Mixing device with ventilation opening and flap, and mixing method

Abstract

The invention relates to a mixing device (1) and mixing method for mixing a rubber compound, comprising a mixing chamber (2), a feed chute (3), which is connected to the mixing chamber via an insertion opening, for charging the mixing chamber, a ventilation system (10) which is suitable for extracting mixing components remaining in the feed chute and which is connected to the feed chute via a ventilation opening (12), and a flap (11) suitable for temporarily completely closing and opening the ventilation opening.

Description

[0001] P2024, 1149 WO N December 9, 2025

[0002] 1

[0003] Description

[0004] Mixing device with ventilation opening and flap as well as mixing process

[0005] The present invention relates to a mixing device with a ventilation opening and a flap for closing the ventilation opening and a mixing method.

[0006] Such mixing devices typically have special venting openings that allow various substances, such as fine particles or gases, to escape from a mixing chamber. Depending on the design, these openings can be configured as, for example, multiple holes or a rectangular opening.

[0007] Their function is particularly crucial in specific mixing processes where volatile substances such as ethanol must escape, for example during the processing of silica rubber compounds. These openings thus fulfill an important role in the mixing process, but can also lead to undesirable material losses.

[0008] The suction created by the ventilation system plays a crucial role in this context. During the mixing process, this suction draws some of the fillers, such as soot, upwards. The particles settle, for example, on a piston in the feed chute or escape into the ventilation system. This material loss negatively impacts resource efficiency and recipe consistency. P2024, 1149 WO N 9 December 2025

[0009] 2

[0010] It is an object of the present invention to at least partially remedy the previously described deficiencies in the prior art.

[0011] The present invention relates to a mixing device for mixing a rubber mixture and a mixing method.

[0012] The scope of the invention is defined by the claims.

[0013] The mixing device comprises at least one mixing chamber and a feed chute for feeding the mixing chamber, in particular with mixing components.

[0014] Mixture components are components from which the rubber mixture is composed or which are at least contained in the rubber mixture.

[0015] The feed chute is connected to the mixing chamber via an inlet opening. Preferably, the feed chute is located at the top of the mixing chamber, so that the introduced mixing components are conveyed from the feed chute into the mixing chamber primarily by the action of gravity.

[0016] The mixing device also includes a ventilation system suitable for extracting mixture components remaining in the feed shaft.

[0017] In particular, fine particles, such as soot particles, or volatile gases remain in the feed chute after introduction or are carried back from the mixing chamber into the feed chute during operation of the mixing device. P2024, 1149 WO N 9 December 2025

[0018] All mixture components or other substances that arise during mixing, whether they enter the feed shaft from the mixing chamber or do not enter the mixing chamber at all and remain in the feed shaft, are hereby summarized as mixture components remaining in the feed shaft.

[0019] The ventilation system is connected to the feed shaft via a ventilation opening.

[0020] The ventilation system is a common system suitable for venting the relevant equipment.

[0021] For this purpose, the ventilation system can include suitable pipes, hoses, conveying devices such as blowers, fans and compressors, cleaning devices such as sieves and filters, as well as fittings and sensors for control, regulation and monitoring.

[0022] The ventilation system can be used to vent several devices, in particular several mixing devices, and optionally also to vent the area around the mixing devices simultaneously.

[0023] The ventilation system is connected to the mixing device via the ventilation opening. For example, the ventilation system is connected to the ventilation opening in the form of a suitable pipe.

[0024] The mixing device further includes a flap suitable for temporarily completely closing and opening the ventilation opening. P2024, 1149 WO N 9 December 2025

[0025] 4

[0026] In other words, during operation of the mixing device, the ventilation opening can be closed by closing the flap and reopened by opening the flap.

[0027] In particular, the ventilation opening can be completely closed by closing the flap, so that no further ventilation of the feed shaft takes place.

[0028] This means that the flap preferably seals the ventilation opening tightly.

[0029] Multiple ventilation openings and flaps may be provided. The ventilation openings may be part of the same or different ventilation systems.

[0030] Closing the flap is therefore equivalent to temporarily switching off the ventilation in the feed shaft (for the time the flap is closed).

[0031] The quick and easy opening and closing of the flap allows the ventilation of the feed shaft to be switched on and off very easily and quickly, and therefore with great precision and in a targeted manner.

[0032] Unwanted stirring up or suction of mixture components, such as soot, silica, chalk or small chemicals, by the ventilation system (so-called dust emission) can thus be advantageously prevented at any desired time.

