DE10043489A1 - Dynamic mixer used for mixing viscous multiple component materials, especially dental material has a mixing element with mixing wings arranged on the side facing the closing part - Google Patents

Abstract

Dynamic mixer has a mixing element (3) with mixing wings (5, 6) arranged on the side facing the closing part (2). The wings are non material-stripping with respect to the wall of the chamber part (1) and have axially free recesses, where the recesses of one wing are covered by the non-free part of the other wing. An inner sleeve (4) which extends up to the first mixing wing is arranged on the closing part. Preferred Features: The mixing wings are arranged in the longitudinal direction. An inner peg (12) is arranged on the closing part. The first mixing wing has inner and/or outer recesses and the second mixing wing has only outer recesses. The mixer has a third mixing wing (14, 15, 16, 17).

Description

The invention relates to two dynamic mixers, in particular for viscous dental materials, with:
a chamber part, a discharge opening at the front end of the chamber part, a closure part arranged at the rear end of the chamber part with inlet openings for individual components to be introduced as well as a central bore for a mixing element and a mixing element rotatable about its longitudinal axis in the chamber part.

In the continuous mechanical mixing of multi-component materials, for example of adhesives or dental impression materials, it is common, depending on the consistency dynami use static or static mixers. The term "static mixer" includes such to understand, which contain fixed mixing devices for example flow pins, past which the individual materials to be mixed flow past and through swirls mixing and other faults. Under the term "dynamic mixer" are to be understood as those, the active mixing devices, for example in the form of rotating Mixing blades included. In these, the components to be mixed are replaced by active ones Transport mixed together.

Static mixers are less because of the high friction loss with tough consistencies suitable, which is why mixers with rotating mixing elements are used in such cases the.

EP 0 492 412 B1 discloses a dynamic mixer which has a housing with an inner diameter Substantially cylindrical chamber part, which has a discharge opening at its front end tion for the mixture, a closing body provided at the rear end of the chamber part per with protruding pipe spigot behind for direct insertion into the outlet opening  of storage containers containing the components to be mixed, and one in the Has chamber part rotatable about its longitudinal axis mixer element that with his back teren end is rotatably mounted in a bore of the end body. The Ab closing body formed as a plate, wherein the mixing element at least one wiper carries, with a cutting edge pointing forward in the direction of rotation, the front surface of the Cover plate sweeps, and rise to the cutting edge in the discharge direction de sloping surface connects.

A disadvantage of this mixer is u. a. the fact that it is a partially uncontrolled Escape of the components to be mixed between the end body and the rotatable Mi shear element due to leaks. In addition, the homogenization not always satisfactory because the individual components adapt to the Push the mixer element past the molded mixer blades.

The problem arises from the above, with the help of a novel dynamic Mi schers to at least partially eliminate the disadvantages mentioned above. That of the invention the underlying problem is, in particular, a dynami that can be produced inexpensively mixers for single use with low-viscosity to tough, stable multi-purpose to develop component materials with a very high level of homogenization or sealing guaranteed degree of efficiency.

This problem is solved according to the invention by a dynamic mixer according to claim 1 and solved a dynamic mixer according to claim 2.

The first dynamic mixer according to the invention has a chamber part, a discharge opening at the front end of the chamber part, a Ver arranged at the rear end of the chamber part closing part with entry openings for individual components to be inserted as well as a central one Bore for a mixing element and a rotatable in the chamber part about its longitudinal axis Mixing element. The mixing element has at least two in a row in the longitudinal direction and radially staggered mixing function-free mixing blades so that the free Passages of the first mixing wing are covered by the second mixing wing. Under the The term "stripping function-free" means the fact that the mixing blades used are not wall-accessible and act as wipers, but a certain distance from the adhere to individual walls. Due to the staggered arrangement of the mixing blades it is guaranteed that material not captured by the first mixing wing with a very high degree of accuracy Probability captured by the second mixing wing, sheared and then with the others Components is mixed.  

The second dynamic mixer according to the invention contains a chamber part, a discharge opening at the front end of the chamber part, a Ver arranged at the rear end of the chamber part closing part with inlet openings for individual components to be inserted as well as a centri rule hole for a mixing element and a rotatable about its longitudinal axis in the chamber part Mixing element. At least one rear end of the mixing element is on the closure part gripping inner sleeve arranged substantially in the longitudinal direction. The sleeve ensures an increase in the stator area (under the term "stator area" all ste existing solid areas necessary for the mixing of the individual components understand) and the sealing surface (under the term "sealing surface" are such surfaces to understand that an uncontrolled outflow of the individual components or the ge prevent or reduce the mixing of components and thus a sealing function exercise). Due to the arrangement as a sleeve encompassing the rear end of the mixing element a high sealing effect can be achieved.

