Device and method for producing nanocellulose

Description

[0001] The invention relates to a device and a method for producing nanofibers, in particular nanocellulose, from a mixture of substances containing fibers, in particular pulp or cellulose.

[0002] To date, a number of devices and processes have been developed for the production of nanofibers from natural raw materials, particularly from cellulose or wood pulp for the production of nanocellulose. In the specialist literature, a distinction is made between microfibers and / or nanofibers, using numerous different terms, such as microfibrillated cellulose (MFC) or nanofibrillated fibers or nanofibrillated cellulose (NFC). Such materials are increasingly being used in many technical fields, for example, as reinforcement materials or as barrier layers for paper, cardboard, and the like.

[0003] Fibers, especially cellulose, are processed by splitting the cell walls and exposing the nanofibers, especially nanocellulose. Accordingly, comminution occurs primarily in the longitudinal direction of the fibers and less by shortening the fibers in the transverse direction.

[0004] Microfluidizers, among others, are known in the state of the art for the production of nanocellulose. In a microfluidizer, such as the one in EP3088605A1, a first fiber-containing fluid stream is crossed with a second fiber-containing fluid stream to cause the cellulose to break down into nanocellulose. The fibers are thus guided under high pressure through a microchannel with a fixed internal geometry, where shear forces and impact effects disrupt the cell walls of the fibers.

[0005] Another method for producing nanocellulose can be implemented in the form of a homogenizer, as disclosed, for example, in JP 2013-104142 A1. In this method, a fiber-containing mixture is forced through a valve seat by a high-pressure pump, then radially pressed through a homogenization gap only a few micrometers wide and then onto a radially arranged impact ring. The effect of such a high-pressure homogenizer is based on the shearing of the fibers caused by the change in fluid velocity, the impact stress on the impact ring, and cavitation.

[0006] It is also possible to produce nanocellulose using a refiner or grinding machine, as disclosed, for example, in WO2013072558A1. In refiners, two corresponding grinding plates are typically brought together, leaving a grinding gap, and a fiber-containing mixture is pressed into the center of the grinding plates. The counter-rotating movement of the fully wetted grinding plates enables the comminution of fibers into nanofibers.

[0007] Previously known processes and / or devices require high energy consumption and are prone to process interruptions due to blockages at narrow points, such as valve seats, channels, nozzles, etc. Furthermore, known devices are not suitable for processing large quantities of a fiber-containing mixture for the production of nanofibers, especially nanocellulose, with low energy consumption.

[0008] In the following explanation, examples from the paper and pulp industry will be used to explain the principle of comminuting fibers into nanofibers. However, the device according to the invention and the associated method can be applied not only to plant fibers, but also analogously to other fiber-containing mixtures of animal origin, such as fibers from sea squirts, or synthetic origin.

[0009] The object of the present invention was to overcome the disadvantages of the prior art and to provide a device and a method by means of which a user is able to carry out a simple, energy-efficient, and inexpensive comminution of fibers of a material mixture, in particular cellulose, to produce nanofibers, in particular nanocellulose. A further object of the invention is to increase process reliability, minimize or even completely avoid blockages, and be able to process large quantities of material mixtures containing fibers, in particular cellulose. Furthermore, the invention is based on the object of increasing the homogeneity of the processed material mixture and / or ensuring continuous production.

[0010] This object is achieved by a device and a method according to the appended claims.

[0011] According to the invention, the fibers to be shredded, in particular cellulose or pulp, are provided in the form of a mixture with a liquid component, in particular water. The mixture can comprise a distribution of fibers with different diameters and / or lengths. Previously shredded fibers can also be included in the mixture. The fibers to be shredded can, in particular, comprise a large number of microfibrils, which typically have a diameter of 10 to 100 nm and a length of 0.5 to 10 µm.

[0012] For the purposes of the present invention, nanofibers are essentially elongated components of fibers or microfibrils that have a thickness direction or diameter in the range of approximately 5 to 30 nm and a significantly larger longitudinal extent. This ratio of longitudinal extent to nanofiber thickness can be expressed as an "aspect ratio" and is typically greater than 50.

[0013] The device according to the invention for producing nanofibers, in particular nanocellulose, of a mixture of substances containing fibers, comprises the features of claim 1.

[0014] The method according to the invention uses such a device and comprises the following process steps: Provision of the device according to the invention; provision of the substance mixture, which comprises at least one liquid component, preferably water, and fibers, preferably cellulose; moving the movable processing body relative to the at least one outlet element at a predeterminable relative speed; forcing the substance mixture containing fibers through the at least one outlet element at a predeterminable process pressure; processing the substance mixture by forming a gap-shaped processing zone for comminuting fibers between the outlet element and a partial surface of the movable processing body exposed to the substance mixture by positioning the outlet element relative to the movable processing body.

