EP2631186B1 - Device for thermosealing waste - Google Patents

Description

The invention relates to a device for welding waste according to the preamble of claim 1.

Devices for welding waste are mainly used in laboratories and medical facilities for safe and low-contamination disposal of toxic or infectious waste and hazardous waste, the waste to be disposed of by means of the device aerosol and liquid-tight sealed in foil bags.

From the DE 2 364 180 A device for packaging waste by welding in foil bag is already known, which comprises a housing having a receiving space for a folded film tube and extending through the receiving space funnel. At the lower end of the funnel, a welding unit with two movable heatable welding jaws is arranged, between which an inwardly folded, guided from top to bottom through the hopper hose section of the film tube can be clamped and welded along a transversely extending over the hose section away weld. For transporting the film tube or hose section, a conveyor unit with two pairs of conveyor rollers is arranged below the welding unit, between which the tube section extends. The conveyor rollers of each pair of rollers are pressed from opposite sides against an edge strip of the tube portion and driven to transport the tube portion in the opposite direction of rotation. The emerging from the conveyor unit film tube consists of a series of contiguous bags, between each of which a weld is arranged. The transport and the Welding of the hose section are triggered by a foot switch.

Next is from the DE 695 17 207 T2 already known a device for welding waste according to the preamble of claim 1 with a combined welding and separating unit, which is capable of heating the plastic of the film tube during welding along a cutting seam to flow to each foil bag when welding its upper end simultaneously to separate from the hose section. In this device, both the heating temperature for welding the tubular film and the duration of the mutual pressing of the two heatable welding jaws preset, the latter by a predetermined delay. As a result, either only individual separate bags or a single long bag can be produced, which is closed only at its two opposite ends, but not several contiguous bags, each containing separately welded waste. Moreover, since the tubular film is heated to flow along the dividing seams, it can not be ruled out that bags of welded waste along one or both dividing lines will leak leaking toxic or infectious material. Last but not least, the lower end of the tube section below the welding and separating unit with the last filled or welded bag is only safely separated if the weight of this lower end or the waste welded therein is greater than the resistance force along which the dividing seam up to the flow of heated tubular film opposes a separation. If the shrink-wrapped waste has only a very low weight, such as used syringes that are contaminated with toxic or infectious material, a safe separation is not always guaranteed.

Proceeding from this, the present invention seeks to improve a device of the type mentioned in that with simple operation, the welded-waste can be welded either in individual separate bags or in several contiguous bags.

This object is achieved in that by a different operation of the sensor optionally a welding cycle for welding the hose portion or a Trennschweißzyklus for welding the hose portion and for separating the lower end is triggered.

The feature of the invention allows a user to decide, on a case by case basis, by a different operation of the sensor, whether to weld a waste batch to be welded in a single bag separate from other bags or in one of a plurality of contiguous bags.

A preferred embodiment of the invention provides that the welding cycle or the separating welding cycle can be triggered by the fact that the sensor is actuated for different lengths. Since the waste is usually to be welded into contiguous bags, it is advantageous if the duration of the operation of the sensor to initiate the welding cycle is shorter than to initiate the separation welding cycle.

In order to make it possible to freely choose the length of a bag, for example, depending on the size of the waste to be welded, a further preferred embodiment of the invention, after a triggering of the welding cycle and / or the Trennschweißzyklus by a subsequent operation of the sensor first Transport the film tube, wherein the length of the transport path is in turn controllable by the duration of the operation of the sensor. Advantageously, the standing in engagement with the conveyor unit hose section is moved down so long until the bag has the desired length or an adjustable maximum bag length has been reached.

At each weld cycle, each bag previously filled with a waste charge is welded in the welding and separation unit along a transverse weld seam which closes the bag located below the weld at the top. This weld also forms the weld at the bottom of the next bag, which is next filled with a waste batch. In this way, a corresponding number of contiguous bags is formed by a number of successive welding cycles, in which a waste charge is trapped aerosol- and liquid-tight between two welds.

