Abstract: Method and device for producing rolls (17) of bags. At least one longitudinal side edge (15, 16) of a line of overlapping bags (17) is folded towards the centre axis of said line of bags. The line is then winded to rolls (17).

Abstract: A bag stack made of low density polyethylene material is disclosed. The bag stack comprises a plurality of bags where consecutive bags are adhesively connected together and where the back walls of the bags in the stack are hot welded together near the tops of the back walls of the bags. When a bag is removed from the stack, the front wall of the following bag is pulled open to permit easy removal of the next bag. A method is disclosed for forming a bag stack in accordance with the present invention.

Abstract: The machine (1) is provided for production of containers (8) having a trapezoid or triangular form in plane, starting from two films (4) of plastic material superposed on each other. The machine (1) comprises a work station (6) provided with a pair of heat sealing and cutting-out elements (18) extending in directions converging towards each other and transverse to the feed direction of the films (4) so as to simultaneously form two adjacent containers (8) disposed in an inverted relationship with each other in the plane of the films (4). The containers (8) are simultaneousLy removed from opposite sides of the work station (6) by respective removing means (7) provided with clamps (22) and are then released from the clamps (22) and fitted on pairs of underlying needles (36) thus forming stacks.

Abstract: A plastic film or sheet, wherein upon immersing a test piece of the plastic film or sheet in ultrapure water, extracting pure water from near the surface of the test piece and evaluating the cleanliness of a resulting bag based on the concentration (number) of fine particles 0.3 .mu.m or greater in size dispersed in the extracted ultrapure water, the measured concentration is no greater than 5 per ml. The process comprises steps of immersing and running a plastic film or sheet (1) in ultrapure water (4) in a clean room (16), and further spraying and washing the film or sheet (1) with ultrapure water after the film or sheet (1) is drawn out, followed by drying, destaticization, cutting and heat sealing.

Abstract: A package material processing machine comprises a feeding device for feeding a package material along a predetermined feed course and a processing roller having an outer circumferential surface opposite to the feed course. The package material is processed by rotating the processing roller with feeding the package material along the feed course.

Abstract: A storage bag and a method and apparatus for forming such a storage bag. The storage bag contains a reclosure tie formed as an integral marginal portion of the bag beyond an edge of the bag. The marginal portion includes overlying layers of bag material that form an elongated structure along an axis with first and second ends. A fused closure is formed in the marginal portion parallel to the axis and over a portion of the marginal portion spaced from one end thereof. This structure defines a tail and open loop that wrap around an opened bag thereby to close the bag in a positive fashion.

Abstract: A gored packing bag which comprises a front body 1, a rear body 2, gores 3,4 formed by gluing the front body and the rear body into a combined situation, and a pair of fasteners 5, 6 in arranged between the front or rear body and the gores, one of a base tape being glued as a whole on an inner surface of the front or rear body close to an open end thereof, while both end portions of the other base tape 8 being glued to a half side of gore 28,29 facing to the front and an intermediate remainder of the gores in the width direction being glued on a corresponding inner surface of the front or rear body, and a fixed portion 30, 31 of remaindered gores in the width direction being glued on a corresponding inner surface of the front or back body.

Abstract: An apparatus for making bags out of a thermoplastic web has a transport unit for feeding a leading end of the web in a transport direction to a cutting/welding station, tools at the station for transversely welding the web and cutting a bag from the leading end of the web, and a device downstream in the direction from the station for stacking and blocking bags cut from the web. A bag-pulling device between the station and the stacker/blocker has an endless drive strand having a pair of stretches extending vertically across a path of the bag between the station and the stacker/blocker and respective horizontally extending deflector rollers carried on the stretches, vertically displaceable therewith, each extending along a respective axis, and each having an outer surface engageable with the web and freely rotatable about the respective axis.

