DYNAMIC MIXER AND DOSING DEVICE

Abstract

A dynamic mixer for a dynamic mixing operation for mixing a liquid or paste-like product, in particular a multi-component product, comprising a core element, a first blade element integrally formed with the core element and helically extending around the core element in a first helix direction, and a second blade element integrally formed with the core element and helically extending around the core element in a second helix direction that is different from the first helix direction, wherein the first blade element and the second blade element are arranged immediately adjacent when viewed in a longitudinal direction of the mixer, the first blade element having a first blade element height, when viewed in the longitudinal direction, and the second blade element having a second blade element height, when viewed in the longitudinal direction that is different from the first blade ele-ment height.

Claims

1. A dynamic mixer for a dynamic mixing operation for mixing a liquid or paste-like product, in particular a multi-component product, comprising a core element, a first blade element integrally formed with the core element and helically extending around the core element in a first helix direction, and a second blade element integrally formed with the core element and helically extending around the core element in a second helix direction that is different from the first helix direction, wherein the first blade element and the second blade element are arranged immediately adjacent, when viewed in a longitudinal direction of the mixer, wherein the first blade element has a first blade element height, when viewed in a longitudinal direction, and wherein the second blade element has a second blade element height that is different from the first blade element height, when viewed in the longitudinal direction.

2. The dynamic mixer according to claim 1, wherein the blade element feeding the product away from a mixer base of the mixer in a feed direction in the dynamic mixing operation of the mixer has the greater blade element height compared to the blade element feeding the product against the feed direction.

3. The dynamic mixer according to claim 1, wherein in the dynamic mixing operation of the mixer, the first helix direction matches a rotational direction of the mixer, and wherein the second helix direction is oriented against the rotational direction.

4. The dynamic mixer according to claim 1, wherein the first blade element has a first pitch and the second blade element has a second pitch different from the first pitch, or wherein the first blade element and the second blade element have an identical pitch.

5. The dynamic mixer according to claim 1, wherein the first blade element extends at least a quarter turn around the core element and/or wherein the second blade element extends at least a complete turn around the core element.

6. The dynamic mixer according to claim 1, wherein a diameter of the core element is larger than a wall thickness of the first blade element and/or the second blade element.

7. The dynamic mixer according to claim 1, wherein, when viewed along a longitudinal direction, a plurality of mixing stages is provided, each comprising a first blade element and a second blade element, and wherein a ratio of the first blade element height to the second blade element height of a respective mixing stage is variable.

8. The dynamic mixer according to claim 1, wherein the first blade element and/or the second blade element taper radially outward from the core element.

9. The dynamic mixer according to claim 1, wherein the mixer is built in layers by means of a generative manufacturing method, in particular by means of a 3D printing process, or wherein the mixer is produced by means of an injection molding process.

10. The dynamic mixer according to claim 1, wherein, when viewed in the longitudinal direction, the first blade element and the second blade element are arranged free of any spacing or are arranged spaced apart with a spacing of not more than 5 mm, preferably of not more than 4 mm, more preferably of not more than 3 mm, more preferably of not more than 2 mm, more preferably of not more than 1 mm, more preferably of not more than 0.5 mm, more preferably of not more than 0.25 mm, more preferably of not more than 0.1 mm.

11. The dynamic mixer according to claim 1, wherein, when viewed in the longitudinal direction, an end edge of the first blade element is arranged at the same height as an end edge of the second blade element, or wherein the first blade element runs into the second blade element, so that the end edge of the first blade element and the end edge of the second blade element are arranged spaced apart by a projecting length, when viewed in the longitudinal direction.

12. The dynamic mixer according to claim 1, wherein the first blade element comprises two blade sections, three blade sections or more than three blade sections and/or wherein the second blade element comprises two blade sections, three blade sections or more than three blade sections.

13. The dynamic mixer according to claim 1, wherein the first blade element and/or the second blade element are arcuately bent, in particular bent in a circular arc shape, when viewed in a radial direction of the mixer.

14. A dosing device for dosing a liquid or paste-like product, in particular a multi-component product, comprising a first dosing pump for dosing a first component of the product, a second dosing pump for dosing a second component of the product, and a dynamic mixer according to claim 1 for mixing the first component with the second component.

15. The dosing device according to claim 14, further comprising a drive mechanism adapted for rotating the mixer about its central axis to dynamically mix the first component and the second component.

Description

[0052] Further advantageous designs and aspects of the invention are subject of the dependent claims as well as the exemplary embodiments of the invention described below. Furthermore, the invention is explained in more detail on the basis of preferred embodiments with reference to the enclosed figures.

[0053] FIG. 1 shows a schematic view of an embodiment of a dosing device;

[0054] FIG. 2 shows a schematic view of an embodiment of a mixer for the dosing device according to FIG. 1;

[0055] FIG. 3 shows a schematic perspective view of the mixer according to FIG. 2;

[0056] FIG. 4 shows a schematic top plan view of the mixer according to FIG. 2;

[0057] FIG. 5 shows a schematic sectional view of the mixer according to section V-V of FIG. 2;

[0058] FIG. 6 shows the detail view VI according to FIG. 2;

[0059] FIG. 7 shows again the detail view VI according to FIG. 2;

[0060] FIG. 8 shows a schematic partial view of another embodiment of a mixer for the dosing device according to FIG. 1;

[0061] FIG. 9 shows a schematic partial view of another embodiment of a mixer for the dosing device according to FIG. 1;

[0062] FIG. 10 shows a schematic top plan view of the mixer according to FIG. 9;

