MIXING ELEMENT FOR A STATIC MIXER

Description

[0001] The invention relates to a mixing element for a static mixer, in particular a dental static mixer, for mixing low to high viscosity components, comprising a flat central part extending along a longitudinal axis L with a front side and a rear side opposite the front side, wherein at least two flow influencing elements are arranged on the front side and / or on the rear side of the central part, which flow influencing elements each enclose at least one passage opening located in the central part and have the shape of prism shells which are substantially perpendicular to the front side and / or the rear side, in particular based on an orthodiagonal quadrilateral, which overlap one another in pairs at a respective side edge or are connected to one another.Furthermore, the invention relates to a static mixer, in particular a dental static mixer, comprising the mixing element and its use for mixing low to high viscosity components.

[0002] Mixing elements for static mixers are known, for example, from DE 10 2017 117198 A1.

[0003] In mixing processes, the components of at least two separate mixture components are repositioned by relative movement to create a new arrangement in the form of a mixture. Depending on the consistency of the components to be mixed, static or dynamic mixers are used. While a dynamic mixer uses rotating mixing elements to homogenize the respective components, in static mixing they are mixed solely by their flow movement. This is achieved by static flow control elements inside a static mixer, which divide, swirl, and recombine the respective components.

[0004] Such mixers are used, among other things, in the dental field for mixing reacting, particularly polymerizing, components, such as for homogenizing the two paste components "Cat" (catalyst paste) and "Base" (base paste) during the manual application of dental impression materials. For this purpose, the paste streams are combined several times and then divided into individual strands until a homogeneous mixture is created.

[0005] The state of the art primarily involves static mixers with helical mixing elements, in which the helix is ​​interrupted several times to divide and merge the paste streams. Newer static mixers, however, feature interconnected mixing chambers arranged longitudinally and transversely to the flow direction, thus ensuring good mixing performance through multiple division and merger of the paste streams.

[0006] For example, DE 10 2017 117 198 A1 discloses a static mixer for mixing pasty and / or flowable components, in which the components flow through cuboid-shaped chambers arranged one behind and next to each other along their flow path and connected to each other via through-openings. The corresponding chambers are defined by transverse walls extending transversely to the flow direction and side walls extending parallel to the flow direction and are in flow communication with each other via through-openings provided in the side walls.

[0007] However, the geometry proposed in DE 102017 117 198 A1 has a disadvantage in mass injection molding production, as the cores that can form such cavities and openings in the injection mold must be very delicate. This very delicate design, however, means that efficient cooling of the corresponding tool sections is not possible, so that they are exposed to high continuous thermal stress (230° to 300°) during injection molding. As a result, the high-alloy tool steel used to manufacture the corresponding tool sections slowly loses its mechanical properties. In the worst case, the tool can even be damaged by the delicate tool sections bursting away, leading to tool failure and production disruption.The use of high-temperature-resistant tool steels can delay this effect, but not prevent it. Therefore, the only solution to this problem currently is a slower process with an extended cooling phase. However, this makes the manufacturing process significantly less economical and results in a loss of production capacity.

[0008] There is therefore a need to provide a static mixer with a mixing element that avoids the aforementioned disadvantage despite mixing chambers arranged longitudinally and transversely to the flow direction.

[0009] The present invention is therefore based on the object of providing a mixing element for a static mixer which has mixing chambers arranged longitudinally and transversely to the flow direction and which have a simple structure. In particular, a mixing element is to be provided which can be produced economically by injection molding and which enables the use of injection molding tools that are easy to temperature-control. Furthermore, the mixing element is to enable improved mixing of at least two low- to high-viscosity components, in particular dental materials. Furthermore, the object is to provide a mixing element and a static mixer whose small extension in the longitudinal direction avoids unnecessary shearing of the components to be mixed and a restriction of the field of vision during application in the oral cavity of a patient.

[0010] The objects of the present invention are achieved by a mixing element according to claim 1 and a static mixer comprising the mixing element according to claim 12, as well as by the use of the static mixer according to claim 14. Preferred embodiments of the invention are disclosed in detail in the subclaims and in the description.

[0011] According to the invention, the objects of the present invention are achieved in that the flow-influencing elements of the mixing element according to the invention have the shape of prism shells that are substantially perpendicular to the front and / or rear side of the mixing element, in particular prism shells based on an orthodiagonal quadrilateral, preferably based on a kite, particularly preferably a rhombus, which overlap or are connected to one another in pairs at each side edge. Within the scope of the present invention, prism shells that are substantially perpendicular to the front and / or rear side of the mixing element are those whose positioning on the front or rear side does not deviate or deviates only slightly from a 90° angle. This is the case if at least their side surfaces are substantially perpendicular to the front or rear side.The side surfaces of the prism shells therefore preferably form a 90° angle of plus / minus 5°, preferably plus / minus 3°, particularly preferably plus / minus 0.5°, with the front and / or rear of the mixing element. In particular, the flow-influencing elements of the mixing element according to the invention are in the form of prism shells arranged at a 90° angle of plus / minus 5°, preferably plus / minus 3°, particularly preferably plus / minus 0.5°, on the front and / or rear of the mixing element, which overlap or are connected to one another in pairs at each side edge.

[0012] The flow influencing elements thus form, in particular together with the inner walls of a mixer sleeve of a static mixer, geometric, preferably diamond-shaped, mixing chambers which are arranged one behind the other with respect to the flow path of the components to be mixed and are tapered towards their respective transitions into one another.

[0013] The choice of such a mixing chamber geometry has the advantage that the component streams to be mixed are inevitably backed up at the transitions between the mixing chambers, which are designed as constrictions. The backflow thus formed in the respective mixing chambers requires a division of the corresponding component stream, since one partial stream is guided through an opening in the front or rear of the mixing element located in the region of the constriction to the parallel component stream and is swirled with it, while the other partial stream continues its flow path. By repeating this process in each of the mixing chambers of the mixing element according to the invention, optimal mixing of the corresponding material, in particular dental material, is achieved. Furthermore, the mixing element according to the invention enables extremely economical production by injection molding due to its simple design.The required injection molding tools can be sufficiently tempered, so that the risk of tool damage and production downtime is significantly reduced.

[0014] In the context of the present invention, a prism shell is generally understood to be the shell of a three-dimensional body, i.e., without a base surface and top surface. This can consist of a continuous curved surface, similar to a body of revolution, or, similar to a prism, be composed of several, in particular polygonal, surfaces. A prism shell according to the invention preferably consists of at least three, in particular at least four, polygonal surfaces, which, in pairs, form the side edges of the prism shell by meeting one another. In this sense, a preferred prism shell has at least three, in particular at least four, optionally rounded, side edges. These can, but do not have to, be arranged perpendicular to the imaginary base surface and / or the imaginary top surface.Therefore, a prism shell in which the imaginary base surface and the imaginary top surface do not correspond in terms of their shape and / or size, and in which the imaginary top surface is horizontally displaced relative to the imaginary base surface, is also considered to be in accordance with the invention. Furthermore, the imaginary top surface does not necessarily have to be parallel to the imaginary base surface.

