WO2014173953A1

WO2014173953A1 - Device and method for folding over and welding film overhangs during the wrapping of stacked goods with a film

Info

Publication number: WO2014173953A1
Application number: PCT/EP2014/058243
Authority: WO
Original assignee: Dücker Group GmbH
Priority date: 2013-04-23
Filing date: 2014-04-23
Publication date: 2014-10-30
Also published as: EP2989010A1; EP2989010B1; DE102013207360A1

Abstract

The invention relates to a device for folding over and welding upper-side film overhangs during the wrapping of stacked goods, in particular of goods which are stacked on pallets, with a film made from plastic, having • - a frame (1) consisting of at least two stands (2) which are connected to one another by way of crossmembers above the maximum stack height, • - an industrial conveying device (3) for transporting the goods which leads through the stands of the frame, • - a rectangular frame (6) which can be moved up and down over the height of the stacked goods on the frame (1) for folding over and welding upper-side film overhangs of the vertical film encapsulation onto the stack upper side, • - between which two or more prestressed cables (11, 12) of constant length are deflected in such a way that they form a rectangle which lies horizontally in the frame, wherein the cables are rigidly fastened with both ends to the frame which can be moved up and down, and • - which cables can be moved transversely and longitudinally with respect to the industrial conveying direction, with the result that the shape and size of the rectangle which is formed by the cables is variable.

Description

DESCRIPTION

Device and method for folding and welding of film overhangs when wrapping stacked goods with a film

The invention relates to a method and a device for folding and welding of top film overhangs when wrapping stacked goods, especially stacked on pallets goods with a plastic film, with a frame consisting of at least two uprights, which are above the maximum stack height by cross members are connected, with a floor conveyor for transporting the goods, which leads between the uprights of the frame and with a on the frame up on the height of the stacked goods up and retractable, rectangular frame for folding and welding of the upper side overlapping foil projections of the vertical foil casing on the stack top.

A device for folding and welding of upper-side film projections is described for example in DE 30 01 541 A1. During the wrapping of the vertical surfaces of the pallet load, the front, frontal, the upper end edge of the pallet load superior foil wall is folded with a folding body on the upper boundary surface of the pallets, then moves a Faitblech the rear, the upper end edge of the palletizing superior foil wall engaging behind in the middle range of rear film wall and the Faltbiech and the folding body are moved simultaneously in the direction of movement of the conveyor track, wherein the rear film wall is folded onto the boundary surface of the Palletteniadung, and the side, trapezoidal film walls are placed on transversely to the direction of movement of the conveyor track movable welding bar on the folded film walls and the upstanding longitudinal edges of these foil walls welded together.

The device works with continuous movement of the floor conveyor and folds the film supernatants successively on the stack surface. Welding takes place only at the longitudinal edges of the lateral film walls, a smooth strip of the film does not take place.

The device according to the invention should preferably be used in conjunction with two other devices. In a previous device, a cover sheet is first placed on the stack. Thereafter, the stack passes through a stretched film curtain on a floor conveyor, which is produced by two each held laterally next to the conveyor with a vertical axis film rolls and are welded in the middle of the transport path. As a result of the movement of the stack of goods, the films are applied to the sides of the stack of goods, with the two films being brought together and welded from the end of the stack of goods. The stack is then covered at its top with a cover sheet and coated on its vertical sides with a film that protrudes from the top. In the device according to the invention, the upper-side Foiienüberstand is folded over and welded. In an oven following the apparatus according to the invention, the film surrounding the stack of goods laterally and on the top side is shrunk. The invention is therefore based on the object to provide a device and a method for folding and welding top film overhangs when wrapping stacks with a film, which space saving and with as little effort the simultaneous folding and welding of all four film projections with a device allows If the device is to be able to process different stack formats and stacking protrusions varying in length, the foil should rest tightly against the stack of goods.

These objects are achieved by the features listed in claim 1 and in claim 7.

