Device for determining rheological properties of suspension made of material comprising fibres for producing container

Abstract

The invention relates to a device for determining the rheological properties of a suspension made of a material comprising fibres for manufacturing a container, comprising a tank for storing the suspension made of a material comprising fibres and a control unit wherein the tank comprises stirring means for stirring the suspension made of a material comprising fibres, and the control unit is designed to determine the rheological properties of the suspension made of the material comprising fibers on the basis of the interaction between the stirring device and the suspension made of the material comprising fibers.

Description

Technical Field

[0001] The invention relates to a device for determining rheological properties of a suspension of a material comprising fibers for producing a container according to independent claim 1 and to a corresponding method according to independent claim 8 . Background Art

[0002] Methods and apparatus for making containers from materials including fibers are well known in the art.

[0003] However, more precise information about the mixing process or suspension characterization of suspensions used for manufacturing containers from fiber-containing materials is not available in the prior art. However, in order to be able to manufacture containers of sufficiently high quality, it is very important to precisely characterize the suspensions made of fiber-containing materials provided for container manufacturing.

[0004] Therefore, in the prior art, a suspension made of a material comprising fibers is usually mixed in a stirring device for a certain predetermined time interval in order to evenly disperse the solid and liquid parts and reduce the particle size of the material comprising fibers. However, in the prior art, the physical properties and / or the exact composition of the suspension made of a material comprising fibers are not accurately characterized. Instead, the quality of the suspension is determined only empirically, for example by visual inspection by an operator.

[0005] However, this method has the disadvantage that it is not possible to determine exactly whether the suspension of the material comprising fibers is sufficiently dispersed, has the desired solid or liquid concentration and / or whether the solid portion has a certain degree of swelling. Therefore, the quality of the suspension of the material comprising fibers produced by the stirring device cannot be clearly determined. This in turn leads to the inability to ensure the production of containers of consistent quality and also to the production of containers of poor quality. Summary of the invention

[0006] Purpose

[0007] In view of the known prior art, the technical object to be achieved by the present invention is to provide a method and a device which allow the quality of a suspension of a material comprising fibers for producing a container to be determined in a precise manner.

[0008] Solution

[0009] This technical object is achieved by a device for determining the rheological properties of a suspension of a material comprising fibers for producing a container according to independent claim 1 and a method for determining the rheological properties of a suspension of a material comprising fibers for producing a container according to independent claim 8. Preferred developments are given in the dependent claims.

[0010] According to the present invention, the device for determining the rheological properties of a suspension made of fiber-containing material for manufacturing a container comprises a tank for storing the suspension made of fiber-containing material and a control unit, wherein the tank comprises a stirring device for stirring the suspension made of fiber-containing material, and the control unit is designed to determine the rheological properties of the suspension made of fiber-containing material based on the interaction between the stirring device and the suspension made of fiber-containing material.

[0011] “Rheological properties of a suspension of a material comprising fibers” are to be understood as the flow properties and / or deformation properties of a suspension of a material comprising fibers. Thus, the rheological properties may be, for example, viscosity with or without a yield point, dilatancy or structural viscosity. However, any other rheological property not explicitly mentioned here may also be considered. It may also be provided that more than one rheological property, in particular two, three or more rheological properties, are determined.

[0012] For example, the fiber-containing material may refer to a plant-based renewable and / or recyclable natural material, such as a cellulose-containing material, in which in particular natural fibers, such as plant fibers, paper fibers or wood fibers, may be used. The fibers may also be flakes or include flakes. The fibers may also have different sizes and / or shapes. For example, the suspension may also include fibers with a specific particle size distribution. The fiber-containing material may also include non-sustainable components, such as synthetic fibers or metal fibers. Preferably, the fiber-containing material is pulp or papier-mâché. However, it may also be any other fiber-containing material suitable for manufacturing a container.

[0013] In addition to the fibers, the suspension made of the material comprising the fibers may also include water and a binder. However, the suspension may also include other ingredients, such as additives or other filling materials. The additive may be, for example, a glue, a thixotropic agent, a hydrophobic agent or any other additive that solidifies the wall of the container made of the material comprising the fibers, has a positive effect on the labelability of the container and / or creates a liquid, light and / or gas barrier in the container and / or has a favorable effect on the processability of the material comprising the fibers, such as improving the coatability of the material comprising the fibers. The filling material may be, for example, starch, chalk, a biocide or any other filling material.