[0015] The base of the prism shells according to the invention is formed by the imaginary base area, which preferably has the shape of an orthodiagonal quadrilateral, in particular an orthodiagonal quadrilateral with rounded corners. An orthodiagonal quadrilateral is understood to be a quadrilateral in which the diagonals intersect at right angles, or in other words, a quadrilateral in which the sums of the squares of the side lengths for the two pairs of opposite sides are equal.

[0016] Particularly preferred orthodiagonal quadrilaterals as the basis for the prism shells according to the invention are kites, in particular with rounded corners, preferably rhombuses, in particular with rounded corners. A kite (also called a deltoid) is a planar quadrilateral in which one diagonal is the axis of symmetry or which has two pairs of adjacent sides of equal length. A special type of kite is the rhombus, namely an equilateral deltoid. Consequently, a rhombus is a planar quadrilateral with four sides of equal length, in which opposite sides are parallel and opposite angles are equal.

[0017] The respective side surfaces forming the prism shells according to the invention can have a polygonal shape, i.e., the shape of a polygon. Preferred polygons according to the invention include convex polygons, in particular convex quadrilaterals. The side surfaces of the prism shells according to the invention are preferably trapezoidal, i.e., quadrilaterals with two parallel sides. Depending on whether the imaginary base surface and the imaginary top surface of the corresponding prism shells are parallel to one another, displaced, and / or congruent, the respective side surfaces can have different forms of convex quadrilaterals, in particular trapezoids.Thus, the side surfaces of the prism shells according to the invention are preferably rectangles if the imaginary base surface and the imaginary top surface are congruent, parallel, and not displaced, and parallelograms if the imaginary base surface and the imaginary top surface are congruent and parallel to each other but displaced horizontally. Otherwise, i.e., if the imaginary base surface and the imaginary top surface are not congruent and / or not parallel to each other, they are trapezoids. The side surfaces of the prism shells according to the invention can be either planar or curved.

[0018] Thus, the subject matter of the invention is a mixing element for a static mixer, in particular a dental static mixer, for mixing low to high viscosity components, comprising a flat central part extending along a longitudinal axis L with a front side and a rear side opposite the front side, wherein at least two flow influencing elements, in particular at least two to 20, preferably at least three to ten, such as 4, 5, 6, 7, 8, 9, flow influencing elements are arranged on the front side and / or on the rear side of the central part, each of which encloses at least one, in particular at least two, passage opening(s) located in the central part, and wherein the flow influencing elements have the shape of prism shells substantially perpendicular to the front side and / or the rear side, in particular based on an orthodiagonal quadrilateral, preferably based on a rhombus,which overlap or are connected to each other in pairs at one side edge.

[0019] The central part of the mixing element according to the invention represents a dividing wall between the flow-influencing elements located on the front side of the mixing element and the flow-influencing elements located on the back side of the mixing element, and thus separates the component flow on the front side from the flow flowing along the back side. The central part preferably has a height of greater than or equal to 10 mm to less than or equal to 100 mm, preferably greater than or equal to 40 mm to less than or equal to 70 mm, particularly preferably greater than or equal to 50 mm to less than or equal to 60 mm, measured along the longitudinal axis L, and / or a width of greater than or equal to 2 mm to less than or equal to 10 mm, preferably greater than or equal to 4 mm to less than or equal to 6 mm, particularly preferably around 5 mm, measured perpendicular to the longitudinal axis L. The thickness of the central part is preferably greater than or equal to 1 mm to less than or equal to 10 mm, preferably greater than or equal to 4 mm to less than or equal to 6 mm.

[0020] The central part according to the invention has a plurality of passage openings through which the component streams flowing separately along the front and rear sides of the central part can at least partially reach the respective other side of the central part and mix there. Accordingly, the central part has a total of at least two, preferably at least two to 50, in particular at least five to 40, passage openings to connect the front side of the central part to the rear side of the central part (and vice versa). The at least two passage openings can have any two-dimensional shape in cross section, such as, in each case independently of one another, a circle, ellipse, rectangle, square, and / or triangle.The surface area of ​​the cross section of the at least two passage openings is preferably, in each case independently of one another, greater than or equal to 0.1 mm 2 to less than or equal to 3.0 mm 2 , preferably greater than or equal to 0.5 mm 2 to less than or equal to 2.5 mm 2 , particularly preferably 1.0 ± 0.25 mm 2 , in particular 0.78 mm 2 . In addition, it can be preferred if the surface area of ​​the cross section of a passage opening on the front side of the central part deviates from the surface area of ​​the cross section of a passage opening on the rear side of the central part, for example in order to allow one component flow from the front side to the rear side, but not the other component flow from the rear side to the front side (and vice versa). The arrangement of the passage openings depends on the flow influencing elements arranged on the front side and / or rear side of the central part.

[0021] Thus, the at least two flow-influencing elements arranged on the front and / or rear side of the central part each enclose at least one, in particular at least two, passage openings, i.e. these are located within and thus in the imaginary base area of ​​the respective prism shell, wherein they are preferably oriented closer to the respective side edges, which overlap or are connected in pairs, than to the center of the respective flow-influencing element. Preferably, no passage openings are located outside the areas enclosed by the flow-influencing elements. This ensures that a component flow located in a mixing chamber formed by a flow-influencing element exits again into a mixing chamber formed by a flow-influencing element, but on the other side of the central part.

[0022] According to the invention, the flow-influencing elements are designed in the form of prism shells, in particular based on an orthodiagonal quadrilateral, which are essentially perpendicular to the front and / or the rear, in particular at a 90° angle plus / minus 5°, preferably plus / minus 3°, particularly preferably plus / minus 0.5°. Within the framework of the aforementioned definition of a prism shell according to the invention, this is considered to be essentially perpendicular to the front and / or the rear if at least its side surfaces are essentially perpendicular to the front and / or the rear. This does not necessarily also apply to the side edges of the prism shell. In this sense, the imaginary base area of ​​the prism shells is represented by a part of the front or rear of the central part.The imaginary cover surface, however, is only represented when the mixing element according to the invention is incorporated into the mixer sleeve of a static mixer, namely by the inner walls of the mixer sleeve.

[0023] Preferred flow-influencing elements have the shape of a prism shell based on a kite, in particular based on a rhombus, preferably an elongated rhombus. It is particularly preferred according to the invention if, in a first embodiment of the mixing element according to the invention, the flow-influencing elements have the shape of prism shells based on a rhombus, in particular an elongated rhombus, in which the imaginary base surface and the imaginary cover surface are diamond-shaped, congruent, parallel, and not displaced. While in a second embodiment of the mixing element according to the invention, the flow-influencing elements have the shape of prism shells based on a rhombus, in particular an elongated rhombus, in which the imaginary base surface and the imaginary cover surface are both diamond-shaped, the imaginary cover surface is neither congruent nor parallel to the imaginary base surface.Nevertheless, according to the invention, in both cases the mixing chambers formed by the respective flow influencing elements are also referred to as diamond-shaped.

