Method for emptying viscous material from a cartridge open on both sides and an emptying device therefore

Abstract

The aim of the invention is to empty a cartridge (100) in a bubble-free manner. This is achieved in that the material (M) is pressed out of the removal opening (100a) of the cartridge (100) into a large-surface distributing head (7) which has a plurality of small outlet openings (17) on the lower face, whereby a plurality of thin strands (S1, S2, S3) are produced, said strands having a very large surface area in comparison to the volume thereof so that gas that is outgassed in the process can be removed via a vacuum applied about the strands. The strands (S1, S2, S3) fall into a collecting container (2) arranged underneath, and after the cartridge (100) is completely emptied, the strands are transported from the collecting container further downwards via the outlet opening (29), which can be found in the base of the collecting container (2), and into the discharge line (20), which is connected thereto and leads to the load, e.g. a metering device (300), by driving the distributing head (7) into the open side of the collecting container (2).

Description

I. Area of ​​application

[0001] The invention relates to the bubble-free emptying of highly viscous, i.e. pasty, substances from delivered transport containers, in particular cartridges. II. Technical background

[0002] When processing highly viscous substances, e.g. in adhesive technology or the cosmetics industry, these substances or their individual components are delivered in transport containers such as cylindrical cartridges, which are usually made of plastic, with a capacity of one or more liters and the viscous material contained therein must be delivered from there to a consumer, e.g. a dosing device or a mixer, bubble-free, i.e. without air inclusions.

[0003] In the following, only cartridges are mentioned, which for the purposes of the present description, however, should include all transport containers that are open on both sides but can be closed, in which a pusher can be moved tightly inside the cartridge - which is usually cylindrical in terms of its inner circumference - and is inserted from the rear end, while the opposite front end has a generally much smaller removal opening, which is closed during transport and can be opened to remove the material.

[0004] The removal from the cartridge and the transport via a supply line - the discharge line - to the remote consumer should take place as required and automatically without complex manual post-processing, and it should be possible to empty the usually expensive materials as residue-free as possible.

[0005] In addition, no air should be able to get into the material during emptying, or even any air still contained in the material should be able to escape.

[0006] Previously, this approach was attempted by placing a degassing nozzle, which can be pressurized with negative pressure, between the discharge line connected to the discharge opening and the discharge opening. However, this can only remove gas bubbles that form after the discharge opening is opened and subsequently connected to the discharge line, but not gas bubbles that are finely distributed within the material, for example.

[0007] It is generally known to degas flowable materials using a thin-film process: The material is guided over a surface in the form of a layer that is as thin as possible, thereby massively increasing the surface area of ​​the flowing material, so that the probability that a gas bubble contained therein comes into contact with the surface of the layer and thus outgasses from the material is greatly increased.

[0008] Furthermore, when removing drums containing viscous material that are delivered as transport containers, it is known to empty such a drum by means of a drum follower plate placed on the material, but to apply negative pressure, in particular vacuum, to the space around it before inserting the drum follower plate into the drum and placing it on the material and to arrange a pressure-tight housing with a negative pressure connection around it for this purpose.

[0009] However, due to the lack of a second opening, the material is pumped out of the only opening on top of the barrel, namely through the hollow piston rod attached to the barrel follower plate and pressing it downwards.

[0010] For this purpose, the barrel follower plate must be pressed against the material with high pressure, for which the stability of the barrel itself in the radial direction is often not sufficient, but the barrel must be held together radially in a corresponding support device.

[0011] The document DE 10 2017 108187 A1 discloses such a device for emptying highly viscous substances from a barrel, i.e. from a container open on one side.

[0012] In the case of cartridges that are open on both sides, the material is to be pushed out through the removal opening on the opposite end face by means of the pusher located therein, which can be moved along the inner cross-section, which is usually round and remains constant in the main direction of extension of the cartridge. III. Description of the invention a) Technical task

[0013] The object of the invention is therefore to provide a method for bubble-free emptying, even of cartridges that are open on both sides, with which gas bubbles present inside the material can be eliminated before delivery to the consumer. Furthermore, the object is to provide a suitable emptying device for this purpose. b) Solution to the task

[0014] This object is achieved by the features of claims 1, 8 and 15. Advantageous embodiments emerge from the subclaims.

