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 method of folding a continuous web of a thermoplastic film material incorporating complementary interengagable profiled fastener elements, and aligning and interengaging the complementary fastener elements. Moreover, also provided is a device over which the web of thermoplastic film material is folded, with the device possessing structure for superimposing and aligning the fastener elements and interengaging the fastener elements which are adapted to be utilized in the production of reclosable plastic bags.

Abstract: A method of accurately punching holes into a moving web of a thermoplastic film material, and more particularly, punching holes into the web through the intermediary of a rotary serrated tube punch. The invention relates to accurately punching holes into an advancing web of thermoplastic film material utilizing a novel rotary serrated tube punch. The film web is continuously advanced over at least a portion of the circumferential surface of a rotatable anvil roll, and tensioned against the anvil roll surface through the use of suitable tensioning devices, such as tension rollers arranged upstream and downstream of the anvil roll. At least one opening is formed in the circumferential surface of the anvil roll which is slightly larger than the size of the hole which is desired to be punched into the film web through the use of the inventive rotary tube punching arrangement.

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 substantially frictionless connecting means providing universal swivel movement which can be used to mount an actuation means such as a hydraulic cylinder, including first and second flexible planar blades interconnected substantially perpendicular to each other so that movement imparted to either or both of the connected members bends the flexible blades.

Abstract: A box indexing table delivers a group of empty boxes from a main conveyor to a box loading machine. The loaded boxes are pushed onto a full box conveyor. Both the main conveyor and the full box conveyor extend completely across the table. The capacity of the loading equipment can be expanded in modular fashion by adding modular tables.

Abstract: Draw tape bags have a high molecular weight, high density polyethylene draw tape which is intermittently stretched so that the tape has central portions of relatively narrow and thin oriented polyethylene and end portions which are relatively wide and thick. The end portions are heat sealed to the sides of the bag panels to secure them. The stretching makes the tape cost more economical and improves the break characteristics while the thick and wide end portions permit good heat sealing without weakening the draw tape. Also disclosed is a method of making such bags.

Abstract: Thermoplastic tape is stretched by a rotating disk having slots extending radially outward from the center of rotation of the disk. The tape is gripped by clips which are moved outwardly in the slots by a cam slot as the disk rotates. The clips grip the tape throughout a length which forms relatively thick and wide unstretched portions of tape with relatively thin and narrow central portions of stretched tape between said clips.

Abstract: In the manufacture of plastic bags having interlocking profiled extrusions for the closure, the extruded plastic profiles are applied to a moving web of film immediately after extrusion of the profiles. The profiles are fused to the web on a first section of a fusing/cooling arcuate plate-like support member. Thereafter, the web is moved to a second cooled section of the arcuate plate-like support which is maintained at a temperature to allow the profiles to freeze to the web. The moving web of film is maintained under tension so that contraction of the film upon release compensates for the contraction of the locking profile as it cools to prevent puckering of the web. The locking profiles are applied to the web in an in-line process, which includes folding and heat sealing the moving web of film to form plastic bags.

Abstract: A disposable plastic bag is provided having a closure formed by a plurality of ripple strips where each ripple strip comprises a band of rows of adjoining waves, the waves being shaped and positioned such that the highest amplitude of one row is adjacent to the lowest amplitude of the nearest rows. In one embodiment, the highest and lowest points of each row have flanges extending therefrom which interlock with the waves of a facing strip. In a second embodiment, the width of each row is regularly varied and the widest portions of each strip interlock with the widest portions of a similar facing strip.

Abstract: A reciprocative apparatus individually folds a plurality of thin, limp, sheet-type articles, such as sandwich bags, and loads them into a carton. The apparatus may include a delivery assembly for sequentially transferring the bags from a conveyor belt to a folding station. A pivotally operated swatter is described for such delivery.The folding station includes a pair of trays forming a platform and a pair of flippers for sequentially folding end portions of a bag upon its middle portion. The initially operated flipper is operated by a pneumatic cylinder. The secondarily operated flipper is connected to a carrier assembly which is supported by springs attached to a frame. Another pneumatic cylinder is also connected to the carrier assembly and to the second flipper through a linkage.

Abstract: A bag folding and loading machine has a pivotal swatter which transfers thin film bags from delivery conveyors to a folding assembly. Vanes on the swatter are located on planes substantially aligned with the direction of motion of the swatter which contacts the bags along three sides of the vanes to form the bags into a U-shaped configuration upon delivery. Pivotal flippers are at the sides of a U-shaped channel into which the bag is delivered. Flippers rotate through 90.degree. to fold the bag in thirds, after which it is transferred to the carton by a stomper.

Abstract: A flexible bag has a releasable closure with a fin extending away from one of the mating pluralities of hook-like protrusions. The fin is joined to the base of the hook-like protrusions to apply disengaging force for opening the closure from the outside of the bag. The closure resists opening force from inside the bag. The protrusions have hook-like ends which have the same shape on all protrusions, which extend in one direction on one of the plurality of protrusions and in the other direction on the other plurality of protrusions. The protrusions are easily extruded from molten thermoplastic and applied to a moving web of film during an in-line bag manufacturing process.

Abstract: A reciprocative apparatus individually folds a plurality of thin, limp, sheet-type articles, such as sandwich bags, and loads them into a carton. The apparatus includes a delivery assembly for sequentially transferring the bags from a conveyor belt to a folding station. A pivotally operated swatter is employed in the delivery assembly which includes a swatter driving mechanism which gradually decelerates the swatter near the end of its forward movement to minimize article wrinkling.

Abstract: Disclosed is a method and apparatus for ensuring uniform distribution of higher and lower viscosity or flow rate resins in a product produced by a coextrusion process. A flow restriction is provided in the flow path of the lower viscosity or flow rate resin to increase the pressure drop of this resin as it passes through a coextrusion die. The increased pressure drop introduced by the flow restriction causes the lower viscosity or flow rate resin to be more uniformly distributed in the extruded product. A specific die construction providing a uniform resin flow channel within the die is also described.

Abstract: An improved Z-fold closure for flexible bags such as thermoplastic bags comprising polyethylene film comprising a pressure sensitive adhesive strip and a protective strip having one or more ribs of sufficient stiffness and dimension so that the strip of adhesive is substantially contacted by only the top portion(s) of the rib(s) when the bag closure is in a stored or "z" fold position.

Abstract: Molten thermoplastic, such as polyethylene, and a hot melt adhesive are coextruded through a channel shaped profile die. While still molten, the channel shaped strip, having adhesive between the ribs thereof, is brought into contact with a moving web of a thermoplastic, e.g. polyethylene film, which is backed up by a roll at a controlled temperature. The temperature differential between the roll and the molten thermoplastic is maintained so that the thermoplastic adheres to the moving web upon contact and thereafter cools to set the thermoplastic in the channel shaped profile. The web is under tension so that contraction of the film upon release compensates for the contraction of the channel shaped strip as it cools.

Abstract: Disclosed is a method and apparatus for ensuring uniform distribution of higher and lower viscosity or flow rate resins in a product produced by a coextrusion process. A flow restriction is provided in the flow path of the lower viscosity or flow rate resin to increase the pressure drop of this resin as it passes through a coextrusion die. The increased pressure drop introduced by the flow restriction causes the lower viscosity or flow rate resin to be more uniformly distributed in the extruded product. A specific die construction providing a uniform resin flow channel within the die is also described.