[0024] The flow-influencing elements preferred according to the invention, in particular the prism shells serving as the base, thus preferably each have four, optionally rounded, side edges, wherein they overlap or are connected to one another in pairs at one of these side edges. In particular, flow-influencing elements preferred according to the invention meet at two of their side edges, in particular at two opposite side edges, with another flow-influencing element preferred according to the invention. In this context, the term "pair" refers to the fact that two flow-influencing elements meet at at least one common side edge.With three flow-influencing elements, the first and second flow-influencing elements, as well as the second and third flow-influencing elements, and optionally also the first and third flow-influencing elements, would meet at least one common side edge. Consequently, the term "paired" does not necessarily require the presence of an even number of flow-influencing elements.

[0025] According to the invention, "overlapping side edges" means that the prism shells in question are at least partially interlocked and do not form a common side edge. In contrast, "interconnected side edges" means the formation of a common side edge.

[0026] In a preferred embodiment of the present invention, the flow-influencing elements each have a common passage on their side edges, which overlap one another in pairs or are connected to one another. This passage enables the component flow on the front or back side to flow into the flow-influencing element following in the direction of flow. In particular, the common passage is formed by imaginarily pushing the respective flow-influencing elements into one another, while removing the respective protruding tips, or in the common side edge of the respective flow-influencing elements. The common passage preferably has a surface area of ​​greater than or equal to 0.1 mm 2 < to less than or equal to 2.5 mm 2 <, preferably greater than or equal to 0.5 mm 2 < to less than or equal to 2.0 mm 2 <, particularly preferably 1.0 ± 0.3 mm 2 <, in particular 1.26 mm 2 <.

[0027] In a particularly preferred embodiment of the present invention, the side edges of the at least two flow-influencing elements, which overlap or are connected to one another in pairs, are arranged on the longitudinal center axis LM of the central part. The longitudinal center axis LM can correspond to an axis of symmetry of the central part. In this sense, the at least two flow-influencing elements are arranged on the front and / or rear side of the central part such that their respective opposite side edges, in particular their side edges which overlap or are connected to one another in pairs, lie on a common axis, in particular the longitudinal center axis LM of the central part. At the same time, the remaining opposite side edges can, but do not have to, each lie on a common axis that coincides with the longitudinal edges of the central part.

[0028] The flow-influencing elements according to the invention are thus arranged in a row, preferably one behind the other with respect to the flow direction of the components to be mixed. Accordingly, the mixing chambers formed by the flow-influencing elements repeatedly narrow and expand in the flow direction, causing the described damming effect.

[0029] The mixing element according to the invention is therefore optimally suited for mixing low- to high-viscosity components, in particular pasty materials, preferably dental materials. Viscosity describes the viscosity of fluids and is specified in Pascal seconds (Pa s). Fluids are divided into three categories: low-, medium-, and high-viscosity. The boundaries between the individual categories are approximately 300 mPa s for the transition between low- and medium-viscosity fluids and approximately 8000 mPa s for the transition between medium- and high-viscosity fluids. High-viscosity fluids also include, in particular, pasty dental materials, preferably 2-component (2K) impression materials, which are in the form of a base paste and a catalyst paste, which must be homogeneously mixed by the mixing element according to the invention or the static mixer according to the invention before use.

[0030] In a first embodiment of the mixing element according to the invention, the central part comprises at least two, in particular at least two to 20, preferably at least three to ten, flow influencing elements arranged on the front side and at least two, in particular at least two to 20, in particular at least three to ten, flow influencing elements arranged on the rear side, which are at least partially offset from one another in the direction of the longitudinal axis L. In particular, the flow influencing elements on the front side of the central part are offset from the flow influencing elements arranged on the rear side of the central part with respect to the longitudinal axis L by the length of at least one quarter of a flow influencing element, preferably at least one third of a flow influencing element (and vice versa).

[0031] Particularly preferably, the flow-influencing elements on the front and / or rear side of the central part are offset from one another by half a flow-influencing element in the direction of the longitudinal axis L. This means that the side edges of the flow-influencing elements, which overlap or are connected to one another in pairs, on one side of the central part are preferably arranged at the level of the respective geometric center of gravity, in particular the center point, of the flow-influencing elements on the other side of the central part (and vice versa).In particular, the side edges of the diamond-shaped flow influencing elements on the front side of the central part, which side edges overlap or are connected to one another in pairs, are arranged at the level of the respective center point of the diamond-shaped flow influencing elements on the rear side of the central part and / or the side edges of the diamond-shaped flow influencing elements on the rear side of the central part, which side edges overlap or are connected to one another in pairs, are arranged at the level of the respective center point of the diamond-shaped flow influencing elements on the front side of the central part.

[0032] In this context, it may be preferred if the at least two flow influencing elements arranged on the front side and the at least two flow influencing elements arranged on the rear side each enclose at least two through-openings located in the central part, wherein one through-opening is arranged in the region, in particular at the constriction, of the side edges of the flow influencing elements on the front side which overlap or are connected to one another in pairs, and the other through-opening is arranged in the region, in particular at the constriction, of the side edges of the flow influencing elements on the rear side which overlap or are connected to one another in pairs.

[0033] With respect to the flow path of the components to be mixed, the passage openings are thus preferably located at the end of a mixing chamber formed by the corresponding flow-influencing element on the front and / or rear side, in particular before the transition to the mixing chamber downstream in the flow direction. This arrangement enables a more efficient distribution of the component flows, since, due to the backpressure created at the transitions between the mixing chambers, a partial flow of the corresponding component flow enters the passage opening located there, but exits the passage opening on the opposite side in a more relaxed (less narrow) area of ​​the correspondingly offset mixing chamber, namely in the area of ​​the geometric center of gravity, in particular the center point, of the opposite flow-influencing element.

[0034] In a second embodiment of the mixing element according to the invention, the middle part is composed of at least two middle part segments, in particular at least two to 20, preferably at least three to ten, such as 4, 5, 6, 7, 8, 9, middle part segments, which are alternately inclined at an angle α to the rear and at an angle β to the front with respect to the longitudinal axis L, wherein preferably one flow influencing element is arranged on the front side and / or on the rear side, in particular one flow influencing element on the front side and one flow influencing element on the rear side, of each middle part segment.

[0035] In this sense, the profile of the center section composed of center section segments, or its cross-section along the longitudinal axis L, describes a zigzag line, in which the center section segments are each inclined relative to one another at an angle (α - β) of greater than or equal to 2° to less than or equal to 178°, preferably greater than or equal to 20° to less than or equal to 160°, particularly preferably greater than or equal to 60° to less than or equal to 120°. Consequently, the individual center section segments, viewed from the front and / or rear side, alternately meet in a forward-facing tip or by forming a pointed cavity extending rearward, and two flow-influencing elements each on the front and rear side thus meet either at a forward-facing tip of two center section segments and thus bluntly, or at the end of a pointed cavity formed by two center section segments and thus pointedly.In both cases, the respective overlapping or interconnected side edges of the adjacent flow influencing elements preferably lie on the bisector of the angle enclosed by the corresponding central part segments.

