Abstract: A sack comprises an inner container and a double-ply outer container which latter comprises a tubular or essentially tubular section of which the opposed severed edges are interconnected by a seam. Alternatively, the outer container comprises two such sections having their severed edges interconnected by respective seams.

Abstract: This invention relates to apparatus for infolding laterally protruding wings of a filled sack onto adhesive strips provided on the top of the sack. Said wings have been formed when the top end portion of the sack has been stretched flat and has been closed by a seam weld and has been folded down onto one half of the flattened top surface of the sack. Two folding bars or folding rods are movably mounted in a machine frame and protrude freely in the direction in which the sacks are conveyed. Said folding bars or rods are adapted to be lowered onto and raised from the top surface of each sack and have outer edges defining fold lines for the wings to be infolded. Holders are mounted in the machine frame on both sides of the sack standing upright on a support. Each of said holders carries a holder frame provided with a gripper arm for engaging one of the wings from below. An upper gripper arm for cooperating with the lower gripper arm is pivoted in each of said holder frames.

Abstract: Apparatus for closing filled sacks, preferably large sacks, which consist at least in part of thermoplastic material, comprises a feeder for feeding the filled sacks into a closing station. The feeder preferably comprises a roller conveyor or a belt conveyor. The apparatus also comprises means for holding the top end portion the sack above the contents of the sack, pressure-applying bars, which are parallel to each other and adapted to be lowered onto the contents of the sack on both sides of the sack end portion, which is held taut, which pressure-applying bars when in a lower position define between them a gap for the passage of the sack between said bars, and closing means provided above the pressure-applying bars. The closing means comprise welding bars and backing bars, which engage the sack end portion between the end-holding means and the pressure-applying bars and are disposed on opposite sides of said sack end portion.

Abstract: Bag-filling apparatus comprises gripping means for gripping flat bags adjacent to their top edges and side edges, vacuum cups for engaging the bag on opposite sides near its top edges and for pulling said top edges apart, and a filling pipe, which is provided with filling hopper halves, which are adapted to be pivotally movable about parallel axes by drive means. The filling hopper halves are hinged on respective axes which are transverse to the line which connects the grippers and the spreading members of the filling hopper halves have in cross-section laterally inverted, outwardly protruding or convex shapes the apices of which are disposed on the line which connects the grippers. The arrangement may be such that the end edges and side walls of the filling hopper halves are in sealing contact with each other when the filling hopper halves are in their swung-in position.

Abstract: For automatically suspending large sacks successively from a filling device, each flattened sack is folded at least once onto itself. Every sack is in turn brought up to stops on a table and scanned for alignment by photocells. The mouth of the sack is pulled open by suckers, transferred to gripper mechanisms which are carried by swing arms and provided with hinged grippers co-operating with wedges inserted in the open mouth, and the sack is then swung from the table to the filling device where it is pushed onto a funnel.

Abstract: Large capacity sacks are successively suspended from holding devices by their mouths and filled with pourable material through a conduit equipped with a dispensing mechanism. During filling, the sack comes to rest on a support which is part of weighing apparatus for controlling the dispensing mechanism. Before the sack contents have reached a predetermined final weight, the holding devices are lowered to relax the sack wall above the level of the contents, whereupon filling is completed at a trickle rate.

Abstract: A piston-cylinder unit causes a web of closure tape material to be withdrawn from a supply reel in steps equal to the width of each closure tape required for closing the folded-over flattened mouth end of a large sack. Each tape is severed from the leading web end by a knife and engaged by a suction bar which is swung together with two welding bars onto an inclined support for the folded-over mouth end.

Abstract: Preparatory to closing a filled upright sack by a zig-zag closure, grippers engage the flattened mouth end of the sack. A support is swung to a position adjacent the flattened end and swing arms cause the end to be folded onto the support. After rollers have been swung onto backing rollers to clamp the folded-over end, the grippers are opened and withdrawn by the swing arms.