[0014] Preferably, the container can be a bottle used in the beverage industry, wherein this design type should not be understood as limiting. The suspension made of the material comprising fibers can also be suitable for making any other type of container. For example, the container can also be a can, a tube or a cup or any other type of container used in the beverage, pharmaceutical, health or food industry.

[0015] The stirring device for stirring the suspension made of the material including the fibers can be designed to evenly disperse the liquid and solid components of the suspension. The stirring device can also be designed to reduce the particle size of the solid components during stirring. In order to disperse and pulverize the solid components of the suspension, the stirring device can include a stirring tool.

[0016] "Interaction" is understood to be an interaction between the stirring device and the suspension made of the material comprising fibers, which interaction causes at least partial mixing of the suspension made of the material comprising fibers in the tank. For example, the interaction can be a force exerted by the stirring device on the surface of the suspension. For example, it can be a shear stress. It can also be an operating parameter of the stirring device, which is directly related to the shear stress. The interaction can also be the shear rate of the suspension caused by the stirring device. It can also be an operating parameter of the stirring device, which is directly related to the shear rate.

[0017] Since the rheological properties of a suspension made of a material comprising fibers are directly related to the processing state of the suspension made of the material comprising fibers, such as physical parameters, it is possible to determine in a simple and accurate manner whether the suspension has the desired processing state by determining the rheological properties. Thus, it is possible to determine, for example, whether the suspension is sufficiently dispersed and whether the swelling process of the solid components of the suspension and / or the crosslinking process of the additives have been completed, based on the rheological properties. With the help of the rheological properties, it is also possible to determine the concentration of the material comprising fibers and / or the concentration of the liquid phase of the suspension made of the material comprising fibers. Thus, based on the specific processing state, the suspension can be clearly characterized and its quality can also be evaluated, for example, with the help of a binary decision such as "yes" or "no", whether it is sufficient. Since the quality of the suspension is in turn related to the quality of the container made of the suspension, it is very important to accurately characterize the suspension.

[0018] In one embodiment, the rheological property may be the viscosity of the suspension made of the material comprising the fibers. During the dispersion or mixing of the suspension and during the swelling process of the solids contained in the suspension, the viscosity changes. If the suspension is well dispersed and the swelling process is complete, the viscosity assumes a constant value. Therefore, the viscosity represents a suitable parameter to clearly characterize the processing state of the suspension.

[0019] In one embodiment, the interaction can be the torque, power consumption or current consumption that must be consumed by the stirring device in order for the stirring device to reach a certain speed when stirring the suspension, and / or the speed of the stirring device that can be reached with a predetermined torque, a predetermined power consumption or a predetermined current consumption. These measured variables can be directly related to rheological properties such as viscosity and are therefore particularly suitable parameters for determining rheological properties.

[0020] In one embodiment, the control unit may be designed to determine the change in the rheological property within a certain time interval.By determining the change in the rheological property over time, information about the time course of the processing state of the suspension made of the material comprising fibers may be obtained.

[0021] In one embodiment, the control unit can be designed to determine an equilibrium value of the rheological property of the suspension made of the material including the fibers if the change in the rheological property within a certain time interval is below a first threshold value. If the liquid and solid components of the suspension are fully dispersed and the swelling process of the solid component is complete, the rheological property converges to a constant value over time or changes only slightly. Thus, by measuring the rheological property it can be precisely determined when the suspension is fully dispersed and when the swelling process is complete.

[0022] In one embodiment, if the equilibrium value deviates from the set value by at least a second threshold value, the solid content and / or liquid content of the suspension made of the material comprising the fibers can be changed. Even if the suspension is well dispersed and the swelling process is complete, the solid and / or liquid content may be set too low or too high. By comparing it with the set value, information about the composition of the suspension can be obtained and corrections can be made if necessary.

[0023] In one embodiment, the device may include a device for manufacturing containers, wherein the tank is connected to the device for manufacturing containers via a discharge line, and if the deviation of the equilibrium value from the set value is less than a second threshold value, the suspension made of a material including fibers can be supplied to the device for manufacturing containers. It can therefore be ensured that only a suspension made of a material including fibers is supplied to the device for manufacturing, the suspension having a desired processing state or sufficient quality, and that containers of stable quality are produced by the device.

[0024] In the method according to the invention for determining the rheological properties of a suspension of a material comprising fibers for producing a container, the suspension of the material comprising fibers is stored in a tank and stirred by means of a stirring device in the tank, wherein the rheological properties of the suspension of the material comprising fibers are determined by means of a control unit based on the interaction between the stirring device and the suspension of the material comprising fibers.

