Abstract: A bag manufacturing and packaging apparatus is adapted to form a strip film into a cylindrical film. The bag manufacturing and packaging apparatus includes a sealing unit with a pair of sealing members facing each other to seal an end portion of the cylindrical film therebetween to package an article. Each of the sealing members includes a sealing jaw, a heating unit, and a heat insulating member. The sealing jaw has a heat generating surface, and configured and arranged to seal the cylindrical film on the heat generating surface. The heating unit is configured and arranged to heat the heat generating surface of the sealing jaw. The heat insulating member insulates the heat conduction from the heating unit to a direction other than a direction toward the heat generating surface of the sealing jaw.

Abstract: A split crimper for use in a crimping assembly for engaging and heat sealing overlapping layers of a packaging material includes a first crimper portion having a crimping surface and a second crimper portion that is secured to the first crimper portion to form a crimper. Portions of the first and second crimper portions cooperate to define an interior cavity, and a heating element is disposed completely within the interior cavity.

Abstract: An adjustable pouch machine comprises a vertical sealer module forms transverse seals between two plies of a pouch web to partially define a plurality of pouches. Rollers selectively tension and relax the web on the vertically oriented wheel, allowing them to drop away from heated lands on emergency and cycle stops. A filler wheel has a plurality of adjustable gripper units mounted directly thereon for transporting independent separate pouches cut from the pouch web. An adjustable knife is selectively provided with changeable knife hub sets to handle a variety of pouch sizes where a filler wheel alternately first fills and seals pouches in a train. Gear linkage accommodates variation in distance between hubs of different sets. Various embodiments, apparatus and methods are described.

Abstract: A split crimper for use in a crimping assembly for engaging and heat sealing overlapping layers of a packaging material includes a first crimper portion having a crimping surface and a second crimper portion that is secured to the first crimper portion to form a crimper. Portions of the first and second crimper portions cooperate to define an interior cavity, and a heating element is disposed completely within the interior cavity.

Abstract: A machine and method for making bags is described and includes a web traveling from an input section to a rotary drum, to an output section. The rotary drum includes at least one seal bar, having a single sealing zone, and a weakening zone disposed within the single sealing zone. The single sealing zone may be a heated perforator, and may include a heating wire. The heating wire may be an NiCr wire stitched into the heater, and be disposed on a cap or on the seal bar. The weakening zone may create a line of weakness that is uniform or varies in intensity. The sealing zone may include temperature zones, cartridge heaters, cooling air, or heated air, or a source of ultrasonic, microwave or radiative energy.

Abstract: A split crimper for use in a crimping assembly for engaging and heat sealing overlapping layers of a packaging material includes a first crimper portion having a crimping surface and a second crimper portion that is secured to the first crimper portion to form a crimper. Portions of the first and second crimper portions cooperate to define an interior cavity, and a heating element is disposed completely within the interior cavity.

Abstract: A first hanger and a second hanger are disposed on a working platform according to a hanging manufacturing apparatus for manufacturing an air enclosure, in which the first hanger is constituted by a first hanging frame and a plurality of first supporting arms and used for hanging a first hot sealing mold, the first hanging frame drives the first hot sealing mold on the plurality of first supporting arms to hot-seal an air cylinder film sheet while being moved to form a plurality of nodes on the air cylinder film sheet, and the second hanger is constituted by a second hanging frame and a plurality of second supporting arms and used for hanging a second hot sealing mold, the second hanging frame drives the second hot sealing mold on the plurality of second supporting arms to hot-seal the air cylinder film sheet while being moved to form a plurality of air cylinders on the air cylinder film sheet.

Abstract: Various device embodiments include first and second plate assemblies. Each plate assembly includes a base, a seal plate, one or more air bladders and a servo motor to provide a linear motion of the seal plate with respect to the base. The device further includes at least one plate assembly motor operably linked to the bases of the plate assemblies to provide a linear motion of the first and second plate assemblies toward each other to perform a sealing operation and away from each other. The device further includes a controller connected to the at least one plate assembly motor and to the first and second servo motors to coordinate the motion of the first and second seal plates to perform a seal operation on a web while traveling with the web.

