JP5743884B2 - Apparatus and method for forming a bag having a fabric consisting of stretched plastic small bands - Google Patents

Description

  The present invention relates to an apparatus and a method for forming a bag having a fabric made of stretched plastic small bands as described in the preamble of claims 1 and 13.

  This type of device is known and has been available on the market for a long time. They usually have an individualizing device for individualizing the supplied textile tubes, which may be further laminated, into tube pieces. These tube pieces are composed of two band-shaped materials that are overlapped with each other, in which case each band-shaped material can be composed of a plurality of layers of different materials. Thereafter, the tube pieces are taken up by at least one transfer device and thereby moved to the individual processing stations. One of these processing stations is a so-called bottom opening station. Here, first, since the end of the tube piece is pulled up, the bottom can be formed at the pulled-up end. Usually, both ends of the tube piece are processed in this way.

  An apparatus capable of forming this type of bag is disclosed in Patent Document 1. In this publication, an apparatus that should be formed at a low cost is proposed in order to keep the development cost for forming it within the limits. In this device, the tube piece is advanced by clock drive. In that case, since the tube piece lies flat and is transported laterally with respect to the main shaft, the processing means arranged on the side can simultaneously process both ends of the tube piece. At the opening station, the tube piece is stopped. Thereafter, the layer above the end of the tube piece is lifted using the aspirator, so that a thin plate sliding in the direction of the main axis can enter between the two material layers of the tube piece. The material layer below the tube piece is fixed on the table (during transfer, the tube piece rests on this table) by negative pressure. The upper material layer is thereby folded out of the upper material layer, resulting in a bottom rectangle. When folding, a so-called corner tack is further generated, and the corner tack is formed on both sides of the bottom rectangle and has a triangular shape. After folding, the sheet is pulled out again and the bag is further transferred. Subsequently, the tube pieces are taken over one after another to the other transfer device, which feeds the tube pieces at a uniform rate and thus continuously to the bottom closure device.

  Thus, after opening the tube end, the bottom rectangle and the corner tack are located in the plane of the tube piece, preferably in the horizontal direction. Even when the bottom is closed, the bottom remains in a horizontal plane. This is because the method of closing the bottom has advantages. Indeed, when forming a bag having a fabric consisting of stretched plastic small bands, it is necessary to join the bottom with hot air or at least a heated adhesive, such as an extrudate. . Only in this way is it known that a very strong and loadable bottom can be formed. Of course, unlike the cold bonding method, it is necessary to press the bottom immediately after joining, so that the bottom is guided through the press drum gap over its entire width. Therefore, it is particularly effective if the bottom does not need to be machined in a plane located parallel to the plane of the tube piece. In this case, the two press drums can act on the bottom over the entire width. This cannot be done, for example, if the bottom is orthogonal to the original bag body. In this case, the connected drum gap cannot press the entire bottom. Within the area of the bottom centerline, where the bag body is located, one press drum must necessarily be interrupted. There, therefore, it is not possible to perform a press, which can result in the non-sealing of the resulting bag.

  Another aspect of machining the bottom in the plane of the bag body is that when the bottom is welded using hot air and the bottom cover sheet is welded onto it, the hot air is evenly distributed over the area to be welded. It is to be brought. Therefore, uniform joining is performed.

  In the past, bag forming machines of the type described above, where the bottom of the bag forming remains in the plane of the tube body, have seen a tendency for output to be very high, which is the cost-benefit-ratio of this type of machine. It will increase significantly. Of course, the processing speed of the tube pieces in the known apparatus is particularly limited by the bottom opening station, where the layer above the end of the tube piece is folded back horizontally in order to open the end of the tube piece. . This is due in particular to the fact that in the stationary phase of the bag, the slider must almost completely rub the end layer of the tube piece. This method is relatively complicated.

German publication DE195502251A1

  The object of the present invention is therefore to propose a device for forming a bag which allows a simpler way to open the end of a tube piece, in which case this end is open. The bottom is opened so that the bottom is located in the plane of the bag body.