[0015] The relative movement of the processing body relative to the outlet element and thus also the outlet opening creates a shear field, at least in the gap-shaped processing zone. The predeterminable process pressure generates a change in the velocity of the fluid or mixture of substances in the processing zone and allows a continuous flow of the mixture of substances, whose fibers are shredded in the shear field, tearing open the cell walls. Long and / or insufficiently shredded or processed fibers and / or other interfering material can be removed from the processing zone by the relative movement of the processing body, preventing clogging of the device. This allows a relatively large quantity of mixture of substances to be processed, and the homogeneity of the processed mixture can also be increased.

[0016] Furthermore, the device according to the invention can be manufactured and operated relatively simply and cost-effectively, as it eliminates complex components. Any wear parts are relatively easy to access and inexpensive to replace, which can significantly increase operating times.

[0017] In known arrangements, such as a refiner, a comparatively high idle power is required for the movement of counter-bodies that are completely immersed in the substance mixture and movable relative to one another. The present invention differs from the prior art in particular in that only a comparatively small partial area of ​​the processing body is exposed to the substance mixture, whereby particularly high energy efficiency can be achieved. The processed substance mixture is greatly accelerated upon exiting the processing zone and can be easily collected in a housing that surrounds at least parts of the processing body and / or the outlet element. Thus, part of the processing body is not in direct contact with the substance mixture.The machining body can therefore be moved with little resistance, which means that the total power consumption can be significantly reduced by the amount of the idle power saved.

[0018] The device and method according to the invention are thus excellently suited for processing mixtures containing synthetic and / or organic fibers. The proportion of fibers in the mixture can be selected from approximately 0.1 to approximately 25 vol.%, preferably from 1 to 8 vol.%, depending on the task at hand.

[0019] By the material mixture being discharged from the outlet element onto a partial surface of the oppositely arranged processing body, a "passive" movement of the movable processing body in one direction of movement can be initiated.

[0020] Furthermore, it may be expedient if the movable processing body is designed to be drivable in a direction of movement substantially laterally, preferably normally, to an outlet element axis of the outlet element by means of a drive device.

[0021] This corresponds to an "active" and thus controllable movement of the movable machining body in the direction of movement. The exit element axis essentially corresponds to an imaginary longitudinal axis through the exit element in the center of the exit opening. The movement occurs essentially lateral, preferably perpendicular, to the exit element axis of the exit element and can be initiated and controlled by the drive device. In this way, the relative speed and thus the magnitude of the shear forces in the machining zone can be adjusted relatively easily.

[0022] In principle, it is also conceivable that the direction of movement of the processing body is essentially opposite to a flow direction of the substance mixture which strikes the material-exposed partial surface of the processing body at a predetermined angle.

[0023] Furthermore, it can be provided that the movable processing body is rotationally symmetrical, for example as a disc, cylinder, cone, drum or band-shaped, such as a chain or belt.

[0024] The geometry of the processing body can be selected by a specialist taking into account the available space, feed rates, drive power, and the like. In certain cases, belt-shaped processing bodies, which are also only partially exposed to the mixture, can therefore be advantageous. Rotationally symmetrical processing bodies also allow for a relatively simple, task-oriented design and can also be very dimensionally stable without requiring excessive energy expenditure for movement, since only a portion of the surface exposed to the mixture is sprayed with the mixture at a time.

[0025] A particularly advantageous embodiment is also one in which the movable processing body is designed as a disc that can be rotated laterally, preferably normally, to the outlet element.

[0026] When designed as a disc or plate, the advantages of low cost, long service life and low maintenance requirements can be particularly well utilized.

[0027] Furthermore, it can be provided that the at least one feed device is designed to be movable parallel to a rotation axis of the disc in order to adjust a predeterminable radial distance of the outlet element axis from the rotation axis.

[0028] This design allows for a standalone or additional option for controlling the relative speed in the machining zone, which can be adjusted relatively easily due to the different peripheral speeds depending on the radial distance from the rotation axis. This measure can be used in addition to or instead of a speed control of the drive device, which offers an effective method for adjusting the shear forces, especially with "passively" driven machining bodies.

[0029] According to a further development, it is possible for the outlet element to have a functional surface that extends at least partially around the circumference of the outlet opening to form a hydrodynamic bearing in the machining zone. The outlet element is preferably formed as a single piece with the functional surface, but can also be composed of several parts and, for example, be designed in the form of a replaceable end section of the outlet element.