The invention makes it possible, during the wrapping of stacked goods with a film in its length changing, top-side film projections of the vertical film casing simultaneously fold over to the top of the deck stack and to weld. Due to the in the horizontal plane in pairs freely movable Stempeiecken in combination with the vertically movable frame changing stack heights and stack bases can be edited. For higher stacks, the frame can move within the frame to a higher position and fold over and weld the film projections in the manner explained below. An adaptation of the device is not necessary. With larger stacking floor area, the stamp corners move farther apart, thus lengthening all four cable sections between the stamp corners. Also on a change of the aspect ratio of the stack can be reacted by the pairwise decoupled in their movement stamp corners. The exposed cable sections in the frame strip the film casing on the four vertical sides of the stack of goods smooth, fold the film projections on the stack surface, the film projections also on the stack surface in a horizontal position smoothed out. Up to what height the frame goes down and from which height so that the smooth strip of the film begins, remains variable.

The two cables are deflected in such a way by the two carriages and four stamp corners that regardless of the position of the stamp corners in the context of the rope tension does not change relevant. Thus, the ropes may be rigidly anchored at both ends to rigid points in the horizontal plane, rope length compensation depending on the length of the rope sections, i.e., rope length compensation. from the position of the stamp corners by, for example, pulleys is not necessary. The tension of the ropes is set once and remains unchanged during operation.

For film supernatants greater length of the film protruding from the stack can bend away. The traversing of the stamp corners and rope sections on the stack vertically from bottom to top leads to trapping the weggeknickten foil projections before folding and welding. In addition, the pairwise control of the stamp corners makes it possible not to fold over the film overhangs at the same time, but successively in preferably two steps. For this purpose, the diagonal juxtaposition of all four stamp corners is divided into two movements, one transverse and one along the conveying direction. The sequence of movements can be chosen freely.

As ropes nylon ropes as well as steel ropes can be used. The vertical suspension of the stamp corners and an elastic coating over the stamp surfaces, preferably made of sponge rubber prevent too strong pressing. The vertical extension and retraction of the heating stemp! From the stamp faces of the stem corners prevents tearing of the fresh weld, since the immediate environment of the weld at Starting the heating stamp is pressed by the stamp surface on the stack surface.

The heating stamps are exchangeably mounted in the stamp corners.

The position of the weld can be chosen almost freely due to the movable stamp corners, for example, depending on the length of the film projections and the stack format. The invention will be explained in more detail with reference to a Ausführungsbeispieis shown in simplified form.

1 shows the device according to the invention with a stack to be wrapped

Fig. 2 shows the up and retractable frame in a view obliquely from below

Fig. 3 is a schematic representation of the courses of the cables

Fig. 4 is a stamp corner in a view obliquely-above Fig. 5 is a stamp corner in a view obliquely-bottom

In the present embodiment, the device is used to fold a protective cover made of plastic film formed on a pallet of corrugated cardboard sheets, paper sheets or fine cardboard on the top of the stack and to weld there with a cover sheet. The cover sheet has already been placed on the stack in accordance with the requirements of the device according to the invention in a preceding device. Likewise, the umzufallende, lateral film coat, the stack in full extent includes and overlaps the top of all four vertical sides, welded around the vertical sides of the Gutstapeis. The film is not visible in the figures. The size of the supernatant is dependent on the selected film format and is in the embodiment between 50mm and 200mm.

As Figure 1 shows, the device comprises a frame 1, which stands on four stands 2, which are connected above the maximum stack height with four cross beams. Through the frame a floor conveyor 3 promotes a Gutstapei formed on a pallet 4. In the conveying direction shows arrow 5. The frame 1 holds a belt drive on guide rails up and retractable frame 6, shown individually in Figure 2, on the left and in the conveying direction On the guide rails 7, in each case two driven with a linear drive carriage 8 are moved in opposite directions, of which in each case two opposite carriages on a further, perpendicular and horizontally to the conveying direction extending transverse rail 9 are rigidly connected. The two parallel transverse rails 9 can thus by moving the carriage 8 on the longitudinal rails 7 within the frame 6 in the conveying direction in opposite directions back and forth, and by moving the frame 6 in the frame 1 up and down. On both of the two transverse rails 9 in turn two each with linear drive counter-movable stamp corners 10 are arranged. The sum of four stamp corners 10 are thus on the cross rails 9 transversely to the conveying direction movable and together form the four corners of a rectangle.