Abstract: A split crimper for use in a crimping assembly for engaging and heat sealing overlapping layers of a packaging material includes a first crimper portion having a crimping surface and a second crimper portion that is secured to the first crimper portion to form a crimper. Portions of the first and second crimper portions cooperate to define an interior cavity, and a heating element is disposed completely within the interior cavity.

Abstract: A device for producing container blanks from a material web having a plurality of tools supported by a rotary tool holder. The tool holder is on rotation arranged to move each tool along a working path along which each tool is engageable with the material web for joining of opposite wall portions of the material web along connecting portions, and a return path along which each tool is disengageable from the material web. Each tool is arranged to be moved together with the material web when the tool is moved along the working path and the tool holder acts as a deflector for the material web when this moves together with the respective tools along the working path. The present invention also relates to a corresponding method for producing container blanks.

Abstract: A method and apparatus for making and winding bags is disclosed. The bag machine includes an unwind section, a forming section, and a winder. The winder has an infeed nip and two spindles. Each spindle is located along a respective one of two alternative film paths. The spindles can be fixed position spindles and the alternative film paths can be predominantly downward. An over speed nip may be provided between the infeed nip and the alternative film paths to separate rolls or to separate all bags. An overlapper can be included. Rods that travel in an elliptical orbit, and/or air nozzles can be part of the overlapper. Air nozzles can also be used to direct the film to the appropriate alternative path. Conveyor belts along the alternative film paths can be used to guide the film. Static pinners can be used to help bold the bags to the conveyor, or the last bag to the roll. Pop-up fingers and air horns can help start the roll on a spindle. Paper banders can be use, as can pneumatic devices.

Abstract: Various device embodiments include first and second plate assemblies. Each plate assembly includes a base, a seal plate and a servo motor to provide a linear motion of the seal plate with respect to the base. The device farther includes at least one plate assembly motor operably linked to the bases of the plate assemblies to provide a linear motion of the first and second plate assemblies toward each other to perform a sealing operation and away from each other. The device further includes a controller connected to the at least one plate assembly motor and to the first and second servo motors to coordinate the motion of the first and second seal plates to perform a seal operation on a web while traveling with the web.

Abstract: A heat sealing jaw for use in cooperation with an opposing backing jaw for sealing layers of film together is described. The heat sealing jaw may be suitable for forming an easy-open feature on a packaging pouch used to contain flowable material. In certain embodiments the heat sealing jaw comprises a jaw body, a heat sealing element secured to the jaw body, a support surface for clamping the layers of film together against the opposing backing jaw, and, a heat sink coupled to the heat sealing element for inducing a temperature gradient along a sealing face of the heat sealing element. The sealing face may have a protrusion for forming a notch within the layers of film. Related apparatuses and methods are also described.

Abstract: A machine and method for making bags is described and includes a web traveling from an input section to a rotary drum, to an output section. The rotary drum includes at least one seal bar, having a first sealing zone, and an adjacent weakening zone. The weakening zone may be a heated perforator, includes a heating wire, or be disposed to create an auxiliary sealed area. The heating wire can have, connected thereto, a source of power that is at an adjustable voltage or magnitude, and/or pulsed, and/or a feedback loop. The heating wire may be an NiCr wire and make intermittent contact with the web and be disposed in an insert. The weakening zone may create a line of weakness that is uniform or varies in intensity, is a separating zone, or includes a heat film, a toothed blade, a row of pins, a source of air, or a source of vacuum. The sealing zones may include temperature zones, cartridge heaters, cooling air, or heated air, or a source of ultrasonic, microwave or radiative energy.

Abstract: A plastic bag making machine is disclosed, and includes a dancer assembly that receives film from which the bags are to be made. The film travels from the dancer assembly to a drum-in nip and then to a sealing drum. After the sealing drum, the film travels to a drum-out nip. Then the film travels to a device-in nip, vertically through a processing device, and then to a device-out nip. A controller is connected to and controls the drum-in nip, the drum-out nip, the device-in nip, the device out nip, the dancer assembly and the sealing drum (including the seal bars and/or the sealing blanket drives). The controller includes a memory in which at least one set of operating parameters used to control the machine is stored.