Abstract: A pouch and a method and apparatus for forming an easy open pouch in a form-fill-seal process is disclosed. The apparatus includes a first bar; a means for cutting, housed within the first bar, the means for cutting including a main cutting blade having two ends, and a tear notch blade attached to the main cutting blade between the ends of the main cutting blade, the tear notch blade disposed at an angle to the longitudinal axis of the main cutting blade; a means for holding the means for cutting within the first bar; a second bar; and means for advancing the means for cutting from the first bar, and through the pouch material, and subsequently retracting the means for cutting from the pouch material, thereby severing the pouch material and cutting a tear notch in an upper transverse seal of a first pouch, and a lower transverse seal of a second pouch.

Abstract: A system for receiving tubular formed film comprising two facing walls and forming plastic bags having headers, open mouths and sealed bottoms into a block or stack of bags. The system includes an opener means for severing a spaced perforation on only one wall of the film to make a bag with an open mouth.

Abstract: A flat trapezoidal container provides a generally frustoconical single cavity for snugly sheathing a flower pot. The container is specifically dimensioned sheath a flower pot so as either (a) to leave therebeneath, a surplus of film in an transition zone which is concealable under the flower pot, or (b) form a hexagonal gusset in the bottom. The container is made from two flat panels of heat-sealable film, each shaped in the general form of a trapezium; or from a single web folded double. The lower portion of the container is ornamentally imprinted along a border extending beneath a generally lateral line above the longitudinal axis of the web; and, with a marker in the upper portion, identifies the contents, or provides instructions for their use or care. When the cavity is distended by being partially filled, the entire container, except for a transition zone, presents a smoothly arcuate surface of the frustum of a cone.

Abstract: A storage bag with soaker pad, and a material and method for making same. The bag of the invention includes a bag having a front and rear panel of a plastic film, the front and rear panels being closed at one end to form a bottom of the bag, the bag being open at the opposite end for receipt of goods to be stored in the bag, a fluid absorbing pad located inside the bag, and an enclosure connected to the inside of the bag for containing the fluid absorbing pad. The material of the invention comprises a bag film connected to a perforated enclosure material with a plurality of soaker pads sandwiched between the two layers. The width of the perforated enclosure material is substantially less than the width of the bag film whereby the soaker pads are continued to a limited space near the center of the material that creates the bottom fold of the resulting bags formed from the material. The method of making the bag of the invention includes a continuous supply of bag film be fed forwardly towards a bag machine.

Abstract: Apparatus is disclosed for producing discrete packages which can be individually varied in length so that they can be used for packaging articles such as cuts of meat which vary in length. The apparatus comprises drive rolls for feeding a flat tube of plastics packaging material through a cut off device. The apparatus may also comprise a heat sealing device (to form the tube into a bag) and a blower head combined with a suction device which opens the leading portion of the bag to facilitate the placing of an article in the bag. A proximity sensor is provided adjacent the cut off device and immobilises the drive rolls when it detects the arrival of a leading portion. In one form of the apparatus the sensor is mounted on a movable carriage which can be quickly moved by hand or by a ram.

Abstract: A handle bag 16 in a bag pack 2 suitable for suspension and opening on a bag rack 4 has a front wall 22, a rear wall 24, a pair of laterally spaced handles 20, and an area of a cold releasable adhesive 8 between the rear wall 24 of the bag 16 and the front wall 42 of its immediately subsequent bag 40. The front wall 22 is joined opposite the rear wall 24 and defines an enclosure 26 having an open top 28, opposed two sides 30 and a bottom 32. The handles 20 and the opposed sides 30 are substantially symmetric with respect to a longitudinal axis 50. The area of the cold releasable adhesive 8 is centered about the longitudinal axis 50 and is positioned closer to the open top 28 than to the bottom 32. The area of the cold releasable adhesive 8 is preferably in the range of about 1 sq. inch to about 4 sq. inches.