[0015] Regarding the Procedure This task is solved by dividing the material into a large number of thin strands when the material is pressed out of the removal opening by means of axial displacement of the pusher.

[0016] Due to this strong increase in surface area, the probability that a gas bubble present in the material will come into contact with the surface of such a thin strand is much higher, and of course, the thinner the strands are, the greater the probability.

[0017] The strands are dropped into a collecting container open at the top and mix with the flowable material present there, which is then conveyed from this collecting container to the consumer via a main conveying line connected to the lower part of the container.

[0018] In order to avoid new gas inclusions forming when the thin strands are reunited in the material in the collecting container, at least the area from the division of the material into the multitude of thin strands, i.e. from the removal opening, up to the upper open end of the collecting container is kept under negative pressure during the emptying process of the cartridge and preferably also during the removal of the material from the collecting container to the consumer.

[0019] The gas contained in an opening gas bubble in the material is then removed from this area and if there is almost a vacuum in the area, no new gas inclusions can form.

[0020] In the context of the present description, negative pressure is understood to mean that this is in particular approximately a vacuum with a residual pressure of at most 50 mbar, preferably at most 10 mbar, preferably at most 1 mbar.

[0021] For forwarding to the consumer, the material is pressurized in the direction of the outlet of the discharge line on the collection container at the latest after the cartridge has been completely emptied, which is preferably done by pushing a discharge piston that is tightly guided in the collection container forward from the open side towards the outlet of the discharge line, preferably towards the bottom of the usually pot-shaped collection container, where this outlet is located in the bottom.

[0022] Since the collection container fills with material in a vacuum environment and such a discharge piston is inserted into the upper open side of the collection container under vacuum, no gas pockets are formed, even if after inserting the discharge piston into the open top of the collection container there was still a free distance between the discharge piston and the top of the filling of material, since this no longer contains any air.

[0023] The division of the material emerging from the discharge opening in a thick strand into a plurality of thin strands is carried out by means of a distribution head which in particular has a plurality of outlet openings for each thin strand.

[0024] Advantageously, this distribution head, which is preferably arranged at a distance above the open top of the collecting container during emptying of the cartridge, is then used, in particular after the cartridge has been completely emptied, as a discharge piston and is introduced into the collecting container and guided downwards in a sealed manner, for which the distribution head must have a suitable dimension.

[0025] On the one hand, this does not require a separate discharge piston, and on the other hand, it avoids the need to position a separate discharge piston under the distribution head and over the opening of the collection container and only then lower it into it, which would be considerably more complex.

[0026] In this case, it is preferable not to push the distribution head alone axially into the collecting container, but together with the cartridge, to whose front end, the removal opening, it is attached, so that the cartridge acts as a plunger that moves the distribution head axially.

[0027] Preferably, the cartridge is moved axially by being fixed with its rear end in both axial directions, i.e. both upwards and downwards, in a cartridge carrier and this cartridge carrier can be moved back and forth in the pressing direction by means of a conveyor drive.

[0028] To press the cartridge out of the cartridge, a cartridge plunger of a cartridge drive is placed on the back of the ejector facing away from the material and pushes this ejector further forward towards the removal opening.

[0029] In order to ensure that the ejector fits tightly against the inner circumference of the cartridge, the cartridge can also be supported radially on its outer circumference.

[0030] Preferably, the area on the outside, i.e. the back, of the ejector up to the point where the cartridge tappet emerges from the cartridge drive is also kept under negative pressure during the emptying process so that there is no air on the back of the ejector that could penetrate into the material in the event of a leak between the ejector and the inner circumference of the cartridge.

[0031] Preferably, instead or additionally, only the area at the rear of the cartridge tappet can be evacuated, but not up to its exit point from the cartridge drive, but only up to a front area of ​​the cartridge tappet.

[0032] In order to be able to empty the cartridge, with the distribution head already attached to its removal opening, is inserted transversely to the pressing direction under the retracted cartridge tappet and fixed in the cartridge carrier in alignment with the cartridge tappet, whereby the cartridge carrier is offset far enough away from the collecting container, in particular upwards, so that when the cartridge is inserted into the cartridge carrier, the distribution head is still above the collecting container.