[0036] The at least two to 20 center section segments are connected to one another in pairs, in particular formed from a single piece of material, and as a whole form the center section of the mixing element according to the invention. The center section thus continues to extend along the longitudinal axis L, but in this second embodiment, unlike the first embodiment of the mixing element according to the invention, it is not planar. Instead, the center section consists of center section segments alternately inclined at an angle α to the rear and at an angle β to the front with respect to the longitudinal axis L.It may be preferred if, independently of one another, the angle α is greater than or equal to 1° to less than or equal to 89°, preferably greater than or equal to 25° to less than or equal to 85°, particularly preferably greater than or equal to 50° to less than or equal to 80°, in particular 75°, preferably with + / - 2°, preferably with + / - 1°, and / or the angle β is less than or equal to -1° to greater than or equal to -89°, preferably less than or equal to -25° to greater than or equal to -85°, particularly preferably less than or equal to -50° to greater than or equal to -80°, in particular 75°, preferably + / - 2°, preferably with + / - 1°, with respect to the longitudinal axis L. In particular, the absolute value of the angle α is equal to the absolute value of the angle β.

[0037] This special design of the central section has the advantage that every second mixing chamber formed by the flow-influencing elements tapers not only in width but also in depth at its transition to the subsequent mixing chamber. Due to this horizontal and vertical reduction in cross-sectional area in the axial flow direction, the flow resistance of a corresponding component flow increases to such an extent that a partial flow of the component flow passes through the passage opening in the central section located in the region of the transition to the subsequent mixing chamber into the opposite mixing chamber on the other side of the central section and mixes with the component flow located there. The remaining mixing chambers, however, in which, in contrast, they expand in depth instead of tapering, enable extensive mixing of recently merged component flows.This effect can be further enhanced by designing the common passages of different sizes at the paired overlapping or interconnected side edges of the flow influencing elements, depending on whether the mixing chamber is tapered or expanded in depth.

[0038] Thus, a mixing element of the second embodiment may be particularly preferred according to the invention, in which the flow influencing elements on the front and / or rear side of adjacent middle part segments alternately meet bluntly or pointedly at their side edges which overlap or are connected to one another in pairs, and the common passage at the side edges which overlap or are connected to one another in pairs of two flow influencing elements which meet at an angle is larger than the common passage at the side edges which overlap or are connected to one another in pairs of two flow influencing elements which meet at an angle.In particular, the common passage at the pairwise overlapping or interconnected side edges of two acutely meeting flow-influencing elements is at least 1.25 times, preferably at least 1.5 times, in particular at least twice as large as the common passage at the pairwise overlapping side edges of two butt-meeting flow-influencing elements. The smaller common passage at two butt-meeting flow-influencing elements increases the flow resistance of the respective component stream in the mixing chambers tapering in depth, while at the same time, in the mixing chambers expanding in depth, the larger common passage of two acutely meeting flow-influencing elements allows for easier mixing and forward flow of the newly merged component streams.

[0039] In addition, a transverse web oriented essentially perpendicular to the longitudinal axis L is preferably arranged between two central section segments on the front side and / or on the rear side in order to stabilize the respective transitions from the individual mixing chambers to one another. In particular, the transverse web has the same width as the central section with respect to the longitudinal axis L. Thus, the side edges of the flow-influencing elements that do not overlap or are not connected to one another in pairs preferably lie on a common line with the respective end edge of the transverse web. The transverse web is preferably joined to the central section or the associated central section segments or is formed integrally. The transverse web can also be created by connecting two central section segments.

[0040] In a further preferred embodiment of the present invention, which is compatible with both the first embodiment and the second embodiment of the mixing element according to the invention, the mixing element further comprises a first side part and a second side part arranged at a distance from the first side part, wherein the middle part is connected to the first side part and the second side part in such a way that the front and the back are aligned substantially perpendicular to the first side part and / or the second side part. In this sense, the middle part, together with the first side part (left side part) and the second side part (right side part), viewed from above or from below, essentially forms the shape of the letter H. The right and / or left side part can be connected to the middle part orthe middle part segments can be joined or formed integrally and facilitates the incorporation of the mixing element according to the invention into the mixer sleeve of a static mixer. In particular, the right and left side parts are intended to bear against two opposite inner walls of the mixer sleeve of a static mixer according to the invention. In this sense, it is preferred if the cross-section of the mixing element defined by the left and right side parts corresponds to the cross-section formed by the inner walls of the mixer sleeve of a static mixer according to the invention. This means that preferably the longitudinal edges of the left and / or right side parts lie in the same plane as the upper edges of the respective flow-influencing elements on the front and / or rear side of the middle part.

[0041] In addition, it may be preferred according to the invention if the mixing element further comprises a base part with at least one inlet opening, in particular with at least two inlet openings, which is aligned substantially perpendicular to the central part and / or to the first side part and to the second side part. The base part can be designed in the shape of a disk or a rectangle, in particular a square, and prevents the components to be mixed from being introduced outside the mixing chambers formed by the flow-influencing elements on the front and / or rear side of the central part. In particular, the base part can also be designed in the form of a mixer lid, which is provided for closing a mixer sleeve of a static mixer.

[0042] In a particularly preferred embodiment of the present invention, the mixing element, in particular the central part with the flow-influencing elements and optionally the first and / or second side part and / or the base part, is an injection-molded part. Alternatively, the mixing element, in particular the central part with the flow-influencing elements and optionally the first and / or second side part and / or the base part, is manufactured using a generative, material-building process. The central part with the flow-influencing elements and optionally the first and / or second side part and / or the base part are preferably formed from a single piece of material.

[0043] The mixing element, in particular the central part with the flow-influencing elements, is preferably made of a material with good sliding properties. This particularly includes a polymeric material with good sliding properties, such as POM (polyoxymethylene), PA (polyamide), PC (polycarbonate), PE (polyethylene), PP (polypropylene), PEEK (polyether ether ketone), PAEK (polyarylether ether ketone), and / or mixtures thereof. According to the invention, it is particularly preferred if the mixing element, in particular the central part with the flow-influencing elements, is made of POM. Optionally, the aforementioned materials can also be fiber-reinforced. Therefore, according to the invention, the mixing element is further preferably made of a fiber-reinforced plastic or fiber-reinforced polymeric material or a fiber-plastic composite.The surface of the mixing element can have a roughness Ra of less than or equal to 2.5 µm, in particular a roughness Ra of less than or equal to 2.0 µm. The roughness Ra is understood as the mean roughness Ra according to VDINDE 3400 and can be determined using known measuring methods. The roughness Ra is preferably greater than or equal to 0.5 µm, in particular greater than or equal to 1.0 µm to less than or equal to 2.5 µm.