Abstract: The mouth end of a large filled sack is held taut and flat by holding means. Parallel folding bars extend downwardly from carriers like the prongs of a comb at both sides of the flattened mouth end. The carriers can be moved towards and away from each other, and raised and lowered, so that the folding bars gather or ruffle the mouth end to form a frill and are then withdrawn.

Abstract: In a method of automatically closing a large upright sack after filling, the top of the flattened filling end of the sack is folded over onto itself and a closure tape is secured to the folded-over portion and one wall of the sack, whereafter the filling end is re-erected substantially vertically, folded in zig-zag fashion and pulled together to form a frill. The ends of the tape project beyond both sides of the filling end so that, after zig-zag folding of the filling end and tape and after the frill has been formed, the tape ends project from the same side of the frill and can be interconnected.

Abstract: Lifting gear for a filled sack comprises a pair of clamping bars between which the gathered and flattened mouth portion of the sack can be clamped after the mouth portion has been slung thereabout. The bars are in the form of parallel cantilever arms and rotatable about an axis parallel thereto, one of the bars also being displaceable to and from the other bar while remaining parallel thereto.

Abstract: Sacks are successively filled and closed in an automatic process by suspending each sack from near the mouth and spreading the side walls apart, filling the sack, allowing it to settle on a support while keeping the side walls taut, bringing the side walls together near the mouth and folding them over onto themselves, welding a closure tape over the folded-over portion and the adjoining unfolded portion of the sack, crimping the unfilled upper part of the sack and gathering it to form a frill, and applying a clamping ring beneath the frill.

Abstract: In an apparatus for separating flattened valved sacks which are reeled in an overlapping formation, the reel is turned by endless belts pressing on the reel periphery as the overlapping sacks are being taken off the reel. A roller presses the overlapping sack formation onto the belts and this roller is disposed at a spacing of no more than about one sack length from the point where the sacks leave the reel.

Abstract: Conveying means which are intermittently rotatable in equal steps take flattened sacks successively from supply means through one step to filling means which are effective to open each sack and fill it, whereupon the conveying means move a further step to take the sack to welding means. Said conveying means comprise two parallel discs turned in synchronism about horizontal shafts which are directed outwardly to define a free passage between the discs. Confronting tongs on the discs are displaceable towards and away from one another to engage the sack at both sides of its mouth at the supply means and convey it up to the welding means at which they deposit the filled sack on a discharge conveyor, the tongs being lowerable towards said discharge conveyor to an extent such that the upper region of each sack becomes buckled.

Abstract: Bags are fabricated from tubular plastics film as they are being filled. A flattened severed tube section of the bag material is clamped across its entire width at the bottom but only near the folded longitudinal edges (or the side pleats if such are provided) at the top. The walls of the tube section are pulled apart at the top between the clamped regions to present a filling aperture and welded together at the bottom across the entire width below the clamped region. After the contents of the bag have been inserted through the filling aperture, the top of the tube section is welded shut above the clamped regions and the bag is discharged.

Abstract: To form stacks of flat folded bags, each bag comprising a mouth portion reinforced by at least one additional ply of bag material, the mouth portion and the base portion are both folded onto the central bag portion about respective fold lines so that their adjacent edges stop short of one another or just touch. The mouth portion is folded about a fold line disposed beyond the reinforcement. The base portion is either folded once about a fold line disposed inwardly of a gusset formed in the base or, if there is no gusset, in Z formation about two fold lines.

Abstract: In an apparatus for successively enveloping stacks of flat workpieces in bags, an inverted said bag is placed over a shaft in which a stack is located. A reciprocatable slide in the shaft comprising upwardly open U-section supporting bars for the stack presses the stack upwardly into the bag against a backing member disposed above the shaft, whereafter rod members enter the shaft in a lateral direction, are received in the U-sections of the supporting bars and are pivotable together with the back member to swing the enveloped stack away from the supporting bars and out of the shaft.