Method for operating a tubular bag machine

Abstract

The invention relates to a method for operating a tubular bag machine (01) with at least one vibration sensor (15, 18, 19) and a vibration evaluation device (16), wherein airborne and / or structure-borne sound signals can be measured with the vibration sensor (15, 18, 19), and wherein the measurement signals of the vibration sensor (15, 18, 19) can be evaluated with the vibration evaluation device (16), wherein a) Air and / or structure-borne sound signals generated by the filling material during the operation of the tubular bag machine (01) are measured with the vibration sensor (15, 18, 19) on the format tube (06), b) the measurement signals of the vibration sensor (15, 18, 19) are evaluated by the vibration evaluation device (16), c) a function signal is output depending on the evaluation results.

Description

[0001] The invention relates to a method for operating a tubular bag machine according to the preamble of claim 1.

[0002] DE 10 2010 028 697 A1 discloses a form-fill-seal machine suitable for packaging bulk goods. A metering device with a screw feeder is provided above the actual form-fill-seal machine, allowing the bulk goods to be fed in metered amounts for individual packaging. A vibration sensor is arranged on the metering device to monitor its proper operation by appropriately evaluating the sound signals at the metering device's hopper. As soon as a foreign object, particularly a metal part, falls into the metering device, corresponding noises and sound signals are triggered, which can be detected by the vibration sensor and evaluated. In other words, the vibration sensor enables damage monitoring to prevent the introduction of foreign objects, especially metal parts.

[0003] The JP H08-217 028 A describes a tubular bag machine with a variety of different sensors for monitoring the various sub-processes. One sensor is also located in the area of ​​the longitudinal sealing unit of the tubular bag machine.

[0004] Based on this state of the art, the object of the present invention is to propose a method for operating a tubular bag machine with a vibration sensor and suitable vibration evaluation device, with which the actual packaging process can be improved.

[0005] This problem is solved by a method according to the teaching of claim 1.

[0006] Advantageous embodiments of the invention are the subject of the dependent claims.

[0007] In conventional tubular bag machines, so-called forming tubes are used to feed the product into the individual pouches before they are sealed by cross-sealing the tubular film. The film tube, formed from the film web using a forming shoulder, runs along the outside of the forming tube. Inside the forming tube, the product is fed from above and falls into the still-open pouches before they are sealed by cross-sealing the film web. With ever-increasing cycle rates in tubular bag production, the rate at which the product must be fed through the forming tube into the pouches also increases. These ever-increasing cycle rates result in a growing number of potential sources of interference that can disrupt the operation of the tubular bag machine.If, for example, the product becomes blocked in the forming tube, the tubular bags will no longer be filled with the desired quantity of product and will therefore be considered rejects. Based on this prior art, the object of the present invention is therefore to propose a method for operating a tubular bag machine that avoids the disadvantages of the prior art described above.

[0008] This problem is solved by a method according to the teaching of claim 1.

[0009] Advantageous embodiments are the subject of the dependent claims.

[0010] The core concept of the inventive method is that, during operation of the form-fill-seal machine, the airborne and / or structure-borne sound signals generated by the product being filled are measured with a vibration sensor on the forming tube. This is because the structure-borne sound signals generated by the product in the forming tube provide significant information about the process state of the packaging process and can, in particular, identify known sources of interference at an early stage. The measurement signals obtained with the vibration sensor on the forming tube are then evaluated by a vibration evaluation device, and a function signal is output depending on the evaluation result. This function signal could, for example, be a stop signal that stops the form-fill-seal machine, for instance, if the product becomes blocked in the forming tube.In particular, the measurement of airborne and / or structure-borne sound signals at the forming tube according to the invention can be used to monitor and control whether the passing or impact of the product in the forming tube or at its lower end generates significant noise patterns that significantly characterize the packaging process. This provides opportunities for fault detection and self-optimization of the form-fill-seal machine.