Unlike the device from the DE 695 17 207 T2 In a Trennschweißzyklus the last filled bag is not separated along a weld that closes the bag at the top, but along a spaced above this weld additional seam. In addition, a further weld is placed at a distance above this cutting seam, which closes the next filled bag at the lower end. Thus, a single bag formed at Trennschweißzyklus is closed at both ends both by a weld and by a parallel separating seam. In this way, a secure hermetic seal of the individual bags along its two ends is ensured and prevents escape of toxic or toxic wastes due to leaks in the separating seams due to there the heating of the plastic material to flow can not be excluded.

According to a further preferred embodiment of the invention, a transport direction of the conveyor unit for the purpose of separating the lower end of the hose section is reversible at Trennschweißzyklus. In this way, in the separation welding cycle, the separation of a filled and sealed bag from the film tube can be facilitated by exerting an upward pulling force on the portion of the tube section located above the filled bag between the conveying unit and the welding and separating unit and thereby this part of the tube section is pulled up.

The sensor serving to control the welding and separating unit and preferably also the conveying unit may be an optical sensor or an ultrasonic sensor. Preferably, an infrared sensor is used which comprises a transmitter and a receiver, the former emitting IR radiation and the latter receiving the IR radiation emitted by the transmitter and reflected back to the receiver by an object in the radiation path of the transmitter. Upon receipt of radiation, the receiver emits a signal, which is forwarded to a controller of the device in order to carry out a corresponding activation of the welding and separating unit and of the conveyor unit, depending on the time and duration of the reception of reflected IR radiation.

In order to avoid that the sensor is actuated by IR scattered radiation from the environment, the sensor operates advantageously in pulse mode. A particularly ergonomic operation of the sensor is possible if, according to a further advantageous embodiment of the invention, on an upper side of the housing is arranged, expedient next to a throw-in opening for injecting the waste to be welded.

The welding and separating unit preferably comprises two heatable welding jaws which, for welding the hose section, approach the hose section by means of a welding jaw drive from opposite sides and can be pressed against the latter.

In order to avoid sticking of the welding jaws on the hose portion and to ensure uniform welding, the two welding jaws each have a connectable to a power source heating wire, which is arranged between a Teflon tape on its side facing the hose section and a rubber band on its side facing away from the hose section is.

A still further advantageous embodiment of the invention provides that at least one of the two welding jaws is resiliently mounted counter to the direction of movement when approaching the hose section and provided with a contact for reversing the direction of the welding jaw drive when the spring outside of a central welding position of the welding jaw by a Resistance in the same movement path is compressed and triggers the contact. The contact is preferably a reed contact, which is triggered by the approach of a permanent magnet during compression of the spring. In this way, a squeezing of a hand or a finger of a user can be prevented, provided that unexpectedly the hand or finger should be introduced from above or from below between the approaching welding jaws. A possible combustion on one of the heating wires is prevented by the power supply to the heating wires is only switched on when the welding jaws have reached a central welding position.

The device according to the invention has a control which serves to activate the conveyor unit and the welding and separating unit when the device is put into operation. Advantageously, this control includes, inter alia, a device which monitors the power supply to the electric welding jaw drive during a movement apart of the welding jaws and the power supply to the drive motor interrupts and preferably reversed briefly when a predetermined current threshold is exceeded. As a result, a squeezing of a hand or a finger of a user can be prevented, as long as the hand or finger unexpectedly from above or below between one of the diverging welding jaws and an opposite rigid part of the welding and separating unit should introduce.

