Abstract: A retaining element for use with elastic sheet material is disclosed. In one form, the sheet material can be provided as a bag (100) having first and second side walls (102, 104). The retaining element can be in the form of an elastic strip attached to one of the side walls. The retaining strip (120) can comprise a heat-unstable activatable material such that it can be applied to the bag in a deadened condition wherein the strip is set and subsequently heated to transition to an activated condition wherein the retaining element is elasticized to provide an elasticized article which can have a shirred appearance. The retaining element can have various configurations and can be activated by various methods.

Abstract: This invention pertains to draw tape equipment, and methods for incorporating draw tapes into plastic and like bags. In general, a continuous plastic web is slit at a slitting station to form layers, and respective free edges. The web then passes to a hole forming station where holes are punched in the top and bottom layers adjacent the free edges. After the holes are punched, edge regions of the top and bottom layers are separated from each other, followed by forming of hems in the separated layers at hem forming stations arranged in parallel with each other. Concurrent with forming of the hems, continuous draw tapes are fed to the hem forming stations and the hems are formed about the draw tapes. The formed hems, with the draw tapes incorporated therein, optionally pass through first temperature control stations where the temperature of the plastic web is controlled to a desired temperature before hem sealing. The formed hems are then sealed to the main bodies of the respective top and bottom layers.

Abstract: A double-ended bag is formed from a tubular woven sheet having at least one tie member extending along the length of the tubular sheet. The tubular sheet is cut to create bag panels and tie member segments in registration. The bag panels are sewn together with the bag panels in registry and the tie member segments in registry.

Abstract: An open mesh carrying bag having a drawstring closure is constructed of an open mesh material provided with a hem at the closure, the hem including a folded-over portion of the material overlapping a further portion of the material, the folded-over portion and the overlapped further portion being secured together in the hem by the drawstring of the drawstring closure, which drawstring is threaded through registered mesh openings in the folded-over portion and in the overlapped further portion to secure together the folded-over portion and the overlapped further portion and to serve as a carrying handle while enabling selective contraction and closing of the drawstring closure by drawing upon the drawstring.

Abstract: A method for manufacturing a web of interconnected bags from a semitubular web of material, in which pockets are formed at a first side of the web and a second side of the web adjacent a first of two longitudinal outer edges of the web. At least one continuous strip is inserted into the pockets before separation of the bags. The strips are cut to predetermined lengths, and their ends are fastened together. The web is welded together along transverse lines substantially perpendicular to the pockets for producing one bag at a time, which is conveyed transversely substantially perpendicular to the direction motion of the web. The pockets project at one of the two sides of the web beyond the pockets on the other side of the web substantially perpendicular to the direction of motion of the web. Each bag is welded and conveyed substantially perpendicular to the direction of motion of the web.

Abstract: A process for manufacturing draw tape bags, unique tubular films used in the process and the resulting draw tape bags are disclosed. The process begins with the step of forming a tubular film having a longitudinal region with a film strength greater than the film strength of the remainder of the tube. Next, the longitudinal region of greater strength is slit out of the tube and into draw tape ribbons, leaving the remainder of the tube in the form of a continuous sheet with two side edges. A hem with a draw tape access hole is next formed from each of the two side edges, each of the hems encasing a draw tape ribbon. Last, transverse seams are formed in the folded continuous sheet to define individual bag edges and the folded continuous sheets is severed to form individual bags. In one embodiment the longitudinal region of greater strength is made from a resin different than the resin making up the remainder of the tube.

Abstract: An open-mesh net bag is formed of a rectangular piece of open-mesh netting and a pair of elongated flexible cords. A central length portion of each cord is interlaced through the meshes of netting piece along a respective end edge region, a pair of loop-forming length portions are intertwined with each other to form a loop with the central length portion, a pair of intermediate length portions are interlaced through the meshes along about one-half the length of the side edge regions, whereupon terminal end portions of the respective cords are connected to each other. A method of forming the open-mesh bag is also disclosed.