[0044] The present invention also relates to a static mixer, in particular a dental static mixer for mixing low- to high-viscosity components, in particular at least two low- to high-viscosity dental materials, comprising a mixing element comprising a flat central part extending along a longitudinal axis L and having a front side and a rear side opposite the front side, wherein at least two flow-influencing elements are arranged on the front side and / or on the rear side of the central part, which flow-influencing elements each enclose at least one passage opening located in the central part and have the shape of prism shells substantially perpendicular to the front side and / or the rear side, in particular based on an orthodiagonal quadrilateral, preferably based on a kite, particularly preferably a rhombus,which overlap or are connected to one another in pairs at each side edge, in particular comprising a mixing element according to the invention, and wherein the static mixer further comprises an elongated mixer sleeve with at least one outlet opening and a mixer cover closing the mixer sleeve with at least two inlet openings for introducing the components to be mixed, wherein the mixer sleeve is provided for receiving the mixing element and the inner walls of the mixer sleeve and the at least two flow influencing elements on the front and / or the rear of the central part, in particular of the mixing element, form at least two interconnected mixing chambers, in particular diamond-shaped mixing chambers.

[0045] The mixing chambers are each formed by the interior space enclosed by flow-influencing elements, in particular the prism shells, which is delimited on one side by the front and / or rear of the central part and on the other side by the inner walls of the mixer sleeve. Thus, it is preferred according to the invention if the edge (upper edge) of the respective flow-influencing element, in particular of the prism shell, opposite the front and / or rear of the central part bears against the respective inner wall of the mixer sleeve, in particular sealingly seals therewith. The mixing chambers formed in this way are connected to one another by the common passages on their side edges, which overlap or are connected to one another in pairs, and optionally by the passage openings located in the central part.The volume of the individual mixing chamber is preferably in the range from greater than or equal to 1 mm 3< to less than or equal to 50 mm 3< , preferably greater than or equal to 10 mm 3< to less than or equal to 30 mm 3< , particularly preferably around 20 mm 3< .

[0046] The mixing chambers formed according to the invention are sealed in such a way that the corresponding component flows must necessarily pass through the mixing chambers along their flow direction and cannot flow past either laterally or in front of or behind the respective mixing chamber.

[0047] The mixer sleeve of the static mixer according to the invention is preferably substantially cylindrical, preferably with a rectangular, in particular a square, cross-section. The maximum diameter or at least one side length of the cross-section of the cylindrical mixer sleeve can be in the range from greater than or equal to 1 mm to less than or equal to 15 mm, preferably greater than or equal to 5 mm to less than or equal to 10 mm, particularly preferably around 7.5 mm, in particular with + / - 1.5 mm. The mixer sleeve preferably comprises at least two cylinder sections, in particular a first cylinder section receiving the mixing element according to the invention with a rectangular, in particular square, cross-section and a second cylinder section containing the at least one outlet opening with a circular cross-section.The interior spaces defined by the inner walls, in particular the two opposing inner walls, of the first cylinder section and the flow-influencing elements, as well as the front and / or rear side of the mixing element, form the respective mixing chambers. At its end opposite the outlet opening, the mixer sleeve has a receiving area, in particular a circular cylindrical one, for connection to the mixer cover that closes the mixer sleeve.

[0048] Preferably, the mixer sleeve and the mixer cover are precisely connected to one another, in particular, they are positively locked together. Preferably, the mixer sleeve and the mixer cover are also designed to be rotatable relative to one another. In particular, the mixer sleeve and the mixer cover are rotatable relative to one another despite the positive locking. According to the invention, it is particularly preferred if the mixer cover seals the mixer sleeve tightly, in particular if the mixer cover has a circumferential groove into which a sealing lip on the mixer sleeve can engage when the mixer cover is locked onto the mixer sleeve.

[0049] The mixer lid is preferably substantially cylindrical and has a diameter of greater than or equal to 1 mm to less than or equal to 30 mm, preferably greater than or equal to 5 mm to less than or equal to 25 mm, particularly preferably greater than or equal to 10 mm to less than or equal to 20 mm, in particular 18 mm, preferably + / - 1 mm, and a height of greater than or equal to 1 mm to less than or equal to 40 mm, preferably greater than or equal to 10 mm to less than or equal to 30 mm, particularly preferably greater than or equal to 15 mm to less than or equal to 25 mm, in particular 20 mm, preferably + / - 1 mm. In this sense, the mixer lid, viewed from the outside, has a circular disk-shaped base plate which has at least two inlet openings for introducing the components to be mixed, in particular for simultaneously introducing the catalyst paste and the base paste of a dental impression material.The inlet openings are preferably each surrounded on the outside by a cylindrical receptacle with a correspondingly larger inner diameter, which is provided for connecting one or more cartridges containing the components to be mixed. Thus, it is preferred if the inner diameter of the inlet openings is in the range from greater than or equal to 0.1 mm to less than or equal to 10 mm, preferably greater than or equal to 1 mm to less than or equal to 8 mm, particularly preferably greater than or equal to 2 mm to less than or equal to 5 mm, and the outer diameter of the receptacle surrounding the inlet openings is in the range from greater than or equal to 0.1 mm to less than or equal to 10 mm, preferably greater than or equal to 2 mm to less than or equal to 7 mm, particularly preferably greater than or equal to 3 mm to less than or equal to 6 mm.

[0050] In particular, the mixer cover can also be designed as an integral component of the mixing element or as a component connected to the mixing element, preferably in the form of a base part, so that the mixer sleeve is directly sealed when the mixing element is inserted.

[0051] The mixer sleeve and / or the mixer cover are preferably made of an injection-moldable plastic such as polyethylene, polypropylene and / or polystyrene or, in the case of the production of tougher mixtures, of higher-quality plastics, in particular of polyamide, polyoxymethylene and / or other impact-resistant polymers or polymer blends.

[0052] The height of the static mixer, in particular of the mixer sleeve, preferably including the mixer lid, i.e. measured from the at least two inlet openings located in the mixer lid to the at least one outlet opening of the mixer sleeve, is preferably greater than or equal to 20 mm to less than or equal to 150 mm, preferably greater than or equal to 60 mm to less than or equal to 90 mm, particularly preferably greater than or equal to 70 mm to less than or equal to 80 mm. This small extension of the static mixer in the longitudinal direction avoids, on the one hand, unnecessary shearing of the components to be mixed and, on the other hand, also a restriction of the field of vision when applying a corresponding impression material in the oral cavity of a patient.

[0053] In a preferred embodiment of the static mixer according to the invention, at least one mixing chamber formed on the front side of the central part, in particular of the mixing element, is connected to at least one mixing chamber formed on the rear side of the central part, in particular of the mixing element, in particular through at least one passage opening located in the central part. Preferably, all mixing chambers formed on the front side of the central part are each connected to at least one, in particular to at least two, mixing chamber(s) formed on the rear side of the mixing element and / or all mixing chambers formed on the rear side of the central part are each connected to at least one, in particular to at least two, mixing chamber(s) formed on the front side of the mixing element.In this way, at least a part of the component flow located on the front or back of the middle part, in particular of the mixing element, can reach the other side of the middle part and mix with the component flow currently present there.