[0030] The use of an outlet element designed in this way allows the formation of a hydrodynamic bearing, whereby the outlet element can be spaced apart from the material-exposed surface at a predefined working distance without contact. The shape and / or size of the material-exposed surface essentially corresponds to the functional surface. This allows for a simple increase in the pressures required to generate the shear forces required to shred the fibers, such as the process pressure of the material mixture and / or the contact pressure of the outlet element, without the outlet element rubbing against the processing body. Rubbing of the outlet element or the functional surface can be avoided, among other things, by forming a fluid wedge in the processing zone.

[0031] Furthermore, it may be expedient if the functional surface has a greater longitudinal extension in the direction of movement than in a transverse direction and / or opposite to the direction of movement.

[0032] By optimizing the shape of the functional surface, a homogenization of the fluid discharge can be achieved along the circumference of the functional surface. This can also improve the stability of the hydrodynamic bearing and the homogeneity and / or quality of the processed fluid mixture.

[0033] Furthermore, it can be provided that the functional surface is designed to be essentially complementary in shape to the partial surface of the movable processing body exposed to the substance mixture.

[0034] Particularly in the case of curved inner or outer surfaces of the processing body, such as a cylinder or cone, this measure can increase the homogeneity of the substance mixture exiting the processing zone, which is formed into an uneven partial surface exposed to the substance. This can significantly contribute to homogenizing the local exit velocities and / or shear forces on the fibers to be processed in the processing zone across the functional surface, thus contributing to improved quality.

[0035] Furthermore, it can be provided that the at least one outlet element is designed to be alignable in a predeterminable solid angle of the outlet element axis relative to the surface of the movable processing body.

[0036] The advantage of this design lies in the adjustability and stabilization of the hydrodynamic bearing. Furthermore, an angular adjustment of the outlet element, especially with "passively" moving bodies, can be used to adjust the relative speed and / or shear forces in the processing zone. This option is relatively simple and cost-effective to implement and allows for an increase in the quality of the processed material mixture.

[0037] According to a particular embodiment, it is possible for the at least one feed device to be designed to be alignable for setting a working distance and / or a solid angle between the at least one outlet element and the partial surface of the movable processing body exposed to the substance mixture.

[0038] This can be done independently or in combination with other measures, such as angular positioning or adjusting the process pressure of the substance mixture.

[0039] It may be particularly advantageous to regulate the relative speed of the moving processing body to adjust the shear forces generated in the gap-shaped processing zone. It may also be advantageous to regulate the working distance between the at least one outlet element and the corresponding partial surface exposed to the substance mixture by means of at least the feed device to adjust the compressive forces on the moving processing body.

[0040] Thus, for example, the contact pressure of the outlet element can be specifically adjusted and thus the exit speed of the processed material mixture can be influenced, whereby the level of the shear forces in the gap-shaped processing zone can be specifically adjusted.

[0041] According to an advantageous further development, it can be provided that a solid angle of the outlet element axis of at least one outlet element is regulated by means of at least one feed device, preferably for forming a necessary liquid wedge of the hydrodynamic bearing.

[0042] This allows the level of shear forces in the machining zone to be precisely adjusted. Furthermore, this measure can be used to compensate for worn exit elements and / or functional surfaces. This allows for improved homogeneity and / or quality of the machined material mixture over the service life or lifetime of the wear parts.

[0043] In particular, it may be advantageous if an end section of at least one outlet element is mounted so as to be at least partially movable relative to the opposite partial surface exposed to the substance.

[0044] The end section of the outlet element can include a functional surface, which stabilizes the hydrodynamic bearing. The end section can be designed to be essentially freely movable, as a kind of floating support for the outlet element, or it can be pre-adjustable, which allows for compensation for wear on the outlet element and / or a functional surface. Furthermore, blockages caused by long and / or insufficiently processed fibers can be avoided.

[0045] It can also be provided that at least two outlet elements are arranged symmetrically in the circumferential direction and / or radial direction relative to the movable processing body.

[0046] By arranging multiple outlet elements, each forming a processing zone with a common processing body, the throughput of the material mixture can be significantly increased. This is particularly advantageous because one or more outlet elements can be relatively easily switched on / off as needed during operation, and even maintenance work on individual outlet elements is possible. Furthermore, this measure can be used to reduce or even completely compensate for any bending moments exerted on the processing body by the process pressure and / or contact pressures. This allows for a more stable and low-maintenance device.

[0047] Furthermore, it can be provided that at least one second outlet element is arranged substantially opposite a first outlet element, wherein the first outlet element is assigned to a first surface of the movable processing body and the corresponding second outlet element is assigned to a second surface opposite the first surface.