Abstract: Disclosed is a sealing apparatus wherein, as a drum (5) and a rotary base (6) are rotated together, a follower (10a) of a rocking support member (9) rockably provided on the outer periphery of the rotary base (6) is guided along a cam groove (15c) of a cam member (15) to drive the rocking support member (9) to rock. When the rotary drum (5) reaches a predetermined rotational position, an anvil (14) supported by the rocking support member (9) is urged onto a horn (8), and then, when it reaches another rotational position, the anvil (14) is moved away from the horn (8). Since the anvil (14) is driven by the rocking motion of the rocking support member (9), entire operation becomes quite simple, and a continuous soft work can be certainly clamped between the horn (8) and the anvil (14).

Abstract: Protective bags made of a plastic film have heretofore been produced by folding two pieces of films by hand, and it is very difficult to mass-produce asymmetrical bags at a low cost. Protective bags made of a film bearing any design are now continuously produced at high speeds by using a film tube blank, inserting a floating separator in the film tube blank, forming openings with symmetrical or asymmetrical continuous or discrete cut lines in the upper and lower surfaces or in both side surfaces in a state where motion of the film tube blank is stopped, depending upon the length of the bag, and cutting the film tube blank at the melt-adhered portion using a cutting edge extending in the direction of width.

Abstract: A cross sealer for a plastic bag making machine includes a frame with an upper moveable seal bar unit and an opposed lower stationary seal bar unit. The movable unit is a lightweight construction seal beam. A rotating shaft spans the cross sealer and is connected by a plurality of eccentric linkages to the seal beam. The linkages moves a seal bar into sealing engagement across the width of the web to the seal bar unit constructed with a support beam and a seal bar connected to the beam. The seal bar unit is mounted as a substantially stationary unit during sealing and is supported by a plurality of air cylinder units for positioning from standby to an operating position. Each air cylinder unit includes an adjustable stop unit secured to the back of the cylinder unit and connected to the cylinder piston for adjusting the movement of the piston and thereby the operative sealing position of the stationary seal bar unit.

Abstract: The line plastic bag machine comprises: first and second side walls; a plurality of rollers mounted between the side walls for receiving a web of plastic film that is trained through the machine over and around the rollers; a main drive motor; a main drive shaft driven by the main drive motor; the rollers including a main drive or chrome roller and a pair of spaced apart shuttle rollers mounted in a shuttle assembly; a drive train for driving from main chrome roller from the main drive shaft; the shuttle assembly being mounted for back and forth movement thereby to position an incremental width of the web of film traveling over the shuttle rollers in a momentary stationary position as the web of film is moving through the machine so that the incremental width of the film is momentarily stationery relative to the side walls; drive apparatus for moving the shuttle assembly; a perforating and sealing head which is movably mounted relative to the side walls for moving upwardly and downwardly over and relative to

Abstract: A cross sealer for a bag making machine includes a frame with an upper seal bar unit and a lower seal bar unit in aligned opposed relation. One is movable seal bar unit which includes a rigid support beam of a lightweight construction and a light weight seal bar connected to the beam by a plurality of adjustable stud units for adjusting the position of the seal bar. A rotating shaft spans the cross sealer and is connected by a plurality of eccentric linkages to the beam between side plates of the frame. The linkages support the beam and seal bar and transfers the sealing force onto the beam and bar for moving the bar into sealing engagement across the width of the web. The opposed seal bar unit is similarly constructed with a beam and a seal bar with the units interconnected by adjustable stud connectors.

Abstract: A method of continuously forming, filling and sealing of packages with a continuous web of film material is disclosed and comprises the steps of providing a continuous web of film material and folding the web to provide confronting sides joined along a bottom edge and forming a vertical seal at spaced intervals along the web. This process forms a series of horizontally disposed pouches having opposed sidewalls separated by the vertical seals with each pouch being unsealed along a top edge. The pouches are then opened by separating the opposed sidewalls and are then filled with a product.

Abstract: An apparatus for manufacturing containers or bags includes a sealer that produces seals on a moving film. These seals are spaced at intervals that determine the length of the containers. An operator can change the desired container length while the film is moving. In response to such changes, a control arrangement adjusts the speed at which the sealer rotates and, in turn, the spacing of the seals and the length of the containers.

