Abstract: Apparatus for flattening and removing tubular plastic film has squeeze rollers, a radial arm with a deflecting roller and a shorter radial arm with a fixed turning rod. The film from the squeeze rollers passes by way of the deflecting roller and turning rod to a winder. The deflecting roller can be swung through 180 degrees while the turning rod is swung through 90 degrees. The turning rod is mounted for swinging movement in a recess in a U-shaped frame and the deflecting roller and squeeze rollers are mounted for swinging movement on one of the legs of the frame. The arrangement allows the size of the turning rod to be maximized.

Abstract: A method for manufacturing a sack or bag with a bottom being rectangular in the filled state and a handle portion joined thereto. An economical method for production by machine, according to the invention includes the following steps carried out sequently. A flattened tube piece (10) is provided with two slits at one end. The slits are substantially parallel to each other and to the lateral edges of the tube. Then a bottom square is formed by folding the tube piece near the slit end with corner tucks (14) and side tucks (16, 18). A prefabricated handle portion (22), including a reinforcing strip (24) and a connection strip (26) is glued or welded such that an edge portion (20) of one side tuck (16) is not covered by the prefabricated handle portion. Subsequently, such side tuck (16) and the corner tucks (14) are folded along a fold line (28) extending through the center of the corner tucks (14) and the uncovered edge portion (20) is glued or welded to the corresponding adjacent section of the handle portion.

Abstract: An apparatus for dividing a continuously conveyed stream of shingled workpieces, such as bags or sacks, into leading and trailing parts has two consecutive endless belt conveyors. The downstream second belt conveyor is driven, during a dividing operation, at a higher velocity than the first upstream conveyor in order to pull the shingled stream apart. After the stream has been divided into the leading and trailing parts the second conveyor is driven at the same velocity as the first conveyor. To provide separation of the stream into parts consisting of an exactly predetermined number of workpieces, an intermediate endless belt conveyor is provided, which extends parallel to the trailing portion of the second belt conveyor and during the dividing operation revolves at a lower velocity than the second belt conveyor. The intermediate conveyor is provided with cams for arresting the leading workpiece of the trailing part of the shingled stream, against an upper pressure belt.

Abstract: To make plastic carrying bags or sacks, sections are cut or are severed by hot wire welding from a gusseted tubular film by a formation of transverse seam welds and transverse severing cuts or by hot wire-welded transverse seam welds. At least in their bottom portion the sections are provided with corner seam welds, which are separately formed in the two folds and which diverge obliquely from the outer fold lines toward the top and/or bottom seam weld and terminate short of the inner fold line and merge into the latter. To prevent in the making of the carrying bags an elongation of the intermediate portion of the tubular film, the latter is initially formed with corner seam welds only in one fold of each of the two gussets before the transverse seam welds and transverse severing cuts or hot wire-welded transverse seam welds are formed. When said corner seam welds have cooled, congruent corner seam welds are formed in the respective other folds.

Abstract: Apparatus for stacking flat articles which in an intermediate portion are formed with locating holes and preferably consist of double bags having opening-defining edges disposed adjacent to their center line. The bags are fed by a wicketer and deposited in a stacking station on an endless stack conveyor and meedled onto raised upstanding stacking pins to form stacks. The stacking pins are operated to be lowered to release the needled stack which then advances to a succeeding severing station provided with a heated knife, which severs the stacks along a center line extending in the direction of stack travel. Additional conveyor belts are provided for retaining the separated stacks on the stack conveyor.

Abstract: An apparatus for stacking and delivering double bags of plastic film receives the bags from a transfer device at a stacking station which includes vertical pins on which the bags are impaled to form a stack. A stack conveyor with built-in grippers moves a completed stack to a severing station where a heated knife separates the double bags lengthwise of their travel while they are still in the grip of the grippers. The severed bags are then transferred to a delivery station where the grippers are released. The conveyor has separate side-by-side runs and separate gripper jaws are carried on each run. The stacking pins and the severing knife are located between the conveyor runs.