[0048] By creating multiple outlet elements, each of which forms a processing zone with a processing body, the throughput of the material mixture can be significantly increased. By arranging two corresponding outlet elements opposite one another, a reduction in bending moments can be achieved, even to the point of complete compensation of the bending moments, for example, on the drive axis of the processing body or even the processing body itself. This measure can be advantageous for both belt-shaped processing bodies and rotationally symmetrical processing bodies, such as a cylinder or a disk, provided that the partial surfaces of the corresponding outlet elements exposed to the material agent are essentially opposite one another at the first and second surfaces.

[0049] Furthermore, it can be provided that at least two outlet elements are arranged along the direction of movement and / or perpendicular to the direction of movement of the processing body.

[0050] It is also conceivable for the outlet elements to be staggered in at least one direction, i.e. offset from one another. The arrangement of multiple outlet elements allows for higher productivity using only a single common processing body. This advantage, analogous to the design of the above-mentioned outlet elements arranged opposite one another on first and second surfaces, can be seen primarily in the fact that the power consumption for driving the movable processing body increases only slightly or is even negligible. This allows a large quantity of material mixture to be processed simultaneously in a very energy-efficient and cost-effective manner. It is therefore easily conceivable that multiple outlet elements could be arranged along a cylinder or even a cone.In principle, the outlet elements can also be arranged opposite one another on the first surface, for example, an outer surface of the cylinder, which can compensate for the bending moments on the drive axis of the machining body. It is also conceivable to arrange the outlet elements in the circumferential direction of a disk, which has the same effect on the disk.

[0051] Also advantageous is an embodiment according to which it can be provided that at least the movable processing body is arranged in a sealed manner by the drive device by means of at least one contacting and / or contactless sealing element, preferably a maintenance-free labyrinth seal, from a housing.

[0052] The relatively simple design of the device according to the invention eliminates the need for complex sealing solutions. Although the mixture of substances is processed under process pressure, the mixture is generally only exposed to atmospheric conditions after it exits. A housing is advantageous for collecting the processed mixture of substances, which shields at least the surfaces exposed to the substance, preferably the entire processing body, from the environment. Simple contact rubber seals, for example, or self-sealing, maintenance-free labyrinth seals, as are known to those skilled in the art, can be used to seal the housing openings, such as the outlet elements or a drive shaft. This enables particularly long maintenance intervals and low manufacturing costs.

[0053] It has proven advantageous to have a collecting container attached to the housing for collecting and / or further processing the processed mixture. In certain cases, a substantially complete sealing of the housing may be advantageous for placing the processing chamber under negative or positive pressure or even for creating a protective gas atmosphere within it, which allows the quality of the processed mixture to be specifically influenced.

[0054] According to a further development, it is possible that a chemical and / or enzymatic and / or mechanical pretreatment of the substance mixture is carried out before the substance mixture is made available, preferably during a grinding process in a refiner.

[0055] Chemical and / or enzymatic pretreatment can be used to specifically influence the separation of fiber components, thereby facilitating comminution into nanofibers, particularly nanocellulose. Such pretreatment can be performed in an external device or in a dedicated section of the supply system. Mechanical pretreatment to adjust a predeterminable fiber length or distribution of fiber lengths and / or diameters is also conceivable. This can be carried out, for example, by refiners and the associated processes known to those skilled in the art. Thus, suitable pretreatment can be used to increase the quality of the processed material mixture.

[0056] Furthermore, it may be expedient if at least the process steps of pressing and processing are repeated with at least parts of the processed mixture of substances.

[0057] By repeatedly processing the fiber-containing material mixture, the quality and homogeneity of the processed material mixture can be increased. It is conceivable to refeed at least part or all of the processed material mixture from one pass through the device. A circulation system between the collecting container and the supply device can be easily used to achieve a predeterminable fiber diameter and / or length distribution. In certain cases, it can be advantageous to adjust the liquid component of the processed material mixture intended for refeeding, for example by adding water. This allows a particularly fine breakdown of the fiber components into nanofibers, in particular nanocellulose, to be achieved with relatively low energy and / or pressure expenditure.

[0058] For a better understanding of the invention, it is explained in more detail using the following figures.

[0059] They show in a highly simplified, schematic representation: Fig. 1: Schematic cross-sectional view through an outlet element and a processing body to explain the functional principle; Fig. 2: Schematic cross-sectional view through an outlet element with a functional surface and a processing body to explain the functional principle; Fig. 3: Schematic cross-sectional view of possible embodiments of the device with two outlet elements which are distributed in the circumferential direction on a first surface (a) and arranged opposite one another on a first and second surface (b); Fig. 4: Schematic cross-sectional view of processing bodies as a cylinder (a), cone (b) or band (c) with multiple outlet elements; Fig. 5: Schematic view of outlet elements in cross section with a tilt around a solid angle (a), with a movable end section (b), with a shape-complementary functional surface (c), or in a bottom view (d); Fig.6Schematic overview of a possible arrangement of a device for producing nanofibers. .

