Method for filling a cylindrical container with clay and a packaging unit of such a container filled with clay

Abstract

A method for filling a container of standardized geometry with clay, having the steps of: d) extruding the clay by an extruder, e) using a pump and / or the pressure built up in the clay by the extruder to pump the clay plasticized by the extruder from the extruder outlet through a conduit into an outlet opening on the underside of a piston element that is adapted to fit through an opening in the container and into its interior, which is substantially cylindrical with an interior cross-section and an opening cross-section which remain substantially constant along the cylinder axis, f) guiding the piston element in the direction of the cylindrical axis by a device with a drive system which is designed to exert pressure against the clay introduced under the piston element into the container.

Description

[0001] The present invention relates to a method for filling a container and such a container filled with clay.

[0002] So-called clay is a plastic mass for creative modelling.

[0003] Clay is a material used in particular for modelmaking in automobile design. However, character designers for example for films, cartoons and video games, industrial designers, artists and architects also use this material to model their three-dimensional designs. It is a special development of the long-known plasticine for this purpose.

[0004] Clay is a mass that is usually based on wax that is plastically deformable at certain temperatures (usually above normal room temperature). Sulphur is used as a filler in most variants. Clay is usually brownish or grey in colour, which makes it easy to see a modelled shape, especially for the designer to check it while modelling.

[0005] For example, before a new car is launched on the market, the process of designing its new body is lengthy and complex: sketches, drawings and 3D CAD models are made. But even today, models of the vehicles are ultimately built, usually in various scale from 1:10 and 1:4 to 1:1. Only then can shapes and proportions be properly assessed on the large scale and in detail. The shapes and proportions of the clay model can also be reworked and finished in fine detail. This is because clay, with a high degree of dimensional stability at room temperature, can for example be milled, planed, carved or sanded. But subsequent material application is also possible, wherein the clay is heated for example in the area of the planned material application using a hot air blower or a radiant heater (to temperatures no higher than in the double-digit Celsius temperature range). In this upper limiting temperature range, particularly around 60 to 70° C., clay can be plastically deformed—without however becoming liquid or even flowing in a pasty manner—and essentially enters into a homogeneous bond with clay material of approximately the same temperature that is added on top. Once cooled, the area added by the application is dimensionally stable again with an essentially homogeneous transition point if carefully worked on and can be worked on again there, including by removing it. Clay can also be painted using known process steps. Overall, then, a model can be produced from clay that is extremely close to the planned model in terms of shape and surface, even identical.

[0006] For such a model, a wooden or metal frame is usually first made, on which panels (for example foam panels) made of polyurethane, for example, are attached, in order to apply clay thereon, as the outer layer of the model that can be modelled as described—usually in layers to create a desired clay layer thickness—and thus to form a preliminary model, at least of the size of the final model overall as far as possible.

[0007] This application still often takes place by hand. The heated clay (below 60° C.) is usually applied with kneading hand movements and worked using spatula-like tools and blades—and more precisely in the temperature range of the clay mentioned above, in which the latter can be plastically deformed and thus adheres well to the frame plates. There are various known measures for better adhesion, such as for example applying a sealant (for example as a paint or spray, especially for binding dust), and / or forming depressions and / or barbed structures, for example by drilling holes or milling grooves, in which the clay can then hold in a form-fit manner as well as adhering. During and after the application, as long as cooling has not yet completely taken place, the sought surface shape of the clay can also be created, at least in some areas, by plastic shaping or at least prepared by appropriate pre-forming and contouring.

[0008] Widespread development of devices is now taking place with which clay can be applied mechanically. In particular, on account of the much greater throughput of clay in this processing, it proves to be advantageous to provide the clay not in the form of bars or rods, as has previously been the case, but in larger (also transportable) packaging units. Attempts have already been made to process clay from a barrel in this way. However, for this experimental process the barrel was filled with clay by hand, because clay, as a plastic mass, cannot be pumped using known methods like a liquid.

[0009] The problem underlying the present invention is to provide clay in larger packaging units in a reproducible quality and as free as possible from air inclusions. This problem is solved by a method with the features of claim 1 and by a product with the features of claim 10.

[0010] According to the invention, a method is provided for filling containers of standardised geometry (containers with essentially the same geometry) with clay and a container filled with clay in this inventive manner.

[0011] According to the invention, the container for which the method according to the invention is devised comprises an opening and an essentially cylindrical interior with a cross-section that is essentially constant along the axis of the cylindrical shape, not only of the interior but also of the opening.