Two steel cables 11, 12 (the ropes are called for better distinction in the following rope A 11 and rope B 12), it can alternatively nylon ropes are used, are stretched between the insides of two diagonally opposite corners of the up and down frame 6 and are among other things at the four stamp corners 10 via Umlenkroilen shown in Figure 4 13 in such a Diverted way that each rope 1 1, 12 each runs two sides of the rectangle formed by the stamp corners 10. For this purpose, the ropes 1 1, 12 with one of its ends on the inside of a corner 14 of the frame are rigidly mounted side by side and run along the conveying direction in the direction of the nearest slide 8.1 on the longitudinal rail 7.1. At this both ropes 1 1, 12 are initially deflected horizontally in the direction of mounted on the slide 8.1 cross rail 9.1 by 90 °. On this first transverse rail 9.1, rope A 1 1 at the first punch corner 10. 1 of the transverse rail 9.1 is again deflected by 90 ° horizontally by means of deflection rollers and then runs along the conveying direction along one side of the rectangle formed by the stems 10 to the opposing punch corner 10 the other, second cross rail 9.2. Rope B 12 is performed by means of rollers through the first punch corner 10.1, maintains its direction and runs along the first cross rail 9.1 to the second punch corner 10.2 of the cross rail 9.1. At the two diagonally opposite stamp corners 10.2, 10.3, both ropes 1 1, 12 are again deflected by 90 ° so that the ropes 1 1, 12 run along the two still open sides of the rectangle formed by the stamp corners 10, wherein rope A 1 1 is guided transversely to the conveying direction along the second transverse rail 9.2 and rope B 12 along the conveying direction from the first transverse rail 9.1 to the second transverse rail 9.2 runs. Analogous to the diagonally opposite punch corner 10.1 both ropes 1 1, 12 are guided at the second punch corner 10.4 of the second cross rail 9.2 in the direction of running on the longitudinal rail 7.2 slide 8.4, with rope A 11 maintains the direction and guided by rollers through the stamp corner 10.4 while rope B 12 is deflected by 90 ° with a deflection roller. At the slide 8.4 both rope A 11 and rope B 12 are deflected by 90 ° in the direction along the conveying direction and led to the inside of the corner 15 of the frame 6, where it fixed with its other end analogous to the diagonally opposite corner 14 rigidly side by side are. By moving the carriages 8 and stems 10, the rectangle formed by the punch corners 10 and ropes 11, 12 can assume any size and shape within the frame 6, the tension of the ropes 11, 12 not being relevant, and the rope lengths not being in position the stamp corners 10 must be adjusted, for example via cable drums.

The stamp corners 10 press the film projections on the stack top and weld them to the cover sheet. Figure 4 and Figure 5 show the structure of a stamp corner.

The base of the stamping corner, the stamping surface 16, with which the stamping corner presses on the stacking surface is designed as angled in the horizontal plane surface and coated with sponge rubber for damping. The angled stamp corner fits snugly against the vertical edge of the stack 4. In the die surface 16 is also a longitudinally angled recess 17 for the heating die 8. The heating punch 18 is fixed with two screw 19 on a vertically up and down lift arm 20. By loosening the two screw 19, the heating punch 18 can be replaced. By means of lifting movement of the lifting arm 20, the heating punch 18 moves out of the punch surface 16 through the recess 17 and welds the pressed-on film projection with the cover film. Figure 4 also shows the pulleys 13 for guiding the ropes 11, 12 through the punch corner.

The device according to the invention operates as follows:

In the device according to the invention the Gutstape! 4 moves with the floor conveyor 3 to a position in the frame 1, similar to the position in Figure 1. The frame 6 and the stamp corners 10 are in their starting position. That is, the frame 6 is located in the frame 1 in a high position above the stack height, the stamp corners 10 are driven far apart, so that of the Stempeiecken 10 and Soaps 11, 12 formed rectangle has the largest possible area. The floor conveyor stops and the frame 6 is lowered to a lower position below the stack surface, for example at half stack height. The four stamp corners 10 then move up to the four vertical edges of the stack 4 and then up along these along the stack height. The cable sections between the stamp corners 10 press in this way the sheathing film on the four vertical sides of the stack 4 and strip them smoothly. Corrugation or rough unevenness in the film are then lifted out and the film is applied to the stack 4. Just above the Stapeloberfiäche the frame 6 stops and the stamp corners 10 travel diagonally together. However, it is also possible to carry out the diagonal movement in two successive steps, for example by reciprocally moving the stamp corners 10 first along the conveying direction and then across the conveying direction or vice versa. In this way, a folding over of the top side protruding film of the lateral film coating on the stack surface. At the same time, the free cable sections of the cables 11, 12 smooth the film projections on the stack surface.