First of all, it is advantageous if the mixing blades are free of rises in the longitudinal direction in which they are spread are formed (i.e. have no inclined blades in the plane of rotation), because in this way there is no discharge effect when the mixing blades rotate and thus the mixing element and its connection point to the drive axis of a not too high one are exposed to mechanical stress. Discharge is only done by pressing lengthways direction of the chamber part accomplished.

Furthermore, it is advantageous that the first arranged at the rear end of the chamber part Mixing wing in the direction of the closure part in the longitudinal direction in such a way at least one mixing pin is shaped such that the viscous material entering from the inlet openings is cut up is passed freely, since this enables a very high shear rate.

At least one essentially in the longitudinal direction is advantageously on the closure part Aligned inner pin arranged as a flow disruptor to increase the Mischwir kung serves.

On the closure part there is at least one in the rear end of the mixing element arranged substantially in the longitudinal direction inner sleeve, which to increase the Stator surface and at the same time serves to increase the sealing surface (this advantageous Aus design refers to the first dynamic mixer according to the invention).

The inner sleeve advantageously extends in the longitudinal direction almost to the first Mixing blades to ensure a very high sealing rate in this way.  

The first mixing wing is advantageously dome-shaped in the deploying longitudinal direction trained to in this way a low mixing and dead volume in the dynami remaining amount (after use) between the first and second mixer To provide mixing blades.

It is also advantageous if the first mixing wing has inner and / or outer recesses has to ensure a better material throughput. The inner recesses can be configured, for example, in the form of circles or ellipses, while the outer Ren recesses represent, for example, semicircular or paraboloid circular segments can.

Furthermore, it is advantageous if the second mixing blade has outer recesses, for example se in the form of circular segments to ensure a higher material throughput th.

Furthermore, the second mixing blade has a material reinforcement in the longitudinal direction of the chamber part kung, for example in the form of a doubled round cross, in order in this way and Way to provide material redundancy for high mechanical resilience.

In addition, the mixing element has at least one in the dispensing longitudinal direction third mixing wing on, for further homogenization of the mixed to be applied Material.

It is also advantageous if the mixing element in the second mixer according to the invention at least two in the longitudinal direction one behind the other and radially offset in such a way stripping-function-free mixing wing has that the free passages of the first mixing wing gels are covered by the second mixing blade in order to achieve an intensive Ensure shear and mixing (see above).

Finally, it is advantageous if in at least one inlet opening at least one transverse to the Passage-oriented web-shaped element is arranged so that any off Hardening when removing the used mixer from the tubular bag / cartridge be pulled out with.

Web-shaped elements that have oval, diamond, are elliptical, polygonal or circular.  

Sprayable plastics such as polyethylene, polypropylene or polystyrene have become particularly popular Proven for housing and end body (chamber part or closure part). For use in the case of tougher mixtures, the use of high-quality materials is particularly important for the mixing element General plastics such. B. polyamide, polyoxymethylene or other impact-resistant polyme ren / blends advantageous.

The invention is explained in more detail with the aid of the following example.

The drawings show:

Fig. 1 shows a cross section through a dynamic mixer;

FIG. 2 shows an excerpt of a cross section with respect to a further variant of the mixer according to the invention;

Fig. 3 is a cross section of a mixing element;

Fig. 4 is a plan view of a first mixing blade;

Fig. 5 is a plan view of a second mixing blade;

Fig. 6 shows a cross section of the dynamic mixer according to the invention and

Fig. 7 is a sketchy bottom view of the mixer according to the invention shown in Fig. 6.

In Fig. 1 a cross section is shown of an inventive dynamic mixer. The dynamic mixer has a chamber part 1 , a discharge opening 13 at the front end of the chamber part 1 , a closure part 2 arranged at the rear end of the chamber part 1 with inlet openings 11 for individual components to be introduced as well as a central bore for a mixing element and a rotatable one about its longitudinal axis in the chamber part 1 Mixing element 3 . The mixing element 3 has two stripping function-free mixing blades 5 , 6 arranged one behind the other and radially offset in such a way that the free passages of the first mixing blade 5 are covered by the second mixing blade 6 . Arranged on the closure part 2 is a sleeve 4 which is oriented essentially in the longitudinal direction and which engages around the rear end of the mixing element 3 .

The mixing blades 5 , 6 are designed to be free of rises in the deploying longitudinal direction (no inclined blades). On the first mixing wing 5 a mixing pin 10 is formed in the direction of the closure part 2 in the longitudinal direction. The first mixing paddle 5 does not run in the wall part 1 , ie it does not touch the housing wall 9 and forms two spacing volumes 7 between it and the first mixing paddle 5 . The closure part 2 has a rear base plate 8 . The mixing element 3 has four third mixing blades 14 , 15 , 16 , 17 in the dispensing direction.

In Fig. 2 an excerpt cross-section is shown with respect to another variant of the mixer according to the Invention.

In this variant, two pins 12 arranged substantially in the longitudinal direction are arranged on the closure part 2 .

Fig. 3 shows a cross section of a mixing element.