  This problem is solved by the features of claim 1. According to this, the device included in the device for opening the end of the tube piece has means for folding the end of the tube piece from a horizontal position to a vertical position. In that case, the two material layers further overlap. Therefore, since the end of the tube piece is folded upward by about 90 degrees, a substantially right angle is formed between the tube piece and the end folded upward. It is also possible in principle to turn back 90 degrees downward. In this way, it is possible to separate the two layers at the end folded back up or down and fold horizontally by a relatively simple opening means. In that case, this step can be carried out simultaneously for two layers and in particular during continuous driving. The end result is a tube piece with an open end, which is indistinguishable from a tube piece provided with an open end in a clock drive, so that known bottom closure stations can be used. Due to the uniform working method for the two material layers, the wicking of the bottom can be carried out more quickly, so that the efficiency is significantly improved.

  By another means of separating and folding the material layer, which is the subject of the subclaims, the two layers are each folded 90 degrees away from each other, so that one material layer is then returned to its original plane again. Then, the other material layer is further folded to the outside of the bag body. The end of the tube piece is thus opened uniformly in both directions after it has been made vertical. Thereby, the opening process can be accelerated considerably. Other details of this opening process will become apparent below in connection with the description of the means for separating the material layers.

  In that case, it is advantageous if the device for opening at least one end of the tube piece has at least two capture devices for this end, in which case each capture device applies. The material layer of the tube pieces to be captured is separable and in that case the material layers can be separated from each other by at least two capturing devices. This capture device is suitable for applying a force to the two outer material layers, in which case the force is directed in the opposite direction. In that case, the force must be large enough to overcome the attractive forces that may be present, for example, that may be caused by electrostatic charging. The trapping device need only move in the horizontal direction when the end of the tube piece is folded 90 degrees with respect to the horizontal. This saves assembly height compared to other devices that form bags with fabrics consisting of stretched plastic small bands. If the capture devices are arranged on a rotating member, such as a disk, for example, the capture devices are temporarily supported at the same speed as the tube pieces. It can be driven by a vector (representing the velocity direction and the absolute value of the velocity). Thus, the end layers of the tube pieces can be separated from one another even when the tube pieces are continuously transferred.

  Particularly suitable for this purpose is an aspirator, which can be placed on the beam. The aspirator can be guided to contact the folded end on both sides. After the negative pressure is supplied to the aspirator, the aspirators can again be separated from each other, so that the material layers are likewise separated from each other. Therefore, the inside of the tube piece can be approached.

  With the device according to the invention, it is of course possible to form bags of various formats. Thus, preferably, the device for opening at least one end of each tube piece has a support, on which the capture device can be fixed. Since the capture device can be attached to this support at various locations, the material layer is captured regardless of the height of the end folded back above the tube piece. In that case, it is advantageous if the support is formed as a guide, which extends parallel to the folded end of the tube piece and thus perpendicular to the plane of the tube piece. . Thus, the height of the capture device can be adjusted by sliding the capture device along the guide. In this case, “height adjustable” means that the distance of the capture device relative to the transfer plane of the tube piece is variable. If the rear bottom has a small width, the 90-fold folded area of the tube piece is already small so that the capture device is brought along the guide to the transfer plane described above. If the bottom width is large, the capture device is far away from the transfer plane. The guide can be formed as a simple bar, on which the capture device can be fixed using suitable fixing means, for example knurled nuts. Tilt of the capture device is prevented when at least two parallel guides are provided for each capture device. Overall, therefore, the capture device is simply and quickly placed at a distance perpendicular to the tube piece. Ultimately, the height of the end folded upward or downward defines the width of the resulting bottom.

  A particularly preferred form of the invention has a spread member, which can be inserted between two material layers at the end of the tube piece to be opened. In addition, it is advantageous if the spread member moves the material layers away from each other by a distance such that they then lie completely horizontally. This type of spread member develops a good effect, especially when driven in combination with the capture device described above. In this case, the spread element can enter without problems into the gap between the material layers already separated from each other by the capture device.