• Fig. 1 eine perspektivische Ansicht einer erfindungsgemäßen Vorrichtung zum Einschweißen von Abfällen in einen Folienschlauch;
• Fig. 2 eine Oberseitenansicht eines Gehäuses der Vorrichtung;
• Fig. 3 eine Oberseitenansicht des Gehäuses nach dem Abnehmen eines Gehäusedeckels;
• Fig. 4 eine perspektivische Ansicht des Gehäuses;
• Fig. 5 eine perspektivische Ansicht des Gehäuses nach dem Abnehmen eines Gehäusedeckels;
• Fig. 6 eine schematische Schnittansicht des Gehäuses zur Erläuterung der Funktionsweise der Vorrichtung;
• Fig. 7 eine auseinander gezogene perspektivische Ansicht einer Fördereinheit, einer Schweiß- und Trenneinheit und eines Gehäuseunterteils des Gehäuses;
• Fig. 8 eine perspektivische Ansicht der Fördereinheit;
• Fig. 9 eine perspektivische Ansicht der Schweiß- und Trenneinheit.

In the following the invention will be explained in more detail with reference to an embodiment shown in the drawing. Show it:

• Fig. 1 a perspective view of a device according to the invention for welding waste into a film tube;
• Fig. 2 a top view of a housing of the device;
• Fig. 3 a top view of the housing after removing a housing cover;
• Fig. 4 a perspective view of the housing;
• Fig. 5 a perspective view of the housing after removing a housing cover;
• Fig. 6 a schematic sectional view of the housing for explaining the operation of the device;
• Fig. 7 an exploded perspective view of a conveyor unit, a welding and separating unit and a housing lower part of the housing;
• Fig. 8 a perspective view of the conveyor unit;
• Fig. 9 a perspective view of the welding and separating unit.

The apparatus 10 of the invention shown in the drawing is used to weld waste into a foil tube 12 made of a thermoplastic film which, during welding, is subdivided by transversal welds into a series of aerosol and liquid tight bags, each containing a batch of wastes.

With the apparatus 10, a plurality of sealed bags may be dispensed as a contiguous strand or in the form of discrete separate bags from a housing 12 of the device 10, from which they fall down into a receptacle (not shown) positioned below the housing 12.

The apparatus 10 includes, in addition to the flat parallelepiped housing 12, a chassis 14 having four elongated legs 16 supporting the housing 12, which are provided with rollers 18 at their lower ends, and a platform 20 mounted on the legs 16 near the lower ends to turn off of the collection container. The housing 12, the chassis 14 and the platform 20 are made of stainless steel. However, the device 10 can also be integrated without the chassis 14 in a work table or in a wall, for example as a built-in device.

The essentially consisting of a lower housing part 22 and a removable cover part 24 housing 12 surrounds an electronics unit 26, a welding and separation unit 28 and a conveyor unit 30, which are housed inside the housing. How best in Fig. 7 shown, the electronics unit 26, the welding and separating unit 28 and the conveyor unit 30 with the lid part 24 removed successively from above into the housing base 22 (in Fig. 7 not shown) are used before the lid part 24 is finally placed.

How best in Fig. 1 shown, the cover member 24 has a circular insertion opening 32 for injecting the waste to be welded, which is surrounded by a flat funnel-shaped edge 34.

How best in Fig. 6 illustrated, the in-outline square trough-like housing base 22 has a flat bottom 36 which is provided with a central bottom opening 38.

As in Fig. 7 illustrated, the electronics unit 26 has a flat bottom plate 40 with a central opening 42 which is aligned with the bottom opening 38 after insertion into the housing lower part 22. About the bottom plate 40 is bent from sheet metal frame-like wall portion 44 with a square outline vertically above, on which, inter alia, a power supply, a rechargeable battery 46 and a on a Printed circuit board mounted electronic control 48 of the device 10 are attached.

As in Fig. 8 illustrated, the conveyor unit 30 has a bottom plate 50, an outline in square inner wall 52 made of sheet metal and an outline square outer wall 54 made of sheet metal, which are bent from the floor panel 50 upwards. The inner wall 52 of the conveyor unit 30 defines a square shaft 56 and is provided on opposite sides of the shaft 56 with two pairs of narrow conveyor rollers 58 in the form of friction wheels, each projecting inwardly into the shaft 56. A first of the two conveyor rollers 58 of each pair has a fixed axis, while a second of the two conveyor rollers 58 of each pair is pivotally mounted and acted upon by a pressure ram 60 with a spring force to press with its peripheral surface against the peripheral surface of the first conveyor roller 58 , The two conveyor rollers 58 of each pair are non-rotatably connected by the inner wall 52 with meshing gears 62, of which the gear 62 of the fixed shaft conveyor roller 58 via a toothed belt 64 and an output shaft 66 of an electric drive motor 68 can be driven, so that the Always turn gears 62 in opposite directions. The drive motor 68 is a drive motor 68 with a reversible direction of rotation, which is arranged in the intermediate space between the inner and outer walls 52, 54.