[0033] Regarding the Emptying device This includes the well-known components such as a base frame to which all other parts are attached, a cartridge drive with a cartridge plunger for pushing the cartridge ejector forward, a discharge line to the consumer which can be connected to the emptying device, a cartridge carrier to which the cartridge can be attached and a first pressure-tight vacuum housing with a negative pressure connection which is located at the transition from the cartridge to the discharge line in order to extract gas escaping from the material in this area.

[0034] For the procedure according to the invention, a pot-shaped collecting container is also provided on the base frame, which is open on one side, usually upwards, and in the lower area of ​​which, in particular in the bottom, the discharge line is connected, as well as a distribution head which divides the thick rod emerging from the removal opening of the cartridge into a plurality of thin strands by comprising a plurality of small outlet openings on its outlet side.

[0035] The distributor head has a fastening device with which it can be attached to the discharge opening of the cartridge so that the thick strand emerging from it flows into the hollow interior of the distributor head and from there to the many outlet openings.

[0036] In order to prevent the thin strands emerging from them from curling due to one-sided adhesion to a point on the circumference of the outlet opening, the outlet openings have a tear-off edge at their free end which surrounds the outlet opening and has a sharp, pointed tear-off edge with an angle of less than 70°, preferably less than 50°, preferably less than 40°.

[0037] In order for the distribution head, which is attached directly to the front lower end of the cartridge and in the underside of which the outlet openings are located, to be able to be inserted tightly into the collecting container, its outer circumference must correspond to the inner circumference of the collecting container and a sealing lip is preferably provided on the outer circumference of the distribution head.

[0038] Furthermore, the outer diameter of the distribution head must be larger than the outer diameter of the cartridge, as the latter partially protrudes into the collection container during operation.

[0039] In order to be able to move the cartridge carrier including the cartridge back and forth in the pressing direction, a discharge drive is provided which can move the cartridge carrier relative to the base frame towards and away from the collecting container, preferably consisting of two discharge working cylinders on opposite sides of the cartridge carrier.

[0040] Furthermore, there is a fixing device on the cartridge holder with which the cartridge can be held firmly on the cartridge holder both in and against the pressing direction.

[0041] To maintain vacuum in the area of ​​the open side of the collection container, a first vacuum housing is provided which is sleeve-shaped and rests on the one hand on the outer circumference of the collection container and on the other hand on the outer circumference of the cartridge aligned therewith, wherein the seal with respect to the cartridge allows a relative movement of the cartridge to this vacuum housing in order to retract the cartridge upwards to such an extent that its removal opening and, above all, a distribution head attached to it are located at a distance above the collection container.

[0042] To insert the cartridge, the cartridge holder in the cartridge carrier is open on one side or can at least be opened to insert the cartridge from the side, for which the cartridge carrier is positioned at a height such that the lower removal opening of the cartridge including the distribution head is located at a distance above the open top of the collection container.

[0043] Then, first, the ring-shaped lid of the sleeve-shaped first vacuum housing is pushed onto the outer circumference of the cartridge from below and then the distribution head is fixed, in particular screwed, onto the lower end of the cartridge, which is only possible after pushing on the lid, since it has a larger outer diameter than the cartridge.

[0044] Preferably, the cover of the first vacuum housing and the distribution head are attached to the cartridge - or to a support sleeve surrounding the cartridge, which is intended to minimize radial expansion of the cartridge when pressurized - before the cartridge is hung in the emptying device.

[0045] The lid can then be pushed down far enough to secure and seal it against the sleeve-shaped lower part of the first vacuum housing, which is preferably always located on the collecting container.