[0012] The method according to the invention comprises the steps:

[0013] a) extruding the clay using an extruder,

[0014] b) pumping the clay plasticised by the extruder by means of a pump and / or by the output pressure built up in the clay by the extruder through a conduit into an outlet opening on the underside of a piston element, which is adapted to fit through the opening of the container and into the interior thereof,

[0015] c) guiding the piston element in the direction of the cylinder axis by means of a device with a drive, which is designed to exert pressure against the clay introduced into the container under the piston element.

[0016] As is known, an extruder is a device used in plastics processing that conveys, compresses and expels plastically deformable masses using (at least) one screw. Initially developed for rubber processing, it has found widespread use for thermoplastics and now even for pasty foods. In screw extruders, the different geometry of the thread cross-section over the length of the extruder screw causes the material processed in the extruder to be transported, compressed, degassed, mixed and homogenised. According to the invention, however, an extruder is used to “knead” the clay and thus to heat it, to plasticise it, to homogenise it and, if need be, to degas it—in other words, to make it pumpable—and to convey it under pressure into a pump and from there (or even, especially without a pump, through the pressure built up in the clay by the extruder) through the conduit. The clay may possibly be in the extruder in an, in particular final, process step of its production, but can also be fed into the extruder (in particular from intermediate storage, for example in the known rod or bar form) specifically for filling into the container according to the invention. Pre-processing steps may advantageously be possible for this purpose, such as, very much by way of example, crushing and / or heating.

[0017] According to the invention, the clay is then conveyed into an outlet opening on the underside of a “piston element”. The piston element is adapted according to the invention to fit through the opening of the container for which the invention is devised, namely in the sense of a cylindrical container already described, as well as into its interior:

[0018] In the removal of liquids with a high viscosity in plastics processing from barrels with a cylindrical basic shape, use is made of so-called “barrel follower plates”, in particular to avoid pumping air inclusions. Such barrel follower plates, for example, are “piston elements” according to the invention, components according to the invention in the manner of a piston, which possibly fit with a circumferential piston seal through the cylinder opening into the barrel, i.e. into the cylindrical interior of the container, wherein sealing rings can thus seal the assembly to the barrel wall. They are inserted into the barrel (after removal of the actual barrel lid) and are possibly provided with sealing rings which can completely seal the barrel follower plate to the barrel wall. In this way, they form a hermetically sealed, rigid cover over the liquid and, together with the barrel or container, completely and tightly enclose the liquid. The barrel follower plates are then actively pressed (guided and driven) onto the material in plastics processing. In known processes, they slide downwards due to their own weight or negative pressure when the material is removed. For this purpose, the containers used in this connection are barrels, the interior of which thus has the essentially cylindrical, in particular circular-cylindrical inner contour (possibly, for example, with stiffening longitudinal or circumferential beads or other deviations from the mathematical cylinder shape, which do not oppose this technical principle according to the invention), wherein the inner contour, again essentially, opens outwards into an outer opening of the interior, namely into the barrel opening, without tapering. According to the invention, however, the piston element is used to avoid air inclusions (not during the removal of, but) during filling the container through step c) according to the invention; preferably by means of a pneumatic cylinder as a drive, the piston element is guided in the direction of the cylinder axis of the container interior by means of a device with the linear drive. These are designed to exert pressure against the clay introduced into the container under the piston element.

[0019] According to the invention, the piston element is adapted to the geometry of the container in such a way that an annular gap is formed in step c) between the piston element and the cylindrical inner sleeve surface of the container. The annular gap can then be sealed by seal or it can, without a seal, serve for the venting. In particular, (but not exclusively) with a seal, however, negative pressure can be generated in the container and / or under the piston element for the purpose of venting by means of a vacuum.

[0020] According to the invention, the clay can be conveyed into the outlet opening on the underside of the piston element by means of a twin arrangement; a switch in the supply line to the piston element leads into a second such supply line and to a second piston element together with a drive device. According to the invention, a first container can thus be filled through the first supply line and by means of the first piston element, whilst in the vicinity of the second piston element the filled container is removed, closed and transported onward and, in order to prepare the next filling, a next container is then immediately inserted into this second piston element for filling. In this way, immediately after the container has been filled through the first supply line and the first piston element, the switch can be “turned over” and the filling of the container already prepared there can begin through the second piston element, without having to wait for the filled container to be removed and for a new container to be filled to be inserted in the vicinity of the first piston element.