As in Fig. 9 illustrated, the welding and separating unit 28 has an outline square frame 70 which defines a passage opening 72 and an outer wall 74 of sheet metal, whose dimensions correspond to those of the outer wall of the conveyor unit 28. In the frame 70, two movable parallel welding jaws 76 are arranged, the opposite ends of which are mounted on carriages which are of a welding jaw drive 78 along parallel guides 80 can be approximated or moved apart. The movement and the respective position of the welding jaws 76 are monitored by the controller 48 via microswitches according to the quiescent current principle. Each welding jaw 76 has a heating wire which can be connected to a current source and which is arranged between a Teflon strip on its side facing the passage opening 72 and a rubber band on its side facing away from the passage opening 72.

The heating wires of the two welding jaws 76 are supplied with power from the controller 48 when the welding jaws 76 are in an intermediate welding position in which they are pressed against the welding between the welding jaws 76 extending hose portion 82 from opposite sides, as in Fig. 6 shown schematically.

In order to prevent injury to a hand or fingers of a user who accidentally get between them in the mutual approach of the two welding jaws 76, the welding jaws 76 are resiliently supported against the direction of movement in their approach to the carriage. Further, a reed contact is disposed on one of the slides, which is triggered by a permanent magnet attached to the welding jaw 76 when the spring is compressed outside the central welding position and thereby the magnet is approximated to the contact.

The welding jaw drive 78 is an electric drive motor, to which power is supplied for the mutual approaching or moving apart of the welding jaws 76. When the welding jaws 76 are moved apart, the power supply to the drive motor 78 is monitored. When the current consumption of the drive motor 78 exceeds a predetermined current threshold indicating that If there is an obstacle in the path of movement of the welding jaws 76 between these and opposite parts of the frame 70, the direction of movement of the welding jaws 76 is temporarily reversed by reversing the polarity of the drive motor 78. Thus, if the obstacle is a user's hand or finger, it may pull the hand or fingers out of the gap between the welding jaw 76 and the frame 70 without the risk of injury.

The outer wall 54 of the conveyor unit 30 and the outer wall 74 of the welding and separating unit 28 have corresponding lateral dimensions, while the wall portion 44 of the electronic unit 26 has larger lateral dimensions. In this way, a receiving space 84 for a folded film tube 86 is formed between the outer walls 54, 74 on the one hand and the wall portion 44 on the other hand, as in Fig. 6 shown.

Before the device 10 is put into operation, the film tube 86 which has been folded into an annular packet is inserted into the receiving space 84, which is accessible from above when the cover part 24 is removed. Subsequently, the upper end of the film tube 86 is folded inward or everted and passed through the limited by the inner wall 52 of the conveyor unit 30 shaft 56. In this case, between the two pairs of conveyor rollers 58 opposite and double superimposed edge strips of the folded inwards and through the shaft 56 and between the welding jaws 76 down guided hose portion 82 of the film tube 86 is clamped. In this way, the tube portion 82 can be transported downwardly through the housing 12 to and from the bottom opening 38, as indicated by the arrow A in FIG Fig. 6 illustrated by the conveyor rollers 58 are driven in the opposite direction of rotation, as indicated by the arrows B in Fig. 6 displayed. After this Closing the lid part 24, the device 10 can be put into operation.