[0033] However, if the extraction of substances that are unintentionally produced during mixing, e.g., (waste) gases, is desired, the venting process can be started at any time. P2024, 1149 WO N 9 December 2025

[0034] - 5 -

[0035] This effectively prevents unwanted material loss during the mixing process. This optimization offers both economic and ecological advantages: because less material is lost during mixing, the process becomes more efficient and less material is required as a mixing component.

[0036] This leads on the one hand to a reduction in material costs (economic advantages), and on the other hand to greater sustainability (ecological advantages).

[0037] A higher proportion of the materials used are processed, resulting in less waste.

[0038] Furthermore, the quality of the manufactured products can be advantageously increased.

[0039] Reducing material losses allows for more precise dosing of the mixture components and thus better reproducibility of the mixing results.

[0040] Furthermore, stopping the venting can lead to a more homogeneous distribution of the mixture components in the mixture, as the mixture components are incorporated more evenly, thus also contributing to a higher product quality.

[0041] Precise dosing and the incorporation of all mixture components into the rubber compound allow for more precise adjustment of the desired properties of the rubber compound, thus improving the quality and performance of the P2024, 1149 WO N 9 December 2025

[0042] 6

[0043] The rubber compound and the end products (rubber products) manufactured from it are advantageously increased.

[0044] For example, the mechanical strength, elasticity, or abrasion resistance of rubber products can be advantageously increased.

[0045] Because the flap reduces material loss and dust emissions, components of the mixing device, such as the ram for conveying materials from the feed chute into the mixing chamber and for closing the mixing chamber, as well as the ventilation system, remain comparatively clean. This reduces the maintenance requirements of the system and extends the service life of the system components.

[0046] Furthermore, the control of the flap can be easily automated.

[0047] Automated controls operate more precisely and consistently than manual interventions. This reduces the risk of errors that could arise from human error.

[0048] The automatic control of the valve ensures that a specific valve position can be set depending on the mixing process. For example, a defined valve position can be pre-programmed for a specific time or based on measured sensor data. This leads to a more stable and better-controlled addition of fillers, improved control of the mixing process, and thus enhanced process stability. P2024, 1149 WO N 9 December 2025

[0049] According to one design, the feed chute is located above the mixing chamber, as previously described.

[0050] According to a specific design, a feed opening for introducing the mixture components from the outside into the feed shaft is again formed at the top of the feed shaft.

[0051] The ventilation opening and the flap are then preferably arranged in an upper third of the feed shaft.

[0052] By arranging the ventilation openings at the top of the feed chute, it can be avoided that an unintentionally excessive proportion of swirled mixture components is drawn in or extracted.

[0053] The ventilation system is only intended to ensure that there is no excessively high concentration of stirred-up particles or gases generated during the mixing process in the feed shaft, or that they do not escape into the environment through the inlet opening.

[0054] According to one version, the mixing device also includes a drive for the automated opening and closing of the flap. Manual intervention is then no longer required.

[0055] The drive can be controlled manually or automatically. P2024, 1149 WO N December 9, 2025

[0056] 8

[0057] Automated control can be achieved, for example, via an MES (Manufacturing Execution System).

[0058] The closing and opening of the flap can be done particularly depending on sensor data.

[0059] For example, it can be provided that the flap opens when a certain temperature, e.g. 130 °C, is exceeded, allowing gas emissions such as methanol, ethanol, water vapor, etc., to escape from the rubber mixture.

[0060] For example, it may also be provided that the flap is opened when a certain particle or gas concentration in the feed shaft is exceeded.

[0061] Furthermore, the control of the valve can be time-dependent (process-wise). For example, the valve can be closed during the introduction of mixture components through the feed chute (feeding) and until the mixture components are completely incorporated into the rubber mixture.

[0062] The mixture components include, for example, raw rubber, soot, especially carbon black, silica and chalk compounds, as well as other chemical additives (small chemicals).

[0063] According to one embodiment, the mixing device further comprises a central control system for controlling the mixing process, wherein the central control system, as previously described, controls the automated opening and closing of the flap. In particular, the central control system may be the MES system. P2024, 1149 WO N 9 December 2025

[0064] According to one design, the flap comprises a metallic material that exhibits the highest possible chemical and physical resistance, e.g., corrosion resistance and chemically inert behavior, as well as the highest possible mechanical and thermal stability, i.e., insensitivity to virtually any type of stress.

[0065] In particular, it may be a metal alloy.

[0066] According to one design, the flap has a sealing strip suitable for sealing any possible gap between the ventilation opening and the flap when the flap is closed.

[0067] The sealing tape is preferably firmly attached to the flap and is made of, for example, a rubber or plastic material.

[0068] The sealing tape preferably surrounds the entire circumference of the flap.