[0063] FIG. 11 shows a schematic partial view of another embodiment of a mixer for the dosing device according to FIG. 1;

[0064] FIG. 12 shows a schematic top plan view of the mixer according to FIG. 11;

[0065] FIG. 13 shows a schematic partial view of another embodiment of a mixer for the dosing device according to FIG. 1;

[0066] FIG. 14 shows a schematic top plan view of the mixer according to FIG. 13;

[0067] FIG. 15 shows a schematic view of another embodiment of a mixer for the dosing device according to FIG. 1;

[0068] FIG. 16 shows a schematic view of another embodiment of a mixer for the dosing device according to FIG. 1;

[0069] FIG. 17 shows a schematic view of another embodiment of a mixer for the dosing device according to FIG. 1; and

[0070] FIG. 18 shows a schematic block diagram of an embodiment of a method for manufacturing the mixer according to FIG. 2, FIG. 8, FIG. 9, FIG. 11, FIG. 13, FIG. 15, FIG. 16 and FIG. 17.

[0071] In the figures, identical or functionally identical elements have been provided with the same reference numbers, unless otherwise indicated.

[0072] FIG. 1 shows a highly simplified schematic view of an embodiment of a dosing device 1 for dosing a liquid or paste-like product P. The product P may, for example, be an adhesive and/or a sealant, in particular a multi-component adhesive and/or a sealant, water, an aqueous solution, a paint, a varnish, a suspension, a viscous raw material, an emulsion, a grease or the like. For example, the product P may be a two-component adhesive. Paste-like product P or paste means a solid-liquid mixture, in particular a suspension with a high content of solids.

[0073] The product P may comprise one or more than one component K1, K2, in particular a first component K1 and a second component K2. The components K1, K2 may be liquid or paste-like. Furthermore, one of the components K1, K2 may also be a solid, in particular a filler, or comprise a solid. The components K1, K2 and the product P are in particular fluids. Fluid here means a flowable material in its broadest sense, meaning, not only liquid or paste-like, but also granular, such as hollow glass spheres, or any mixture or even a mixture that is inhomogeneous in particle size and/or material. The components K1, K2 may also be pairings of any kind of different fluids, so, just as an example, a liquid and a granular component.

[0074] The product P may be, as mentioned above, filled with fillers, for example. Particularly suitable fillers used are microballoons. Microballoons are hollow polymer spheres or hollow glass spheres that are being used, for example, as fillers for epoxy and polyester resin systems as well as for polysulfides and polyether systems. This can result in weight reduction and/or thickening of the product P. Such microballoons in the form of hollow glass sphere may, for example, have a bulk density of 140 g/l to 150 g/l, a specific weight of 0.26 g/cm.sup.3, a particle size distribution of 50 m and a maximum particle size of 200 m. Microballoons are, in particular in a range of 0 bar to 15 bar, compressible. This means that, when the product P is filled with microballoons, said product may be compressible or have compressible characteristics. Hollow glass spheres are hard and burst at a certain pressure. Hollow polymer spheres are deformable and as such compressible. Hollow glass spheres, too, may be compressible at least to a certain extent.

[0075] Compressible may mean that the product P is practically or substantially compressible. Incompressible may further mean that the product P is practically or substantially incompressible. For example, the product P may show a compressibility (volume change) of about 20% at a pressure of about 15 bar. In a range from 15 bar to 30 bar, compressibility (volume change) may be characterized as virtually incompressible as compared to a lower pressure range of 0 bar to 15 bar. Above 30 bar, the product P may then be compressible again, since the microballoons may burst or collapse. In particular with hollow plastic spheres, the microballoons may be damaged, for example pressed in, such that a permanently changed volume and/or weight occurs.

[0076] A fluid whose density is not depended on pressure is called incompressiblein contrast to compressible fluids. One property of fluids is compressibility, which describes the change in density of a fluid with pressure change and the property of volume change with temperature change. The compressibility of a fluid is the decision criterion with regard to a distinction between gas (compressible) and liquid (almost incompressible). The terms hydraulics (almost incompressible fluids such as liquids, mostly oil) and pneumatics (compressible fluids such as gases, mostly air) refer to techniques that realize and control force with fluids. A further distinction is made between perfect fluids and real fluids.

[0077] The dosing device 1 comprises at least one dosing pump 2, 3. The dosing device 1 may, as shown in FIG. 1, comprise two dosing pumps 2, 3, in particular a first dosing pump 2 and a second dosing pump 3, or any number of dosing pumps 2, 3, such as three dosing pumps. The dosing pumps 2, 3 may be, for example, progressive cavity pumps, gear pumps, piston dispensers or the like. The dosing pumps 2, 3 are preferably embodied as progressive cavity pumps.

[0078] A progressive cavity pump preferably comprises a stator accommodated in a pump housing and comprising a resiliently deformable elastomeric member having a center aperture. The aperture preferably comprises a screw-shaped or helical internal contour. A rotatable rotor comprising a screw-shaped or helical external contour corresponding to the elastomeric member is preferably provided in the stator. The rotor may be driven by a drive member, in particular an electric motor, via a drive shaft.

[0079] The drive shaft may be fixedly connected to the rotor by means of a flexible shaft, a flex shaft or a universal shaft. When the rotor is rotated, the product P or the respective components K1, K2 is fed away from the drive shaft in a feed direction F of the dosing pump 2, 3 using the endless piston principle through the interaction with the elastomeric member of the stator. The feed volume depends on the speed, size, pitch and geometry of the rotor.