[0025] Since the rheological properties provide unambiguous information about the processing state of a suspension made of a material comprising fibers, measuring the rheological properties is a simple and precise way of characterizing a suspension with respect to a desired processing state or a desired quality.

[0026] In one embodiment, the rheological property may be the viscosity of the suspension made of the material comprising the fibers. Since the viscosity is related in particular to the dispersion and solid fraction of the suspension, the swelling degree of the solid fraction of the suspension and / or the particle size distribution, it is a parameter particularly suitable for determining the processing state of the suspension or its quality.

[0027] In one embodiment, the interaction may be the torque, power consumption or current consumption consumed by the stirring device in order to achieve a certain speed when stirring the suspension, and / or the speed of the stirring device that can be achieved with a predetermined torque, a predetermined power consumption or a predetermined current consumption. These measured variables can be directly related to rheological properties such as viscosity and are therefore particularly suitable parameters for determining rheological properties.

[0028] In one embodiment, it can be provided that the control unit determines the change in the rheological property within a certain time interval. By determining the change in the rheological property over time, information about the time course of the processing state of the suspension made of the material comprising fibers can be obtained.

[0029] In one embodiment, it can be arranged that the control unit determines an equilibrium value of the rheological property of the suspension made of the material comprising the fibers if the change in the rheological property within a certain time interval is below a first threshold value. If the suspension is sufficiently dispersed and / or the swelling process of the solid part of the suspension is complete, the rheological property converges to a constant value. Thus, by measuring the rheological property it can be precisely determined when the suspension is sufficiently dispersed and when the swelling process is complete.

[0030] In one embodiment, it can be provided that if the equilibrium value deviates from the set value by at least a second threshold value, the solid content and / or liquid content of the suspension made of the material comprising the fibers is changed. Even if the suspension is well dispersed and the swelling process is complete, the solid and / or liquid content may be set too low or too high. By comparing it with the set value, information about the composition of the suspension can be obtained and corrections can be made if necessary.

[0031] In one embodiment, it can be provided that, if the deviation of the equilibrium value from the set value is less than a second threshold value, the suspension made of the material comprising fibers is supplied from the tank to the device for manufacturing containers via the discharge line. It can thus be ensured that only the suspension made of the material comprising fibers is supplied to the device for manufacturing containers, which has the desired processing state or sufficient quality, and thus that containers of stable quality are produced by the device.

[0032] In one embodiment, it can be provided that the discharge line comprises a pump device for conveying the suspension of the material comprising fibers from the tank to the device for producing containers, and that the rheological properties of the suspension of the material comprising fibers are determined in the discharge line by means of the energy consumption of the pump device for quality control, and / or that the line comprises a sensor, and that the rheological properties of the suspension of the material comprising fibers are determined in the discharge line by means of the sensor for quality control. By quality control of the suspension of the material comprising fibers, an additional control mechanism can be implemented in order to ensure that the suspension has a sufficiently high quality when it is supplied to the device for producing containers. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A device for determining rheological properties of a suspension of a material comprising fibers for producing a container according to one embodiment is shown;

[0034] Figure 2 A device for determining rheological properties of a suspension of a material comprising fibers for producing a container is shown according to a further embodiment. DETAILED DESCRIPTION

[0035] Figure 1 An apparatus 100 for determining rheological properties of a suspension 102 of a material comprising fibers for producing a container is shown according to one embodiment.

[0036] According to the present invention, the device 100 comprises a tank 101 for storing a suspension 102 made of a material comprising fibers and a control unit 106. The tank 101 further comprises a stirring device 104 for stirring the suspension 102 made of a material comprising fibers. The tank 101 may comprise a tank body 103, in which the stirring device 104 may be embedded. According to the present invention, the control unit 106 is designed to determine the rheological properties of the suspension 102 made of a material comprising fibers based on the interaction between the stirring device 104 and the suspension 102 made of a material comprising fibers.

[0037] Optionally, the tank 101 may comprise a supply line 108 for a suspension 102 made of a material comprising fibers. Figure 1In the embodiment described, one optional supply line 108 is provided, but in an alternative embodiment, multiple optional supply lines 108, for example two, three or five supply lines, can be provided, via which different components of the suspension 102, such as liquid and solid components, can be separately supplied to the tank 101. This has the advantage that the solid or liquid part of the suspension can be flexibly arranged. Also optionally, a discharge line 109 can be provided, by means of which the suspension 102 made of the material including the fibers can be discharged from the tank 101. Figure 1 The arrangement of the supply line 108 and the discharge line 109 shown is to be understood as exemplary. The supply line and the discharge line can also be arranged at any other location of the tank 101. Furthermore, the tank 101 can include an optional external circulation line, by means of which the suspension made of material comprising fibers stored in the tank 101 can be additionally circulated. Optionally, the circulation line can determine a sensor for determining rheological properties of the suspension made of material comprising fibers.