In operation, the device 10 is controlled by means of a contactlessly above the housing lower part 24 protruding infrared sensor 88 which projects into a punched next to the opening 32 opening 90 in the cover part 24. As in FIGS. 2 and 3 illustrated, the sensor 88 comprises a pulse operating, emitting IR radiation transmitter 92 and an adjacent to the transmitter 92 arranged IR receiver 94. The receiver 94 is responsive when vertically upwards from the transmitter 92 emitted IR radiation from one above of the sensor 88 at a distance of less than 0.2 m in the radiation path of the IR radiation moving object is reflected back to the receiver 94. In addition to the transmitter 92 and the receiver 94, the sensor 88 also includes an indicator light 96, which indicates various operating states of the device 10 by different colors.

After switching on a arranged on the bottom of the housing 12 battery disconnect switch 98 for connecting the battery 46, the device 10 is in stand-by mode, in which the device 10 can not be controlled by means of the sensor 88. The activation takes place by pressing a reset button 100 on the lower housing part 22, whereupon the indicator lamp 96 lights up in a first color. When using the device 10 for the first time after inserting a new film tube 86 into the receiving space 84, the hose section 82 of the film tube 86 in the welding and separating unit 28, which is turned inwards, is guided downward through the shaft 56 and the remaining housing 12 Welding jaws 76 closed by a transverse over the hose section 82 extending weld, which then forms the lower end of the first bag.

In use of the apparatus 10, when the sensor 88 is activated, one of the user may select one of two desired modes, namely, a welding cycle and a separation welding cycle.

The welding cycle is triggered by moving an object, for example the user's hand, over the sensor 88 into the IR radiation path. Thereafter, the indicator light 96 begins to flash in a different color, indicating that the device 10 is waiting and waiting for another input from the user. When the user again moves the hand over the sensor 88, transport of the hose portion 82 is initiated by driving the two pairs of conveyor rollers 58 of the conveyor unit 30. The transport takes place until the user again moves the hand away from the sensor 88 or until an adjustable maximum bag length is reached. The user can thus control by the residence time of the hand above the sensor 88, the length of the film bag to be formed to receive the waste. Before or during transportation, the user may throw a batch of the waste into the throw-in port 32 from where they fall into the upwardly open hose section 82 or bag which has previously been welded in the welding and separation unit 28 at the lower end. When the user moves his hand away from the sensor 88, a welding operation is then initiated again to close the top of the bag. In the welding operations, the two welding jaws 76 are approached from opposite sides of the hose portion 82 and pressed against it. Then, current is supplied to the heating wires in the welding jaws 76 to weld the hose portion 82 therebetween along a weld extending transversely across the hose portion 82 and thus hermetically seal the film bag close. Between the upper end of a bag and the lower end of a subsequently formed bag a single weld is arranged in each case. The film tube is not severed in the welding cycle to form a continuous string of bags which are closed at both ends by parallel welds, the contents of each bag being hermetically separated from the contents of the adjacent bags.

The splice cycle is triggered by holding an object, such as the user's hand, over the sensor 88 for a period of more than 2 to 3 seconds. In this case, the indicator light 96 flashes in still another color and the separation welding cycle is initiated. As with the welding cycle, a hand-controlled transport of the hose portion 82 is first initiated, which lasts until the user moves the hand away from the sensor 88 again or a maximum adjustable bag length is reached. Before or during transport, the user can, as in the welding cycle throw the waste into the insertion opening 32, from where they fall into the already sealed at the bottom of foil bag. As the user moves his hand away from the sensor 88, a first welding operation is initiated in which the bag is welded at the top by a transverse weld, as previously described for the welding cycle. However, after the welding jaws 76 have been moved apart again, in the separation welding cycle, the hose section 82 is again moved downwardly a short distance by the conveyor unit 30, preferably by about 5 centimeters. Thereafter, the two welding jaws 76 are again approximated to the hose portion 82 and pressed against this, but the heater wires more power than in the welding process is supplied. Due to the greater amount of heat generated thereby, the hose portion 82 between the welding jaws 76 is heated to flow. If this is the case after expiration of a preset period of time previously determined by tests, the direction of rotation of the drive motor 68 of the conveyor unit 30 is reversed by reversing the polarity and power is again briefly supplied to the drive motor 68. As a result, the part of the hose section 82 located between the conveying unit 30 and the welding and separating unit 28 is moved backwards, ie upwards, and thus along a separating seam extending between the welding jaws 76 from the lower end of the hose section 82 projecting downwards beyond the welding jaws 76 demolished the last welded bag. This latter then falls either immediately or at the latest when moving apart of the welding jaws 76 down into the receptacle. After the welding jaws 76 have been moved apart, the hose section 82 is once again moved downward a short distance by the conveyor unit 30 and then welded again along a weld before the next cycle can be initiated. In this way, individual bags are produced at the Trennschweißzyklus with shrink-wrapped waste, which are closed at both ends by two parallel seams, a weld adjacent to the bag contents and arranged directly at the bag end seam.