Abstract: In a process of making T-shirt bags a flat tubular film that is provided on each side with at least one gusset is provided with top end seam welds, which close the gusset portions to form handle loops, and with cutouts, which are similar to the neckline of a T-shirt and extend through the inner creases of the side gussets, and the tubing is then folded on itself about its longitudinal center line and is thereafter formed at its bottom end with seam welds, which join all plies, and is formed between adjacent top end and bottom end seam welds with transverse perforation lines or with hot wire-welded joints to separate adjacent bags from each other. Before the folding of the tubular film on itself about its longitudinal center line those portions of the tubular film which are subsequently provided with the top end seam welds are provided with layers of a release agent which extend across the web and prevent a welding of the web.

Abstract: Apparatus for severing bags from a two-ply web of thermoplastic material. The apparatus includes web guide rollers defining a nip, and a plurality of peripheral grooves in the guide rollers in which upper and lower air directing tubes are positioned to guide a web as it passes downstream of the feed rollers. A continuously transversely moving severing knife is provided downstream of the feed rollers and below the plane defined by the moving web. A pair of welding jaws are provided adjacent the cutting knife to grip the web in a plane below the web movement plane to weld the plies of the web together and to deflect the web into position for providing a transverse cut therein by means of the severing knife. A pivot lever is provided to pivot downstream ends of the lower air directing tubes in a downward direction to prevent interference between the downwardly deflected web and the downstream ends of the air directing tubes.

Abstract: A process of manufacturing sacks from synthetic thermoplastic material. A tubular structure is formed from webs of plastic film in that the side portions are infolded and their overlapping margins are adhesively joined by an adhesive seam, tubular sections are severed from the tubular structure and the tubular sections are provided with bottom seam welds and are then filled and provided with top seam welds. The two plastic film webs are moved in unison, and cut sections of oriented plastic material are provided, which cut sections are shorter than the distance between the subsequently formed bottom and top seam welds as measured along the flattened sacks. The cut sections are introduced between the plastic film webs with such a spacing relative to each other that the spaces between the bottom and top seam welds are to be formed. The plastic film webs and the fabric sections are brought together and are laterally offset from each other.

Abstract: An extrusion die for a blow head for making blown plastic films comprises inner and outer rings, which are made of a ferrous material, particularly steel, and define between them an annular orifice. Those surfaces of the inner and outer rings which define the die orifice are covered by a layer consisting of a metallic material having a higher thermal conductivity than steel.

Abstract: Apparatus for cutting stacks of flat workpieces, particularly of undershirt-shaped bags from stacked tubular film sections made of thermoplastic material and formed with side gussets and with top and bottom end seam welds. The apparatus includes a group of two punch-and-die sets, which are mounted in a transversely movable machine frame and include punches associated with drive means for moving the punches up and down, and die plates, which are fixed to the machine frame, and also includes a conveyor for intermittently feeding the stacks to and for removing them from the punches and dies. At least two punch-and-die sets and a drive motor associated with them are arranged in a row in a carriage, which is guided for reciprocation in the machine frame in a direction which is transverse to the direction of travel of the stacks. The carriage is adapted to be secured in the machine frame in two operating positions, in each of which at least one of the punch-and-die sets protrudes laterally from the machine frame.

Abstract: Apparatus for stacking and conveying flat articles that are preferably provided with locating holes and preferably consist of bags that have been severed from a tubular or semitubular plastic film web and have been closed by welding. The bags are carried from a forming station to a pair of adjacent, parallel stacking conveyors by a rotatable wicketer having spaced pairs of radial transfer arms. The stacking conveyors include endless belt like carries that pass around rotatable wheels or rollers and are intermittently driven. The carriers include upstanding stacking pins or stacking needles, which extend from and are secured to carrying plates mounted on the carriers. Two spaced, adjacent stacking conveyors are provided and different tools for acting on the intermittently conveyed stacks of bags are selectively provided and detachably secured to the frame of the apparatus between the stacking conveyors.