[0046] After inserting the cartridge and, if necessary, closing the cartridge holder in the circumferential direction, the upper end of the cartridge, in which the ejector is located when filled, is located within a second, cap-shaped vacuum housing, which sits tightly on the upper edge of the cartridge at the bottom and is sealed at the top against the circumference of the cartridge tappet, which passes through it. c) Examples of implementation

[0047] Embodiments of the invention are described in more detail below by way of example. They show: Figure 1a: the emptying device according to the invention in perspective view, Figure 1b, c: the emptying device of the Figure 1a in side views in a first and a second transverse direction, Figure 2a: the emptying device viewed in the second transverse direction in vertical section, with the press head above the suspended cartridge, Figure 2b:the emptying device viewed in the first transverse direction and cut in the pressing direction, with the pressing head adjacent to the pusher and inside the cartridge, Figure 3a: in a vertical section according to Figure 2a , but with the distribution head retracted as a discharge piston in the collecting container, Figure 3b: the emptying device in the same operating position, viewed in the same direction as Figure 2b , Figure 4a: a longitudinal section through a full cartridge in the delivery state, Figure 4b: a cartridge in longitudinal section with a distribution head attached to the dispensing opening, Figure 4c: a perspective view of the distribution head, Figure 5: a schematic diagram of a dosing unit, Figure 6a - c: inserting the cartridge into the emptying device.

[0048] As the Figures 1a to 3bAs can be seen, the emptying device consists of a base frame 1 in the form of a base plate 1 - preferably with lateral wheels that are bent downwards inwards towards each other for sliding around a guide 501 as in Figure 5 shown - on which two discharge working cylinders 13, 14, here as pneumatic cylinders, are arranged at a distance in a first transverse direction 11, which together form the discharge drive 6, since they are arranged with their pressing directions 10 parallel to one another and the respective piston rod 13a, 14a can be extended vertically upwards from their respective cylinder 13b, 14b.

[0049] The upper free ends of these two piston rods 13a, 14a, which are synchronously movable, are connected to one another via a yoke 23, on which the cartridge drive 4 protrudes centrally in the form of preferably only one cartridge working cylinder 15, this time with the bottom of the cylinder 15b pointing upwards, so that the piston rod 15a extends downwards therefrom as a cartridge tappet 15a and projects through an opening in the yoke 23, which is formed in the cartridge receptacle 16 of a cartridge carrier 3, into a cartridge 100 suspended therein and is aligned with it.

[0050] The cartridge carrier 3 consists of a rectangular profile which is open, preferably continuously, on at least one side in the second transverse direction 12 and which is preferably fastened to the underside of the yoke 23, which is narrow enough in the first transverse direction 11 to dip between the two discharge working cylinders 13, 14.

[0051] In the lower horizontal plate of the rectangular profile there is a second transverse direction 12 - see Figure 1a - open, U-shaped, from top to bottom continuous, recess, which is dimensioned so that a cartridge 100 with its surrounding, outwardly pointing edge 100b1 at the filling opening 100b can be suspended thereon, by the cartridge 100 being pushed into the cartridge receptacle 16 in the second transverse direction 12 in such a way that it rests with the filling opening 100b pointing upwards with this upper edge 100b1 on the cartridge carrier 3, i.e. its edge region running around the cartridge receptacle 16, and preferably with the aid of a fixing device 3a, as in the enlargement of the Figure 2b represented, held.

[0052] The process of inserting a cartridge will be explained later using Figure 6a to c described.

[0053] In this suspended state, the cartridge 100 extends through the cartridge holder 16 and points downwards with its generally smaller removal opening 100a at the opposite end.

[0054] As in Figure 4a As shown, this removal opening 100a is closed in the transport state by a closure element, usually a closure screw 102 that can be screwed onto the thread, in particular the internal thread 100a1 of the removal opening 100a, and inserted into the opposite filling opening 100b there is a pot-shaped ejector 101 that lies tightly against the inner circumference of the cartridge 100, the friction of which is so great that it cannot move out of the filling opening 100b automatically, even due to the material M present between the ejector 101 and the closure element 102.

[0055] For emptying, according to the invention, the closure element 102 is removed and instead a distribution head 7 is fastened to the removal opening 100a, preferably with its own thread, in particular external thread, screwed as a fastening device 7a to the thread, in particular internal thread 100a1, which will be explained later.

[0056] In the Figures 1a to 3b the cartridge is already equipped with such a distribution head 7, which, viewed from above, has a greater transverse extent, in particular a larger diameter, than the cartridge 100.