[0054] Finally, a further subject matter of the present invention is the use of a mixing element according to the invention and / or a static mixer according to the invention, in particular a dental static mixer, preferably comprising the mixing element according to the invention, for mixing at least two low- to high-viscosity components. The at least two low- to high-viscosity components are preferably at least two low- to high-viscosity dental materials, in particular 2-component (2K) dental materials, such as 2K plastics or 2K adhesives. 2K adhesives and 2K plastics are compositions that are mixed from two different components for curing prior to application. In particular, these are at least two pasty dental materials, such as a base paste and a catalyst paste of a 2-component (2K) impression material.

[0055] In a preferred embodiment of the use according to the invention, one low- to high-viscosity component, in particular one low- to high-viscosity dental material, preferably the catalyst paste (Kat), is introduced on the front side of the middle part and the other low- to high-viscosity component, in particular the low- to high-viscosity dental material, preferably the base paste (Base), is introduced on the back side of the middle part.

[0056] During the mixing process, one component (Cat) is first introduced through a first inlet opening into a first mixing chamber on the front side of the middle section, and the other component (Base) is first introduced through a second inlet opening into a first mixing chamber on the back side of the middle section. The two components are then mixed on their way towards the at least one outlet opening by the two component streams being split, swirled and then recombined several times. Starting from the first mixing chamber, the respective component stream is partly directed into the corresponding opposite first mixing chamber on the other side of the middle section and / or partly into a second mixing chamber downstream in the direction of flow on the same side of the middle section, so that the two component streams split longitudinally and transversely after they have been introduced.This process is repeated repeatedly in the subsequent mixing chambers on the front and / or back of the central section as the mixing process continues. In this way, with each subsequent mixing chamber flowing through, the two components become increasingly homogenized, so that they should be completely homogenized upon exiting through at least one discharge opening and thus during discharge, especially during application.

[0057] The invention is explained in more detail with reference to the figures, without limiting the invention to these embodiments. They show: Fig. 1a,1b: a static mixer according to the invention 0 with a mixing element according to the invention 1 and mixer sleeve 2 and mixer cover 3 Fig. 2: a section of the front 10A and the back 10B of the middle part 10a mixing element according to the invention 1 Fig. 3: a mixing element according to the invention 1 in a first embodiment Fig. 4a,4b: a schematic representation of a mixing element 1 according to the invention Fig. 5: a mixing element according to the invention 1 in a second embodiment with a middle section segments 10-1, 10-2 composite middle part

[0058] The Figuren 1a and 1b show a static mixer according to the invention 0 comprising an elongated mixer sleeve 2 and one the mixer sleeve 2 tightly closing mixer lid 3 and a mixing element according to the invention 1.

[0059] Figur 1a shows the individual components of the static mixer 0 separated from each other in the external view. The mixing element shown here 1 includes a middle section 10with flow influencing elements arranged thereon, which is perpendicular to a first side part 11 as well as to the first page section 11 spaced second side part 12 aligned and connected to them. Furthermore, the mixing element comprises 1 a substantially perpendicular to the central part 10 and to the first page 11 and second side part 12 aligned base part 13. The mixing element 1 can be inserted into a lower opening of the mixer sleeve 2 and completely absorbed by it. The mixer sleeve 2 has a cylindrical outlet opening at its upper end 21 which are used to apply the material fed through the inlet openings 31 and 32 the mixer cover 3 to be introduced and after passing through the mixing element 1homogenized low to high viscosity components. The inlet openings are on the outside 31 and 32 each surrounded by a cylindrical holder for attaching the cartridge(s) containing the respective components.

[0060] Figur 1b shows a cross section through the Figur 1a shown static mixer 0, in which the mixing element is in the direction defined by the mixer cover 3 closed mixer sleeve 2 In this arrangement, the first and second side parts as well as the upper edges of the flow influencing elements of the mixing element are located on two opposite inner walls of the mixer sleeve 2 The inner walls of the mixer sleeve form 2 as well as the flow control elements on the front 10A and on the back 10B of the middle part 10at least two front mixing chambers each 201A , 202A and at least two rear mixing chambers 201B , 202B The front mixing chambers 201A , 202A and the rear mixing chambers 201B , 202B are connected to each other and to each other. Thus, during the mixing process, a 31 on the front 10A of the middle part 10 introduced component (cat) and one through the inlet opening 32 on the back 10B of the middle part 10 introduced component (base) on its way towards the outlet opening 21 divided, swirled and brought together again several times and thus optimally homogenized.

[0061] In Figur 2 is a section of a mixing element according to the invention with a view of the front 10A (top) and the back10B (below) of the middle part 10 The section shows two on the front 10A or on the back 10B arranged flow influencing elements 101A, 102A or 101B , 102B. The flow influencing elements 101A, 102A, 101B, 102B have the shape of substantially vertical on the front 10A or the back 10B standing prism shells based on an orthogonal quadrilateral, in particular a rhombus. Accordingly, each prism shell and thus also each flow influencing element 101A, 102A, 101B, 102B four side edges, which in the case shown here are perpendicular to the front 10A or the back 10B stand: a first side edge lying on top 1011A , 1021A or 1011B , 1021B, a second side edge on the right 1012A , 1022A or 1012B , 1022B,a third side edge at the bottom 1013A, 1023A or 1013B , 1023B and a fourth side edge on the left 1014A , 1024A or 1014B , 1024B. The opposite first and third side edges are 1011A - 1013A , 1021A - 1023A or 1011B - 1013B , 1021B - 1023B and thus in particular the side edges that overlap or are connected to each other in pairs 1011A / 1023A or 1011B / 1023B the flow influencing elements 101A, 102A or 101B, 102B on the longitudinal center axis LM of the middle section 10 arranged.

[0062] Figur 3 shows a first embodiment of a mixing element according to the invention 1 for a static mixer 0. The mixing element comprises a flat, along a longitudinal axis L extending middle section 10with a front 10A and one of the front 10A opposite back 10B. Both on the front 10A as well as on the back 10B There are several flow influencing elements in the form of vertically mounted on the front 10A or the back 10B standing prism shells composed of rectangular side surfaces arranged on the basis of a rhombus, each of which has two in the middle part 10 located triangular passages. The flow influencing elements 101A, 102A or 101B, 102B on the front 10A and on the back 10B of the middle part 10 are in pairs on each side edge 1011A / 1023A or 1011B / 1023B connected to each other. The front 10A of the middle part 10 flow control elements 101A, 102A and the one on the back 10Bof the middle part 10 flow control elements in the direction of the longitudinal axis L are arranged offset from each other by half a flow influencing element. In the course of this, one of the flow influencing elements 101A, 102A, 101B, 102B enclosed passage openings 101.1 , 102.1 in the area, especially at the narrow point, of the paired side edges 1011A / 1023A the flow influencing elements 101A, 102A on the front 10A of the middle part 10 and the other of the flow influencing elements 101A, 102A, 101B, 102B enclosed passage openings 101.2 , 102.2 in the area, especially at the narrow point, of the paired side edges 1011B / 1023B the flow influencing elements 101B, 102B on the back 10B of the middle part 10 arranged.