Abstract: When manufacturing bags from tubular paper sections of a single layer or multiple layers, at least one end of each flat, tubular section is expanded into a bottom square. Lateral flaps formed in this way are folded such that they overlap and partially cover corner flaps. In order to easily bond expanded bottom squares together, the regions of the tubular sections which are to be bonded together are provided with coatings of thermoplastic which are heated and pressed together.

Abstract: A welding unit for forming defining weld lines in an elongate web, preferably in a bag-making machine, includes a drive means, which is arranged in an endless loop, and at least one sealing jaw. The sealing jaw is connected to the drive means for movement along said loop. A fixed guide means extends in an endless loop essentially in parallel with the drive means. Each sealing jaw is received on a carriage, which is connected to the drive means and has at least one follower element, which is adapted to abut against and move along the guide means.

Abstract: A seal bar assembly which includes a support structure (21), and at least a first seal bar segment (22) and a second seal bar segment (23) mounted substantially parallel to each other on the support structure. The seal bar segments define a gap (28) therebetween. Each seal bar segment has two ends, with mounting means (26) positioned proximate to each end of both the first and second seal bar segments for mounting the ends of the seal bar segments to the support structure. The mounting means are adapted to permit one or both ends of each seal bar segment to move toward or away from the support structure, but the mounting means do not permit the seal bar segments to significantly move transversely with respect to each other. In this manner, the seal bar segments remain substantially parallel to each other, and the gap between the seal bar segments is maintained substantially constant.

Abstract: The invention concerns an apparatus for welding the tubular sections of sacks, bags or the like, having a rotating drum and with welding stations arranged on the periphery of the drum which rotate, fixed in position, with the drum, wherein the welding stations are arranged laterally each on one end side of the drum. To ensure a crease-free processing of the tubular sections to be welded, grippers that can be caused to open and close are arranged on the drum in individual welding stations, for the seizing, holding and release of the tubular sections. A movable welding jaw of the welding station forms a flat bearing surface for the zone of the tubular section to be welded, while the drum itself, has a cylindrical peripheral surface.

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: Methods of converting pitch on a pouch machine include using a standard drive table with above table change parts including sealer wheel, filler wheel and knife. The sealer wheels and filler wheels are retained at respectively the same diameters to facilitate use of the common drive and to facilitate maintenance of the pouch web path through the machine for all pouch pitch ranges. Pouch stations on the sealer and filler wheels are not limited to whole degree movements and pouch web speeds are preferably maintained constantly for all pouch pitch ranges.

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: An arrangement in a bag-making machine for forming weld lines in a web continuously fed through the machine, preferably a flattened plastic film tube, comprises a cylindrical, freely rotatable drum; a driving belt which is adapted to rotate the drum and pressed against part of the circumferential surface of the drum; and a number of transverse sealing jaws which, as the drum rotates, are movable into engagement with and drivable together with the web for welding the web through a predetermined angle of drum rotation. In order to achieve a high speed of the web, preferably about 150 m/min., and high flexibility in respect of the available range of bag length, the sealing jaws are freely movable relative to the drum outside the circumferential surface thereof and controlled by a control device which is adapted to hold each sealing jaw in a stand-by-position out of engagement with the web, and successively to bring each sealing jaw into engagement with the web with a certain time delay relative to each other.

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.

Abstract: An apparatus and method for making individual flexible web products whereby a web material is tucked outwardly from the surface of a product drum by fixed projections, severed and sealed, and provided to one or more transfer points. The products are there transferred to open or more transfer drums with corresponding indentations, which deliver the products to packing devices. An alternative embodiment provides multiple delivery points by using lateral-shifting transfer drums. The apparatus and method provides a simple means to vary and control flexible product width without introducing a multiplicity of moving parts, and discloses means to enhance separation of individual products during transfer while increasing overall production rates.