[0057] On the base frame 1, in particular the base plate 1, a collecting container 2 is mounted between the two discharge working cylinders 13, 14 and in alignment with the cartridge working cylinder 15 - which is usually also pneumatically operated - and the cartridge 100 fixed in the cartridge holder 16.

[0058] The distribution head 7 fits tightly into the upwardly open, pot-shaped collecting container 2.

[0059] The yoke 23 can be raised so far that the distribution head 7 is located above the collecting container 2, and moved down so far that the distribution head 7 sits on the bottom of the collecting container 2.

[0060] The piston rod, i.e. the cartridge tappet 15a, of the cartridge working cylinder 15 carries a pressing head 24 at the lower, free end, the downward-facing end face of which is adapted to the concave curvature of the upper side of the ejector 101 and fits into it.

[0061] The cartridge working cylinder 15 is dimensioned such that when the piston rod 15a is fully retracted into its cylinder 15b, i.e. raised, the pressing head 24 is located at a height completely above the suspended cartridge 100 and, in the fully extended state, close to the bottom of the cartridge 100 at its removal opening 100a, with only the cup-shaped ejector 101 in between.

[0062] In the lower region of the emptying device 200, preferably in the bottom of the collecting container 2, there is also an outlet opening 29 which is connected to a discharge line 20 which leads to a remote consumer for the material M.

[0063] For feeding material M from the cartridge 100 to the discharge line 20 and thus to the consumer, a cartridge 100 must first be installed in the emptying device as shown in Figure 2a shown.

[0064] For this purpose - see the Figures 6a to c - first prepare the cartridge 100 according to Figure 6a , by optionally first pushing a circumferentially closed support sleeve 103 onto the outer circumference of the cartridge 100 from its lower, emptying-side end, which also has an edge projecting radially outwards at the upper end, up to the edge 100b1 of the cartridge 100, wherein the support sleeve 103 then preferably extends downwards over the entire cylindrical part of the cartridge 100.

[0065] Subsequently, the annular lid 21b of a first vacuum housing 21 is pushed from the emptying-side end onto the outer circumference of the cartridge 100 or - if present - the support sleeve 103 so far that the distribution head 7 can then be fastened to the lower removal opening 100a, in particular can be screwed into its internal thread 100a1.

[0066] This sequence is necessary because the outer circumference of the distribution head 7 is larger than the outer circumference of the cartridge 100 and also the inner circumference of the cover 21 b.

[0067] Subsequently, the cartridge 100 - optionally with surrounding support sleeve 103 as well as lid 21b and distribution head 7 - is inserted into the cartridge receptacle 16 in the second transverse direction 12 and by means of the fixing device 3a the edge 100b1 and optionally the edge of the support sleeve 103 located underneath are pressed firmly onto the upper side of the cartridge receptacle 16, wherein these parts are preferably sealed against one another by concentrically circumferential O-rings 27 located therebetween.

[0068] According to Figure 6bthe cartridge plunger 15a is moved back upwards to such an extent that the press head attached to it and the bell-shaped second vacuum housing 22 placed over it from above are located so far above the top side of the cartridge holder 16 that the insertion of the cartridge 100 in the second transverse direction 12 is possible.

[0069] The two discharge working cylinders 13, 14 are extended with respect to their piston rods 13a, 14a to such an extent that the distribution head 7 attached to the cartridge 100 is then located at a height above, but vertically aligned with, the collecting container 2.

[0070] Subsequently, according to Figure 6c the cover 21b is moved downwards and tightly connected to the upper side of the sleeve-shaped lower part 21a of the first vacuum housing 21, wherein the cover 21b still lies tightly against the outer circumference of the cartridge 100 or support feet 103, sealed by means of, for example, an O-ring 27.

[0071] Alternatively, the sleeve-shaped lower part 21a can be moved upwards along the outer circumference of the receiving container 2 until it reaches the lid 21b and then be tightly connected to it.

[0072] Based on this in Figure 6c In the hanging position shown, the piston rod 15a of the cartridge drive 4, which represents the cartridge working cylinder, is first moved downwards until the press head 24 dips into the cartridge 100 and rests against the upper side of the ejector 101.