[0080] The first dosing pump 2 is operable to dose the first component K1. The second dosing pump 3 is operable to dose the second component K2. The volumetric flow rates of the two-component K1, K2 may be different. The dosing pumps 2, 3 are mounted on a flow block 4. The dosing pumps 2, 3 are preferably arranged parallel to one another. Alternatively, the dosing pumps 2, 3 may also be positioned in a V-shaped manner with respect to one another.

[0081] The flow block 4 may, for example, be made from a steel or an aluminum material. The flow block 4 may be made of several parts. In the flow block 4 a first channel 5 is provided, through which the first component K1 may be passed. The flow block 4 further comprises a second channel 6, through which the second component K2 may be passed. The channels 5, 6 may be positioned in a V-shaped manner relative to one another, as shown in FIG. 1. Alternatively, the channels 5, 6 may also be positioned parallel to one another or sectionally parallel to one another. In the flow block 4, pressure sensors for detecting a respective pressure of the components K1, K2 may be integrated in the channels 5, 6.

[0082] Further provided on the flow block 4 is a drive mechanism 7. The drive mechanism 7 may comprise an electric motor, for example. The drive mechanism 7 may be arranged between the two dosing pumps 2, 3, as shown in FIG. 1. Alternatively, the drive mechanism 7 may be mounted at any location on the flow block 4. The drive mechanism 7 comprises a drive member 8, such as an electric motor, and a drive shaft 9 passing through the flow block 4 and extending between the channels 5, 6. The drive member is operable to drive the drive shaft 9. However, the drive mechanism 7 is optional.

[0083] Facing away from the dosing pumps 2, 3, a mixing device 10 is disposed on the flow block 4. The mixing device 10 may be mounted directly to the flow block 4. However, additional structural components (not shown) may be provided between the flow block 4 and the mixing device 10. The mixing device 10 is operable to mix the first component K1 and the second component K2 into product P.

[0084] The mixing device 10 comprises a mixing tube 11 adapted to be connected to the flow lock 4 by means of a union nut (not shown), for example. The mixing tube 11 preferably is a plastic part, in particular an injection-molded plastic component. The mixing tube 11 may be a disposable part. For example, the mixing tube 11 may be disposed of after one-time use or after a predetermined period. The mixing tube 11 comprises a hollow cylinder-shaped base section 12 and a nozzle section 13 facing away from the flow block 4 and which may be embodied frustoconically.

[0085] The base section 12 and the nozzle section 13 are integrally formed, in particular are made of one material. Integrally here means that the base section 12 and the nozzle section 13 form a common structural component, such as in the form of an injection-molded plastic component. Made from one material here means that the base section 12 and the nozzle section 13 are made from the same material throughout. The nozzle section 13 is operable to apply the product P. For this purpose, the dosing device 1 is may be positioned by means of a robot, for example. The mixing tube 11 may be accommodated in a stabilizing support tube 14. The support tube 14 may be a steel tube, for example. The support tube 14 prevents the base section 12 of the mixing tube 11 from bulging, when pressure is applied to said mixing tube 11.

[0086] A mixer 15 is accommodated in the mixing tube 11. The mixer 15 may also be referred to as helical mixer panel, mixing helix, mixer insert or mixing insert. The mixer 15 may be either a static mixer or a dynamic mixer. Static mixer here means a mixer that does not comprise any moving parts and that is not rotating but standing still relative to the mixing tube 11. Such a static mixer comprises in particular mixing members or mixing elements, wherein the two components K1, K2 are intermixed by being turned over multiple times while they are fed through the mixing device 10.

[0087] With this principle the two components K1, K2 are intermixed by repeated re-layering of the components K1, K2. To achieve a high-quality mixture, various parameters may be dimensioned differently in such a mixer 15. For example, the geometry of the mixing members, the number of mixing members and a diameter of the mixer 15 may be dimensioned. In such static mixers, a laminar flow can generally be assumed for fluids with medium to high viscosities.

[0088] In contrast to this, a dynamic mixer comprises a drive such as in the form of the drive mechanism 7. The drive member 8 is coupled by means of the drive shaft 9 to the mixer 15 such that the mixer 15 is rotatable in the mixing tube 11 about an axis of symmetry or central axis M15 of the mixer 15.

[0089] When feeding the components K1, K2 or the product P through the mixing device 10, a pressure acting on the product P builds up in the mixing tube 11 due to the flow resistance of the mixer 15, while the product P is dosed by means of the dosing pumps 2, 3. In mixers as described in the introduction, this pressure drops approximately linearly from the flow block 4 in the direction of the nozzle section 13. Because the product P is compressible within a certain pressure range when filled with microballoons, the microballoons may expand and thus the product P may be pressed out of the nozzle section 13, when the dosing process is stopped, i.e. when the dosing pumps 2, 3, are standing still.

[0090] This pressing out of the product P may cause the formation of droplets on the nozzle section 13, which is undesirable since the formation of droplets may cause blobs to form either at the end of a product bead just placed or at the beginning of subsequent placement of a product bead. Thus the components K1, K2 must advantageously mixed such that the pressure applied in the mixing device 10 to the product P, which is filled with fillers, is as low as possible.

[0091] FIG. 2 shows a schematic side view of an embodiment of a mixer 15 for the mixing device 10. FIG. 3 shows a schematic perspective view of the mixer 15. FIG. 4 shows a schematic top plan view of the mixer 15, FIG. 5 shows a schematic sectional view of the mixer 15 according to section V-V of FIG. 2 and FIGS. 6 and 7 both show the detail view VI according to FIG. 2. In the following, reference is made simultaneously to FIGS. 2 to 7.