After folding and smooth strip of film overhangs press the four stamp corners 10, the film projections by descending the frame 6 on the cover sheet, wherein the pressing surface of the die surface 16 of the stamp corners 10 corresponds. During pressing, the heating dies 18 are extended out of a recess 17 in the stamp surface 16 of the stamping corners 10 and welding the film projections to the cover film. The heating punch 18 moves back into the stems 10, before the punch corner 10 lifts by raising the frame 6 again from the stack surface. In this way, a tearing of the fresh weld by gluing the film is prevented with the Heizstempei 18, since the immediate vicinity of the weld is pressed at startup of the Heizstempels 8 of the die surface 16 on the stack surface. If the stamp corners 10 no longer have any contact with the stacking surface of the stack 4, the stack 4 can be conveyed further out of the region of the frame 1 by means of the floor conveyor 3. The stamp corners 10 and the frame 6 return to their original position and the process is completed.

Claims

PATENT CLAIMS

1.

Device for folding and welding film overhangs on the top when wrapping stacked goods, in particular goods stacked on pallets, with a plastic film

- a frame consisting of at least two stands, which are connected to one another by cross members above the maximum stacking height,

- an industrial conveyor device for transporting the goods, which passes between the stands of the frame,

- a rectangular frame that can be moved up and down on the frame above the height of the stacked goods for folding and welding top-side film projections of the vertical film casing onto the top of the stack, with guide rails being mounted lengthwise and transversely on the frame, on which four stamp corners are movably arranged ,

- between which two or more pre-tensioned ropes of constant length are deflected so that they form a rectangle lying horizontally in the frame, with both ends of the ropes being rigidly attached to the frame that can be moved up and down, and

- which can be moved transversely and lengthways to the floor conveyor direction, so that the rectangle formed by the ropes can be changed in shape and size.

2.

Device according to claim 1, characterized in that two guide rails are fixedly arranged on the frame in the longitudinal direction, on which two guide rails are mounted so that they can move transversely to the conveying direction.

3.

Device according to claim 1 or 2, characterized in that the ropes are designed as nylon ropes.

4,

Device according to one of claims 1 to 3, characterized in that the stamp corner has the shape of two opposing rectangles in cross section and is designed to be vertically elastically resilient.

5.

Device according to one of claims 1 to 4, characterized in that the undersides of the stamp corners are covered with an elastic material, preferably foam rubber, and have extendable heating stamps as welding elements which are heated by heating strips.

6.

Device according to claim 5, characterized in that the

Heating stamps are mounted interchangeably with the heating tapes.

7.

Method for folding and welding top-side foil excesses when wrapping stacked goods with a device according to claim 1, with the steps:

- moving the stacked goods into the area of the frame, - lowering the frame that can be moved up and down with a wide distance between stamp corners and goods at least to a position below the stacking surface,

- Smooth strips of the enveloping film on the sides of the stack using the tensioned ropes by moving the stamp corners to the edges of the stack and raising the frame along at least part of the stack height,

- Folding over the overlapping film on the top by bringing the stamp corners together diagonally at a short distance from the stack surface,

- fixing the excess film on the cover film on the top of the stack by lowering the frame and pressing the stamp corners onto the top of the stack,

- Welding the film projections to the cover film using a heating stamp that can be extended from the underside of the stamp corner.

8th.

Method according to claim 7, characterized in that

The film overhangs are not folded over at the same time, but one after the other in a predetermined sequence.

9.

Method according to claim 7 or 8, characterized in that after welding the heating stamp first moves back into the stamp corner and only then is the stamp corner raised.