However, in both the weld cycle and the seal weld cycle, the thermoplastic material of the film tube is heated along the seams to a temperature such that a plurality of overlying or overlapping layers of the plastic material hermetically bond together along the seams.

By pressing the reset button 100, the welding cycle and the separating welding cycle can be stopped at any time.

Claims (10)

1. Apparatus (10) for welding waste into a film tube (86), having a housing (10) which surrounds a receiving space (84) for the folded-up film tube (86), a chute (56), through which an inwardly folded-over tube section (82) of the film tube (86) extends from top to bottom, a conveying unit (30) which transports the tube section (82) downwards through the chute (56), a welding and severing unit (28) for welding the tube section (82) along transversely running seams and for severing a lower end of the tube section (82), and a contactlessly operating sensor (88) for actuating the welding and severing unit (28), characterized in that a welding cycle for welding the tube section (82) or a severing and welding cycle for welding the tube section (82) and for severing the lower end can be triggered selectively by way of different actuation of the sensor (88).
2. Apparatus according to Claim 1, characterized in that the welding cycle and the severing and welding cycle can be triggered by way of a different length of time period for the actuation of the sensor (88).
3. Apparatus according to one of the preceding claims, characterized in that, after triggering of the welding cycle or the severing and welding cycle, first of all transport of the tube section (82) can be triggered by way of a further actuation of the sensor (88), it being possible for the length of the transport path to be controlled by the time duration of the actuation of the sensor (88).
4. Apparatus according to one of the preceding claims, characterized in that, during the welding cycle, the welding and severing unit (28) welds the tube section (82) along a welded seam which runs transversely over the tube section (82) and closes a bag which is arranged below the welded seam at the upper end.
5. Apparatus according to one of the preceding claims, characterized in that, during the severing and welding cycle, the welding and severing unit (28) first of all welds the tube section (82) along a welded seam which runs transversely over the tube section (82) and closes a bag which is arranged below the welded seam at the upper end, in that the welding and severing unit (28) subsequently severs a lower end of the tube section (82) along a severing seam which is arranged above the welded seam, and in that the welding and severing unit (28) finally welds the remaining part of the tube section (82) along a welded seam which is arranged above the severing seam.
6. Apparatus according to one of the preceding claims, characterized in that, during the severing and welding cycle, a transport direction of the conveying unit (30) can be reversed in order to sever the lower end of the tube section (82).
7. Apparatus according to one of the preceding claims, characterized in that the sensor (88) is an infrared sensor.
8. Apparatus according to one of the preceding claims, characterized in that the sensor (88) comprises a transmitter (92) and a receiver (94) which receives radiation which is emitted by the transmitter (92) and is reflected to the receiver (94) by an object in the radiation path of the transmitter (92) and supplies a signal to a controller (48) which activates the welding and severing unit (28) and the conveying unit (30).
9. Apparatus according to one of the preceding claims, characterized in that the sensor (88) is a sensor which works in pulse operation.
10. Apparatus according to one of the preceding claims, characterized in that the sensor (88) is arranged on an upper side of the housing (12).

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