[0073] As a result, the cartridge 100 is fixed in all horizontal directions, so that this represents a first part of the fixing device 3a, and at the latest when the press head 24 is immersed in the cartridge 100, the press piston is released from the bottom of the second, pot-shaped vacuum housing 22, so that this now presses downwards onto the laterally projecting edge 100b1 with its lower annular edge - which represents the second part of the fixing device 3a - by means of a spiral spring 28, which is arranged concentrically around the piston rod 15a between this second vacuum housing 22 and the yoke 23, more precisely the upper side of the cartridge carrier 3, which is rectangular in side view.

[0074] If the pressing head 24 is then moved further downwards according to Figure 2a , b, he pushes the ejector 101 downwards in front of him, whereby the material M located in the cartridge 100 is pressed out downwards via the removal opening 100a and the distribution head 7 attached thereto and falls into the collecting container 2, which preferably has a volume such that it can hold the entire contents of a cartridge 100.

[0075] As soon as the ejector 101 has reached the lower, removal-side end of the cartridge 100 and the latter is empty, the Figures 3a , bthe piston rods 13a, 14a of the two discharge working cylinders 13, 14 are synchronously retracted downwards into the cylinders 13b, 14b, so that the yoke 23 with all parts fastened to it, i.e. both the cartridge carrier 3 and the cartridge 100 and the press head 24 located in the lower area thereof, move downwards together, whereby the distribution head 7 first moves into the upper open end of the collecting container 2 - the inner circumference of which is conically widened upwards at the upper end to facilitate retraction - and moves further downwards with its circumferential sealing lip 25 tightly fitting against its inner circumference, initially until the distribution head 7 sits on the material M located in the collecting container 2.

[0076] By moving even further downwards, the distribution head 7, as a discharge piston 5, pushes the material downwards out of the collecting container 2 into the discharge line 20 and thus to the distant consumer.

[0077] According to the invention, the material M degassed as follows: The task of the distribution head, as in Figure 4c shown in perspective, consists in dividing material M emerging through the removal opening 100a in a single thick strand, which enters the top of the internally hollow distribution head 7, into a plurality of thin strands S1, S2, S3 by arranging a plurality of outlet openings 17 with a comparatively small diameter in the underside of the distribution head 7.

[0078] In order for the strands S1, S2, S3 to emerge from these outlet openings 17 in a straight line downwards, a circumferential sharp tear-off edge 18 is formed around each outlet opening 17, which is achieved, for example, by arranging an annular groove 19 around each outlet opening 18 in the - generally flat - underside of the distribution head 7, which annular groove 19 together with the inner circumference of the outlet opening 17 forms the circumferential sharp, i.e. acute-angled in cross-section, tear-off edge 18.

[0079] As a result, the strands S1, S2 fall parallel to one another downwards into the collecting container 2, instead of deflecting sideways as is possible with one-sided adhesion and reuniting very quickly with neighboring strands S2, S3, because this large surface area, which is maintained on the thin strands S1, S2, S3 for as long as possible, is needed in order to open gas inclusions in the strand and allow the gas to escape.

[0080] The distribution head 7 is located above the collecting container 2, which is why it is also necessary for the strands S1, S2, S3 to fall straight downwards.

[0081] To prevent air from the environment from getting into the material M again when the material is pressed out and collected in the collecting container 2, a first vacuum is formed around it.

[0082] For this purpose, the first vacuum housing 21 is provided, which is provided with a vacuum connection 8 and whose upper, annular cover 21b with its upper through-opening lies tightly against the outer circumference of the cartridge 100 and whose sleeve-shaped lower part 21a with its lower through-opening lies tightly against the outer circumference of the collecting container 2, each sealed, for example, by O-rings 27.

[0083] In order to ensure that no air can be pressed past the seal of the ejector 101 into the material M in the cartridge when the press head 24 is inserted into the cartridge 100 and rests on the ejector 101, the bell-shaped second vacuum housing 22, which has its opening pointing downwards, sits on the upper edge 100b1 of the suspended cartridge 100 with its peripheral walls on this edge 100b1.

[0084] The cartridge tappet 15a of the cartridge working cylinder 15 can be pushed tightly through an opening in the upwardly facing bottom of the pot-shaped second vacuum housing 22, wherein O-rings 27 are preferably used again for sealing.