[0092] The mixer 15 is a monolithic structural component, in particular a structural component that is made from one material. The mixer 15 may be made of a plastic material, a ceramic material, a metal material or a composite material. The mixer 15 is preferably produced by means of a generative or an additive manufacturing method. Compared to a plastic injection molding process, for example, this allows for various degrees of freedom in the structural design of the mixer 15. The mixer 15 is preferably produced by means of a 3D printing process.

[0093] A 3D printing process is a method in which material such as plastic powder is applied layer by layer, thus producing the three-dimensional geometry of the mixer 15. Typical materials for 3D printing processes are plastic, synthetic resins, ceramics and metals. Thus a layered structure can be demonstrated microscopically for the mixer 15. Furthermore, the mixer 15 comprises a rougher surface as compared to an injection-molded plastic part. The rougher surface may be advantageous when intermixing the components K1, K2.

[0094] The mixer 15 comprises a core element 16. The core element 16 is preferably constructed rotationally symmetrical to the central axis M15. For example, the core element 16 has a circular cross-section Q16. The cross-section Q16 is shown hatched in FIG. 5. However, the cross-section Q16 may have any geometry. For example, the cross-section Q16 may be oval, ellipsoidal, polygonal, in particular square or triangular, star-shaped or diamond-shaped. The core element 16 preferably has a diameter D16 (FIG. 5). The diameter D16 may be 4 mm, for example. However, the diameter D16 may take on any value.

[0095] The mixer 15 comprises a mixer base 17 and a mixer tip 18. A longitudinal direction L15 of the mixer 15 is oriented from the mixer base 17 in the direction of the mixer tip 18. The longitudinal direction L15 is oriented parallel to the central axis M15 or coincides with said central axis. The longitudinal direction L15 coincides with the feed direction F of the product P or the components K1, K2 along the mixer 15. The mixer 15 is also associated with a radial direction R15 (FIGS. 5 and 6). The radial direction R15 is oriented perpendicular to the central axis M15 and points away from the central axis M15.

[0096] The mixer base 17 is constructed cuboid and extents over two obliquely arranged side faces 19, 20 toward a chisel-shaped tip 21. The mixer base 17 further comprises an interface 22 operable to connect the mixer 15 with the drive shaft 9 of the drive mechanism 7. The interface 22 may be a circular aperture, in particular a boring, completely penetrating through the mixer base 17. The interface 22 may have a diameter D22. The diameter D22 may be 2.5 mm. However, the diameter D2 may take on any value.

[0097] Accordingly, the drive shaft 9 may comprise an engaging portion, in particular a hook, engaging the interface 22 or being hooked into said engaging portion. This allows for quick coupling of the mixer 15 to the drive shaft 9. Alternatively, the interface 22 may also have any geometry that makes it possible to connect the mixer 15 quickly and easily to the drive shaft 9 in a detachable manner. For example, the interface 22 may be an internal thread extending along the central axis M15. Accordingly, the drive shaft 9 may comprise a corresponding external thread. In this case, the mixer 15 may simply be screwed onto the drive shaft 9. The interface 22 may also be embodied in the shape of a tenon, a mortise or a clip connection.

[0098] The mixer base has a height H17, when viewed along the longitudinal direction L15. The height H17 may be 5.5 mm, for example. However, the height H17 may take on any value. The mixer tip 18 is preferably cuboid or bar-shaped. The mixer tip 18 is arranged perpendicular to the central axis M15. The mixer tip 18 may have a height H18, when viewed along the longitudinal direction L15. The height H18 may be 2 mm, for example. However, the height H18 may take on any value. The height H18 may also be zero so that there is no mixer tip 18 at all. This means that the mixer tip 18 is expendable.

[0099] A mixing area 23 of the mixer 15 is provided between the mixer base 17 and the mixer tip 18. The mixing area 23 is operable to mix the components K1, K2 to turn them into the product P. The mixing area 23 comprises a height H23, when viewed in the longitudinal direction L15. The height H23 may be 150 mm, for example. However, the height H23 may take on any value. The mixing area 23 is divided into a plurality of mixing stages 24 to 29. The number of the mixing stages 24 to 29 is arbitrary. For example, as seen is FIGS. 2 and 3, six mixing stages 24 to 29 are provided. In particular, a first mixing stage 24 to a sixth mixing stage 29 are provided. However, more or less than six mixing stages 24 to 29 may be provided. Preferably, the number of the mixing stages 24 to 29 is an even number. For example, four, six, eight, ten or more than ten mixing stages 24 to 29 are provided.

[0100] Each mixing stage 24 to 29 comprises a first blade element 30 with a first helix direction W30 (FIG. 4). The first blade element 30 is integrally formed with the core element 16 and extends screw-like or spirally around the core element 16. The first blade element 30 is a guide blade element or may be referred to as such, in the case where the mixer 15 is a static mixer. In the case where the mixer 15 is a dynamic mixer, the first blade element 30 is a moving blade element or may be referred to as such. The first blade element 30 may also be referred to as first mixing member or first mixing blade.

[0101] Each first blade element 30 comprises a first blade section 31 and a second blade section 32. The two blade sections 31, 32 are integrally formed with the core element 16 offset relative to each other by 180. The two blade sections 31, 32 have the same first helix direction W30. This means that the first blade element 30 winds around the core element 16 with the blade section 31, 32 in a double helix shape or double spiral shape.