Abstract: A method of packaging an article comprises wrapping the article in a plastic film; and heat sealing the film using a sealing apparatus comprising a main sealing element, and a second sealing element attached at an angle to the main sealing element, and shorter than the main sealing element, such that when the film is sealed, a sealed notch that can be used to initiate opening of the package is made. A package comprises an article wrapped in a plastic film, the film being heat sealed to form a seal, the seal comprising a main seal, and a second seal attached at an angle to the main seal, and shorter than the main seal, and defining a sealed notch that can be used to initiate opening of the package. A sealing apparatus for making an easily opened package comprises a main sealing element, and a second sealing element attached at an angle to the main sealing element, and shorter than the main sealing element, and capable of creating a sealed notch that can be used to initiate opening of the package.

Abstract: An apparatus for use in removing hazardous material I from an elongated pipe P comprises an elongated upper work section 41 from which a plurality of in-line lower debris collection and disposal bags 47 depend. The upper work section and the bags are made of flexible sheet material. The upper work section has a bottom formed with a plurality of in-line chutes 52 that extend between adjacent bags. A plurality of gloves 48 are mounted to the upper work section. Upon wrapping and securing the upper work section about a pipe with the chutes inclined therefrom, insulation may be manually worked from the pipe and channeled by the chutes into the bags for collection and storage. A method of manufacturing the apparatus from two continuous webs of flexible material is also disclosed.

Abstract: A plastic bag manufacturing method to produce bags with a removable release strip in covering relation over an adhesive deposit adjacent an upper edge of the bag rear panel, in which the height of the release strip is increased to provide continuity along the length thereof to enable urging the strip, as required during the bag manufacturing process, in a machine direction, and the lower release strip portion is notched at locations coinciding with the bag side edges so that these bag side edges are fused for their entire lengths with no inhibiting of this fusing process by the release strip being in an interposed position between the overlying upper edges of the bag front and rear panels.

Abstract: An apparatus (31) and a method are disclosed for temporarily separating multiple webs (51,53) while performing an operation (123,125,133) thereon, including the feeding of multiple webs (51,53), the provision of a retractable web separator (68) for temporarily separating the webs, the performance of an operation (123,125,133)) upon the webs, the provision of a gripping device (65) for gripping the webs and assisting in moving the webs (51,53) along a predetermined path (83), and the provision of a sealing device (71) for sealing the webs together to form a package seal (73). The retractable separators (68) are mounted on a conveyor (83) and each separator (68) in turn temporarily separates the webs (51,53), for insertion of a port (45), fitting or the like, whereupon the separator (68) may be retracted and the port (45) may be sealed into the packages (41) being manufactured. The preferred separator (68) has a shaped head (170) on the end of a reciprocating shaft (158).

Abstract: Fine paper that is sized with a 2-oxetanone alkaline sizing agent and that does not encounter machine feed problems in high speed converting or reprographic machines, including continuous forms bond paper and adding machine paper, processes for converting the paper into envelopes, continuous forms bond paper and adding machine paper, and paper products of the processes.

Abstract: A plastic bag comprises first and second opposing panels fixedly connected to each other along a pair of sides, a primary bottom, and a secondary bottom. The primary and secondary bottoms extend between the pair of sides. The sides and the secondary bottom define a receptacle space having a mouth formed opposite the secondary bottom. The plastic bag further comprises a bottom header disposed between the primary and secondary bottoms and including first and second opposing header panels. The first header panel is extruded with and extends downward from the first body panel. The second header panel is extruded with and extends downward from the second body panel. The bottom header includes an opening for mounting the plastic bag to a dispensing post.

Abstract: A reclosable bag includes a detachable reclosure tie having a tail portion formed by a series of spaced elongated seals and a closed loop. Apparatus for forming the reclosure tie with a bag includes first and second sealing jaws with external and internal grippers for holding web material. The first sealing jaw carries cutting and perforating knives and a cooling block that directs cooling air onto the knives to prevent the knife temperature from rising to the melting temperature of the web material. Each sealing jaw contains a heating block with complementary sealing surfaces for forming various seals including the seals that form the tail portion of the reclosure tie.