[0085] The air contained in this vacuum housing 22 is sucked out via the vacuum connection 9, which is also present on this vacuum housing 22, as soon as it sits on the cartridge and before the press head 24 moves into the cartridge, for which purpose the second vacuum housing 22 is preferably dimensioned such that the press head 24 does not lie tightly against the inner circumference of the cup-shaped second vacuum housing 22.

[0086] In order to ensure that any residual air that may still be present between the distribution head 7 and the surface of the material - despite the first vacuum - is not pressed into the material M but is discharged when the distribution head 7 is moved into the collecting container 2, a vent valve 30 can be provided in the rear side, the top side, of the distribution head 7 facing away from the material, i.e. from the bottom of the collecting container 2, which would release air entering the hollow interior of the distribution head 7 via the lower outlet openings 17 upwards into the first vacuum.

[0087] This vent valve 29 can be a simple membrane which is permeable to air but not to the material M to be conveyed.

[0088] In this way, any air inclusions still present in the material M in the cartridge 100 can be removed before the material M reaches the consumer via the discharge line 20.

[0089] Figure 5 shows a typical dosing unit with a dosing device 300, via whose dosing nozzle 301 the viscous material M is to be dosed in exactly specified quantities.

[0090] The emptying device 200 according to the invention is connected to the dosing device 300 via the discharge line 20, wherein both the dosing device 300 and the emptying device 200 preferably have an analogously designed base plate 1, so that both can be pushed onto the same guide 501 and can be positioned at the correct distance from one another. LIST OF REFERENCE SYMBOLS

[0091] 1Base frame, base plate 2Collecting container 3Cartridge carrier 3aFixing device 4Cartridge drive 5Discharge piston 6Discharge drive 7Distribution head 7aFastening device 8Vacuum connection 9Vacuum connection 10Pressing direction 111. Transverse direction 122. Transverse direction 13Discharge working cylinder 13aPiston rod 13bCylinder 14Discharge working cylinder 14aPiston rod 14bCylinder 15Cartridge working cylinder 15aCartridge plunger 15bCylinder 16Cartridge holder 17Outlet opening 18Tear-off edge 19Annular groove 20Discharge line 211. Vacuum housing 222. Vacuum housing 23Yoke 24Pressing head 25Sealing lip 26Cavity 27O-ring 28Coil spring 29Outlet opening 30Vent valve, diaphragm 100Cartridge 100aRemoval opening 100a1Internal thread 100bFilling opening 100b1Rim, flange 101Ejector 102Closing element, screw plug 200Emptying device 300Dosing device 500Dosing unit 501Guide MMaterial S1 - S3Strand

Claims

1. Method for emptying in a bubble-free manner viscous material (M) out of a cartridge (100) open to both sides, which has a pusher (101) therein that is tightly fitting and can be moved in a pressing direction (10) and a closable removal opening (100a) at the other end, in that - by pushing the pusher (101) forward, i.e. in the direction of the removal opening (100a), the material M is pressed out of the removal opening (100a), characterized in that - in pressing out the material (M), it is divided into a plurality of thin strands (S1, S2, S3), - the strands (S1, S2, S3) are dropped into a collecting container (2) open at the top on the outlet opening (29) of which in its lower portion in particular a discharge line (20) is tightly connected, and - at least the area from dividing the material (M) into the plurality of thin strands (S1, S2, S3) up to the upper open end of the collecting container (2) is kept under negative pressure during the emptying process.

2. The method according to claim 1, characterized in that the negative pressure is a vacuum with a residual pressure of at most 50 mbar, in particular at most 10 mbar and in particular at most 1 mbar.

3. The method according to any of the preceding claims, characterized in that - the material (M) that is in the collecting container (2) is pressurized in the direction of the outlet opening (29), i.e. the end of the discharge line (20), at the latest after fully pressing the material (M) out of the cartridge (100), - in particular by pushing forward a discharge piston (5) guided tightly in the collecting container (2).

