Abstract: A string zipper is provided for use in the manufacture of material for reclosable plastic bags. The string zipper includes a first profile and a complementary mating profile which, when interlocked and properly attached to the bag walls render the bag easy to open from the outside and hard to open from the inside. One of the profiles is formed of polyethylene material that includes an optical brightener to facilitate properly orienting the zipper on a sheet of plastic material. During manufacture of plastic bag material, the zipper is passed through a black light so that the profile containing the brightener can be detected and thus the profiles may readily be distinguished from one another and properly oriented on the sheet material to obtain the desired force differential feature on the final bag.

Abstract: A package closure for such packages as reclosable plastic bags includes male and female interlocking profiles and a tear bead on one side of a zipper tape film. On the other side of the zipper tape film are two tear containing strips, preferably of ethylene vinyl acetate. In use, the zipper tape film is in a folded condition with male and female profiles interlocked. This places the tear containing strips on opposite sides of the outside of the folded zipper tape film, where they cooperate in serving to seal and bond packaging film to the zipper tape film, and to prevent the tear formed when the package is initially opened from running to the profiles.

Abstract: A method for stabilizing and aligning interlocked male and female profiles of a plastic zipper strip during attachment of the strip to a polymeric film requires the use of profiles having stabilizers, perhaps taking the form of wedges. The stabilizers, disposed in pairs on each side of the interlocked male and female members of the profiles, mechanically cooperate with one another to maintain the profiles substantially parallel to one another and incapable of rocking about a longitudinal axis. The stabilizers on the male profile may be inboard, outboard or at the same distance from the interlocked male and female members as their respective stabilizers on the female profile. The facing surfaces of the stabilizers may be inclined so as to provide a wedging action with respect to one another.

Abstract: A string zipper is provided for use in the manufacture of material for reclosable plastic bags. The string zipper includes a first profile and a complementary mating profile which, when interlocked and properly attached to the bag walls render the bag easy to open from the outside and hard to open from the inside. One of the profiles is formed of polyethylene material that includes an optical brightener to facilitate properly orienting the zipper on a sheet of plastic material. During manufacture of plastic bag material, the zipper is passed through a black light so that the profile containing the brightener can be detected and thus the profiles may readily be distinguished from one another and properly oriented on the sheet material to obtain the desired force differential feature on the final bag.

Abstract: A reclosable bag is formed of walls defining a closure with a mouth. The closure includes a male profile extending along an internal surface of one of the walls and a female profile adapted to interengage with the male profile and extending along an internal surface of the other wall. The male and female profiles are extruded from a polymeric resin. At least one of the male and female profiles includes at least one rib of another polymeric material coextruded therewith and extending longitudinally therealong. The polymeric material of the rib has a lower melting point than the polymeric material of the profiles, so that it will melt when a side seal is made transversely across the closure and will flow into and caulk any openings remaining after the interlocked profiles have been flattened.

Abstract: A method for manufacturing reclosable packages on a form, fill and seal machine includes the step of providing a continuous sheet of thermoplastic material with a Z-fold extending longitudinally therealong before the sheet is wrapped around a filling tube for forming and filling the packages. The Z-fold is maintained on the tube of thermoplastic material thus formed until it reaches a loop opener on the outside surface of the filling tube. The loop opener transforms the Z-fold into a loop extending longitudinally along and outwardly from the filling tube and from the tube of thermoplastic material wrapped therearound. Simultaneously, a continuous plastic zipper having a pair of mutually interlocking profiles is directed into the tube of thermoplastic material along a channel on the outside surface of the filling tube.

Abstract: A reclosable bag is formed of a first wall and a second wall of a polymeric sheet material joined to form an enclosure with a mouth defined by the wall edges. The bag has a closure for selectively opening and sealing the mouth. The closure includes a first and a second mutually interlocking profile, each of which extends along and is bonded to the internal surface of its respective first and second wall. The first and second mutually interlocking profiles are extruded from a synthetic polymeric resin material. For at least one of the first and second mutually interlocking profiles, the synthetic polymeric resin material is mixed with a blowing agent which provides the profile with a fine-celled foam structure.

Abstract: A reclosable bag is formed of walls defining a closure with a mouth. The walls have interlocking profiles on their internal surfaces adjacent to the mouth to enable the bag to be sealed. One of the two profiles has a spreader which fits between and spreads the interlocking members on the other profile to bring about a more effective sealing of the bag.

Abstract: A reclosable plastic bag is provided having a zipper with profile strips on opposed walls. The profile strips consist of male and female profiles each surrounded by stabilizing wedges with the male wedges within the female wedges. An interlayer of low temperature melt material is interposed between at least a portion of each of the profile strips and its associated wall. The interlayer may span the full width of the profile strip or only a partial width of the strips.

Abstract: A plastic bag having a reclosable plastic zipper is provided with a tamper-evident, non-reclosable peel seal formed by coextruding an adhesive onto a side strip adjacent to the interlocking zipper. The coextrusion causes the adhesive to preferentially adhere to the side strip when the peel seal is broken. A method for manufacturing the reclosable plastic zipper includes the steps of coextruding a zipper profile including a plane area with an adhesive on the plane area, slitting the profile lengthwise, and folding over one of the resulting sides of the zipper to interlock them with one another.