Abstract: A system for suspending a pack of thermoplastic bags, loading bags, removing loaded bags and for automatically opening the next bag preparatory to loading it by having a pack of handled bags suspended from laterally spaced elongated rods of a rack. A novel gradually releasably adherent bond is created between the rear wall of a leading bag and the front wall of a following bag in the bag pack. As the leading bag is removed from a bag rack, the bond will gradually and fully open the mouth and body of the following bag for loading.

Abstract: A bag pack comprises a plurality of easy open handle bags. The bags are easy to open because the exterior surfaces of the bags are cold-welded together so that when one bag is pulled from the pack, the adjacent next bag is at least partly open. The external surfaces of the bags are not welded to the internal surfaces of the bags during the pressure welding process, because the material that forms the external surface of the bag is treated with a corona discharge, which renders the external surface more susceptible to cold weldings. Optionally a static charge is induced on the bags so that each bag is at a different voltage than the adjacent bags so the bags attract each other, and the panels of each individual bag repel each other, to contribute to the easy open feature.

Abstract: Apparatus is disclosed for producing discrete packages which can be individually varied in length so that they can be used for packaging articles such as cuts of meat which vary in length. The apparatus comprises drive rolls for feeding a flat tube of plastics packaging material through a cut off device. The apparatus may also comprise a heat sealing device (to form the tube into a bag) and a blower head combined with a suction device which opens the leading portion of the bag to facilitate the placing of an article in the bag. A proximity sensor is provided adjacent the cut off device and immobilizes the drive rolls when it detects the arrival of a loading portion. In one form of the apparatus the sensor is mounted on a movable carriage which can be quickly moved by hand or by a ram.

Abstract: An infinite heat sealing assembly preferably for heat sealing a thermoplastic heat-shrinkable plastic film, has a heat sealing assembly for cutting and sealing a seam in a film or layers of film without regard to the length of the seam. The heat sealing assembly includes a heated blade and a plurality of belt conveyors for conveying the film with a desired tracking through the assembly. An adjustable angle blade and slotted film support ramp result in improved sealing of heavier gauge films by increasing the dwell time of the film on the heated blade.

Abstract: A thermoplastic bag structure and a method for forming handle-containing bags in roll-form. The method includes the steps of forming a continuous collapsed tube; forming pairs of closely spaced seals transverse to the tube at bag length distances apart; forming a transverse line of weakness between each pair of seals; simultaneously or thereafter folding the marginal edges of the tube inwardly toward each other; forming and removing a cut-out region at one end of each sealed segment of the tube so that on removal of the cut-out region, the cut defines loop handles and a bag mouth region in each bag; again folding the marginal edges of the tube inwardly toward each other; and convolutely winding the structure to form severable bags on a roll.

Abstract: The invention provides self-opening polyethylene film bag stacks which do not require a separate adhesive layer between adjacent bags. The self-opening bag stack according to the invention preferably include a plurality of stacked t-shirt type high density polyethylene film bags releasably adhered together. At least an upper portion of the outer surface of the front and rear walls of each of the bags in the bag stack has been corona treated and at least one localized compressed area extends transversely through the bag stack in the upper portion of the bags such that the stack has a decreased thickness in the localized compressed area and so that adjacent outer wall corona treated surfaces defined by the localized compressed area are releasably adhered together.

Abstract: A bag for packing a light-sensitive material is disclosed. The bag has an outermost surface and an innermost surface and is essentially consisting of a material for making the bag which comprises not less than 70% by weight of polyethylene and 1 to 10% by weight of a light shielding material based on the weight of the material, in which a Vicat softening point of the outermost surface is higher by not less than 20.degree. C. than a Vicat softening point of the inner most surface. Further a method for producing a bag is disclosed.