[0038] The upwardly open design and shape of the tank 103 should also be understood as exemplary. The tank 103 can also adopt any other shape and, for example, can also be closed upward, thereby preventing possible contamination of the suspension 102 made of the material including fibers stored in the tank 101.

[0039] The term "rheological properties of the suspension 102 made of a material comprising fibers" is to be understood as meaning the flow properties and / or deformation properties of the suspension 102 made of a material comprising fibers. The rheological properties may be, for example, viscosity with or without a yield point, dilatancy or structural viscosity. However, any other rheological property not explicitly mentioned here may also be considered. It may also be provided that more than one rheological property, in particular two, three or more rheological properties, is determined.

[0040] For example, the fiber-containing material may refer to a plant-based renewable and / or recycled natural material, such as a cellulose-containing material, in which in particular natural fibers, such as plant fibers, paper fibers or wood fibers, may be present. The fiber may also be a sheet or include a sheet. The fiber-containing material may also include non-sustainable components, such as synthetic fibers or metal fibers. Preferably, the fiber-containing material is pulp or papier-mâché. However, it may also be any other fiber-containing material suitable for manufacturing a container.

[0041] In addition to the material comprising fibers, the suspension 102 made of the material comprising fibers may also include water and a binder. However, the suspension may also include other ingredients, such as additives. The additives may be, for example, glue, a thixotropic agent, a hydrophobic agent or any other additive that solidifies the wall of the container made of the material comprising fibers, has a positive effect on the labelability of the container, creates a liquid, light and / or gas barrier and / or improves the processability of the suspension made of the material comprising fibers, such as the coatability.

[0042] Container is preferably the bottle used in beverage industry.However, it can also be any other container, for example the can, tube or cup used in beverage, pharmacy, health care or food industry.

[0043] "Interaction" is understood to be an interaction between the stirring device 104 and the suspension 102, which interaction causes at least partial mixing of the suspension 102 made of the material including fibers in the tank 101. For example, the interaction can be a force applied by the stirring device on the surface of the suspension. For example, it can be a shear stress. It can also be an operating parameter of the stirring device, which is directly related to the shear stress. The interaction can also be the shear rate of the suspension caused by the stirring device. It can also be an operating parameter of the stirring device, which is directly related to the shear rate.

[0044] exist Figure 1 In the described embodiment, the stirring device 104 is designed as a disk stirrer, which can rotate around the axis 105. This particular type of design of the stirring device 104 can have a favorable effect on the dispersion process of the suspension 102 made of the material comprising fibers. In an alternative embodiment, the stirring device 104 can also be implemented as a pitch blade, propeller, anchor or spiral stirrer, for example. Any other type of design of the stirring device 104 that is suitable for dispersing the solid and liquid components of the suspension made of the material comprising fibers, which is not explicitly listed here, can also be provided. In one embodiment, it can also be provided that more than one stirring device 104 is provided in the tank 101.

[0045] The control unit 106 can be implemented as a computer or server system and can be connected to various components of the device 100 via a cable or wireless connection 107, which components can be controlled or adjusted and / or data can be read. The component can refer to, for example, the tank 101 or the stirring device 104. For example, the control unit 106 can be designed to read or control or adjust the operating parameters of the stirring device 104, such as torque, rotation speed, current consumption and / or power consumption and any other operating parameters of the stirring device 104 that are not explicitly listed here. In addition, the control unit 106 can be designed to adjust specific operating parameters of the stirring device 104 so that a specific rotation speed of the stirring device 104 can be achieved when stirring a suspension made of a material including fibers, and / or to adjust the rotation speed of the stirring device 104 so that a specific value of an operating parameter can be achieved.

[0046] According to the invention, the control unit 106 is designed to determine the rheological properties of the suspension 102 made of material comprising fibers based on the interaction between the stirring device 104 and the suspension 102 made of material comprising fibers.

[0047] The interaction can be, for example, the torque, power consumption or current consumption that the stirring device must consume in order to achieve a certain speed when stirring the suspension and / or the speed of the stirring device that can be achieved with a predetermined torque, predetermined power consumption or predetermined current consumption.