  In another form of the invention, the device for opening the end of the tube piece comprises at least one pressure roller, which forms a gap with the counter layer, through which the tube piece is opened. At least portions of the end portions formed can be inserted, and compressed air can be supplied to these portions. Therefore, this pressure contact roller has the problem of flattening the raised bottom and fixing it to an open shape. Therefore, it is possible to omit the coining die, which is unsuitable for use when the tube pieces are continuously transferred, disclosed in the patent publication mentioned at the beginning. The counter layer can also consist of other rollers. In particular, it is advantageous if an individual pressure roller is associated with each side of the device, so that the open ends of the tube pieces can be pressed separately.

  In an apparatus for forming a bag having a fabric made of stretched plastic small bands, bottoms are usually formed at both ends. Since the bottom opening stations often require a lot of built-in space, it is particularly effective to arrange them displaced in the transfer direction. This concept works particularly effectively when a device having the above-described member is used to open at least one end of the tube piece. However, in principle, this idea is independent of the components described above. In that case, the expression “displaced in the transfer direction” means that the processing step is first performed at one end of the tube piece, and after the tube piece is further transferred, at the other end of the tube piece, It means that the same processing steps are performed. In this way, it is possible to form bags with very small bottom center spacing. In this case, the bottom interval is the interval from the fold line to the fold line. In this case, the fold line is a fold line that folds the end region upward with the fold line as the center. The steps of folding the tube ends are preferably performed in the order described above, but the method steps can also be performed simultaneously for the two ends. This is because the corresponding device components do not require a lot of space.

  The great advantage of the displaced arrangement is seen in particular in that the individual members of the bottom opening station with the capture member and the spread member are accessible from both sides of the device and thus very well. This advantage is obtained especially when considering that there are a large number of movable components in the bottom opening station that are subject to wear and therefore must be regularly repaired or replaced. .

  Other embodiments of the invention will be apparent from the specific description and from the claims.

It is a principle figure of the apparatus which forms a textile bag. FIG. 3 is a perspective view showing a bottom opening station in an apparatus according to the present invention. FIG. 3 is a view along III-III in FIG. 2. FIG. 4 is a view along IV-IV in FIG. 3. FIG. 5 is a view taken along line V-V in FIG. 2.

  FIG. 1 diagrammatically shows the individual steps of processing a textile tube into a bag, as is done in the bag forming apparatus 1.

  First, the fabric tube 2 is supplied to the bag forming apparatus 1. This is preferably done by drawing the fabric tube forming the scroll 3 in the drawing device 4. The tube 2 is then subjected to a so-called opening in the layer separation station 5. In that case, the fabric tube is guided to wrap around the internal tool, which separates the two layers from each other, so that if the layers are bonded together in one of the tube forming steps, Is done. Only when the layers are separated can it be ensured that subsequent manufacturing steps can be carried out properly. Next, the separated layers of the tube are overlaid again.

  The fabric tube is in turn fed to the transverse cutting device 6, which individualizes the fabric tube into individual tube pieces.

  The tube or tube piece is then transferred in the direction of its longitudinal axis, so that the initial transfer direction z is changed to the new transfer direction x, so that the tube piece is no longer in its tube longitudinal axis direction z, In contrast to that, the end of the tube piece can be reached from the side for the purpose of forming the bottom.

  In the next station, the bottom opening station 8, both ends of each tube piece are opened and the so-called bottom square is laid. In the subsequent valve station 9, the valve is placed and fixed on one of the two open ends. The open bottom is then closed in the bottom closing station 10, in which case the two flaps are stacked on top of each other and joined together permanently, for example by welding. At the end of the original bag forming process, in the cover sheet station 11, each bottom cover sheet is mounted on the bottom. To that end, the cover sheet can be welded as well. The resulting bags are then stacked on the bag stack 12 and are unloaded therefrom in a manner not described in detail.

  FIG. 2 shows the details of the opening station 5 in the device according to the invention. The tube piece 13 is laid flat on the surface of the mounting portion 14, for example, on the surface of the table, and is transferred in the x direction and thus horizontally by a transfer device not shown in detail. In order to open the end 15 of the tube piece according to the invention, this end is first moved from a horizontal position to a vertical position. In order to allow this folding, a counter layer must be supplied to the tube piece. For this purpose, the tube piece 13 is passed under the folding band 16. This folding band is stationary with respect to the tube piece and thus moves with respect to the mounting part. However, the tube piece can also move relative to the folding band 16. This is the case, for example, when the folding band is stationary. The folding band is flexible but can be formed from a strongly biased material. However, this preferably consists of a steel sheet, which is connected in a manner not shown to the mounting part 14 or to the machine mount. Steel sheets have the advantage that they have a smaller thickness at the same load capacity compared to other components. If the tube piece 13 is passed through, the tube piece is then guided through a guide member 17, for example a guide lamina.

