and the zipper sealing station, the zipper material is accumulated each time the zipper material is advanced without concurrent advancement of the packaging material.

Abstract: Methods and apparatus for controlling the registration of one elongated continuous structure (e.g., plastic zipper) with attachments or formed features (e.g., sliders or pre-seals) as it is fed to a sealing station, where it is joined to another elongated continuous structure (e.g., packaging film) with formed features (e.g., thermoformed pockets). The latter elongated continuous structure will be intermittently advanced through the machine, pulling the former elongated continuous structure joined thereto forward. Registration is accomplished by tacking the respective elongated continuous structures together while the respective features on the elongated continuous structures are in proper registration. After tacking, the respective portions of the elongated continuous structures immediately downstream of the tack zone are advanced to the sealing station in proper registration.

Abstract: Methods and apparatus for eliminating unattached remnants or tails of bag making film adjacent a string zipper during manufacture of reclosable bags. Gathered film tails may interfere with slider insertion or slider operation or may cause the film to be pulled off of or peeled away from the string zipper during slider operation. After trimming, the tails of the film are welded to the zipper by conductive heat sealing or equivalent means.

Abstract: Methods and apparatus for controlling the tension of one continuous material (e.g., plastic zipper) with attachments or formed features (e.g., sliders or formed slider end stops) as it is fed to a sealing station, where it is joined to and later pulled by another continuous material (e.g., packaging film). The tension control scheme can be applied in cases wherein the packaging film advances a single package length per advancement as well as cases wherein the packaging film advances a distance equal to multiple package lengths per advancement. A tension control zone is created between a pair of nip rollers disposed in zipper processing equipment and a zipper sealing station inside a thermoforming packaging machine by applying a predetermined torque to one of the nip rollers using a torque control device. The zipper processing equipment may comprise a zipper shaping station and a slider insertion station.

Abstract: A method of manufacture involves the following steps: extruding a first zipper strip comprising a first zipper flange and a first closure profile; extruding a second zipper strip comprising a second zipper flange and a second closure profile that is interlockable with the first closure profile; interlocking the first and second closure profiles; and welding the first and second zipper flanges together in a first zone and welding the first and second closure profiles together in a second zone by applying energy to both zones in one operation or in separate operations. A generally T-shaped zone of fusion is formed. The second zone forms the top of the T shape, while the first zone forms the stem of the T shape. The first zone forms respective flange seals, while the second zone forms either back-to-back preseals or back-to-back slider end stops when the zipper is cut, depending on whether the zipper is sliderless or slider-actuated.