Abstract: An apparatus and method for producing zipper closure bags from a continuous tube which includes advancing the tube along a continuous path for travel with a rotating metering roll, the metering roll having circumferentially spaced apart ports corresponding to a bag width, and a receiving conveyor having vacuum port-equipped sealing bars for receipt of the tube from the metering roll and for providing across seals defining adjacent paths.

Abstract: A system for suspending a pack of thermoplastic bags, loading bags, removing loaded bags and for automatically opening the next bag preparatory to loading it by having a pack of handled bags suspended from laterally spaced elongated rods of a rack. The bags have been corona discharge treated to such an extent that the application of pressure will cause adjacently facing regions to releasably adhere together until a moderate force separates them. During removal of a bag from the bag pack at least a portion of the front wall of the next bag will follow the bag being removed for a short distance before separation thereby opening said next bag rendering it ready for loading. An improved means for applying the requisite pressure is disclosed herein.

Abstract: A flat trapezoidal container provides a generally frustoconical bag with a single cavity when at least partially filled with a pulverulent material such as soil which may have a live plant growing therein, or comestible goods such as popcorn and other snacks which rely heavily upon spur-of-the-moment purchases by a customer who must first be visually attracted to the goods, thereafter be visually convinced of their freshness, and have the opportunity to smell and/or touch the goods prior to purchasing them. The container may also be specifically dimensioned to snugly sheath a flower pot so as to leave therebeneath, a surplus of film in an empty transition zone which is concealable under the flower pot. The container is made from two flat panels of heat-sealable film, each shaped as a trapezium; or from a single web folded double.

Abstract: A thermoplastic film bag pack where each bag has a bottom, front, rear, and gusseted side walls, an inside and outside surface and a cut-edge mouth portion. The mouth portion has double film loop handles as integral extensions of the walls at its opposite ends. The external surface of the bag at the cut-edge region of the mouth between handles has been subjected to a corona discharge treatment to such an extent that adjacently facing cut-edge regions will be releasably adherent until a moderate force separates them. This condition provides for effective dispensing of grocery bags. A method of forming the bags and a system for dispensing is also disclosed.

Abstract: Containers are produced from a sheet of flexible material having a thermally bondable inside surface. In one embodiment the material is formed into a T-shaped intermediate structure having two pleats (302 and 303) having a uncreased, mutual central portion (300). The intermediate structure also has two overlapping side wall portions (295) extending from the pleats.

Abstract: The present invention relates to a method and apparatus for producing communication articles such as postcards, envelopes or the like in each of which display surfaces for information or the like are separably bonded with a synthetic resin therebetween by heating for concealing information such as correspondence or a printed display medium and then mailing it. It is an object of the invention to enable easy and smooth separating of a film-containing sheet and accurate insertion of a film in a sheet.

Abstract: A method for manufacturing reclosable plastic bags or packages includes the step of presoftening the complete length of the zipper before it is introduced into the space between two plies of plastic sheet material, which form the sides of the plastic bag or package. The presoftening enables the zipper, which may comprise interlocked male and female profiles, to be fused together and completely flattened when a seal bar clamps thereacross to form a side seal area transverse to the zipper.

Abstract: A method of making a gift bag which contains a pair of ribbon loops in the neck which, when pulled in opposite directions, form a cluster at the top of the bag about which the ribbons can be tied to form a fancy package.The method of in-line production of such gift bags includes laying a pair of ribbons near opposite edges of a sheet and folding the edges to form flaps over the ribbon; folding the sheet longitudinally at the middle, punching spaced-apart holes in the sheet-enfolded flaps at intervals corresponding to the width of the bag; guiding the ribbons into registry with the punched holes; sealing along a transverse zone passing through the middle of the punched hole and cutting along the transverse zone to separate the bags.