[0021] The conduit between the pump and the piston element can have a (particularly rigid) pipe section in which a static and / or a dynamic mixer is arranged:

[0022] The mixing of fluid components, for example in the production of plastics, before introducing plastic into the sprue of a mould or for example before applying it to a fibre fabric or fabric for producing GRP or CFRP is generally carried out through a tubular passage (mixer) with mould elements (turbulence elements) in its interior, which variously redirect, deflect, locally dam, generate turbulence and / or swirl the through-flowing fluid and thus mix it. As is well known, feed lines then lead into this mixer, in particular in the number of fluid components from which the plastic is to be mixed together. In order to achieve a particularly uniform complete mixing of the components, it has proved to be advantageous and has become established not to simply arrange the turbulence elements in the tubular passage in a fixed manner (static mixer), but rather to form them in a rotating manner (dynamic mixer). Known devices for mixing at least two fluid components by means of dynamic mixers have the at least two component feed lines and a rotary drive with a drive shaft, and the device is then adapted to place a tubular feed element in a fluid-tight line connection with the component feed lines, and to place the drive shaft in a rotary drive connection with the mixer insert by means of a rotary drive connection structure of a mixer insert (which has a support rod element with at least one swirling element and which is adapted for use in the feed element) when the mixer insert is inserted into the feed element and the feed element is inserted into the line connection with the component feed lines. Such a rotary drive connection structure on known mixer inserts is generally an opening lying essentially radially to the axis of rotation, into which a hook is hooked at the end of the drive shaft in order to establish the drive connection. The mixer insert and feed element can (also according to the invention) be single-use or disposable items. According to the invention, however, these (static or dynamic) mixers are preferably not used to mix components, but advantageously shear and / or homogenise the plasticised clay so as to be flowable according to the invention. This also prevents, for example, optical changes in the clay and a reduction in its quality due to separation, for example in the form of streaking. The clay can also be sheared, for example by means of a device with a (static or dynamic) mixer, between the extruder and the pump.

[0023] In order to adjust the plasticity and thus the flowability of the clay in the extruder, pressure in the clay can be measured in the area of the extruder outlet and the pump inlet, the pressure difference can be calculated by a computer system and the pressure in the extruder can be regulated using a control system. The control system can also adjust the pump speed using this pressure difference-i.e. with a pressure difference as the controlled variable and the pump speed as the manipulated variable.

[0024] In order to improve the flowability of the clay, the pump and / or a flange between the extruder and the pump and / or the conduit and / or the pipe section at least in sections and / or the piston plate and / or the bottom of the container and / or its lateral surface can be a temperature regulated at least in regions by means of a heating device.

[0025] In order to be able to check the condition of the clay, more precisely after the extruder, before and / or after the pump, if necessary before and / or after the mixer, and / or before the piston element, a line branch can be provided in each case there (for example also from a bypass for this purpose), by which clay can be taken as a sample.

[0026] The pump is preferably a screw-spindle pump, which has proved suitable for pumping very highly viscous liquids (which clay does not belong to), but possibly also a gear or piston pump, for example.

[0027] These and other advantages and features of the invention are described in further detail by reference the following figure of an embodiment of the invention.

[0028] The FIGURE is a schematic representation of a device for carrying out the method according to the invention.

[0029] FIGURE shows a diagrammatic representation of a device for performing the method according to the invention.

[0030] The FIGURE represents a method for filling a container 2 of standardised cylindrical geometry (namely in particular a barrel 2) with clay 4.

[0031] As can be seen, container 2 has an opening 6 and a cylindrical interior 8 with a cross-section that remains constant along cylinder axis 10 (the cylindrical shape)—not only of interior 8, but also of opening 6.

[0032] The represented procedure has the following steps:

[0033] a) extruding clay 4 by means of an extruder 12,

[0034] b) pumping clay 4 plasticised and pressurised by means of extruder 12 by means of a pump 14 through a conduit 16 into an outlet opening 18 on the underside of a piston element 20 which is adapted to fit through opening 6 of container 2 and into its cylindrical interior 8,

[0035] c) guiding piston element 20 in the direction of cylinder axis 10 by means of a device 22 with a drive 24 which is designed to exert pressure against clay 4 introduced into container 2 under piston element 20.

[0036] Extruder 12 is a device which conveys, compresses and ejects clay 4 by means of a screw 26. The different geometry of the thread cross-section over the length of extruder screw 26 causes clay 4 processed in extruder 12 to be transported, compressed, degassed, mixed and homogenised. Clay 4 is in extruder 12 in a final process step of its production (including in particular the mixing of its primary components (not shown), mixing and homogenisation—possibly also in other devices (not shown) in the conduit upstream of extruder 12). Here, extruder 12 is then used further to “knead” clay 4 and thus to heat it, plasticise it, homogenise it, degas it—in other words to make it pumpable, so to speak—and to convey it under pressure into pump 14, a screw spindle pump 14, and from there through conduit 16.