Abstract: An apparatus is provided for continuously sealing a thermoplastic draw tape to a thermoplastic bag at a sealing section. The bag forms one of a plurality of bags formed on a continuous web of thermoplastic material. The bag includes a hem defining a channel wherein the draw tape is disposed. The section of the bag which includes the hem and the tape thus includes a plurality of layers of thermoplastic material. The apparatus comprises a conveyor for continuously moving the web; a first sealing station for forming a heat seal through at least two of the layers of the hem and tape, the seal being formed on a first side of the bag; and a second sealing station for forming a heat seal through the rest of the layers of the hem and tape at the sealing section on a second side of the bag. The first and second sealing stations form the seals while the web is continuously moved by the conveyor.

Abstract: An apparatus for the continuous production of individual flexible products from a folded web of material, in particular, heat sealable thermoplastic material, is described having improved means for providing tension relief in such web material, and for tucking such web material outwardly from the surface of the product drum. The tuck rolls remain extended above the surface of the product drum throughout product drum rotation, and are retracted by cam arrangement to provide tension relief. Three alternative support assemblies and related cam arrangements are disclosed, two of which employ adjustable, compressible tuck roll support assemblies.

Abstract: An apparatus for manufacturing bags in which a band of a packing material is shaped into a tube about a shaping mandrel and which comprises a reciprocating transverse sealing device for dividing the tube into separate bags, a rotatable conveying device frictionally engaging the tube in an area of the shaping mandrel for intermittently feeding the tube, and a drive for synchronously moving the rotatable conveying device and the transverse sealing device during feeding the tube by a bag length.

Abstract: A bag making machine and method for the continuous production of bags from a folded web of thermoplastic material is provided. The apparatus includes a capability for making bags of differing widths as well as making bags having consistent widths for the particular size of bag selected. The apparatus includes a rotatable drum having a plurality of sever and seal stations for forming individual positioned about the outer periphery of the drum. A source of a continuous folded web of thermoplastic material is also provided, and continuously fed onto the surface of the drum. Means positioned between adjacent sever and seal stations tuck the web of material inwardly from the periphery of the drum. To prevent the occurrence of stretching forces which may adversely affect the web and the resulting width of the bags during processing, a film tension compensation means is provided for maintaining a constant path length for the web of material between the web source and the sever and seal stations.

Abstract: A machine for making plastic bags from plastic film utilizes a rotatable drum having an adjustable diameter. The drum is constructed of a plurality of slats and includes a gear mechanism adapted for infinite variation of the drum diameter between a first smaller diameter and second larger diameter. A sealing blanket is provided for the drum and is automatically adjusted for different drum diameters to provide proper tension of the film as it passes around the expandable drum. The gear mechanism is operated manually or automatically by a motor mounted in the drum and can alter the drum diameter while the machine is running.A chill roll, a rotary handle hole punching unit, a perforator/cutter station and phase variators are also included. When the machine is used to make bags having printed material thereon, a comparator unit may also be used.

Abstract: A bag making machine and method for the continuous production of bags from a folded web of thermoplastic material is provided. The apparatus includes a capability for making bags of differing widths. The apparatus includes a rotatable drum having a plurality of sever and seal stations for forming individual positioned about the outer periphery of the drum. A source of a continuous folded web of thermoplastic material is also provided, and continuously fed onto the surface of the drum. Means positioned between adjacent sever and seal stations tuck the web of material inwardly from the periphery of the drum.

Abstract: The rotary bag making machine of the present invention is adapted to make side seal bags having a plastic drawstring through a hem in the top of the bag. More specifically. The rotary bag machine of the present invention includes a two part, elongate sealing bar having sealing edges, the first part of which is heated to a first temperature for sealing two layers of plastic bag material and the second part of which is heated to a second higher temperature for sealing the six layers which are present when hems are formed with inserted drawstrings. The second part of the seal bar is not only designed to form the seal but to heat weld together the drawstring plastic so that it will not separate or tear apart when the bag is gathered and subsequently tied with the drawstring.

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 method and apparatus are provided for continuous fabrication of bags from a longitudinally advanced multi-layer thermoplastic film web fed tangentially onto a rotating drum for carrying out transverse web seam welding and severing, the principal novel feature being provision of preliminary heating carried out across at least part of the width of web at which the final seam and sever is to take place. The preliminary heating step is advantageous where the thickness of film layers to be sealed and severed is not uniform across the width of the web or in which the uniform thickness of the film layers is such that seaming and severing in a single step requires an undesirably long time for continuous high speed production. The method can be adapted for production of bags of different widths.