[0060] By way of introduction, it should be noted that in the variously described embodiments, identical parts are provided with identical reference symbols or component designations. The disclosures contained throughout the description can be applied analogously to identical parts with identical reference symbols or component designations. Furthermore, the positional information chosen in the description, such as top, bottom, side, etc., refers to the directly described and illustrated figure, and these positional information must be applied analogously to the new position in the event of a change in position.

[0061] In Fig. 1A device 1 for producing nanofibers 5, in particular nanocellulose 6, from a material mixture 2 containing fibers 3, in particular cellulose 4, is schematically shown. The cross-sectional view illustrates the functional principle for comminuting the fiber-containing material mixture 2. According to the invention, a movable processing body 7 is arranged opposite the at least one outlet element 11. A gap-shaped processing zone 16 is formed between the outlet element 11 and a partial surface 10 of the movable processing body 7 exposed to the material mixture.

[0062] As in Fig. 1Schematically shown, the substance mixture 2 comprises a liquid component and fibers 3, which may in particular consist of pulp 4 or cellulose. The substance mixture 2 is pressed through the outlet element 11 with a predeterminable process pressure 15. The movable processing body 7 can, for example, be set into a relative movement passively by the exit of the processed substance mixture 2 from the processing zone 16 in a movement direction 23. Likewise, the processing body 7 can be set into a relative movement actively by, for example, Fig. 6 shown, drive device 20 in the direction of movement 23. When the substance mixture 2 containing fibers 3 passes through the outlet element 11, the shear forces occurring in the gap-shaped processing zone 16 are used to comminute the fibers 3, in particular the cellulose 4, into nanofibers 5, in particular nanocellulose 6.

[0063] The exemplary embodiment in Fig. 1represents a processing body 7 designed as a disk 22. In this case, the processing body 7 is mounted rotatably or movably about a rotation axis 24. The outlet element 11 has an outlet element axis 21, which essentially corresponds to an imaginary longitudinal axis through the outlet element 11 in the center of the outlet opening 12. As can be seen from Fig. 1 in conjunction with Fig. 2 As can be seen particularly clearly, the relative speed 27 in the machining zone 16 can be adjusted by the radial distance 25 between the exit element axis 21 and the rotation axis 24.

[0064] From the overview of Fig. 1 with Fig. 2 to Fig. 6 It can be seen that the movable processing body 7 is guided past the outlet element 11 in a direction of movement 23. This relative movement preferably occurs substantially laterally, particularly preferably perpendicular to an outlet element axis 21.

[0065] In Fig. 2A further and possibly independent embodiment of the device according to the invention is shown. In this embodiment, the outlet element 11 has a functional surface 13 that at least partially surrounds the outlet opening 12. As shown, the functional surface 13 can be formed integrally with the outlet element 11. However, it is also conceivable for the functional surface 13 to be connected to the outlet element 11 as part of an end section 14 or as a separate component in order to ensure easy replaceability. When the substance mixture 2 passes through or is pressed through the outlet element 11, a hydrodynamic bearing 29 can be formed in the processing zone 16. In this case, the processing zone 16 comprises the functional surface 13 and the corresponding opposite partial surface 10 exposed to the substance medium.By forming a fluid wedge in the hydrodynamic bearing 29, contact of the outlet element 11 and / or the functional surface 13 with the machining body 7 can be avoided.

[0066] Furthermore, Fig. 2 It can be seen that the outlet element 11 has a working distance 17 to the partial surface 10 exposed to the mixture. Such a working distance 17 can also be used for the Fig. 1 schematically shown device can be adjusted.

[0067] The design of a feed device 18 for positioning the outlet element 11 is shown by way of example in the Fig. 3 , 4 and Fig. 6 presented and analogously to the Fig. 1, 2 and 5 As can be seen in particular from the Fig. 3a and bAs can be seen, the feed device 18 can be used to move the at least one outlet element 11 in the direction of the processing body 7 and / or transversely thereto. Such a feed device 18 can be used in particular to adjust the working distance 17.

[0068] In the Fig. 3a and b as well as Fig. 4a to c Devices 1 are shown schematically in which two or more outlet elements 11 are arranged relative to a processing body 7. Fig. 3a represents two exit elements 11, which are symmetrically spaced from a first surface 8 of the processing body 7 from the rotation axis 24. In Fig. 3bA situation is schematically shown, wherein two outlet elements are arranged substantially opposite and symmetrical to each other on a first surface 8 and a second surface 9 of the processing body 7, respectively. By designing the processing body 7 as a disk 22, Fig. 3a and b illustrated embodiments, compensation for any bending moments on the disc 22 and thus the rotation axis 24 can be compensated.