[0102] The first blade element 30 has a diameter D30 at its outer circumference U30 (FIG. 4). The diameter D30 may be 12.6 mm, for example. However, the diameter D30 may take on any value. The first blade element 30 or the blade sections 31, 32 of the first blade element 30 comprises or comprise, respectively, two end edges 33, 34 spaced apart in the longitudinal direction L15 and arranged parallel to one another. However, the first blade element 30 immediately following the mixer base 17 in FIG. 6 comprises only one such end edge 33. The end edges 33, 34 are positioned rotated relative to one another. In particular, the end edges 33, 34 are oriented perpendicular to one another. End edge 33 may be referred to as bottom or first end edge, and end edge 34 may be referred to as top or second end edge.

[0103] The respective first blade element 30 of each mixing stage 24 to 29 has a first blade element height H30. The first blade element height H30 may be 9.37 mm, for example. However, the first blade element height H30 may take on any value. The first blade element height H30 is in particular defined as a distance of the end edges 33, 34 of a respective first blade element 30 from one another, when viewed in the longitudinal direction L15.

[0104] Each blade section 31, 32 of each first blade element 30 comprises a blade base 35 by means of which the respective blade section 31, 32 is integrally connected to the core element 16, and a blade tip 36 arranged spaced apart from the blade base 35 in the radial direction R15. The blade sections 31, 32 may taper from the blade base 35 in the direction of the blade tip 36, when viewed in the radial direction R15. This means that a wall thickness of the respective blade element 30 or the blade sections 31, 32, respectively, decreases in the radial direction R15. However, the wall thickness may also be constant.

[0105] Each mixing stage 24 to 29 is associated with a second blade element 37 separate from the first blade element 30. The second blade element 37 being separate from the first blade element 30 here means in particular that the second blade element 37 and the first blade element 30 are to separate structural components or members of the mixer 15, which in particular do not contact or touch each another. In particular, the blade elements 30, 37 are only in connection with each other via the core element 16. The first blade element 30 and the second blade element 37 of each mixing stage 24 to 29 are positioned adjacent or neighboring, when viewed in the longitudinal direction L15. The second blade element 37 may also be referred to as second mixing member or second mixing blade.

[0106] The second blade element 37 extends screw-like or spirally in a second helix direction W37 that is different that is different from the first helix direction W30 (FIG. 4) around the core element 16. The second blade element 37 is also integrally formed with the core element 16. Like the first blade element 30, the second blade element 37 comprises two blade sections 38, 39, in particular a first blade section 38 and a second blade section 39. The blade sections 38, 39 extend around the core element 16 in a double spiral shape or double helix shape. In the case where the mixer 15 is a static mixer, the second blade element 37 is a guide blade element or may be referred to as such. In the case where the mixer 15 is a dynamic mixer, the second blade element 37 is a moving blade element or may be referred to as such.

[0107] The second blade element 37 has a diameter D37 (FIG. 4) at its outer circumference U37 (FIG. 5). The diameter D37 is preferably equal to the diameter D30. The second blade element 37 comprises two end edges 40, 41 spaced apart and arranged parallel to one another. The end edges 40, 41 are arranged perpendicular to the central axis M15. The end edges 40, 41 are preferably rotated relative to one another. In particular, the end edges 40, 41 are oriented perpendicular to one another. The end edges 33, 34, 40, 41 have a width B (FIG. 5). The width B may be 2 mm. However, the width B may have any other value. End edge 40 may be referred to as bottom or first end edge, and end edge 41 may be referred to as top or second end edge.

[0108] The respective second blade element 37 of each mixing stage 24 to 29 has a second blade element height H37. The second blade element height H37 may be 15.63 mm, for example. However, the second blade element height H37 may take on any value. The second blade element height H37 is in particular defined as a distance of the end edges 40, 41 of a respective second blade element 37 from one another, when viewed in the longitudinal direction L15.

[0109] The first blade elements 30 and second blade elements 37 are alternately arranged in the mixing area 23 such that always one first blade element 30 is arranged between two second blade elements 37 and one second blade element 37 between two first blade elements 30. However, this does not apply to the first blade element 30 shown at the very top in FIGS. 6 and 7, adjoining the mixer base 17, and also not to the second blade element 37 shown at the very bottom in FIGS. 2 and 3, adjoining the mixer tip 18.

[0110] The blade sections 38, 39 of the second blade element 37 each comprises a blade base 42 by means of which the respective blade section 38, 39 is integrally connected to the core element 16, and a blade tip 43 arranged spaced apart from the blade base 42 in the radial direction R15. A wall thickness of the second blade element 37 or the blade section 38, 39, respectively, tapers in the radial direction R15 from the blade base 42 in the direction of the blade tip 43. This means that a wall thickness decreases, when viewed in the radial direction R15. However, the wall thickness may also be constant.

[0111] As shown in FIG. 4, the first helix direction W30 has a left-handed or counter-clockwise orientation, and the second helix direction has a right-handed or clockwise orientation. The helix directions W30, W37 may also be reversed. However, the helix directions W30, W37 are always oppositely oriented. This means that the first blade element 30 and the second blade element 37 of each mixing stage 24 to 29 are different from one another in their helix direction W30, W37.