[0069] The sealing tape is preferably arranged on one of the flat sides of the flap.

[0070] In particular, the flap preferably has essentially the shape of the ventilation opening, e.g. a rectangular shape or a rounded shape (elliptical shape, circular shape) with two opposite flat sides.

[0071] The sealing tape can be replaced independently of the flap, if necessary. P2024, 1149 WO N 9 December 2025

[0072] The sealing tape advantageously guarantees a tight seal of the ventilation opening through the flap.

[0073] The invention also relates to methods for mixing a rubber mixture in a mixing device.

[0074] All previously described features and forms of implementation may also apply in the following, and all subsequently introduced features and forms of implementation may also apply to the previously described mixing device.

[0075] A procedure includes at least the following steps, preferably, but not necessarily, in the order mentioned.

[0076] In one step the flap is closed or is already closed.

[0077] In one step, mixing components are added to the mixing chamber through the feed chute, while the flap is preferably closed.

[0078] In one step, one waits until the addition

[0079] The mixing components are incorporated into the rubber compound after being swirled. This incorporation is carried out by mixing tools in the mixing chamber.

[0080] In one step, the incorporated mixture components are (further) mixed in the mixing chamber.

[0081] Preferably, the flap is opened in one step during mixing and after incorporation. P2024, 1149 WO N 9 December 2025

[0082] The opening time can be predetermined or dependent on sensor data such as reaching a certain particle or gas concentration in the feed chute or reaching a certain temperature.

[0083] Another procedure includes at least the following steps:

[0084] - Closing of the flap or presence of a closed flap,

[0085] - Mixing the mixture components to create the rubber mixture in the mixing chamber,

[0086] - Heating the mixture components,

[0087] - Opening the flap as soon as gases diffuse out of the heated mixing chamber.

[0088] The heating of the mixture components can only be triggered and carried out by the (mechanical) mixing process.

[0089] The steps of the procedure can therefore take place simultaneously, between or after the steps of the previously defined procedure, whereby at least some steps of the procedures are the same.

[0090] Diffusion occurs, for example, after a fixed time, so the flap opens after this time. Alternatively, a specific gas concentration can be defined at which the flap opens. This gas concentration can be detected, for example, by a sensor in the feed chute.

[0091] The implementation forms include the steps of the individual procedures or both procedures previously introduced in the aforementioned P2024, 1149 WO N 9 December 2025.

[0092] 12

[0093] The sequence was carried out, in particular first the steps of the procedure introduced first and then the steps of the procedure introduced afterwards.

[0094] In practical applications, the aforementioned steps, and in particular the opening and closing of the flap, are repeated several times at suitable times as described.

[0095] According to one embodiment, the mixing device further includes a central control system, e.g., an MES system for controlling the mixing process, which has access to all available sensor data from the mixing device, whereby the central control system controls an automated opening and closing of the flap depending on external control commands or depending on the available sensor data, if the sensor data exceeds certain predetermined limits.

[0096] Corresponding limit values ​​can be, for example, certain maximum temperatures or certain (limit) concentrations as described above.

[0097] The features of the described implementation forms of the mixing device and the process are not mutually exclusive and can be combined with each other.

[0098] The invention is described in more detail below with reference to exemplary embodiments and accompanying figures. The invention is not limited to the exemplary embodiments shown in the figures.

[0099] Similar or seemingly identical elements in the figures are marked with the same reference symbol. The figures and P2024, 1149 WO N 9 December 2025

[0100] 13

[0101] The proportions in the figures are not necessarily to scale.

[0102] Figure 1 shows a schematic representation of a first embodiment of a mixing device according to the invention.

[0103] Figure 2 shows a detailed view of an embodiment of the mixing device with flap when the flap is open.

[0104] Figure 3 shows a detailed view of an embodiment of the mixing device with flap when the flap is closed.

[0105] Figure 4 shows an embodiment of the flap.

[0106] Figure 5 is a diagram showing the percentage reduction of soot quantities on a piston and in a filter of an embodiment of the mixing device.

[0107] Figures 6 and 7 show photographs of exemplary designs of the ventilation openings.

[0108] Figure 1 shows a first embodiment of the mixing device 1. The mixing device 1 comprises a mixing chamber 2 in which mixing components can be mixed by mixing tools.

[0109] Furthermore, the mixing device 1 comprises a feed chute 3, which is arranged above the mixing chamber 2 and through which the mixture components are fed into the P2024, 1149 WO N 9 December 2025

[0110] 14

[0111] Mixing chamber 2 is inserted. The feed shaft 3 is open at the top through a feed opening 4 for this purpose.