[0011] The method according to the invention improves packaging processes in which pre-formatting is carried out using a pre-formatting flap. In these packaging processes, the product is first measured with a suitable measuring device, for example, a scale, and then prepared for the further packaging process by being dropped onto a pre-formatting flap that is initially still closed. In the next work step, the pre-formatting flap is opened and the measured quantity of the product is filled downwards into the opened tubular bag. By measuring the acoustic signal patterns in the area of ​​the pre-formatting flap, the acoustic signal patterns generated when the product impacts the flap can be detected and monitored.

[0012] The point on the forming tube where the sound signals are detected by the vibration sensor is, in principle, arbitrary. In a first preferred embodiment, the vibration sensor is arranged at the upper end of the forming tube below a pre-forming container or hopper. In this way, the vibration sensor can measure and thus monitor the sound signal pattern generated by the material in the pre-forming container or hopper.

[0013] Alternatively or additionally to the first method variant, the vibration sensor can also be positioned between the upper and lower ends of the forming tube. In this way, the vibration sensor can measure and analyze the sound signal pattern generated by the material as it passes through the forming tube by contacting the inside of the tube. This type of measurement is particularly suitable for detecting blockages in the forming tube and for taking appropriate action.

[0014] As an alternative to the first two methods, the vibration sensor can be positioned at the lower end of the format tube, above a transverse sealing unit. This sensor then measures and analyzes the sound signal pattern generated by the product upon impact with the sealing jaws. This makes it possible, in particular, to detect when no product or far too little product has been fed in, resulting in only a weak sound signal pattern upon impact with the sealing jaws.

[0015] The type of functional signal output based on the evaluation result of the vibration sensor's measurement signals is essentially arbitrary. As described above, for example, the entire form-fill-seal machine can be stopped as soon as a malfunction is detected by evaluating the acoustic signals. According to a preferred method variant, a functional signal is output based on the evaluation result. This signal synchronizes the discharge pulse of a scale, which weighs the product above the pre-formatting flap, with the opening pulse of the pre-formatting flap. This synchronization between the pre-formatting flap and the scale's discharge pulse eliminates unwanted interference caused by signal fading between the discharge pulse and the scale and the pre-formatting flap.

[0016] The method according to the invention is explained below by way of example with reference to the drawing.

[0017] It shows: Fig. 1 A schematically represented tubular bag machine in cross-section during the execution of the method according to the invention.

[0018] Fig. Figure 1 shows a schematic representation of a tubular bag machine 01, wherein in Fig. Figure 1 shows only those parts of the tubular bag machine 01 that are necessary for understanding the invention. A film web 03 is unwound from a supply roll 02 and then formed into a film tube 05 on a forming shoulder 04. The film tube 05 slides downwards on the outside of a forming tube 06, driven by a film take-up unit 07, whereby the film tube 05 is guided by a Fig. 1 longitudinal sealing device not shown, is longitudinally sealed parallel to its transport direction.

[0019] Below the format tube 06 is a transverse sealing device 08 with two transverse jaws 09 for creating transverse seams, through which the film tube 05 is transversely welded into individual tubular bags 10. A separating device 11 is integrated into the transverse jaws 09, with which the individual tubular bags 10 can be separated from each other after transverse welding.

[0020] The material 12, used to fill the tubular bags 10, is measured by a measuring device, for example, a scale 13, so that the fill quantity intended for each tubular bag 10 is achieved. The measured material falls into the hopper 14 below due to an opening impulse in the scale 13. The hopper 14 then concentrates the material to the diameter of the forming tube 06. A first vibration sensor 15 is located at the upper end of the forming tube 06 and below the hopper 14. This sensor detects airborne and / or structure-borne sound signals as the material passes through the hopper 14. The corresponding measurement signals are transmitted via a cable to a vibration evaluation device 16, allowing the signals to be analyzed and disturbances in the area of ​​the hopper 14 to be detected.For example, by appropriately comparing the vibration signal patterns with pre-stored target patterns, the vibration evaluation device can identify 16 disturbances and then, depending on this, initiate, for example, a machine stop.