[0112] However, the first blade element 30 and the second blade element 37 are not only different in their helix direction W30, W37, but also in that the blade elements 30, 37 have different blade element heights H30, H37, when viewed in the longitudinal direction L15. As mentioned above, the first blade element height H30 may be 9.37 mm, for example. As mentioned above, the second blade element height H37 may be 15.63 mm, for example. This means that the second blade element height H37 is greater than the first blade element height H30. Vice versa, the first blade element height H30 may also be greater than the second blade element height H37.

[0113] Thus, within each mixing stage 24 to 29 a height ratio of the blade elements 30, 37 may be specified, wherein each mixing stage 24 to 29 along the longitudinal direction L15 can be divided into eight eighths. Thus, with the dimensions of the blade element heights H30, H37, a dividing ratio, stage ratio or ratio of the first blade element height H30 to the second blade element height H37 or a blade element height ratio of to results. However, the blade element height ratio may also be to , 2/8 to 6/8, to , 6/8 to 2/8 or to . The ratio of the blade element heights H30, H37 is thus adjustable to the pertinent use case of the mixer 15 over a large range.

[0114] In addition to the different helix directions W30, W37 and the different blade element heights H30, H37, the blade elements 30, 37 may also be different from one another in their pitch. Pitch or thread pitch here means a distance along the longitudinal direction L15 that is covered by a complete turn or 360 turn of the respective blade element 30, 37. In the embodiment of the mixer 15 shown in FIGS. 2 to 7, however, the blade elements 30, 37 have identical pitches.

[0115] As FIGS. 2, 3, 6, and 7 show, the first blade elements 30 and the second blade elements 37 are positioned immediately adjacent or neighboring, when viewed in the longitudinal direction L15. Immediately may here mean that, when viewed in the longitudinal direction L15, a respective bottom end edge 33 of a first blade element 30 is arranged at the same height as a respective top end edge 41 of an adjacent second blade element 37. Accordingly, a top end edge 34 of another first blade element 30 is also on the same height as a bottom end edge 40 of the adjacent second blade element 37, when viewed in the longitudinal direction L15.

[0116] Thus the blade elements 30, 37 preferably extend around the core element 16 such that, when viewed in the longitudinal direction L15, no areas of the core element 16 are free from blade elements 30, 37. This means that immediately may mean that the blade elements 30, 37 are arranged free of any spacing or without any spacing, or free of any gaps or without any gap.

[0117] However, immediately may also mean that between the respective end edges 33, 41 or 34, 40, when viewed in the longitudinal direction L15, a slight spacing (not shown) may be provided. This spacing, however, is preferably less than the smaller blade element height H30, H37 of the two blade elements 30, 37. For example, the spacing is less than 5 mm, more preferably less than 4 mm, more preferably less than 3 mm, more preferably less than 2 mm, more preferably less than 1 mm, more preferably less than 0.5 mm, more preferably less than 0.4 mm, more preferably less than 0.3 mm, more preferably less than 0.2 mm, more preferably less than 0.1 mm. However, the spacing most preferably equals zero, a explained above. This means that the blade elements 30, 37 most preferably are adjacent to each other without any spacing, preferably, however, without contacting one another (FIG. 6).

[0118] The mixer 15 may further comprise a marking member 46 (FIG. 2). The marking member 46 may be a steel pin or a steel bolt, for example. For example, the marking member 46 may be arranged roughly between the mixing stages 26, 27. The marking member 46 may, for example, be melted into the mixer 15 or adhered to it. The mixer 15 may also be constructed in layers around the marking member 46. In a dynamic operation of the mixer 15, the marking member 46 may be used to check whether the marking member 46 rotates with the core element 16 or not during a mixing operation by means of a suitable sensor. In the event the marking member 46 no longer rotates with the core element, it can be assumed that the core element 16 is broken or sheared off. The mixer 15 can then be replaced.

[0119] The functionality of the mixing device 10 of the mixer 15 is explained below. In the case where the mixer 15 is a static mixer, the mixer 15 stands still in the mixing tube 11 and does not rotate about the central axis M15. During operation of the dosing device 1, the dosing pumps 2, 3, feed the components K1, K2 in the feed direction F along the mixer 15. The two components K1, K2 first reach the mixer base 17. Due to the mixer base 17 being embodied roof-shaped and having a chisel-shaped tip 21, an accumulation of the components K1, K2 directly at the mixer base 17 is prevented.

[0120] The components K1, K2 reach the first blade element 30 of the first mixing stage 24. For example, the first component K1 may be dosed unto the first blade section 31 and the second component K2 may be dosed unto the second blade section 32. Due to the feeding effect of the dosing pumps 2, 3, the components K1, K2 are helically feed in the first helix direction W30, i.e. counter-clockwise, in the direction of the second blade element 37 of the first mixing stage 24.

[0121] During the transfer of the components K1, K2 from the first blade element 30 to the second blade element 37 of the first mixing stage 24, which is arranged immediately below said first blade element, the two components K1, K2 are turned over and thus intermixed due to the different helix directions W30, W37 of the blade elements 30, 37. Along the second blade element 37, the now already partially intermixed components K1, K2 are feed in the second helix direction W37 along the feed direction F to the subsequent first blade element 30 of the second mixing stage 25 and transferred to said first blade element and, in doing so, turned over again and intermixed further. This process is repeated at each mixing stage 24 to 29 until the homogeneously mixed product P exits at the nozzle section 13 for dosing.

[0122] The second blade element height H37 of the second blade element 37 being greater than the first blade element height H30 of the first blade element 30 facilitates feeding the components K1, K2 in the feed direction F, thereby making it possible to achieve a pressure reduction in comparison to known mixers, whose blade element have identical blade element heights. This effectively prevents excessive pressure build-up in the mixing device 10 and thus compressing the product P. The product P pressing out is significantly reduced in comparison with known mixers. It is possible to apply a product bead at a dosing start and a dosing end easier and without the formation of blobs.