The mixing element 3 essentially consists of two stripping function-free mixing blades 5 , 6 arranged one behind the other and radially offset in the longitudinal direction, the free passages of the first mixing blade 5 being covered by the second mixing blade 6 . In the longitudinal direction, the mixing element 3 has four further third mixing blades 14 , 15 , 16 , 17 .

Fig. 4 shows a top view of a first mixing wing.

The first mixing blade 5 has inner and outer recesses 18 , 19 .

Fig. 5 shows a plan view of a second mixing blade.

The second mixing blade 6 has a material reinforcement 21 and outer recesses 20 in the longitudinal direction of the chamber part 1 .

FIGS. 6 and 7 show a cross section and a diagrammatic bottom plan view of the mixer in accordance OF INVENTION dung. An inlet opening 11 has a diamond-shaped, web-shaped element 22 oriented transversely to the flow direction.

Claims (16)

1. Dynamic mixer, in particular for viscous dental materials, with:
a chamber part ( 1 ), a discharge opening ( 13 ) at the front end of the chamber part ( 1 ), a closure part ( 2 ) arranged at the rear end of the chamber part ( 1 ) with inlet openings ( 11 ) for individual components to be introduced and a central bore for a mixing element and a mixing element ( 3 ) rotatable about its longitudinal axis in the chamber part ( 1 ), characterized in that the mixing element ( 3 ) has at least two stripping-function-free mixing blades ( 5 , 6 ) arranged one behind the other and radially offset in such a way that the free passages of the first th mixing blade ( 5 ) are covered by the second mixing blade ( 6 ). 2. Dynamic mixer, with:
a chamber part ( 1 ), a discharge opening ( 13 ) at the front end of the chamber part ( 1 ), a closure part ( 2 ) arranged at the rear end of the chamber part ( 1 ) with inlet openings ( 11 ) for individual components to be introduced as well as a central bore for a mixing element and a mixing element ( 3 ) which can be rotated about its longitudinal axis in the chamber part ( 1 ), characterized in that at least one inner sleeve ( 4 ) oriented essentially in the longitudinal direction and encompassing the rear end of the mixing element ( 3 ) is arranged on the closure part ( 2 ). 3. Dynamic mixer according to one of claims 1 to 2, characterized in that the mixing blades ( 5 , 6 ) are designed without a rise in the longitudinal direction in which they are brought out. 4. Dynamic mixer according to one of claims 1 to 3, characterized in that at the rear end of the chamber part ( 1 ) arranged first mixing wing ( 5 ) in Rich direction closure part ( 2 ) in the longitudinal direction such at least one mixing pin ( 10 ) is formed that the viscous material entering from the inlet openings ( 11 ) is passed without cutting. 5. Dynamic mixer according to one of claims 1 to 4, characterized in that at least one essentially longitudinally aligned inner pin ( 12 ) is arranged on the closure part ( 2 ). 6. Dynamic mixer according to one of claims 1 or 3 to 5, characterized in that on the closure part ( 2 ) at least one, the rear end of the mixing element ( 3 ) encompassing, substantially longitudinally aligned inner sleeve ( 4 ) is arranged. 7. Dynamic mixer according to one of claims 1 to 6, characterized in that the inner sleeve ( 4 ) extends in the longitudinal direction up to almost the first mixing blade ( 5 ). 8. Dynamic mixer according to one of claims 1 to 7, characterized in that the first mixing blade ( 5 ) is dome-shaped in the discharging longitudinal direction. 9. Dynamic mixer according to one of claims 1 to 8, characterized in that the first mixing wing ( 5 ) has inner and / or outer recesses ( 18 , 19 ). 10. Dynamic mixer according to one of claims 1 to 9, characterized in that the second mixing blade ( 6 ) has outer recesses ( 20 ). 11. Dynamic mixer according to one of claims 1 to 10, characterized in that the second mixing blade ( 6 ) in the longitudinal direction of the chamber part ( 1 ) has a material reinforcement ( 21 ). 12. Dynamic mixer according to one of claims 1 to 11, characterized in that the mixing element ( 3 ) has at least a third mixing blade ( 14 , 15 , 16 , 17 ) in the longitudinal direction in which it is brought out. 13. Dynamic mixer according to one of claims 2 to 5 or 7 to 12, characterized in that the mixing element ( 3 ) has at least two stripping function-free first and second mixing blades ( 5 , 6 ) arranged in the longitudinal direction one behind the other and radially offset in such a way that the free passages of the first mixing wing ( 5 ) are covered by the second mixing wing ( 6 ). 14. Dynamic mixer according to one of claims 1 to 13, characterized in that in at least one inlet opening ( 11 ) at least one cross-directionally oriented web-shaped element is arranged. 15. Dynamic mixer according to claim 14, characterized in that the web-shaped element ( 22 ) in the flow direction is oval, diamond, elliptical, polygonal or circular. 16. Use of a dynamic mixer according to one of claims 1 to 15 to mixing of viscous multi-component materials, in particular dental materials lien.