  After the end 15 of the tube piece 13 has been moved to the vertical position, the tube piece is fed into the original bottom opening station 18, schematically shown in this figure. In this bottom opening station 18 there are two suction beams which act on both sides of the folded end and are guided in the direction z or vice versa so that the material layer is Separated from each other. At the same time, the suction beam is also moved in the x direction in order to be able to act on the transported bag. Now, the inside of the end 15 of the tube piece 13 can be approached. A spread member, which presses the material layers away from each other, is inserted into this internal space until the material layers are again positioned horizontally. This situation is shown with an open bottom 19.

  The second end 15 ′ of the tube piece 13 is performed in the same manner, but displaced relative to the opening of the first end 15. The first end is already open in the bottom opening device 18 and the second end 15 'is inserted under the folding band 16'. Using the guide member 17 'and the bottom opening device 18', an open bottom 19 'is formed in the manner described above. The displaced arrangement of the components is effective when trying to produce a bag with a very small bottom center spacing A.

  When leaving the bottom opening station 8, there is a tube piece with an open bottom 19, 19 ', in which case all components of the opened bottom are substantially in the plane of the mounting part 14. positioned.

  Another view of the bottom opening station 8 can be seen in that each bottom opening device 18, 18 'is torqued by a dedicated drive. This is indicated by the motor 22 provided in the bottom opening device 18. A similar motor provided in the bottom opening device 18 'is not seen in the display shown. The motors of the bottom opening devices 18, 18 'in particular supply a driving moment to the suction bar, so that this suction bar can move the material layers away from each other. The spread member is also supplied with torque by this motor.

  Forming the end of the bottom opening device 18, 18 'is the pressure roller 23, 23', which is used for the purpose of pressing the newly opened bottom and thereby fixing it in place. It is done. In that case, the folding edge that occurs in the bottom-open frame is flattened to form the correct folding edge, so that the tendency of the bottom to rise again is reduced. As the counter pressing member for the pressure rollers 23 and 23 ', the mounting portion 14 or the counter pressing rollers 24 and 24' are used. The press rollers 23 and 23 'are arranged at the same height when viewed in the transfer direction x in FIG. However, these rollers 23, 23 'can also be arranged displaced from each other, so that immediately after the opening process, the opened bottom can be pressed in the manner described above.

  FIG. 3 shows a display along III-III in FIG. In this FIG. 3 details of the bottom opening station 8 can be seen. In order to capture the material layer at the end 15 of the tube piece 13, a suction bar is provided, of which the viewer-side suction bar 20 can be seen. A suction device is arranged on the side of the suction bar 20 opposite to the observer, and the suction device can capture the viewer side of the end 15 of the tube piece 13.

  Since the device 1 according to the invention can form bags with various bottom widths, the folded end 15 of the tube piece 13 can have various heights H. This aspirator should act as close as possible to the upper end of the end 15 so that the end can be properly opened by the aspirator. For this purpose, the suction bars 20, 20 ′ are detachably fixed to the vertical guides 21, 21 ′, so that the suction bars follow the double-ended arrow y along the folded end 15. Can be slid along and thus its height H can be adjusted. The guide can be formed in various ways. This can be a solid or hollow, round or rectangular profile.

  FIG. 4 shows a display along IV-IV in FIG. In addition to the front suction bar 20 and the front guide 21, a suction bar 20 'and a guide 21' are also seen.

  FIG. 5 shows a display along VV in FIG. The pressure roller 23 is supported in a lever arm 25 or a lever arm pair. The lever arm 25 itself is supported in the machine frame or in the attachment point 26 of the machine frame. In one embodiment, the lever arm 25 can swing about and can be fixed on a shaft 27 that is rigidly coupled to the attachment point. For this purpose, a dedicated but not shown clamping device can be provided. By fixing the lever arm 25 on the shaft 27, the interval between the peripheral surfaces of the counter pressing roller or the mounting portion 14 can be fixedly adjusted. In this way, the open bottom is supplied with a pressing force only if a pressing force is also required to move the components of the opened bottom to a horizontal plane.