[0112] In the example, a plunger 5 also protrudes through the feed opening 4 into the feed shaft 3, with the help of which mixing components, such as rubber bales, can be pushed from the feed shaft 3 into the mixing chamber 2.

[0113] In addition to the feed opening 4, further openings for introducing mixture components into the feed shaft 3 are possible, for example, chutes for introducing powdered components.

[0114] Furthermore, a ventilation system 10 is provided, which is connected to the feed shaft 3. The ventilation system 10 vents the feed shaft 3 during operation, particularly when (waste) gases are formed.

[0115] In particular, it is planned that unwanted particulate dust or gases forming will be extracted from the feed shaft 3.

[0116] A flap 11 is provided at the connection between the ventilation system 10 and the feed shaft 3 for opening and closing a ventilation opening 12, which connects the feed shaft 3 to the ventilation system 10. The flap 11 can be opened and closed mechanically. The position of the flap 11 can preferably be adjusted and controlled automatically. P2024, 1149 WO N 9 December 2025

[0117] 15

[0118] Figures 2 and 3 show the ventilation opening 12 and the flap 11 in further detail using a further embodiment.

[0119] Figure 2 shows the flap 11 in an open state. In the exemplary embodiment, the flap 11 has, for example, a substantially rectangular shape with two flat sides 11a.

[0120] In the example, the ventilation opening 12 is also essentially a rectangular gap, but can also include one or more round or square holes, which can be covered by one or more flaps.

[0121] The flap 11 is attached to a wall of the loading shaft 3 via hinges 13.

[0122] An actuator 15 is used to adjust the flap 11. The actuator 15 has, for example, a hydraulic, pneumatic, or electromechanical (or otherwise suitable) drive. The actuator can be controlled, for example, manually or, preferably, automatically.

[0123] Triangularly shaped protective plates 14 are arranged next to the flap 11 in the example to limit the gap between the open flap 11 and the ventilation opening 12.

[0124] Figure 3 shows the closed state in which the flap 11 closes the ventilation opening 12, preferably airtight.

[0125] In this closed state, the venting of feed shaft 3 is therefore inactive. P2024, 1149 WO N 9 December 2025

[0126] To activate the ventilation, it is sufficient to reopen flap 11. The ventilation system 10 itself is preferably not switched on or off during this process. Preferably, a single ventilation system is provided for venting several mixing devices.

[0127] Figure 4 shows flap 11 itself in detail.

[0128] In the illustrated embodiment, a groove 16 is provided on the surface of the flap 11, preferably on a flat side 11a.

[0129] A sealing tape, for example a rectangular closed sealing tape, for example made of rubber or plastic, can be attached in the groove 16, for example glued or plugged in, so that the sealing tape closes any remaining gap between the rim of the ventilation opening 12 and the flap 11, preferably airtight.

[0130] The flap 11 itself preferably comprises or consists of a chemically inert metal alloy.

[0131] As shown in Figures 2 and 3, the venting of the mixing device 1 can be stopped (closing the flap) or restarted (opening the flap) at any time by means of flap 11.

[0132] This can be done automatically, in particular. P2024, 1149 WO N 9 December 2025

[0133] 17

[0134] Preferably, the control of the flap 11 is connected to a central control system of the mixing device 1, for example an MES system.

[0135] Depending on the stage of the mixing process, defined times or measured sensor data, flap 11 can be automatically closed or opened at any time, as required.

[0136] One possible scenario is that during the feeding process, i.e., the introduction and mixing of components via the feeding chute 3 into the mixing chamber 2, fine particles are stirred up. During this process, the flap is preferably closed so that the particles are not drawn in by the ventilation system.

[0137] This advantageously prevents an increased proportion of particles from settling in the feed shaft 3 and especially on the piston 5.

[0138] The proportion of particles drawn into the ventilation system 10, which then need to be separated out, for example, by a designated filter, can also be reduced. This protects the ventilation system 10 and means the filter within the ventilation system needs to be cleaned or replaced less frequently.

[0139] The diagram in Figure 5 illustrates, using an exemplary process execution, by what percentage the amount of soot decreases in an exemplary setup of the mixing device after carrying out an exemplary P2024, 1149 WO N 9 December 2025.

[0140] The mixing process is reduced by closing valve 11.

[0141] The diagram compares the amount of soot deposited with the valve closed and open for three different quantities of soot supplied. The decrease in the amount of soot deposited with the valve closed compared to with the valve open is given as a percentage.

[0142] One column in the diagram represents the soot removal in the filter of the ventilation system 10 (the left column, shown in lighter gray) and another column represents the soot removal on the piston 5 in the feed shaft 3 (the right column, shown in darker black).