Abstract: Method and apparatus for the manufacture of non-roping thermoplastic draw tape handles for insertion into thermoplastic bags and in particular for the continuous application of an adhesive coated reinforcing layer of material to the handled portion of the thermoplastic draw tape to reduce roping.

Abstract: Apparatus and methods for manufacturing draw tape bags from a web of plastic material are disclosed. The apparatus and methods relate to draw tape bags in which a hem seal, enclosing the draw tape, is formed in the bag without stopping the movement of the web through the hem sealing station.

Abstract: A draw tape bag is formed from a plastic web. An edge folding unit, a notching unit, a tape inserting unit, a heat sealing unit and a web folding unit form a compact continuous line in a rectangular path. The hem folder includes a L-shaped plate within the hem to receive a draw tape. The plate is pivotally mounted the tape within the hem. A wheel is rotatably and pivotally mounted for pulling the hem onto the plate. A single strap on a roll has a width equal to both tapes. The roll is driven and the strap passes over a knife to sever the strap from the tapes. A tension control roll is coupled to moving the strap and controls the strap feed to hold a constant tape tension. A folding board includes spaced edge channels in a V-shape for folding the flat web. An air layer is interposed between the web and the folding channels to provide a low friction movement.

Abstract: An apparatus and process to permit high speed continuous motion heat sealing in the transverse direction of a moving, multiple layer web of polyethylene film. The apparatus includes a circular drum with a heated seal bar mounted flush with its cylindrical surface. The web of film wraps around the cylindrical surface of the drum and moves at the same speed. The web is pressed against the cylindrical surface by a least one rubber nip roll and is heat sealed in the area of the seal bar. The invention is particularly adapted for presealing the ends of the drawtape in the manufacture of drawtape bags.

Abstract: Apparatus for heat sealing the respective layers of film in a pair of hems in a moving web of film in the manufacture of draw tape bags. A pair of hot air hem sealer units is provided each of the units including a hot air hem sealer heat exchanger having a plurality of nozzles which direct hot air against a continuously moving film. The nozzles are in line with film movement and the film is backed up by a metal plate positioned between the hems. Following the heating phase cool compressed air is directed against the film in the heated area to cool the film prior to contact with the hem seal on the other side of the bag. The heat exchanger includes a plurality of circumferential grooves which deliver hot air to the nozzles. A thermocouple controls the temperature of the hot air.

Abstract: A draw type bag with two single draw tapes having a front wall and back wall of flexible sheet material joined to each other along edges of the bag. Tubular channels extend along opposed transverse top edges of the front and back walls. The channels define an open mouth for the bag. Each of the channels has openings at the opposite ends of the top edges of the bag. A pair of draw tapes extends through both of the channels. One end of each of the tapes is attached to opposite side edges of the bag beneath the openings in one of the channels and the other end of each of the tapes extends through the openings at the corresponding ends of the other of the channels so that the tapes cross each other in both channels and wrap around the mouth of the bag whereby when the tapes are pulled the mouth of the bag is drawn tightly together.

Abstract: A method and apparatus for forming draw tape bags wherein the bag material moves continuously during the manufacture, except for the last step. The apparatus may be used with an in-line system wherein a tube is extruded and a side gusset is formed to create a hem; or the apparatus may be used with an off-line system wherein folded bag material is used, and a continuous hemmer is provided to turn the loose edges. In the off-line system a constant tension dancer precedes the hemmer to maintain constant tension on the web regardless of the size of the supply roll. The web continues to move, and a cutter is actuated to move through a circle and engage the web to punch finger holes in the hem. A reel of a strip of material is continuously fed, the strip being slit longitudinally to provide the draw tapes which are inserted into the hems. A tape guide tensions the tape and assures that the tape is well within the hem, the hems are sealed, and the bags are side welded.