  In other embodiments, the lever arm is rotatably mounted on the shaft 27. Alternatively, the lever arm 25 can be rigidly coupled to a shaft that is rotatably mounted in the mounting location. In the embodiment described above, the pressure roller 23 acts on the opened bottom by a predetermined force, for example, its own weight.

  In order to press the opened bottom, the mounting part 14 shown in FIG. 2 can be used as a counter layer for the pressure roller. Another possibility is of course to provide a counter-pressing roller 24, with which the pressure roller 23 forms a rolling gap, in which the open bottom 19 can be pressed. The counter-pressing roller can be arranged to be rotatable but fixed to the gantry.

DESCRIPTION OF SYMBOLS 1 Bag formation apparatus 2 Textile tube 3 Roll 4 Pull-out apparatus 5 Opening station, layer separation station 6 Transverse cutting apparatus 7 Apparatus which changes the transfer direction 8 Bottom opening station 9 Valve station 10 Bottom closing station 11 Cover sheet station 12 Bag stack 13 Tube Piece 14 Placement portion 15, 15 'End of tube piece 16, 16' Folding band 17, 17 'Guide member 18, 18' Bottom opening device 19, 19 'Opened bottom 20, 20' Suction bar 21, 21 'Vertical guide 22 Motor 23, 23' Pressure roller 24 Counter pressing roller 25 Lever arm 26 Mounting portion 27 Axis A Bottom center distance H Height of end 15 x Transfer direction of tube piece 13 y Transfer direction x and extension direction x Direction perpendicular to the plane formed by the z tube piece 13 Direction extending

Claims (4)

An apparatus for forming a bag from a piece of tubing comprising a fabric consisting of stretched plastic small bands and consisting of two layers of material overlapping each other,
At least one transfer device for transferring said tube piece in a transfer direction (x) extending transversely to its extension direction (z), wherein said tube piece is in a horizontal position; Said at least one transfer device capable of feeding;
And at least one device for opening at least one end of the tube piece to form a bottom later,
At least one device for opening at least one end of the tube piece;
Means for folding back the end of the tube piece, by means of which the ends of the tube piece can be moved from the plane of the tube piece to a plane (y) extending substantially perpendicular to it; And in that case, the means for folding, wherein the material layers further overlap each other,
Means for separating and folding the material layers, wherein the means allows the material layers to be folded substantially 90 degrees apart, so that the open bottom is located in the plane of the tube piece; Means for separating and folding;
Two capture devices, wherein each capture device can capture a material layer at the corresponding end of the tube piece and the two material layers can be separated from each other; With
At least one device for opening at least one end of the tube piece has a support, the capture device can be fixed to the support, and the support is the tube piece Is formed as a guide, oriented perpendicular to, in which case the capture device is height adjustable by sliding along the guide;
The capture device comprises one or more aspirators disposed on the beam;
At least one device for opening at least one end of the tube piece is two devices for opening the respective end of the tube piece, each of these devices having a dedicated drive Each device is provided ,
At each end portion of the tube piece, means for raising each end portion of the tube piece are arranged displaced from each other in the transfer direction of the tube piece,
The capturing device for capturing one end of the tube piece is disposed so as to be displaced from each other with respect to the capturing device for capturing the other end of the tube piece. A device that forms a bag from a piece of tubing that does   The device for opening the end of the tube piece has a spread member, the spread member can be introduced between two material layers at the end of the tube piece, and the spread member The device according to claim 1, characterized in that these material layers can be folded back into the plane of the tube piece.   At least one pressing roller is provided, the pressing roller forms a gap with the counter layer, through which at least part of the open end of the tube piece can be guided, and to these parts The apparatus according to claim 1, wherein compressed air can be supplied. Each device for opening at least one end of the tube piece, according to any one of claims 1 to 3, characterized in that it has a dedicated drive device.

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