[0063] The Figuren 4a and4b show schematic representations of an embodiment of a mixing element according to the invention 1.

[0064] Figur 4a shows the scheme of a first embodiment of a mixing element according to the invention 1 with a planar middle section 10, where the left side shows a front view and the right side a sectional view. In this embodiment, the 10A of the middle part 10 flow control elements 101A, 102A and the one on the back 10B of the middle part 10 flow control elements 101B, 102B (shown as dashed lines) are offset from each other by half a flow control element. This means that the side edges overlapping or connected in pairs 1011A / 1023A the flow influencing elements 101A, 102A on the front 10A of the middle part 10 at the height of the respective center point of the diamond-shaped flow influencing elements 101B, 102B on the back 10B of the middle part 10 and the side edges overlapping or connected in pairs 1011B / 1023B the flow influencing elements 101B, 102B on the back 10B of the middle part 10 at the height of the respective center point of the diamond-shaped flow influencing elements 101A, 102A on the front 10A of the middle part 10 are arranged. The passage openings 101.1 , 102.1 or 101.2 , 102.2 are thus located in relation to the flow path of the components to be mixed at the end of a flow influencing element 101A, 102A or 101B, 102B on the front 10A and the back 10Bformed mixing chamber, which allows a more efficient division of the component flows due to the back pressure created at the transitions of the mixing chambers. In addition, a (partial forward flow of the component flows is also possible), since both the front-side flow influencing elements 101A, 102A as well as the rear flow influencing elements 101B, 102B with each other at their pairwise overlapping or interconnected side edges 1011A / 1023A or 1011B / 1023B through a common passage 101A.1 or 101B.1 are connected.

[0065] Figur 4b shows the scheme of a second embodiment of a mixing element according to the invention 1 with a middle section composed of several middle section segments inclined backwards at an angle α and forwards at an angle β 10,where on the left side a front view is shown and on the right side a sectional view. In this embodiment, on the front side 10-1A, 10-2A one middle section segment each 10-1 , 10-2 one flow influencing element each 101A, 102A and on the back 10-1B, 10-2B one middle section segment each 10-1, 10-2 one flow influencing element each 101B, 102B This means that the flow influencing elements 101A, 102A on the front 10-1A, 10-2A the middle section segments 10-1, 10-2 at their pairwise overlapping or connected side edges 1011A / 1023A sharply meet, while the flow influencing elements 101B, 102B back 10-1B, 10-2B the middle section segments 10-1 , 10-2 at their pairwise overlapping or connected side edges 1011B / 1023B The common passage is 101A.1on the side edges that overlap or are connected to each other in pairs 1011A / 1023A the pointedly meeting flow influencing elements 101A, 102A twice as large as the common passage 101B.1 on the side edges that overlap or are connected to each other in pairs 1011B / 1023B the butt-fitting flow control elements 101B, 102B This increases the flow resistance of the respective component stream in the rear mixing chambers, which taper in relation to the depth, while at the same time an easier forward flow of the respective component stream can take place in the front mixing chambers, which expand in relation to the depth. The separation of the component streams into the respective opposite mixing chambers is achieved by the flow influencing elements. 101A, 102A or 101B, 102B enclosed passage openings 101.1 , 101.2 ,102.1 , 102.2 guaranteed.

[0066] Figur 5 shows the second embodiment of a mixing element according to the invention 1 for a static mixer 0 , in which the middle section is composed of several middle section segments that are alternately inclined backwards and forwards. As on the front sides 10-1A, 10-2A the middle section segments 10-1, 10-2 is also on the back 10-1B, 10-2B the middle section segments 10-1, 10-2 one flow influencing element each 101A, 102A or 101B, 102B in the form of a vertical on the front sides 10-1A , 10-2A or the backs 10-1B, 10-2B standing prism shell composed of trapezoidal side surfaces on the basis of a rhombus, which has two rectangular openings 101.1 , 101.2 , 102.1, 102.2 The flow influencing elements 101A, 102A or 101B, 102B overlap in pairs on one side edge each 1011A / 1023A or 1011B / 1023B, which creates a common passage 101A.1 or 101B.1 formed by a between the middle part segments 10-1, 10-2 on the front 10-1A, 10-2A or the back 10-1B, 10-2B arranged crossbar 101-1A or 101-1B is stabilized. Due to the special course of the middle section segments, every second mixing chamber formed by the flow influencing elements tapers at its transition to the subsequent mixing chamber not only in terms of its width but also in terms of its depth, whereby the flow resistance of a corresponding component flow increases in the axial direction in such a way that a partial flow of the component flow passes through the passage openings enclosed by the flow influencing elements into the opposite mixing chamber and mixes with the component flow located there. Bezugszeichen:

[0067] 0 Static mixer 1 Mixing element, especially for a static mixer 10 Middle part of the mixing element 1 10-1,10-2 Middle section segments of the middle section 10 101.1,101.2, 102.1,102.2 Passage openings in the middle section 10 10A Front of the middle section 10 10-1A,10-2A Front of the middle section segments 10-1,10-2 101A,102A Flow control elements on the front 10A of the middle part 10 or on the front 10-1A,10-2A the middle section segments 10-1,10-2 101A.1 common passage of the flow influencing elements 101A,102A 1011A,1021A first side edge of the flow influencing elements 101A, 102A 1012A,1022A second side edge of the flow influencing elements 101A, 102A 1013A,1023A third side edge of the flow influencing elements 101A, 102A 1014A,1024A fourth side edge of the flow influencing elements 101A, 102A 101-1A Crossbar on the front 10-1A, 10-2A the middle section segments 10-1,10-2 10B Back of the middle section 10 10-1B,10-2B Back of the middle section segments 10-1,10-2 101B,102B Flow control elements on the back 10B of the middle part 10 or on the back 10-1B,10-2B the middle section segments 10-1,10-2 101B.1 common passage of the flow influencing elements 101B,102B 1011B,1021B first side edge of the flow influencing elements 101B, 102B 1012B,1022B second side edge of the flow influencing elements 101B, 102B 1013B,1023B third side edge of the flow influencing elements 101B, 102B 1014B,1024B fourth side edge of the flow influencing elements 101B, 102B 101-1B Crossbar on the back 10-1B, 10-2B the middle section segments 10-1,10-2 11first side part of the mixing element 1 12 second side part of the mixing element 1 13 Bottom part of the mixing element 1 2 Mixer sleeve of the static mixer 0 21 Outlet opening in the mixer sleeve 2 201A,202A Mixing chambers formed by the inner walls of the mixer sleeve 2 and the front flow elements 101A,102A 201B,202B Mixing chambers formed by the inner walls of the mixer sleeve 2 and the front flow elements 101A,102A 3 Mixer cover that covers the mixer sleeve 2 closes 31,32 Inlet openings in the mixer cover 3 L Longitudinal axis LM Longitudinal central axis of the middle section 10 α Angle at which a midsection segment 101 or 102 backwards relative to the longitudinal axis L is inclined βAngle at which a midsection segment 101 or 102 forward relative to the longitudinal axis L is inclined