[0037] Clay 4 is then fed into outlet opening 18 on the underside of “piston element”20. This, a so-called barrel follower plate 20, is adapted to fit through opening 6 of container 2, onto which piston element 20 is thus arranged, as well as into its interior 8.

[0038] It is a component in the form of a piston, which here with a circumferential piston seal 26 fits through cylinder opening 6 into barrel 2, i.e. into cylindrical interior 8. It is inserted into barrel 2 (after removing the actual barrel lid—not represented). Seal 26 completely seals barrel follower plate 20 to the barrier wall. Piston element 20 thus forms a hermetically sealed, rigid cover over clay 4 in the barrel and, together with barrel 2, completely and tightly encloses clay 4. Barrel follower plate 20 is then actively (guided and driven) pressed onto material 4. According to the invention, piston element 20 is now used to avoid air inclusions (not during removal, but) when filling container 2 through the above-mentioned step c): by means of a pneumatic cylinder as drive 24, piston element 20 is guided in the direction of cylinder axis 10 of container interior 8 by means of a device 22 with linear bearings. These are designed to exert pressure against clay 4 introduced into container 2 under piston element 20. For venting, a vacuum pump 28 also generates negative pressure in container 2 under piston element 20.

[0039] Conduit 16 between pump 14 and piston element 20 comprises a rigid pipe section 30, in which a (dynamic) mixer 34 is arranged, which is driven in rotation by a motor 32. Here, its swirling elements are not so much used for mixing components, but also advantageously shear and / or homogenise clay 4 which has been plasticised so as to be flowable according to the invention. This also prevents, for example, optical changes to clay 4 and a reduction of its quality due to separation, for example in the form of streaking.

[0040] In order to adjust the plasticity and thus the flowability of clay 4 in extruder 12, pressure in the clay is measured in the area of extruder outlet 36 and pump inlet 38 and the pressure difference is calculated by an EDP 40 and the pressure in the extruder is regulated by means of a control 40.

[0041] In order to further improve the flowability of clay 4, pump 14 and conduit 16 and pipe section 30 in sections and piston plate 20 and container 2 are temperature regulated in sections by means of a heating device 42.LIST OF REFERENCE NUMBERScontainer, barrel 2

[0043] clay 4

[0044] container opening 6

[0045] container interior 8

[0046] cylinder axis 10

[0047] extruder 12

[0048] pump 14

[0049] conduit 16

[0050] outlet opening 18

[0051] piston element 20

[0052] linear guide device 22

[0053] drive 24

[0054] extruder screw 25

[0055] piston seal 26

[0056] vacuum pump 28

[0057] pipe section 30

[0058] motor 32

[0059] dynamic mixer 34

[0060] extruder outlet 36

[0061] pump inlet 38

[0062] EDP and control 40

[0063] heating device 42

Claims

1-10. (canceled)11. A method for filling a container of standardized geometry with clay, comprising the steps of:a) extruding the clay by an extruder;b) pumping the clay plasticized by the extruder and an outlet of the extruder by a pump and / or by pressure built up in the clay by the extruder through a conduit into an outlet opening at an underside of a piston element adapted to fit through an opening of the container and into an interior of the container, which is essentially cylindrical with a cross-section of the interior essentially constant along a cylinder axis and the opening;c) guiding the piston element in a direction of the cylinder axis by a device with a drive designed to exert pressure against the clay introduced under the piston element into the container.

12. The method according to claim 11, wherein the piston element is adapted to the geometry of the container so that in step c) an annular gap is formed between the piston element and a cylindrical inner sleeve surface of the container.

13. The method according to claim 12, wherein the annular gap between the piston element and the cylindrical inner sleeve surface of the container is sealed by a seal, or is used for ventilation without a seal.

14. The method according to claim 12, wherein the annular gap between the piston element and the cylindrical inner sleeve surface of the container is sealed by a seal and negative pressure is produced in the container and / or under the piston element by a vacuum pump for venting.

15. The method according to claim 11, wherein the conduit has a pipe section in which a static and / or a dynamic mixer is arranged.

16. The method according to claim 11, wherein pressure in the clay is measured at the extruder outlet and at the pump inlet and a pressure difference is calculated by an EPC and the pressure in the extruder is regulated by a control with the pressure difference as a controlled variable and pump speed as a manipulated variable.

17. The method according to claim 11, wherein the pump and / or a flange between the extruder and the pump and / or the conduit and / or the pipe section at least in sections and / or the piston plate and / or the bottom and / or the lateral surface of the container is temperature regulated at least in regions by a heating device.

18. The method according to claim 11, wherein the pump is a screw-spindle pump.

19. The method according to claim 11, wherein the linear drive is a pneumatic cylinder.

20. A cylindrical container filled with clay according to claim 11.

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