[0048] The control unit 106 may include a storage device. A database may be stored in the storage device, wherein the corresponding rheological properties may be assigned to at least one interaction between the stirring device 104 and the suspension 102 made of the material including the fibers in the database. For example, the corresponding viscosity value may be assigned to at least one specific torque required to reach a specific rotation speed of the stirring device 104. Correspondingly, the corresponding viscosity value may also be assigned to at least one current consumption and / or at least one power consumption required to reach a specific rotation speed of the stirring device 104. In the database, the specific processing state of the suspension may be assigned to at least one rheological property of the suspension made of the material including the fibers. The processing state may include, for example, solid concentration, dispersion, swelling degree of the suspension made of the material including the fibers, and / or the cross-linking degree of the optional additive. In the database, the specific quality value of the suspension may be assigned to at least one processing state of the suspension made of the material including the fibers. For example, the quality value may be binary classified as sufficient or insufficient. Therefore, the control unit may be designed to determine not only the rheological properties based on the interaction, but also the processing state or quality of the suspension. In order to be able to produce containers with stable quality using the suspension 102, the accurate characterization of the suspension and the determination of its quality are basic prerequisites.

[0049] In one embodiment, it can be arranged that the control unit 106 includes artificial intelligence and that the interaction between the suspension and the material comprising fibers (e.g., the torque that the stirring device 104 must consume in order for the stirring device 104 to reach a specific rotational speed) is fed to the artificial intelligence as a parameter. The artificial intelligence can be designed to determine the rheological properties based on the parameters. In one embodiment, it can be arranged that the artificial intelligence determines the processing state of the suspension based on the rheological properties, such as the dispersion of the suspension, the swelling degree of the solid part contained in the suspension, and / or the cross-linking degree of the additive optionally contained in the suspension. The artificial intelligence can also be designed to determine whether the processing state is consistent with the desired processing state and whether the suspension has the desired quality. The artificial intelligence can be trained with the aid of different interaction data sets measured at different suspensions made of materials comprising fibers and including different components and / or different processing states. In one embodiment, the artificial intelligence can be a neural network.

[0050] Alternatively, it can also be arranged that the control unit 106 comprises a deterministic algorithm, the interaction between the stirring device 104 and the suspension 102 made of the material comprising fibers can be provided as a parameter to the deterministic algorithm, and the deterministic algorithm can determine the rheological properties of the suspension 102 based on the provided parameters. The deterministic algorithm can also be designed to determine the processing state and / or quality of the suspension based on the rheological properties.

[0051] In one embodiment, the rheological property may be the viscosity of the suspension 102. Viscosity is a particularly suitable rheological variable in order to determine and check the processing state of a suspension made of a material comprising fibers, or in order to make statements about the quality of a suspension made of a material comprising fibers. This is because the viscosity of the suspension 102 changes during the dispersion or mixing of the suspension 102 and during the swelling process of the solids contained in the suspension 102 or during the crosslinking process of the additives optionally contained in the suspension. In contrast, if the suspension is sufficiently dispersed and the swelling or crosslinking process is complete, the viscosity converges to a constant value, so that it can be determined in a particularly accurate manner by measuring the viscosity whether the suspension 102 has the desired processing state or the desired quality.

[0052] In order to determine rheological parameters, such as viscosity, in one embodiment it can be provided that the torque, power consumption or current consumption that must be consumed by the stirring device 104 in order to achieve a specific rotational speed is determined by means of the control unit 106. Alternatively, it can also be provided that the control unit 106 determines the rotational speed of the stirring device that can be reached with a predetermined torque, a predetermined power consumption or a predetermined current consumption. To this end, the control unit 106 can, for example, access a database stored in a storage unit. In addition, the control unit 106 can use well-known physical relationships to determine the rheological properties, as will be briefly explained below using viscosity, torque and rotational speed as an example.

[0053] The following relationship applies to viscosity :

[0054]

[0055] in describes the shear stress, describes the shear rate, where the shear stress is proportional to the torque M consumed by the stirring device 104 , and the shear rate is proportional to the rotational speed n at which the stirring device 104 rotates to stir the suspension 102 .

[0056] If the control unit 106 now determines the torque that must be consumed by the stirring device 104 in order to reach a specific rotational speed, for example 60 revolutions per minute, 120 revolutions per minute, 240 revolutions per minute or 360 revolutions per minute, the control unit 106 can determine the viscosity of the suspension 102 made of the material comprising fibers with the help of the relationship provided above.

[0057] Alternatively, it may also be arranged that the control unit 106 sets a predetermined torque M of the stirring device 104 and determines the rotation speed n at which the stirring device 104 rotates, and the viscosity of the suspension 102 made of the material including fibers may be determined based on the relationship given above.

