Plasticizing unit, forming machine, system and method for plasticizing, computer program product, storage medium and use of a plasticizing unit

Abstract

A plasticizing unit for plasticizing a plasticizable material (2) comprising a melting cylinder (3), a plasticizing screw (4) arranged in the melting cylinder (3), a screw drive (5) for driving longitudinal movements of the plasticizing screw (4) relative to the melting cylinder (3), and a machine control (6) for controlling the screw drive (5), wherein the melting cylinder (3) has a feed opening (7) for feeding the plasticizable material (2), and wherein the plasticizing screw (4) has a screw flight (8) with at least one geometric parameter variable along a length of the plasticizing screw (4), in particular a variable flight depth (h1,h2) and / or a variable flight pitch (S1,S2), characterized in that the machine control (6) is configured to - to receive a material signal which is indicative of a material property of the plasticizable material (2) and / or a resistance exerted by the plasticizable material (2) on the plasticizing screw, - to determine a longitudinal position of the plasticizing screw (4) based on the material signal, which longitudinal position (X1,X2) correlates with the material signal on the one hand and with at least one geometric parameter in the area of ​​the feed opening (7) on the other hand, and - to control the worm drive (5) to position the plasticizing screw (4) according to the specified longitudinal position (X1,X2).

Description

[0001] The present invention relates to a plasticizing unit and a system for plasticizing a plasticizable material according to the preambles of claims 1 or 11 as well as methods and computer program products for plasticizing a plasticizable material.

[0002] Generic plasticizing units have: - a mass cylinder with a feed opening for feeding the plasticizable material, - a plasticising screw arranged in the mass cylinder, which has a screw flight with at least one geometric parameter that can be varied along a length of the plasticising screw, in particular a variable flight depth and / or a variable flight pitch - a screw drive for driving longitudinal movements of the plasticizing screw relative to the mass cylinder and - a machine control system for controlling the screw drive.

[0003] Within the framework of the generic system, the machine control can be connected to a computer server.

[0004] Plasticizing screws with, for example, variable flight depth are generally known; for example, reference can be made to AT 11398 U1.

[0005] Another plasticizing unit is known from JP H07-205 230 A. To stabilize the physical properties of the melt, the screw torque is determined for a specific rotational speed while the injection molding cavity is being filled. The melt pressure is varied based on deviations in the screw torque.

[0006] Further plasticizing units with measures to stabilize the plasticizing process are known from the documents JP 2001- 260 193 A, JP 2015- 020 344 A and US 2001 / 0 023 997 A1.

[0007] The modification of geometric parameters of a screw flight usually serves to adapt the screw flight to the specific requirements of the plasticizable material, for example with regard to granulate size and introduced shear heat, ie the plasticizing screw is optimized for one type of material.

[0008] However, there is also an increasing desire to process plastic recyclate. Recyclate is plastic that has been obtained by shredding waste or old molded parts for reuse (i.e., "recycled plastic").

[0009] However, recyclate generally does not exhibit the same well-defined material parameters that are now common, for example, in freshly produced plastic granules. In particular, variations in granule size, i.e., the characteristic size of the individual granules, are often observed in practice.

[0010] The object of the invention is therefore to provide a plasticizing unit, a system, a method and a computer program product with which a wider range of materials can be plasticized.

[0011] With regard to the plasticizing unit, this object is achieved by the features of claim 1. This is achieved by the machine control being designed to - to receive a material signal indicative of a material property of the plasticisable material and / or a resistance exerted by the plasticisable material on the plasticising screw, - to determine a longitudinal position of the plasticising screw on the basis of the material signal, which longitudinal position correlates with the material signal on the one hand and the at least one geometric parameter in the area of ​​the feed opening on the other hand, and - to control the screw drive to position the plasticizing screw according to the specified longitudinal position.

[0012] With regard to the system, the object is achieved with the features of claim 11, namely in that the at least one computer server is designed to - to receive a material signal indicative of a material property of the plasticisable material and / or a resistance exerted by the plasticisable material on the plasticising screw, - to determine a longitudinal position of the plasticising screw on the basis of the material signal, which longitudinal position correlates with the material signal on the one hand and the at least one geometric parameter in the area of ​​the feed opening on the other hand, and - to transmit the longitudinal position to the machine control, and in that the machine control is designed to control the screw drive for positioning the plasticizing screw according to the transmitted longitudinal position.

[0013] Protection is also sought for a molding machine with a plasticizing unit according to the invention. Molding machines can include injection molding machines, transfer presses, presses, and the like.

[0014] With regard to the method, the problem is solved by the features of claim 12, namely by - a plasticisable material is plasticised by means of a plasticising screw which has a screw flight with at least one geometric parameter which can be varied along a length of the plasticising screw, in particular a variable flight depth and / or a variable flight pitch, - a material signal is detected which is indicative of a material property of the plasticisable material and / or a resistance exerted by the plasticisable material on the plasticising screw, - on the basis of the material signal, a longitudinal position of the plasticising screw is determined, which longitudinal position correlates with the material signal on the one hand and the at least one geometric parameter in the area of ​​the feed opening on the other hand, and - the plasticizing screw is positioned according to the determined longitudinal position.