Claims

1. Mixing element (1) for a static mixer (0), in particular a dental static mixer, for mixing low-to high-viscosity components, comprising a flat middle part (10) extending along a longitudinal axis L and having a front side (10A) and a rear side (10B) opposite the front side (10A), characterized in that at least two flow influencing elements (101A, 102A, 101B, 102B) are arranged on the front side (10A) and / or on the rear side (10B) of the middle part (10), each of the flow influencing elements (101A, 102A, 101B, 102B) enclosing at least one passage opening (101.1, 101.2, 102.1, 102.2) located in the middle part (10), characterized in that the flow-influencing elements (101A, 102A, 101B, 102B) having the form of prism shells standing substantially perpendicularly on the front side (10A) and / or the rear side (10B), which overlap or are connected to one another in pairs at a respective side edge (1011A / 1023A, 1011B / 1023B).

2. Mixing element (1) according to claim 1, characterized in that the flow influencing elements (101A, 102A ,101B, 102B) each having a common passage (101A.1,101B.1) at their side edges (1011A / 1023A, 1011B / 1023B), which overlap or are connected to each other in pairs.

3. Mixing element (1) according to claim 1 or 2, characterized in that the side edges (1011A / 1023A, 1011B / 1023B) of the at least two flow influencing elements (101A, 102A, 101B, 102B), which overlap or are connected to each other in pairs, are arranged on the longitudinal center axis LM of the middle part (10).

4. Mixing element (1) according to any of claims 1 to 3, characterized in that the middele part (10) exhibiting at least two flow influencing elements (101A, 102A) arranged on the front side (10A) and at least two flow influencing elements (101B, 102B) arranged on the rear side (10B), which are at least partially offset from each other in the direction of the longitudinal axis L.

5. Mixing element (1) according to claim 4, characterized in that the at least two flow-influencing elements (101A, 102A) arranged on the front side (10A) and the at least two flow-influencing elements (101B, 102B) arranged on the rear side (10B) each include at least two through-openings (101.1, 101.2, 102.1, 102.2) located in the middle part (10), wherein the one through-opening (101.1, 102.1) is arranged in the region of the pairwise overlapping or interconnected side edges (1011A / 1023A) of the flow-influencing elements (101A, 102A) on the front side (10A) and the other passage opening (101.2, 102.2) is arranged in the region of the pairwise overlapping or interconnected side edges (1011B / 1023B) of the flow-influencing elements (101B, 102B) on the rear side (10B).

6. Mixing element (1) according to any of claims 1 to 3, characterized in that the middle part (10) is composed of at least two middle part segments (10-1, 10-2) which are alternately inclined at an angle α to the rear and at an angle β to the front with respect to the longitudinal axis L, wherein a flow influencing element (101A, 102A, 101B, 102B) is arranged on the front side (10-1A, 10-2A) and / or on the rear side (10-1B / 10-2B) of each middle part segment (10-1, 10-2).

7. Mixing element (1) according to claim 6, characterized in that the angle α is greater than or equal to 1° and less than or equal to 89°, preferably greater than or equal to 25° and less than or equal to 85°, particularly preferably greater than or equal to 50° and less than or equal to 80°, and / or the angle β is less than or equal to -1° and greater than or equal to -89°, preferably less than or equal to -25° and greater than or equal to -85°, particularly preferably less than or equal to -50° and greater than or equal to -80°, with respect to the longitudinal axis L.

8. Mixing element (1) according to claim 6 or 7, characterized in that the flow influencing elements (101A, 102A, 101B, 102B) on the front side (10-1A, 10-2A) and / or rear side (10-1B, 10-2B) of adjacent middle part segments (10-1, 10-2) alternately meeting each other obtusely or acutely at their side edges (1011A / 1023A, 1011B / 1023B) overlapping or connected to each other in pairs, wherein the common passage (101A.1) at the pairwise overlapping or interconnected side edges (1011A / 1023A) of two flow influencing elements (101A, 102A) meeting each other acutely is larger than the common passage (101B.1) at the pairwise overlapping or interconnected side edges (1011B / 1023B) of two flow influencing elements (101B, 102B) meeting each other obtusely.

9. Mixing element (1) according to any of claims 6 to 8, characterized in that on the front side (10-1A, 10-2A) and / or on the rear side (10-1B, 10-2B) between two middle part segments (10-1, 10-2) in each case there is arranged a crossbar (101-1A and 101-1B, respectively) oriented substantially perpendicular to the longitudinal axis L.

10. Mixing element (1) according to any of claims 1 to 9, characterized in that the mixing element (1) further comprises a first side part (11) and a second side part (12) arranged at a distance from the first side part (11), and the middle part (10) is connected to the first side part (11) and the second side part (12) in such a way that the front side (10A) and the rear side (10B) are aligned substantially perpendicular to the first side part (11) and / or the second side part (12).

11. Mixing element (1) according to any of claims 1 to 10, characterized in that the mixing element (1) further comprises a bottom part (13) with at least one inlet opening, in particular with at least two inlet openings, which is oriented substantially perpendicular to the middle part (10) and / or to the first side part (11) as well as to the second side part (12).

12. Mixing elemment (1) according to any of claims 1 to 11, characterized in that the prism shells are formed on the basis of an orthodiagonal quadrilateral,13. Static mixer (0), in particular dental static mixer, for mixing low- to high-viscosity components, comprising a mixing element (1) according to any of claims 1 to 12, characterized in that the static mixer (0) further comprising an elongated mixer sleeve (2) with at least one outlet opening (21) and a mixer lid (3) closing the mixer sleeve (2) and having at least two inlet openings (31, 32) for introducing the components to be mixed, characterized in that the mixer sleeve (2) is provided for receiving the mixing element (1), and the inner walls of the mixer sleeve (2) and the at least two flow-influencing elements (101A, 102A, 101B, 102B) on the front side (10A) and / or the rear side (10B) of the middle part (10) forming at least two interconnected mixing chambers (201A, 202A, 201B, 202B).

14. Static mixer (0) according to claim 13, characterized in that at least one mixing chamber (201A, 202A) formed on the front side (10A) of the middle part (10), respectively, is further connected to at least one mixing chamber (201B, 202B) formed on the rear side (10B) of the middle part (10), respectively.

15. Use of a mixing element (1) according to any of the claims 1 to 12 or a static mixer (0) according to claim 13 or 14 for mixing at least two low- to high-viscosity components, in particular at least two low- to high-viscosity dental materials.