[0058] Since the viscosity of the suspension 102 made of the material comprising fibers is particularly related to the dispersion of the suspension 102, the solid part of the suspension 102, the swelling degree of the solid part of the suspension 102 and / or the degree of crosslinking of the additives optionally contained in the suspension, it is a parameter particularly suitable for determining the processing state of the suspension 102 or the quality of the suspension. In particular, when the dispersion, swelling and / or crosslinking process is not yet completely completed, the viscosity value changes over time, and when the dispersion, swelling and / or crosslinking process is completed, the viscosity value converges to a constant value. Thus, for example, it is known that when the swelling process of the material comprising fibers is completed, as the swelling of the material comprising fibers increases, the viscosity of the suspension made of the material comprising fibers increases and converges to a constant value. This relationship can also be observed for other rheological properties.

[0059] Therefore, the measurement of the time course of rheological properties, such as viscosity, is a particularly suitable method in order to monitor the processing state of the suspension 102 made of material including fibers or to determine when the suspension 102 has reached a desired processing state and / or a certain quality. By determining the time course of rheological parameters based on the interaction between the suspension 102 made of material including fibers and the stirring device 104 and using data stored in a database of the storage unit and / or well-known physical relationships, the control unit 106 can thus determine whether the desired processing state of the suspension 102 has been reached or whether further stirring of the suspension 102 is required to reach the desired processing state. Therefore, the processing time of the suspension made of material including fibers can also be optimized.

[0060] To this end, the control unit 106 may be designed to determine the equilibrium value of the rheological property of the suspension 102 made of the material including the fibers if the variation of the rheological property within a certain time interval is below a first threshold value. As already described above, when the dispersion, swelling and / or crosslinking process is completed, the rheological property converges to a constant value. If there is only a slight variation of the rheological property over time, for example a variation per minute, which variation may be less than 1% or 0.1% or 0.01% of the absolute value of the rheological property, it may be determined by the control unit 106 that the suspension has an equilibrium state and the dispersion, swelling and / or crosslinking process is completed.

[0061] However, in some cases, such a situation may also occur: although the suspension 102 is fully dispersed and the dispersion, swelling and / or cross-linking process is completed, the suspension does not have the desired solid and / or liquid concentration. For example, the solid portion of the suspension may be too high or too low. Taking this into account, the control unit 106 can be designed to compare the equilibrium value with the set value stored in the database, thereby determining whether the suspension 102 has the desired solid and / or liquid concentration. If the control unit 106 determines that the deviation of the equilibrium value from the set value is at least one second threshold value when comparing, the control unit 106 can determine that the solid or liquid concentration is inconsistent with the expected value, and change the solid content and / or liquid content of the suspension made of the material including the fiber.

[0062] If the control unit 106 determines that the deviation of the determined equilibrium value from the set value is smaller than a second threshold value, the control unit 106 may be designed to determine that the suspension 102 made of the material including fibers has reached a desired processing state.

[0063] For example, the suspension 102 can then be fed to another device for further processing. For this purpose, the suspension can be discharged from the device 100 via the discharge line 109. Optionally, a valve can be arranged at the outlet of the tank 101 connected to the discharge line 109. If the control unit 106 determines that the quality of the suspension 102 is sufficient as in the case just described, the control unit 106 can be designed to open the valve so that the suspension can be discharged from the tank 101 via the discharge line 109.

[0064] Now combine Figure 2 Describe this situation in more detail.

[0065] Figure 2 A device 200 for determining rheological properties of a suspension of a material comprising fibers for producing a container is shown according to a further embodiment.

[0066] In addition to combining Figure 1 In addition to the described device 100, the device 200 also comprises a device 203 for producing a container from a suspension 102 made of a material comprising fibers, wherein the suspension 102 can be supplied to the device 203 for producing a container via a discharge line 109. For this purpose, a pump device 205 for conveying the suspension 102 made of a material comprising fibers can be provided in the discharge line 109. Furthermore, a sensor 202 for determining the rheological properties of the suspension 102 made of a material comprising fibers in the discharge line 109 can be arranged in the discharge line 109.

[0067] Corresponding to the combination Figure 1 In the described embodiment, the control unit 106 can also communicate with the Figure 2 The controllable and / or readable components of the device 200 are shown connected. For example, the control unit 106 can be connected to the device 100, the pump device 205, the sensor 202 and / or the device for manufacturing the container 203.

