Abstract: A zipper profile for a fastener assembly is provided. The profile includes a male element and a female element. The female element has a pair of jaws that are movable with respect to one another about a common fulcrum region, and a pair of arms each of which are coupled to a corresponding one of the pair of jaws at the fulcrum region. Each of the arms has an end opposite from the fulcrum region that is shaped for engagement with a slider, and the jaws have an open position and a closed position. The arms are disposed to cause movement of the jaws between the closed position and the open position when the arms experience displacement about the fulcrum region. Displacement about the fulcrum region may be effectuated by motion of a slider relative to the arms. The male element is captured by the female element when the jaws are in the closed position and released when the jaws are in the open position.

Abstract: A feedblock for coextrusion apparatus permits profile adjustment of individual layers through the use of flow tuning valves that extend across the width of a main flow through the feedblock.

Abstract: A plastic clip is located at each end of a plastic zipper of a thermoplastic bag and fused with the ends of the profile elements of the zipper into a single mass by melting the clip to the zipper material.

Abstract: A thermoplastic bag having a zipper that is operated by a slider is provided with end termination clips that firmly holds the two zipper elements together to resist stresses applied by normal use and also stops the slider from going off past the end of the zipper. The end termination clip is formed by clamps consisting of plastic members between which are sandwiched the zipper and fin and wherein the clamping members are held together by a plastic rivet through the film. In one embodiment the end termination clips include hook structure for engaging a detent in the slider which provides the bag user with the feel of a definite parking position for the slider when the bag is closed.

Abstract: In the manufacture of thermoplastic film zipper bags and the like heat sealing the film to the zipper produces a seal line that shrinks, resulting in unsightly apearance. A system and method are disclosed for restoring the shrunk seal line to its orginal length by corrugating and stretching it between mating teeth. A method is also disclosed for restretching the seal without corrugation.

Abstract: A thermoplastic bag having a zipper that is operated by a slider is provided with end stops that are integral with the ends of the zipper and prevent the slider from going off past the end of the zipper and coming off the bag. There is also disclosed a method for forming these end stops by ultrasonically smashing the ends of the zipper.

Abstract: A method for continuously controlling the pressure in a bubble formed of a continuously extruded seamless blown thermoplastic film tubing which is being conducted generally upwardly through a cooling water bath. More particularly, the method contemplates controlling the internal bubble pressure through the intermediary of a Photohelic pressure controller which is utilized to monitor the differential prevailing between the internal bubble pressure and that of the water bath encompassing the bubble. The invention also relates to an apparatus for controlling the internal pressure of a bubble constituted from a seamless blown thermoplastic film which is extruded and conducted through an external cooling water bath, employing the method pursuant to the invention.

Abstract: A plastic reclosable fastener with slider for opening and closing the reclosable fastener on plastic bags and the like is disclosed. The plastic reclosable fastener and slider include a provision for restraining the slider in closed position and maintaining the male and female elements of the slider in interlocking relation when the slider reaches the closed end of its travel along the tracks of the slider.

Abstract: Small bags, such as sandwich bags and food storage bags, are folded in thirds along parallel fold lines and individually inserted into a box-like dispenser. A rupturable line extends along a top and adjacent side edge of the dispenser which, when ruptured, provides an opening in the dispenser at the corner of the top and adjacent side edge to facilitate removal of the folded bags.

Abstract: The present invention relates to a method for the extrusion of tubular thermoplastic films, in particular films produced from polymers such as high density polyethylene, polypropylene, and the like. The method comprises coextrusion of the polymer in the form of a tube which has adhered to its surface, another polymer which is characterized by having a significantly higher melting point than the melting point of the first polymer tube. The tubular films produced in this manner exhibit improved physical properties including a reduced tendency for rupturing or splitting in the machine direction when stresses are applied to such films.

Abstract: There are disclosed improved die structures for the extrusion of a tubular sheet of thermoplastic film material. The die comprises a housing having an opening therethrough, a mandrel located in the opening and spaced from the wall thereof to form an annular conduit, and a base plate positioned at one end of the opening and attached to the housing. The mandrel is spaced from the base plate by a plurality of spacers and releasably connected thereto by attaching means extending through some or all of the spacers. Recesses are optionally provided in the immediate vicinity of each spacer to increase the volume of molten material flowing past the spacer.

Abstract: In a thermoplastic extrusion system where a single extruder feeds molten polymer through a manifold to a plurality of separate extrusion orifices, a valve system is provided which distributes and regulates the flow of the molten polymer to the individual extrusion orifices.

Abstract: In a thermoplastic extrusion system where a single extruder feeds molten polymer through a manifold to a plurality of separate extrusion orifices, a valve system is provided which distributes and regulates the flow of the molten polymer to the individual extrusion orifices.

Abstract: In a thermoplastic extrusion system where a single extruder feeds molten polymer through a manifold to a plurality of separate extrusion orifices, a valve system is provided which distributes and regulates the flow of the molten polymer to the individual extrusion orifices.