[0069] The supply of the at least one outlet element 11 can be achieved via a separate supply device 19 or via a common supply device 19 for providing the substance mixture 2 containing fibers 3. For the sake of simplicity, an illustration of such supply devices 19 in the Fig. 1, 2 , 4 and 5 waived.

[0070] The movable processing body 7 can be designed according to the invention as a rotationally symmetrical body, such as a cylinder or a drum or a cone or a disc 22, as in the Fig. 4a, 4b and 3. Alternatively, it is possible to design the movable processing body 7 in the shape of a belt, such as a chain or belt, as can be seen from Fig. 4c schematically shown. In particular, Fig. 3 and 4 It can be seen that several outlet elements 11 can be assigned to a jointly used processing body 7. The movable processing body 7 can be connected to a drive device 20, as can be seen from Fig. 3 , 4 and 6 Such a drive device 20 can be designed, for example, as a hydraulic or pneumatic motor, and particularly preferably as an electric motor, and can have a speed control.

[0071] The Fig. 3 , 4 and6 The schematically illustrated feed device 18 can be designed to be alignable or positionable for setting a working distance 17 and / or a solid angle 26 between the at least one outlet element 11 and the partial surface 10 of the movable processing body that is acted upon by the substance mixture. It is also conceivable that several outlet elements 11 can be positioned jointly relative to the processing body by means of a common feed device 18. Furthermore, Fig. 3 and 4 It can be seen that at least two outlet elements 11 can be arranged in the circumferential direction and / or radial direction relative to the movable processing body 7. The outlet elements 11 can be arranged symmetrically and / or offset from one another on a first surface 8 and / or second surface 9.

[0072] Not shown is a special embodiment on cylinders, cones, belts or chains, in which at least one second outlet element 11 is arranged substantially opposite a first outlet element 11, wherein the first outlet element 11 is arranged on a first surface 8 of the movable processing body 7 and the corresponding second outlet element 11 is arranged on a second surface 9 opposite the first surface 8. This situation is for a processing body 7 designed as a disk 22 from Fig. 3b and can be extrapolated by the person skilled in the art to other rotationally symmetrical and / or band-shaped processing bodies 7.

[0073] In Fig. 5a to d several outlet elements 11 are shown in various possible embodiments.

[0074] Fig. 5aillustrates an outlet element 11 whose outlet element axis 21 is arranged at a preferably predeterminable solid angle 26 relative to a normal partial surface 10 of the processing body 7 that is exposed to the substance mixture. Such positioning of the outlet element 11 can be achieved by means of a feed device 18, as previously explained. The design of a hydrodynamic bearing 29 can also be clearly seen from this schematic representation.

[0075] In Fig. 5b Another example of an outlet element 11 is shown schematically, in which an end section 14 of the outlet element 11 is mounted at least partially movable relative to the opposite, medium-exposed partial surface 10. In this way, a type of floating mounting of the end section 14 can be achieved during the formation of the hydrodynamic bearing 29, without causing jamming or clogging of the end section 14.

[0076] Fig. 5c shows a schematic sectional view through an outlet element 11, a functional surface 13 surrounding the outlet element opening, and a curved processing body 7. The functional surface 13 is essentially designed to complement the shape of the partial surface 10 of the processing body 7 exposed to the substance mixture. Concave and convex shapes of the functional surface 13 are particularly conceivable, as shown particularly well in Fig. 5c visible.

[0077] In Fig. 5dA further possible embodiment of an outlet element 11 and a functional surface 13 is schematically indicated in a bottom view. The functional surface 13 is designed with a greater longitudinal extent in the direction of movement 23 than in a transverse direction thereto and / or opposite to the intended direction of movement 23. The movement arrows shown schematically indicate the homogeneous exit of the processed substance mixture 2. When using a functional surface 13 shaped in this way, its shape can be optimized by a person skilled in the art for the respective application and geometry of the processing body 7. As explained above, the processing zone 16 should be formed essentially between the functional surface 13 and the corresponding partial surface 10 exposed to the substance.

[0078] The Fig. 5a to d The outlet elements 11 shown and their combination can be incorporated into the description of the Fig. 2 , 3 , 4and 6 be included and, for the sake of brevity, will not be discussed separately, but reference will be made to the relevant discussions.