[0068] In order to perform a quality control of the suspension 102 supplied by the device 100 to the discharge line 109, it can be provided that the control unit 106 is designed to determine the energy consumption of the pump device 205 for conveying the suspension 102 made of the material comprising fibers and to determine the rheological properties of the suspension 102 made of the material comprising fibers based on the energy consumption of the pump device 205. As already described above in connection with the stirring device 104, the rheological properties of the suspension are also dependent on the energy consumption of the pump device through which the suspension 102 is conveyed. Therefore, the control unit 106 can also determine the rheological properties of the suspension 102 made of the material comprising fibers based on the energy consumption and thus determine the processing state and / or the quality of the suspension 102 made of the material comprising fibers. Since the composition of the suspension 102 and / or its processing state in the discharge line 109 can no longer be changed, by determining the energy consumption by means of the pump device 205, the suspension 102 made of the material comprising fibers can preferably be quality controlled before it is supplied to the device 203 for producing containers.

[0069] Additionally or alternatively, the quality control of the suspension can be performed via a sensor 202 arranged in the discharge line 109. In one embodiment, the sensor 202 can be implemented as a Coriolis mass flow sensor. With the aid of the Coriolis mass flow sensor, for example, the viscosity and / or density of the suspension 102 can be determined, and based on this, the processing state of the suspension 102 can be determined by the control unit 106, and the suspension 102 provided by the device 100 can be quality controlled.

[0070] In one embodiment, it can be provided that the control unit 106 is designed to interrupt the supply of the suspension 102 made of a material comprising fibers from the device 100 to the device 203 for producing a container, if the control unit 106 determines, based on the energy consumption of the pump device 205 and / or the rheological properties determined by the sensor 202, that the processing state of the suspension 102 made of a material comprising fibers does not correspond to the desired processing state of the suspension 102 made of a material comprising fibers or its quality does not correspond to the desired quality. In this case, it can be provided that the suspension 102 made of a material comprising fibers is directed back into the device 100 by means of the pump device 205 and is further stirred and / or the liquid or solid portion of the suspension is changed until the desired processing state and / or the desired quality of the suspension 102 is reached.

[0071] Additionally or alternatively, it can also be provided that the discharge line 109 is connected to the tank 101 or the device 100 via a return line, and that the suspension made of the material comprising fibers or a part of the suspension made of the material comprising fibers can be led from the discharge line 109 back to the tank 101 via the return line. Furthermore, it can be provided that the suspension made of the material comprising fibers can be circulated through the discharge line 109 and the tank 101 via the return line. Such an arrangement can be made, for example, if the suspension made of the material comprising fibers is not to be supplied to the device 203 for manufacturing containers. In this case, the circulation of the suspension can ensure that the suspension made of the material comprising fibers remains homogeneous in the discharge line 109 and that the material comprising fibers does not settle in the discharge line 109. Optionally, the return line can include a sensor, which can be designed to determine a first processing state or a first quality of the suspension made of the material comprising fibers returned via the return line. Optionally, the control unit can be designed to compare a first processing state or a first mass of a returned suspension of material comprising fibers with a second processing state or a second mass of the suspension in the tank and to determine whether the first processing state or the first mass of the returned suspension is consistent with a specific processing state or a specific mass value.

[0072] If, however, the energy consumption of pump device 205 and / or sensor 202 determines that suspension 102 has a desired processing state or the quality of suspension 102 has a desired value, the suspension of material comprising fibers can be fed further to device 203 .

[0073] Even if errors occur when determining the quality of the suspension in the tank 101, the quality control in the discharge line 109 ensures that only a sufficiently high-quality suspension is supplied to the device 203 for producing containers and ensures the quality of the containers produced by means of the device 203 for producing containers.

[0074] In one embodiment, the device 203 for manufacturing a container may include a mold. The mold may in turn include a perforated cavity, which may represent a negative mold of the container to be manufactured. In order to manufacture the container, it may be configured to apply a suspension 102 supplied by the device 100 via a discharge line 109 to the mold. Due to the perforations of the mold and the overpressure present in the mold, the material comprising the fibers is deposited at the wall of the mold, and the liquid component of the suspension is again drawn out of the mold through the perforations. The device 203 may also include a component for curing the suspension made of the material comprising the fibers. In this case, the component may be, for example, a heat wave, an infrared wave or a microwave, by means of which electromagnetic radiation of a corresponding wavelength may be applied to the suspension deposited at the wall of the mold.