Abstract: In a method for forming reclosable packages on a conventional form-fill-and-seal (FFS) machines, first and second interlocking members are fed toward and longitudinally parallel to the filling tube thereof in an uninterlocked condition. A thermoplastic film is wrapped around the filling tube enclosing the first and second interlocking members, and the lateral edges of the film are bonded together to form a longitudinal seam. At least one of the first and second interlocking members is attached by a heat sealing bar to the inside of the tube so formed from the thermoplastic film. A fold is formed in the tube between the first and second interlocking members to bring the members into a facing relationship, and the members are then interlocked with one another. At intervals, transverse seams are formed to produce individual reclosable packages, which may also be separated from one another. The packages are filled with product during the course of their manufacture.

Abstract: In a method for forming reclosable packages on a conventional form-fill-and-seal machine, a "Y-type" zipper strip is fed toward and longitudinally down the filling spout thereof. A thermoplastic film is wrapped around the filling spout enclosing the zipper strip, and the lateral edges of the film are bonded together to form a longitudinal seam. The zipper strip webs are attached by sealing bars to the inside of the tube so formed from the thermoplastic film between the fill tube and the sealing bars. At intervals, transverse seams are formed to produce individual reclosable packages, which may also be separated from one another. The packages are filled with product during the course of their manufacture.

Abstract: A closure device, preferably made of plastic, serves for closing bags. It consists of a male section (1) and a female (2, 5 and 6), which are respectively joined to film (3 and 4) and may be detachably connected together. In order to ensure that such a closure device may be readily closed while at the same time being simple and cheap to produce, at least two spaced continuous projections (8) are provided on the side of the film (3) opposite to the male section (1). Similar projections (9) may advantageously be placed on the opposite side of the female section.

Abstract: A plastic bag with a recloseable zipper-type closure is formed with grip strips on its lips to ease the opening of the bags. The grip strips are extruded from a grip strip extruder which is moved relative to a movement of the zipper type profile to produce a regularly repeating pattern. The strips facilitate opening the bag even with wet or oily fingers. A method and apparatus for forming the same is also disclosed.

Abstract: A reclosable bag is formed of walls defining a closure with a mouth. The closure includes an asymmetric arrowhead male profile extending along an internal surface of one of the walls and a female profile having stubs adapted to interengage with said male profile and extending along an internal surface of the other wall. Both profiles also include stabilizer wedges on both sides thereof and parallel thereto across the width of the bag. The stabilizer wedges give the zipper formed by the male and female profiles a wide-track feel, and determine the force required to open the bag both from inside and from outside.

Abstract: A plastic bag with a recloseable zipper-type closure is formed with grip strips on its lips to ease the opening of the bags. The grip strips are extruded from a grip strip extruder which is moved relative to a movement of the zipper type profile to produce a regularly repeating pattern. The strips facilitate opening the bag even with wet or oily fingers. A method and apparatus for forming the same is also disclosed.

Abstract: A zipper closure strip for attachment to the top of a formed, filled and sealed package is provided. The zipper strip has a pair of interlocking profile members that extend from bowed webs which conform generally to the cross section of the top of the filled package. The strip may thus straddle the top of the package, gable fashion, and be bonded to the top of the package by heat seals, adhesive or the like. A slider seats on the profile members for urging them into engagement or forcing them apart. A blade protrudes through the slider from a plunger to enable the film at the top of the package beneath the closure strip to be slit. The zipper may be cuffed to expose the top end of the package to facilitate opening.

Abstract: A four corner bag especially suitable for packaging dry cereal, and method of making the bag from sheet or plastic film material. The bag is provided with opposite wall panels joined at a closed bag bottom and closed opposite sides, the panels defining an openable bag top provided with a reclosable fastener along the inner ends of upstanding pull flanges. Lower corner chamfer seals extend from the closed bottom to the sides of the bag. Upper corner chamfer seals extend from adjacent to the ends of the reclosable fastener to the top edges of the pull flanges. Thereby, when the bag is filled, the chamfer seals will free the four corners of the bag from interfering with easy reception and packing of the filled bag in a fairly close fitting carton.

Abstract: A bag with an openable mouth carries a reclosable extruded plastic zipper inside the mouth. The zipper has complementary profiles separably interlockable in a closed condition of the zipper. A gasket flange structure in separably sealingly grippingly interengageable by and between the profiles in the closed condition of the zipper, and may also serve as a tamper evident or tamper discouraging device.

Abstract: A method and apparatus for forming a vertical tubular form fill package feeding the film vertically downwardly over a spout, pressing the outer lateral edges of the film together between pressure rollers, feeding joined strips of plastic zipper consisting of interlocking elements and attaching webs between the outer edges of the film and the spout, positioning guide bars on either side of the zipper between the zipper webs and sealing bars outwardly of the guide bars with the sealing bars simultaneously forming a fin seal at the outer edge and joining the zipper webs to the inner surfaces of the film between the fin seal and the spout and thereafter cross-cutting and sealing to form packages enclosing contents dropped through the spout.