[0079] In Fig. 6 A schematic overview of the device 1 according to the invention is shown. Only one outlet element 11 is aligned relative to the movable processing body 7. The positioning of the outlet element 11 is carried out by means of a feed device 18. The supply of the substance mixture 2 takes place via a supply device 19. The processing body 7, designed as a disk 22, is driven by a drive device 20 in a direction of movement 23. As can be seen from Fig. 6As can be seen, the device 1 has a housing 28, which is shown in the open state. The housing 28 serves to collect the material during processing and can be sealed by means of one or more sealing elements 30, at least with respect to the drive device 20. Such sealing elements 30 are also shown, for example, in Fig. 3 and can be designed to be contact-type or contactless. The processed substance mixture 2 can be collected in a collecting container 31. It is also conceivable that the supply device 19 is connected to the collecting container 31 in order to implement a circulation principle.

[0080] Within the scope of the present invention, the individual process steps can also be automated and preferably controlled via a central system control system (not shown). Furthermore, operation via a control panel or touchscreen for monitoring and controlling the system is also envisaged.

[0081] The setting of a predeterminable distribution of fiber lengths and / or fiber cross-sections and / or their distribution can thus be specified by the user and controlled by a system control system. Repeated passage of at least portions of the processed material mixture 2 can also be used to adjust the homogeneity and / or quality of the nanofibers 5 or nanocellulose 6.

[0082] The consistency of the material mixture 2 can influence the quality of the processed material mixture 2. With the present device 1 and the corresponding method, suspensions, i.e. material mixtures 2, with a fiber content of 0.1 to approximately 10 vol.%, preferably 1 to approximately 8 vol.%, can be processed safely and easily. Material densities of up to 25 vol.% and above are also conceivable. In this case, it may be necessary under certain circumstances for the skilled person to resort to suitable supply devices 19 capable of conveying material mixtures 2 with such high densities while applying a sufficiently high process pressure 15. High-pressure feed screw arrangements, for example, are particularly suitable for this purpose.

[0083] The embodiments show possible embodiments, whereby it should be noted at this point that the invention is not limited to the specifically illustrated embodiments thereof, but rather various combinations of the individual embodiments with each other are also possible and this possibility of variation lies within the skill of the person skilled in the art in this technical field due to the teaching of technical action by means of the objective invention.

[0084] The scope of protection is determined by the claims. However, the description and drawings must be used to interpret the claims. Individual features or combinations of features from the various embodiments shown and described may represent independent inventive solutions. The problem underlying these independent inventive solutions can be derived from the description.

[0085] All information on value ranges in this description is to be understood as including any and all sub-ranges thereof, e.g. the information 1 to 10 is to be understood as including all sub-ranges starting from the lower limit of 1 and the upper limit of 10, ie all sub-ranges begin with a lower limit of 1 or greater and end with an upper limit of 10 or less, e.g. 1 to 1.7, or 3.2 to 8.1, or 5.5 to 10.

[0086] For the sake of clarity, it should finally be pointed out that, in order to better understand the structure, some elements have been shown out of scale and / or enlarged and / or reduced in size. List of reference symbols 1 device 30 Sealing element 2 mixture of substances 31 Collection container 3 fiber 4 cellulose 5 Nanofiber 6 Nanocellulose 7 Machining body 8 first surface 9 second surface 10 Substance mixture exposed partial area 11 Exit element 12 Exit opening 13 Functional area 14 final section 15 Process pressure 16 Processing zone 17 Working distance 18 Delivery device 19 Supply facility 20 drive device 21 Exit element axis 22 disc 23 Direction of movement 24 axis of rotation 25 Radial distance 26 Solid angle 27 relative speed 28 Housing 29 hydrodynamic bearing

Claims

1. A device (1) for the production of nanofibres (5), especially of nanocellulose (6) from a fibre-containing (3, 4) substance mixture (2), including: - at least one discharge element (11) with a discharge opening (12), for the passage of a fibre-containing substance mixture (2); - at least one feeding device (19) for the supply of the fibre-containing substance mixture (2) at the discharge element (11) with a predeterminable process pressure (15); - at least one positioning device (18) for the positioning of the discharge element (11); wherein for the disintegrating of the fiber-containing substance mixture (2) a movable processing body (7) is arranged opposite relative to at least one discharge element (11), whereby on the passage of the fiber-containing (3) substance mixture (2) through the discharge element (11) a slit-like processing area (16) between the discharge element (11) and a substance mixture-exposed partial area (10) of the movable processing body (7) is formed.

2. The device (1) according to claim 1, characterized in that the movable processing body (7) is formed to be drivable, by means of a drive unit (20), in a direction of movement (23) primarily sideways, preferably normal, to a discharge element axis (21) of the discharge element (11) and / or, in that the movable processing body (7) is formed rotationally symmetrical, for example as a disk (22), cylinder, cone, or band-shaped, such as for example a chain or belt.