Abstract: An apparatus for making flat packaging bags from a flexible web of indeterminate length includes a machine frame; a sled mounted on the machine frame for travel parallel to the direction of web advance; a first drive for reciprocating the sled parallel to the direction of advance; a mandrel mounted on the sled; a tubular folding body fixedly mounted on the machine frame and coaxially surrounding the mandrel for bending the web about the mandrel to form a web hose; a first sealing shoe mounted on the sled; a second drive for pressing the first sealing shoe against an outer face of the mandrel for providing a longitudinal sealing seam on the web hose situated between the mandrel and the first sealing shoe; a second sealing shoe mounted on the machine frame for displacements perpendicularly to the direction of web advance; a third drive for actuating the second sealing shoe for providing a transverse sealing seam on the web hose; and a cutter for severing a length of web hose from the web.

Abstract: A self-supporting bag comprising a part constituting the trunk and a part constituting the bottom both made of a multilayer plastic film comprising a heat adhesive plastic layer as the inner layer thereof is provided. The inner layer or the outer layer of the multilayer plastic film of the part constituting the trunk has a section comprising convex parts and concave parts adjacent with each other.The linear ribs are formed by pressing a positive mold having linear protrusions at the top face against the multilayer plastic film to form linear troughs on the film with decrease of the thickness of the pressed part of the film and a raised part at the upper edges of the troughs on the film and by fixing the raised parts on the film.

Abstract: A method and apparatus for forming recloseable plastic bags having engageable mating profiles wherein the bags are made to have an initially open mouth. The profiles which are made to be in an closed condition are opened by a blade apparatus which engages and opens the profiles at a point after the tubing is fused or tacked to thereby maintain proper alignment of the profiles when the bags are made.

Abstract: A method of manufacturing bags that are rectangular when collapsed and which comprise two superimposed flat sides, sealed at the edges, and a handle member. The method comprises the steps of: laying out a web forming three parallel subordinate webs, one extending longitudinally in the middle and one on each lateral side thereof; folding two top flanks out of the middle subordinate web to create a handle-top portion; V-folding a center strip of the middle subordinate web to create a handle member; providing the handle member with a finger slot and with depressions that allow the middle part to be pulled apart along the handle member to form a gusset; bringing the two lateral subordinate webs together; and attaching the lateral subordinate webs together along seams to create bag edges and cutting off the bags along their edges.

Abstract: Twin compartment packets, e.g. tea bags, are formed with the compartments connected at the heads of the packet and optionally at the tails. The packets are produced from a pair of compartmented tubular webs that are brought together with the compartments in register, the webs then being interconnected at the compartment end seals and severed at those seals to form the separate packets. Apparatus for performing the process deposits doses of tea at spaced intervals onto the two separate webs before forming them into the tubular compartmented webs, brings the compartments of the two webs into register, interconnects the registered compartments, and separates the interconnected compartments into individual packets while the web advances continously through the apparatus. The process is capable of high production rates because the webs are able to move through the successive stages at a uniform speed.

Abstract: An apparatus for providing transverse weld seams and transverse detaching cuts or for providing detaching weld seams on a tubular or semi-tubular web of thermoplastic synthetic resin, and for stacking the detached sections includes a transverse welding and transverse detaching station for detaching sections having bottom weld seams and any leading head weld seams from the web and a stacking station for retaining or fixing the supplied sections. The web is moved intermittently. To cool the trailing weld seams of the sections without causing the sections to stick together adjacent to the bottom weld seams during stacking, a drum is provided which rotates about a transverse axis between the transverse welding and transverse detaching station and the stacking station. The wall of the drum includes at least two wall parts. The drum is adapted to be driven in step with the welding process by rotating the drum through an angular increment related to the number of wall parts of the drum in each revolution.