Abstract: A draw tape bag forming apparatus includes an edge folder for folding the edges of pliable plastic web to form a hem in the edge. A draw tape is fed into the open hem which is then heat sealed along the inner edge of the hem wall to form a tubular hem. The web is of an indefinite length and moves continuously through the machine. The heat sealed hem is an expanded air-filled type hem. An electrostatic generator unit is mounted downstream of the ballooned hem. The generator unit includes a charging bar mounted in spaced relation to reference ground plate to form a gap with the ballooned hem passing therebetween. The hem is aligned with the bar. A 120 volt power supply is connected to the charging bar and establishes a high voltage along the length of the bar.

Abstract: Method and apparatus for the manufacture of non-roping thermoplastic draw tape handles for insertion into thermoplastic bags and in particular for the continuous application of a reinforcing layer of material to the handled portion of the thermoplastic draw tape to reduce roping.

Abstract: In the manufacture of draw tape bags hems are formed in the opposing panels of the moving web of folded thermoplastic film by utilizing tucker bars, that tuck the hem for the draw tape bags, equipped with a series of rubber wheels that pull the film diagonally so that it is tight against the edge of the folding boards.

Abstract: An improved thermoplastic film heat bonding apparatus includes a heated seal bar, a support member supporting the heated seal bar for reciprocating motion against a platen and a resilient coupling between the support member and the heated seal bar to allow deflection of the heated seal bar with respect to the support member providing better conformance between the platen and the face of the seal bar contacting the platen for more uniform and repeatable heat seals. Springs are used to provide the resilient coupling between the support member and the heated seal bar. One mounting providing both resilient coupling and continuous adjustable spacing between the support member and the heated seal bar includes a bracket supporting a threaded member passed through the support member and a coil spring biasing the bracket and support member apart. The bracket is itself resiliently mounted to the heated seal bar also by compression coil springs.

Abstract: Apparatus for sealing a hem in a moving web of plastic film having a structure including a folding surface having a web passing on one side of the surface and an edge of the web on the other side of the surface to produce a hem in the web prior to leaving the surface. Heat sealing apparatus is supported adjacent the structure for heat sealing the hem while the web is moving and prior to the sealed hem leaving the surface. The surface is provided with an opening in alignment with the heat sealing apparatus and the heat sealing apparatus seals the hem through the opening.

Abstract: Apparatus for producing a machine-direction heat seal in a moving web of plastic film including a block adapted to be supported on one side of the hem and having a plurality of rollers mounted thereon at spaced locations in tandem for engaging the film along the path of the heat seal to be formed in the hem. The block has a corresponding plurality of surfaces each of which is adapted to be engaged by a side of one of the rollers. A heater is provided for heating the block and its plurality of surfaces and the rollers are maintained in contact with the plurality of surfaces whereby movement of the hem though the heat sealing apparatus causes the plurality of rollers to rotate and maintain contact with the plurality of surfaces whereby the rollers are in turn heated by conduction from the block and produce the heat seal in the hem.

Abstract: Apparatus for producing a machine-direction intermittent heat seal in a moving web of plastic film including a block adapted to be supported on one side of the hem and having a plurality of wheels having heat conducting surfaces spaced around the periphery and mounted on the block at spaced locations in tandem for engaging the film along the path of the intermittent heat seal to be formed in the hem. The block has a corresponding plurality of surfaces each of which is adapted to be engaged by a side of one of the wheels. Gears interconnect the wheels to maintain the wheels in register with the intermittent portions of the heat seal in the hem during rotation of the wheels.

Abstract: Apparatus for heat sealing a hem in a moving web of plastic film using a plurality of rollers or wheels mounted on a block at spaced locations for engaging the film along the path of a heat seal to be formed in the hem. The rollers are heated by contact of one of their sides against a heated block. The small force holding the rollers against the heated block is provided by a slight angular orientation of the roller relative to the direction of film travel.

Abstract: Draw tape bags are made with folding surfaces which decrease in width to the final bag height. One edge of each side of a moving web of film is tucked onto a side of a surface to produce a hem in each edge of the moving web. Rollers, which are canted with respect to the direction of movement of the web, pull the hem of the film tight against the surface to insure that the web is at the final bag length when the web leaves the surfaces.