[0143] As shown in the diagram, it was found that the amount of soot deposited on the piston after a mixing process advantageously decreases by approximately 17% to 18%, regardless of the amount of soot supplied (3 kg, 5 kg or 7 kg).

[0144] As further shown in the diagram, it was also found that the amount of soot deposited in the filter after a mixing process was reduced by 23% (5 kg) to 49% (3 kg).

[0145] Finally, Figures 6 and 7 show, for further explanation, black and white photographs of exemplary embodiments of the ventilation openings 12, which could be closed with flap 11 according to the invention. P2024, 1149 WO N 9 December 2025

[0146] 19

[0147] Figure 6 shows a slit-shaped ventilation opening 12 and Figure 7 shows a ventilation opening 12 in the form of two circular holes.

[0148] Both figures serve only as examples to illustrate different opening types.

[0149] The flaps according to the invention are not shown here. P2024, 1149 WO N 9 December 2025

[0150] 20

[0151] Reference symbol list

[0152] 1 Mixing device

[0153] 2 mixing chambers

[0154] 3 Feed shaft

[0155] 4 Loading opening

[0156] 5 stamps

[0157] 10 Ventilation system

[0158] 11.

[0159] 11a flat sides of the flap 12 ventilation opening

[0160] 13 hinges

[0161] 14 mudguards

[0162] 15 Actuator

[0163] 16 Nut

Claims

P2024, 1149 WO N December 9, 2025 21 Patent claims 1. Mixing device ( 1 ) for mixing a rubber mixture, comprising a mixing chamber (2 ) , a feed shaft (3) for feeding the mixing chamber, which is connected to the mixing chamber via an inlet opening, a ventilation system (10) which is suitable for extracting mixture components remaining in the feed shaft, and which is connected to the feed shaft via a ventilation opening (12), and a flap ( 11 ) , suitable for temporarily completely closing and opening the ventilation opening.

2. Mixing device according to claim 1, wherein the feed chute is arranged above the mixing chamber, wherein a feed opening (4) for introducing the mixture components from the outside into the feed chute is formed at the top of the feed chute. and wherein the ventilation opening and the flap are located in an upper third of the feed shaft.

3. Mixing device according to one of claims 1 or 2, wherein the mixing device further comprises a drive ( 15) for automated opening and closing of the flap .

4. Mixing device according to claim 3, wherein the mixing device further comprises a central control system for controlling the mixing process, the central control system controls the automated opening and closing of the flap.

5. Mixing device according to any one of claims 1 to 4, wherein the flap comprises a metallic material and preferably P2024, 1149 WO N 9 December 2025 It features a sealing strip suitable for sealing any possible gap between the ventilation opening and the flap when the flap is closed.

6. Method for mixing a rubber mixture in a mixing device (1) comprising a mixing chamber (2), a feed chute (3) for feeding the mixing chamber, a ventilation system (10) for extracting mixture components remaining in the feed chute, and which is connected to the feed chute via a ventilation opening (12), as well as a flap ( 11 ) , suitable for temporarily completely closing and opening the ventilation opening, The following steps should be carried out comprehensively, preferably in the order listed: - Closing the flap, - Addition of mixing components into the mixing chamber through the feed chute, - Wait until the added swirled mixture components are incorporated into the rubber mixture, - Mixing the mixture components, - Opening the flap.

7. Method for mixing a rubber mixture in a mixing device (1) comprising a mixing chamber (2), a feed chute (3) for feeding the mixing chamber, a ventilation system (10) for extracting mixture components remaining in the feed chute, and which is connected to the feed chute via a ventilation opening (12), and a flap ( 11 ) suitable for temporarily completely closing and opening the ventilation opening, P2024, 1149 WO N 9 December 2025 23 The following steps should be carried out comprehensively, preferably in the order listed: - Closing the flap, - Mixing the mixture components to create the rubber mixture in the mixing chamber, - Heating the mixture components, - Opening the flap as soon as gases diffuse out of the heated mixing chamber.

8. Method comprising the steps according to claims 6 and 7, preferably in the order mentioned.

9. Method according to any one of claims 6 to 8, wherein the aforementioned steps and in particular the opening and closing of the flap are repeated several times at suitable times.

10. Method according to any one of claims 6 to 9, wherein the mixing device further comprises a central control system for controlling the mixing process, which has access to all available sensor data from the mixing device, the central control system controls the automated opening and closing of the flap depending on external control commands or depending on the available sensor data, if the sensor data exceeds certain predetermined limits.

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