3. The device (1) according to one of the preceding claims, characterized in that the movable processing body (7) is formed as a disc (22) rotatable sideways, preferably normal, to the discharge element (11).

4. The device (1) according to claim 3, characterized in that the at least one positioning device (18) is formed movable parallel to a rotation axis (24) of the disc (22), for the setting of a predeterminable radial distance (25) of the discharge element axis (21) from the rotation axis (24).

5. The device (1) according to one of the preceding claims, characterized in that the discharge element (11) is formed with at least in part a functional surface (13) surrounding the discharge opening (12) for the formation of a hydrodynamic bearing (29) in the processing area (16).

6. The device (1) according to claim 5, characterized in that the functional surface (13) has a larger longitudinal extension in the direction of movement (23) than in a transverse direction and / or against the direction of movement (23), and / or, in that the functional surface (13) is formed essentially complementary in shape to the substance mixture-exposed partial surface (10) of the movable processing body (7).

7. The device (1) according to one of the preceding claims, characterized in that the at least one discharge element (11) is formed adjustable to a predeterminable solid angle (26) of the discharge element axis (21) relative to the surface area (8) of the movable processing body (7) and / or, in that the at least one positioning device (18) is formed adjustable for the setting of an operating distance (17) and / or a solid angle (26) between the at least one discharge element (11) and the substance mixture-exposed partial surface (10) of the movable processing body (7) and / or, in that an end section (14) of at least one discharge element (11) is mounted at least partially movable relative to the opposed substance mixture-exposed partial surface (10) and / or, in that at least two discharge elements (11) are arranged symmetrically in the circumferential direction and / or the radial direction relative to the movable processing body (7).

8. The device (1) according to claim 2, characterized in that at least one second discharge element (11) is arranged essentially opposite to a first discharge element (11), whereby the first discharge element (11) is allocated to a first surface area (8) of the movable processing body (7) and the corresponding, second discharge element (11) is allocated to the second surface area (9) opposing the first surface area (8) and / or, in that at least two discharge elements (11) are arranged along the direction of movement (23) and / or normal to the direction of movement (23) of the movable processing body (7) and / or, in that at least the movable processing body (7) is arranged sealed off from the drive unit (20) by a housing (28) by means of a contacting and / or contact-free sealing component (30), preferably a maintenance-free labyrinth seal.

9. A process for the production of nanofibers (5), especially of nanocellulose (6), from a fiber-containing (3), especially pulp (4), substance mixture (2), including the following process steps: - provision of a device (1), according to one of the claims 1 to 8; - provision of a substance mixture (2), which includes at least one liquid component, preferably water, and fibers (3), preferably pulp (4); - movement of the movable processing body (7) relative to at least one discharge element (11) at a predeterminable relative speed (27); - pressing of the fiber-containing (3) substance mixture (2) through the at least one discharge element (11) at a predeterminable process pressure (15); - processing of the substance mixture (2) through the formation of a slit-like processing area (16) for the disintegrating of fibers (3) between the discharge element (11) and a substance mixture-exposed partial surface (10) of the movable processing body (7) through the positioning of the discharge element (11) relative to the movable processing body (7).

10. The process according to claim 9, characterized in that the movable processing body (7) is moved, by means of a drive unit (20), in a direction of movement (23), primarily sideways, preferably normal, to a discharge element axis (21) of the discharge element (11) and / or, in that at least one discharge element (11) with a discharge opening (12) formed with an at least in part circumferential functional surface (13) is used for the formation of a hydrodynamic bearing (29) between the discharge element (11) and a substance mixture-exposed partial surface (10) and / or, in that the relative speed (27) of the moved processing body (7) for the setting of the shear forces formed in the slit-like processing area (16) is controlled and / or, in that an operating distance (17) between the at least one discharge element (11) and the corresponding substance mixture-exposed partial surface (10) for the setting of compressive forces on the moved processing body (7) is controlled by means of at least one positioning device (18).

11. The process according to one of claims 9 or 10, characterized in that a solid angle (26) of a discharge element axis (21) of at least one discharge element (11), preferably for the formation of the necessary fluid wedge of the hydrodynamic bearing (29) is controlled by means of at least one positioning device (18).

12. The process according to one of claims 9 to 11, characterized in that before the supply of the substance mixture (2), a chemical and / or enzymatic and / or mechanical pre-treatment of the substance mixture (2), preferably in the course of a grinding process in a refiner, is carried out.

13. The process according to one of claims 9 to 12, characterized in that at least the process steps of pressing through and processing are repeated with at least parts of the processed substance mixture (2).