[0123] In the case where the mixer 15 is used as a dynamic mixer, the drive mechanism 7 rotates the mixer 15 inside the mixing tube 11 about the central axis M15. A rotational direction DR (FIG. 4) of the mixer 15 preferably corresponds to the first helix direction W30. This means that the mixer 15 is driven left-handed or counter-clockwise. Due to the different helix directions W30, W37 of the blade elements 30, 37 of the mixing stages 24 to 29, the components K1, K2 are being fed against the feed direction F by means of the first blade element 30 and in feed direction F by means of the blade elements 37.

[0124] This means that the first blade elements 30 are operable to accumulate the components K1, K2 or to create the reverse turbulence, whereas, due to its opposite second helix direction W37, the second blade elements 37 feed the components K1, K2 in the feed direction F in the direction of the nozzle section 13. However, because the second blade element height H37 of the second blade element 37 is greater than the first blade element height H30 of the first blade element 30, the feeding effect of the mixer 15 is greater in the feed direction F than against the feed direction F. This means that the mixer 15 itself has a feeding effect.

[0125] Thus the components K1, K2 or the product P, respectively, can be fed with significantly reduced pressure build-up in the feed direction F, as compared to known mixers that, due to identical blade element heights, do not have a feeding effect themselves. This means that the second blade elements 37 are operable to feed the components K1, K2 in the feed direction F and/or to reduce pressure and the first blade elements 30 are operable to create the reverse turbulence or to accumulate the components K1, K2. A turning over or intermixing of the components K1, K2 always occurs at a transition from a first blade element 30 to a second blade element 37 and vice versa.

[0126] The compressible product P pressing out is thus exponentially minimized because the pressure build-up is reduced. Thus, the application at dosing start and dosing end is easier and cleaner. The mixing quality or the intermixing of the two components K1, K2 is thus better with reduced overall height, when viewed along the longitudinal direction L15. The speed of the drive mechanism 7 can also be reduced. This reduces shear forces acting on the components K1, K2 or the product P, respectively. Moreover, at the end of the dosing operation, the rotational direction DR is reversible so that the second blade elements 37 feed against the feed direction F. The product P is thereby pulled back from the nozzle section 13. This allows for a further reduction in the risk of the product P pressing out.

[0127] FIG. 8 shows a schematic partial view of another embodiment of a mixer 15. The mixer 15 according to FIG. 8 is different from the mixer according to FIGS. 2 to 7 in that the first blade element 30 and the second blade element 37 overlap one another. In particular, the first blade element 30 runs into the second blade element 37 and vice versa. Thus the blade sections 31, 32 are partially arranged between the blade sections 38, 39 and vice versa. The end edges 34, 40 or the end edges 33, 41 of the blade elements 30, 37, respectively, are thus positioned spaced apart by a projecting length U.

[0128] FIG. 9 shows a schematic partial view of another embodiment of a mixer 15. FIG. 10 shows a schematic top plan view of the mixer 15. The mixer 15 according to FIGS. 9 and 10 is different from the mixer according to FIGS. 2 to 7 in that the blade elements 30, 37 have a wall thickness tapering in the radial direction R15. This means that the wall thickness decreases, when viewed in the radial direction R15. Moreover, the blade elements 30, 37, in particular the blade sections 31, 32, 38, 39 of the blade elements 30, 37 are arcuately curved or bent, in particular curved or bent in a circular arc. A tangential transition is provided between the blade sections 31, 32, 38, 39 and the core element 16. The pitch of the second blade element 37 is, for example, three times the pitch of the first blade element 30.

[0129] FIG. 11 shows a schematic partial view of another embodiment of a mixer 15. FIG. 12 shows a schematic top plan view of the mixer 15. The mixer 15 according to FIGS. 11 and 12 is different from the mixer according to FIGS. 2 to 7 in that the blade elements 30, 37, in particular the blade sections 31, 32, 38, 39 of the blade elements 30, 37 are arcuately curved or bent, in particular shaped in a circular arc, when viewed in the radial direction R15. In contrast to the embodiment of the mixer according to FIGS. 9 and 10, a tangential transition is not provided between the blade sections 31, 32, 38, 39 and the core element 16. The wall thickness of the blade elements 30, 37 is preferably constant.

[0130] FIG. 13 shows a schematic partial view of another embodiment of a mixer 15. FIG. 14 shows a schematic top plan view of the mixer 15. The mixer 15 according to FIGS. 13 and 14 is different from the mixer according to FIGS. 2 to 7 in that the blade elements 30, 37 each comprise more than two blade sections 31, 32, 38, 39. The first blade element 30 comprises three blade sections 31, 32, 44, and the second blade element 37 also comprises three blade sections 38, 39, 45. The blade sections 31, 32, 44 of the first blade element 30 and the blade sections 38, 39, 45 are positioned at a circumferential angle of 120 to each other.

[0131] FIG. 15 shows a schematic view of another embodiment of a mixer 15. The mixer 15 according to FIG. 15 is different from the mixer according to FIGS. 2 to 7 in that a different ratio of the blade element height H30, H37 is selected. The first blade element height H30 is, for example, 6.25 mm and the second blade element height H37 is, for example, 18.75 mm. The blade element height ratio between the blade element heights H30, H37 thus is 2/8 to 6/8, for example.