[0075] Optionally, downstream of the device 203 for manufacturing containers, a transport device 204 can be provided for transporting away containers made of material comprising fibers manufactured by the device 203. With the aid of the transport device 204, the manufactured containers can be conveyed, for example, to a downstream device for processing containers, such as a labeler, a filler, a capper or any other device suitable for processing containers. Alternatively, it can also be provided that the containers manufactured by the device 203 are supplied to a storage device with the aid of the transport device 204.

[0076] In one embodiment, it can be arranged that a plurality of devices 203 for manufacturing containers are connected to the apparatus 100 via corresponding discharge lines 109. For example, it can be arranged that 5, 10 or 50 devices 203 for manufacturing containers are connected to the apparatus 100. Therefore, the container throughput can be increased by the apparatus 200.

Claims

1. A device (100) for determining rheological properties of a suspension (102) of a material comprising fibers for manufacturing a container, the device comprising a tank (101) for storing the suspension (102) of the material comprising fibers and a control unit (106), wherein the tank (101) comprises a stirring device (104) for stirring the suspension (102) of the material comprising fibers, and the control unit (106) is designed to determine the rheological properties of the suspension (102) of the material comprising fibers based on the interaction between the stirring device (104) and the suspension (102) of the material comprising fibers.

2. The device according to claim 1, wherein the rheological property is the viscosity of the suspension (102) made of a material comprising fibers.

3. The device according to claim 1 or 2, wherein the interaction is a torque, power consumption or current consumption that must be consumed by the stirring device (104) in order for the stirring device (104) to reach a certain rotational speed when stirring the suspension, and / or a rotational speed that the stirring device (104) can reach with a predetermined torque, predetermined power consumption or predetermined current consumption.

4. The device according to one of claims 1 to 3, wherein the control unit (106) is designed to determine a change in the rheological property within a specific time interval.

5. The device according to claim 4, wherein the control unit (106) is designed to determine an equilibrium value of the rheological property of the suspension (102) made of material comprising fibers if the change of the rheological property within the specific time interval is below a first threshold value.

6. The device according to claim 5, wherein the solid content and / or the liquid content of the suspension (102) made of the material comprising fibers can be changed if the equilibrium value deviates from a set value by at least a second threshold value.

7. The device according to claim 5, comprising an apparatus (203) for manufacturing a container, wherein the tank (101) is connected to the apparatus for manufacturing the container via a discharge pipeline (109), and if the deviation of the equilibrium value from the set value is less than a second threshold value, the suspension (102) made of a material including fibers can be supplied to the apparatus (203) for manufacturing the container.

8. A method for determining the rheological properties of a suspension (102) of a material comprising fibers for producing a container, wherein the suspension (102) of a material comprising fibers is stored in a tank (101) and stirred by means of a stirring device (104) in the tank, wherein the rheological properties of the suspension (102) of a material comprising fibers are determined by means of a control unit (106) based on the interaction between the stirring device (104) and the suspension (102) of a material comprising fibers.

9. The method according to claim 8, wherein the rheological property is the viscosity of the suspension (102) made of a material comprising fibers.

10. The method according to claim 8 or 9, wherein the interaction is the torque, power consumption or current consumption consumed by the stirring device (104) in order to enable the stirring device (104) to reach a certain rotational speed when stirring the suspension, and / or the rotational speed that the stirring device (104) can reach with a predetermined torque, predetermined power consumption or predetermined current consumption.

11. Method according to one of claims 8 to 10, wherein the change of the rheological property within a specific time interval is determined by the control unit (106).

12. The method according to claim 11, wherein an equilibrium value of the rheological property of the suspension (102) made of material comprising fibers is determined by the control unit (106) if the change of the rheological property within the specific time interval is below a first threshold value.

13. The method according to claim 12, wherein if the equilibrium value deviates from a set value by at least a second threshold value, a solid content and / or a liquid content of the suspension (102) made of a material comprising fibers is changed.

14. The method according to claim 12, wherein the suspension (102) made of a material comprising fibers is supplied from the tank (101) to an apparatus (203) for manufacturing containers via a discharge line (109) if the deviation of the equilibrium value from a set value is less than a second threshold value.

15. The method according to claim 14, wherein the discharge line (109) comprises a pump device (205) for conveying the suspension (102) of the material comprising fibers from the tank (101) to the device (203) for producing the container, and the rheological properties of the suspension (102) of the material comprising fibers are determined in the discharge line (109) by means of the energy consumption of the pump device (205) for quality control, and / or wherein the discharge line (109) comprises a sensor (202), and the rheological properties of the suspension (102) of the material comprising fibers are determined in the discharge line (109) by means of the sensor (202) for quality control.

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