Abstract: A storage bag and a method and apparatus for forming such a storage bag. The storage bag contains a reclosure tie formed as an integral marginal portion of the bag beyond an edge of the bag. The marginal portion includes overlying layers of bag material that form an elongated structure along an axis with first and second ends. A fused closure is formed in the marginal portion parallel to the axis and over a portion of the marginal portion spaced from one end thereof. This structure defines a tail and open loop that wrap around an opened bag thereby to close the bag in a positive fashion.

Abstract: A method for making bags of synthetic material in which a tubular foil web of synthetic material is advanced in steps corresponding to the length of one bag. A continuously heated pair (11) of welding jaws grips the tubular foil web (3) of synthetic material prior to cutting and fixes the web in position. The tubular foil web (3) is then cut by means of the transverse cutting knife (10) before the heat of the pair (11) of welding jaws is completely transferred to the tubular foil web (3) of synthetic material. Then the heat is completely transferred to weld the bottom seam of the bag.

Abstract: According to the invention, an apparatus is provided for feeding a continuous plastic film from a source of supply to a plastic film processing machine such as a plastic bag making machine and the like, which includes first and second take up rolls for taking up and rewinding the plastic film. First guide means is disposed at a position in the path for directing the plastic film from the source of supply to the first take up roll via the first guide means. Second guide means is disposed downstream of the first guide means in the path for directing the plastic film from the second take up roll to the processing machine via the second guide means. The plastic films can be sandwiched between and heat cut widthwise by first heat cutting means and first receiving means, whereby the plastic film from the source of supply is connected to the plastic film to the processing machine, while the plastic film to the first take up roll is connected to the plastic film from the second take up roll.

Abstract: A piercing blade for perforating slits in a continuous tubular web of thermo-plastic material is shown. The blade is used in a machine to form individual bags from the tube by heat sealing the bottom and perforating the top of the next bag. The piercing teeth in the blade have formed in the front face a number of horizontal grooves which serve to pick up the edge of the top layer of the slit to form a burr thereon and thus separate the two plys of the tubular web, facilitating the opening of the top of the bag when it is separated from the roll of continuous tubular material.

Abstract: A method and apparatus for supplying gas to a vacuum drum device and which substantially reduces or eliminates the problem of particle and debris buildup in the vacuum passages of the device is provided. The apparatus supplies gas, preferably at a pressure greater than atmospheric pressure, to the vacuum ports of a vacuum drum and includes a source of vacuum, a source of gas, and a rotatable vacuum drum. The drum includes a plurality of vacuum ports on the surface thereof, with the vacuum ports communicating with a plurality of vacuum passages extending generally outwardly from the interior of the drum. A valve alternately connects the passages to the vacuum source and to the source of gas. The selective exposure of the vacuum ports to either a source of vacuum or a source of gas prevents smoke, particles, and other contaminants from being drawn into the vacuum passages of the drum during operation of the system.

Abstract: A web of packaging material includes a pair of flaps folded onto a backing sheet and laterally heat sealed at uniform positions along the web, forming pairs of bags having laterally opposed openings. The web is perforated at the heat seals to allow ease of separation of the pairs of bags from the web, while longitudinal perforations allow for the separation of the bags of each pair from each other. Releasable adhesive strips are provided on closure flaps to allow closure of the openings of the separated bags. The bags are filled by draping them over a carrier bar, passing them under a blower and filler, and subsequently separating the bag pairs from each other and sealing them.

Abstract: A process for making a roll of plastic bags made from a two-ply web sealed along its sides. Perforations for the top edges of each bag are made simultaneously and separately in each of the two plys of the web forming the bag. The bottom of each bag is formed by a transverse seal. To further enhance ease of opening, at least a portion of the top edge on one ply of the bag is non-coincident with the top edge on the other ply of the bag.

Abstract: In a bag making machine utilizing clamp bar assemblies in combination with a sealing drum, the improved clamp assembly wherein the clamp is coupled to a channel bight, the clamp and channel being related to the conventional pivot shaft by means of a circumferentially-extending pivot pin and with clearance between the channel and pivot shaft.