[0132] This means that in this embodiment of the mixer 15, the first blade element height H30 is smaller than in the embodiment of the mixer 15 according to FIGS. 2 to 7, and the second blade element height H37 is correspondingly greater. Due to the increased second blade element height H37 and the decreased first blade element height H30 a further pressure reduction in the mixing device 10 can be achieved, in particular during dynamic operation of the mixer 15. Furthermore, a feeding effect in the feed direction F is improved.

[0133] FIG. 16 shows a schematic view of another embodiment of a mixer 15. The mixer 15 according to FIG. 16 is different from the mixer according to FIGS. 2 to 7 in that lesser blade element heights H30, H37 are selected for the first blade element 30 and the second blade element 37. The first blade element height H30 is, for example, 7.5 mm and the second blade element height H37 is, for example, 12.5 mm.

[0134] This results again in a ratio of the blade element heights H30, H37 of to . Due to the reduced blade element heights H30, H37, the mixer 15 according to FIG. 16 comprises not six but eight mixing stages 24 to 29. The number of mixing stages 24 to 29 is arbitrary, as mentioned above. The increased number of mixing stages 24 to 29 allows for an even better intermixing of the components K1, K2 to be achieved.

[0135] FIG. 17 shows a schematic view of another embodiment of a mixer 15. In this embodiment of the mixer 15, only one blade element 37 is provided. The second blade element height H37 may be 37.5 mm, for example. Considered in regard to the mixing area 23, this corresponds to 32/8. The second blade element 37 is in particular a feeding screw.

[0136] In addition to the first blade elements 30 and the second blade element 37, several third blade elements 47 are also provided. The third blade elements 47 are constructed identical to the first blade elements 30, but do not comprise the first helix direction W30 but the second helix direction W37 of the second blade elements 37. The blade elements 30, 47 are alternately arranged. The first blade element height H30 and a third blade element height H47 of the third blade elements 47 may be equal. For example, the blade element heights H30, H47 are each 9.37 mm. Here, not a first blade element 30 but a third blade element 47 directly abuts the mixer tip 17.

[0137] A ratio of the blade element heights H30, H47 is 4/8 to 4/8. The second blade element 37 arranged at the end of the mixer 15 having an enlarged second blade element height H37 allows for the product P to be fed against the feed direction F by reversing the rotational direction DR of the mixer 15 at the end of the dosing operation to prevent the product P from pressing out. This means that the second blade element 37 then no longer feeds the product P in the feed direction F but against the feed direction F. This allows for a particularly effective prevention of a dripping of the product P after the dosing operation is stopped. In addition, the dosing pumps 2, 3 are adapted to run in reverse to equalize pressure.

[0138] FIG. 18 shows a block diagram of a preferred embodiment of a method for manufacturing a mixer 15 as described above. The method is in particular an additive or a generative manufacturing method. For example, a 3D printing process may be used. With a 3D printing process, the mixer 15 is constructed in layers in any number of steps S1 to SN, for example from a powder bed, in particular from a plastic powder bed.

[0139] The use of a generative manufacturing method allows for the geometry of the mixer 15 to be designed arbitrarily complex. In particular geometries that cannot be produced or only produced with increased effort with traditional methods such as plastic injection molding, for example, due to difficult or the lack of demoldability.

[0140] Although the present invention has been described using examples, it can be modified in many ways.

LIST OF REFERENCE CHARACTERS

[0141] 1 Dosing device [0142] 2 Dosing pump [0143] 3 Dosing pump [0144] 4 Flow block [0145] 5 Channel [0146] 6 Channel [0147] 7 Drive mechanism [0148] 8 Drive member [0149] 9 Drive shaft [0150] 10 Mixing device [0151] 11 Mixing tube [0152] 12 Base section [0153] 13 Nozzle section [0154] 14 Support tube [0155] 15 Mixer [0156] 16 Core element [0157] 17 Mixer base [0158] 18 Mixer tip [0159] 19 Side face [0160] 20 Side face [0161] 21 Tip [0162] 22 Interface [0163] 23 Mixing area [0164] 24 Mixing stage [0165] 25 Mixing stage [0166] 26 Mixing stage [0167] 27 Mixing stage [0168] 28 Mixing stage [0169] 29 Mixing stage [0170] 30 Blade element [0171] 31 Blade section [0172] 32 Blade section [0173] 33 Terminating edge [0174] 34 Terminating edge [0175] 35 Blade base [0176] 36 Blade tip [0177] 37 Blade element [0178] 38 Blade section [0179] 39 Blade section [0180] 40 End edge [0181] 41 End edge [0182] 42 Blade base [0183] 43 Blade tip [0184] 44 Blade section [0185] 45 Blade section [0186] 46 Marking member [0187] 47 Blade element [0188] B Width [0189] DR Direction of rotation [0190] D16 Diameter [0191] D22 Diameter [0192] D30 Diameter [0193] D37 Diameter [0194] F Feed direction [0195] H17 Height [0196] H18 Height [0197] H23 Height [0198] H30 Height [0199] H37 Height [0200] H47 Height [0201] K1 Component [0202] K2 Component [0203] L15 Longitudinal direction [0204] M15 Central axis [0205] P Product [0206] Q16 Cross-section [0207] R15 Radial direction [0208] S1 Step [0209] SN Step [0210] U Projecting length [0211] U30 Circumference [0212] U37 Circumference [0213] W30 Helix direction [0214] W37 Helix direction [0215] Circumferential angle