Abstract: Apparatus for heat sealing a pair of hems in a moving web of film having structure including a pair of spaced surfaces over which each hem of the pair of hems is adapted to pass. A first block is supported by the structure with respect to one of the surfaces and on one side of one of the hems. A plurality of rollers is mounted on the first block at spaced locations in tandem for engaging the film along the path of the heat seal to be formed in the one hem. A second block is supported by the structure with respect to the other of the surfaces and on one side of the second hem. The second block has a plurality of rollers mounted thereon at spaced locations in tandem for engaging the film along the path of a heat seal to be formed in the second hem. Heaters are provided for each of the blocks and the respective plurality of rollers whereby movement of the hems through the heat sealing apparatus causes the plurality of rollers mounted on the blocks to rotate and produce the heat seals in the pair of hems.

Abstract: A thermoplastic draw tape having thick and wide end portions with a relatively thin and narrow central portion between them is produced by movable clamps which stretch the tape between stationary clamps to produce the stretched, oriented portions of the tape. A plurality of movable clamps and a plurality of stationary clamps produce a plurality of stretched central portions so that the stretching time can be greater than the cycle time of bag making machinery with which the stretching apparatus is synchronized.

Abstract: A thermoplastic draw tape for bags is produced by stretching thermoplastic between a first pair of nip rollers running at a relatively slow speed and a second pair of nip rollers running at a higher speed. A rotating cylinder has hot and cool sections spaced around the circumference. The draw tape is heated in intermittent sections which are stretched as they pass through the nip rolls to produce a relatively thin and narrow central portion between end portions which pass over the cool sections of the rotating cylinder.

Abstract: A draw tape for thermoplastic bags is made by feeding tape to a first pair of nip rolls rotating at a relatively slow speed and a second pair rotating at a fast speed. The tape is stretched to form thin and narrow central portions between end portions of unstretched tape. The first nip rolls are increased in speed, or are released to interrupt the stretching. When the rolls are closed, one of them is momentarily retarded or backed up, to produce a rapid transition in the tape between the unstretched end portion and the stretched central portion.

Abstract: A thermoplastic tape having thick and wide end portions with a relatively thin and narrow stretched central portion between them is produced by a first pair of nip rolls running at a slow speed, and a second pair of nip rolls running at a higher speed. The tape between the nip rolls is intermittently moved away from, and toward said first nip rolls to stretch it to produce the relatively thin and narrow central portion. The second pair of nip rolls is mounted on a pivoted arm so that they are movable toward, and away from said first nip rolls. Alternatively, an idler roll between the two pairs is moved toward, and away from, the first nip rolls.

Abstract: A method of inserting a continuous, pliable strip into each hem formed along an edge, an edge of one of a pair of superposed panels forming an elongated, continuous web, the hem being formed by turning an edge portion of a panel inward between the panels. Each strip is fed from a position outside the web on the hemmed side of the web, across the hem(s) to a position between the panels within the web, reversed in direction and fed to a position between the portions of the panel forming a hem. Each strip is then turned from a transverse direction to a longitudinal direction and fed longitudinally into the hem. An apparatus for performing the steps of the method is described for use in the manufacture of thermoplastic film draw strip bags and feeds a pair of extremely thin and flexible plastifilm strips into a pair of hems, each formed in one of a pair of superposed panels, eventually forming the sides of the finished bag.

Abstract: A drawstring is mounted near the open mouth of a plastic bag by a pressure sensitive tape that freely laterally encloses the drawstring except for projecting free ends, the tape being formed or treated so as to be non-sticky with respect to the drawstring. A high speed production method of making the bags comprises the steps of laying a continuous length of drawstring material across a series of spaced bags, applying strips of pressure sensitive tape to each bag to freely laterally enclose the drawstring length there and severing the drawstring length between bags.