Abstract: Apparatus for cooling tubular plastic films extruded from a film blowing head. Air cooling means consisting of co-axial pipes extending axially through the film blowing head supply the cooling and inflating air and withdraw the same from the inflated parison. Vertically inner cooling rings are disposed substantially concentrically to the axis of the parison downstream of the annular extrusion die orifice of the blowing head. The inner cooling rings define nozzle gaps and have air guiding surfaces, which face the wall of the parison and are convexly curved in a longitudinal section of the inner cooling rings and during the operation of the apparatus are swept by the cooling air blown out of said nozzle gaps. An outer cooling air jet concentrically surrounds the extruded parison and serves to blow air in a direction which is approximately parallel to the direction of travel of the parison. The inner cooling rings are concentric to the parison.

Abstract: In a stacking apparatus for sheets delivered by a double belt conveyor including spaced parallel conveyor belts, a stacking station beneath the discharge end of the conveyor is supplied with sheets by parallel suction arms which move at the conveying speed between the conveyor belts and therebeyond, are lowered to the stacking station to deposit a sheet while the suction effect is interrupted, and are then returned to the conveying plane.

Abstract: In stacking apparatus for flat articles such as flattened bags, radial arms mounted on each of two spaced hubs and having suction nozzles at their leading sides place the articles onto needles. The arms are rotatable about their longitudinal axes. They can be turned outwards through an acute angle by cam and cam follower means and are turned back after the articles have been placed on the needles.

Abstract: In an apparatus for making plastics carrier bags from a web of tubular film of thermoplastic material, a feeding mechanism intermittently conveys the webs by one bag width and a severing mechanism cuts the web into half tubes along an undulating curve. A carriage displaceable in the machine frame transversely to the feeding direction of the web is reciprocated by a drive derived from a first rotating control cam through gearing. A cutting knife pivotable in the carriage about its longitudinal axis passes through the plane of the tube about an axis perpendicular thereto and is so controlled by an oscillating drive derived from a second rotating control cam that its edge is substantially tangential to the undulating curve at the cutting point. A detour assembly retards one of the half tubes to bring the bag side edge zones into phase and each half tube is formed into bags by a transverse sever-sealing device.

Abstract: To undo the interconnection caused at cut edges of stacks of plastics bags that have been stamped, at least those zones of each stack where stamping has taken place are continuously bent over at least one supporting edge by being pulled thereover.

Abstract: A valved bag consists of a collapsed section of a tubular plastic film, which has been formed in that the side portions of a plastic film web have been infolded to overlap each other and which has been provided with transverse top and bottom seam welds and in the overlap area of the side portions has been provided with two spaced apart parallel longitudinal seams, which join only said side portions and terminate or are interrupted at a distance from the top seam weld so as to provide a filling passage. In order to simplify the manufacture of the valved bags, the longitudinal seams consist of strips of adhesive and are in contact with both side portions of the film web at both edges of the overlap area. One of said side portions is provided with an adhesive bond-inhibiting agent adjacent to the filling passage at least across the strip of adhesive.

Abstract: In apparatus for stacking flat articles such as flattened bags, two spaced rotatable hubs carry radial transfer arms provided with suction nozzles. By perforations on one side of the articles, the latter are collected up to the desired stacking height on prongs provided at one side of endless conveying members of an intermittently operative conveyor. The other sides of the articles hang over the other side of the conveying members where the latter are provided with supporting frames or plates which project laterally beyond the conveyor and are mounted at their central region on two parallel pivot shafts which are secured to the coveying members, extend transversely thereto and are spaced apart sufficiently to enable them to pass over direction-changing drums or wheels of the conveying members.

Abstract: In a transverse severing apparatus for webs of thermoplastic material, two parallel pressure bars are lowerable onto and raisable from a section or sections to be severed from the web. The upstream pressure bar clamps the leading end of the web to a backing bar. The second pressure bar, which is disposed between a severing knife and the upstream bar, tensions the web clamped between a pair of feed rollers and the upstream pressure bar before the severing knife cuts the web.