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: The present invention relates to a machine for sealing material in sheets, which have been pre-coated with beads of glue affected by heat, preferably electronically printed toner beads, the beads coming into engagement with each other after folding the sheet into such as the configuration of an envelope or the like, the sheet then being advanced into the machine for adhering the beads to each other. In accordance with the invention, the machine includes a first sealing zone (12) and a second sealing zone (13), which are arranged at 90.degree. to each other with advancing means (36,38, 34,47) for conveying the respective sheet through the sealing zones, each sealing zone having one or more pairs of rotationally driven sealing discs (14,15,18,19,23,26). Each pair of sealing discs includes a first disc (14,15,23) heated by heating means, and a second, preferably freely rotating, disc (18,19,26) engaging against the first disc with a pre-settable pressure.

Abstract: In a bag making machine utilizing clamp bar assemblies in combination with a sealing drum, the improved clamp bar assembly wherein the clamp bar is related to the conventional pivot shaft by means of a pivot pin floating in a slightly oversized hole.

Abstract: Bags for packaging cut tobacco are severed from a continuous longitudinally moving film sheet along transverse welding seams 28 which are made by a thermal welding unit 29 having three, transverse-welding jaws, during each working cycle. The welding unit can be moved to and fro and is movable with the film sheet 25 for a part section (conveying section). During the return movement of the welding unit to its starting position, the film sheet is conveyed onwards by a special draw element, until a conveying cycle has been completed.

Abstract: Apparatus for folding, bonding and severing a longitudinally extending web, comprising a rotatable disc having a plurality of circumferentially spaced-apart, radially extending protrusions at its periphery, means for rotating the disc, means for feeding the longitudinally extending web onto the disc during rotation thereof, so that outer extremities of the protrusions contact the web at its medial region to cause folding of the web so that its sides overlap one another between the protrusions, means for bonding the folded web at its overlapping sides between adjacent protrusions during rotation of the disc, and means for severing the folded web at its overlapping sides between adjacent protrusions during rotation of the disc. Also disclosed is a corresponding method wherein the longitudinally extending web is folded, bonded and severed.

Abstract: Apparatus for making bags from a folded web of thermoplastic material includes a rotating drum to which the web is continuously applied. As the drum rotates through a given arc length, the web is tucked outwardly from the periphery of the drum in progressively deeper folds wherein the depth of tuck determines the width of the bag. A cam, controlling the depth of tuck is movable in a rectilinear radial direction for adjusting the depth of tuck, thereby controlling the bag width.

Abstract: An apparatus for transversely sealing layers of thermoplastic material wherein platen-equipped upper and lower cross bar conveyors are provided for the sealing, there is provided means for jogging the thermoplastic web material incident to heat-up of the platens to prevent scorching of the web and means for stretching the layered web during sealing to overcome the tendency for differential longitudinal shrinkage.

Abstract: For producing transverse seams on tube bag machines, two conjointly, oppositely moving sealing tool jaws (15, 16) are provided, which are movable on a carriage (6) during the sealing process.For driving the sealing tool and selecting an appropriate stroke length, the frame (5) on which the carriage (6) rests is movable up and down by a pair of coupled cam-actuated levers (19). The axes of rotation (34) of two levers (19), and thus the distances travelled by their uncoupled, flapping ends, are adjustable along the lengths of the levers. This is accomplished by turning a spindle (3) bearing oppositely wound screw threads, which sets adjustment bodies (30) with sliding blocks (4) for the two-armed levers (19).Thus, packages of varying heights can be efficiently sealed, since the sealing mechanism always seals in the middle of the package height, regardless of stroke length selected.

Abstract: An apparatus for heat sealing of plastic bags having a main assembly for sealing, which includes drive and control means and a removeable heat sealing head having confronting heat transfer means between and in contact with which the bags pass, such that confronting side walls thereof are heat sealed, the heat sealing head constituting a sub-assembly provided with its own drive means and adapted to be received in said main assembly through a single drive means.