4. The method according to any of the preceding claims, characterized in that - the division of the material (M) into a plurality of thin strands (S1, S2, S3) is executed by way of a distributing head (7), which in particular has a plurality of outlet openings (17) for each of the thin strands (S1, S2, S3), - the distributing head (7) is also used as a discharge piston (5).

5. The method according to any of the preceding claims, characterized in that - for pressing the material (M) out of the cartridge (100), a cartridge plunger (15a) of a cartridge drive (4) is placed to the pusher (101) pushing it forward.

6. The method according to any of the preceding claims, characterized in that - for pushing the discharge piston (5) forward in the collecting container (2), the discharge piston is inserted into the collecting container (2) and is pushed forward towards the outlet opening (29) and in particular in the direction of the discharge line (20), - in particular the entire cartridge (100) with the discharge piston (5) fixed thereto is pushed forward in the direction of the outlet opening (29).

7. The method according to any of the preceding claims, characterized in that the area at the outside, i.e. back side, of the pusher (101) up to the exit point of the cartridge plunger (15a) from the cartridge drive (4) is kept under negative pressure during the emptying process.

8. Emptying device (200) for emptying viscous material (M) out of a cartridge (100) open to both sides, which has a pusher (101) therein that is tightly fitting and can be moved in a pressing direction (10), and a closable removal opening (100a) at the other end, in particular for performing the method according to any of the preceding claims, comprising - a base frame (1), - a collecting container (2) for material (M) mounted to the base frame, - a cartridge carrier (3) guided movably in a pressing direction (10) relative to the base frame (1), - a cartridge drive (4) including a cartridge plunger (15a) for pushing the pusher (101) of the cartridge (100) in a forward direction, - a discharge piston (5) tightly guided in the collecting container (2), - a discharge drive (6) for moving the discharge piston (5), characterized in that - the cartridge carrier (3) has a fixing device (3a) by way of which the cartridge (100) can be fastened firmly to the cartridge carrier (3) in and against the pressing direction, - a distributing head (7) for dividing the strand of material (M) exiting the removal opening (100a) into a plurality of thin strands (S1, S2, S3) and having a fastening device (7a) for being fastened to the removal opening (100a), - the distributing head (7) fits tightly and movably in a pressing direction (10) in the collecting container (2) and can be used as a discharge piston (5), - a first pressure-tight vacuum housing (21) with a negative pressure connection (8) is provided, which is in tight contact with the collecting container (2) and the outer circumference of the cartridge (100), even if the latter is moved relative to the vacuum housing (21).

9. The emptying device (200) according to claim 8, characterized in that - a second pressure-tight vacuum housing (22) with a negative pressure connection (9) is provided, which, on the one hand, is in close contact with the outer circumference of the cartridge (100) above a cartridge receptacle (16) in the cartridge carrier (3) and, on the other hand, is passed through in a tight manner by the cartridge plunger (15a).

10. The emptying device according to any of the preceding apparatus claims, characterized in that the distributing head (7) is formed so that it can be fastened in a pressing direction (10) at a fixed distance to the removal opening (100a) of the cartridge (100).

11. The emptying device according to any of the preceding apparatus claims, characterized in that - the discharge drive (6) is positioned between the cartridge carrier (3) and the base frame (1), - a discharge drive (6) is positioned, respectively, in particular on both sides of the cartridge receptacle (16), - the discharge drive (6) includes at least one, in particular two, discharge working cylinders (13, 14).

12. The emptying device according to any of the preceding apparatus claims, characterized in that - the cartridge drive (4) includes at least one cartridge working cylinder (15).

13. The emptying device according to any of the preceding apparatus claims, characterized in that the cartridge receptacle (16) in the cartridge carrier (3) is open or can be opened to the side for laterally inserting the cartridge (100).

14. The emptying device according to any of the preceding apparatus claims, characterized in that the cartridge plunger (15a) passes through a bell-shaped second vacuum housing (22) and a coil spring (28) acting as a pressure spring is arranged between the yoke (23) and the upper end of the vacuum housing (22).

15. A dosing unit (500 comprising a doser (300) for dosing viscous material, as well as an emptying device (200) for emptying viscous material out of a cartridge (100) open to both sides characterized in that the emptying device (200) is configured according to any of the claims 8 to 14.

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