[0021] After the product 12 has passed through the hopper 14, it falls further down through the forming tube and impacts a pre-forming flap 17, which is initially still closed. The closed pre-forming flap 17 initially retains the product 12 until the tubular bag below is conveyed further and sealed by the cross-sealing device 08, allowing the next tubular bag to be filled. The airborne and structure-borne sound signals generated when the product 12 impacts the top of the pre-forming flap 17 can be measured with a vibration sensor 18. The measurement signals from the vibration sensor 18 are also evaluated in the vibration evaluation device 16, and suitable function signals are output depending on the measurement result.In particular, the ejection impulse of the scale 13 can be synchronized with the motion control of the preformatting flap 17 by suitable evaluation of the sound signals detected by the vibration sensor 18.

[0022] As soon as the pre-formatting flap 17 is opened after the underlying tubular bag has been transported further, the contents fall onto the still closed transverse sealing jaws 09 of the transverse sealing device 08. The resulting airborne and / or structure-borne sound signals can be detected by a vibration sensor 19 and evaluated by the vibration evaluation device 16. This makes it possible, in particular, to determine if no contents have fallen downwards, for example, if an undesirable malfunction has occurred in the formatting tube 06 due to a blockage of the contents 12.

Claims

[1] Method for operating a tubular bag machine (01) with a film web (03) that can be unwound from a supply roll (02), a forming shoulder (04) for forming the film web (03) into a film tube (05), a film take-up (07) acting against the film tube (05) for advancing the film tube (05), a vertically oriented forming tube (06) for receiving and filling the film tube (05) with a product (12), a longitudinal sealing device for welding the film tube (05) parallel to its transport direction by means of a longitudinal seam, a transverse sealing device (08) with transverse jaws (09) movable relative to each other for welding the film tube (05) transversely to the transport direction to create transverse seams, a separating device (11) for separating finished tubular bags (10) from the film tube (05), and with at least one vibration sensor (15, 18, 19) as well as a vibration evaluation device (16), wherein the vibration sensor (15,18, 19) Airborne and / or structure-borne sound signals can be measured, and wherein the vibration evaluation device (16) can be used to evaluate the measurement signals of the vibration sensor (15, 18, 19), characterized by , that the vibration sensor (18) is arranged in the area of ​​a pre-formatting flap (17), wherein a) During operation of the tubular bag machine (01), air and / or structure-borne sound signals generated by the product being filled are measured with the vibration sensor (15, 18, 19) on the format tube (06), wherein the vibration sensor (18) measures the air and / or structure-borne sound signals generated by the product when it hits a pre-formatting flap (17), b) the measurement signals of the vibration sensor (15, 18, 19) are evaluated by the vibration evaluation device (16), c) depending on the evaluation results, a function signal is output with which the ejection pulse of a scale (13), with which the filling material (12) is weighed above the preformatting flap (17), is synchronized with the opening pulse of the preformatting flap (17). [2] Method according to claim 1, characterized by , that the vibration sensor (15) is arranged at the upper end of the format tube (06) below a pre-formatting container or hopper (14), wherein air and / or structure-borne sound signals generated by the fill material in the pre-formatting container or hopper (14) are measured with the vibration sensor (15). [3] Method according to claim 1 or 2, characterized by , that the vibration sensor (18) is arranged between the upper end and the lower end of the format tube (06), wherein the vibration sensor measures air and / or structure-borne sound signals generated by the filling material (12) as it passes through the format tube (06). [4] Method according to any one of claims 1 to 3, characterized by , that the vibration sensor (19) is arranged at the lower end of the format tube (06) above a transverse sealing unit (08), wherein the vibration sensor (19) measures air and / or structure-borne sound signals generated by the filling material when it hits the transverse sealing jaws (09).

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