[0015] With regard to the computer program product, the problem is solved by the features of claim 13, namely by instructions which cause an executing computer to - to receive a material signal indicative of a material property of the plasticisable material and / or a resistance exerted by the plasticisable material on the plasticising screw, - to determine a longitudinal position of the plasticising screw on the basis of the material signal, which longitudinal position correlates with the material signal on the one hand and the at least one geometric parameter in the area of ​​the feed opening on the other hand, and - to control the screw drive for positioning the plasticising screw according to the transmitted longitudinal position and / or to transmit the longitudinal position to a machine control system.

[0016] Protection is also sought for a computer-readable storage medium on which a computer program product according to the invention is stored.

[0017] A fundamental aspect of the invention is to position the plasticizing screw in the mass cylinder on the basis of the material signal, for example a material property such as the density and / or the characteristic particulate size and / or the flowability, and / or a resistance exerted by the plasticizable material on the plasticizing screw, such as the torque applied to the plasticizing screw, in such a way that material filled / added into the mass cylinder via the feed opening reaches that part of the screw flight which has a geometry optimized for the material (at least one geometry parameter).

[0018] For this purpose, according to the invention, a longitudinal position of the plasticizing screw in the mass cylinder must be determined, which correlates, on the one hand, with the material signal and, on the other hand, with at least one geometric parameter in the area of ​​the feed opening. This means, for example, that a plasticizing screw with a decreasing flight depth along its length is retracted a certain distance when the material signal indicates that the granule size is decreasing.

[0019] The extent to which the plasticizing screw is retracted, or more generally, the extent to which the longitudinal position of the plasticizing screw is changed, can be determined in various ways. First, a specific value of the material signal could be assigned to a certain longitudinal position, for example, using a look-up table, and thus correlated. Alternatively or additionally, the longitudinal position of the plasticizing screw could be subject to a higher-level control or regulation, so that a change in the material signal causes a change in the longitudinal position of the plasticizing screw.

[0020] The longitudinal position does not have to be an absolute position specification, but can also be specified as a change in a position.

[0021] Similarly, the material signal does not have to contain absolute values, for example of density or particulate size, but can be provided as a change value, for example.

[0022] In plasticizing units according to the invention, which are used, for example, as part of injection molding machines, the control of the longitudinal position determined according to the invention can be interrupted by injection processes or the like. According to the invention, the determined longitudinal position can then be approached, for example, during a dosing process.

[0023] When determining which longitudinal position correlates with the present material signal, certain boundary conditions or prerequisites can be checked.

[0024] For example, it could be checked whether granules (ground material) or the like of the plasticizable material fit completely into the respective screw flight, ie are not larger than the flight depth.

[0025] Alternatively or additionally, it could be checked whether more plasticizable material is conveyed per revolution (e.g. in kg / revolution) than a screw drive energy can melt per revolution, otherwise the drive could reach its torque limit.

[0026] Plasticizing units according to the invention are typically used to plasticize thermoplastics. However, the invention can generally be used with any materials that can be plasticized or further plasticized by the application of heavy heat via the plasticizing screw and, if necessary, additional heating. This includes, in particular, recyclate, regranulate, regrind, and / or agglomerate.

[0027] In the case of plastic granules, the characteristic particle size is often specified as an (average) granule size or something similar. For general masses that can be plasticized within the meaning of the present invention, one can generally speak of the characteristic particle size of the material or at least of the particulate fraction.

[0028] The mass cylinder can generally be a circular-cylindrical container in which the plasticizing screw is movably arranged. However, the invention can also be used in plasticizing units in which two or more plasticizing screws are arranged in one mass cylinder.

[0029] The plasticizing screw according to the invention has at least one screw flight with at least one geometric parameter that can be varied along the length of the plasticizing screw (e.g., flight depth and / or flight pitch). However, embodiments in which two or more screw flights with at least one geometric parameter that can be varied along the length of the plasticizing screw are used are certainly conceivable.

[0030] Longitudinal movements of the plasticizing screw are understood in the sense of the present invention as movements which are parallel to a longitudinal axis of the mass cylinder and / or the plasticizing screw.

[0031] In addition to driving these longitudinal movements, the screw drive can also drive the rotation of the plasticizing screw. In principle, however, another screw drive (rotary drive) can also be used to drive the rotation.

[0032] The machine control can preferably be part of the central machine control of the forming machine, although versions with a separate machine control for the plasticizing unit are conceivable in principle.

[0033] The machine control can be set up for both controlled and regulated control of the screw drive and, if necessary, for controlling other machine components.

[0034] However, the determination of the longitudinal position of the plasticizing screw, so that the longitudinal position correlates with the material signal on the one hand and the at least one geometric parameter in the area of ​​the feed opening on the other hand, can also be carried out according to the invention by a computer server, wherein the computer server is signal-connected to the machine control.

[0035] The computer server can be a single dedicated computer centrally configured for the function according to the invention. However, the invention can also be used with other computer server architectures, e.g., in conjunction with edge computing devices and / or virtualized servers.

[0036] Advantageous developments of the invention are defined in the dependent claims.

[0037] As already mentioned, the material signal can include at least one of the following: a density of the plasticizable material and / or a characteristic particulate size of the plasticizable material and / or a flowability of the plasticizable material and / or a torque applied to the plasticizing screw. The latter is a material signal indicative of the resistance exerted by the plasticizable material on the plasticizing screw. The remaining examples mentioned are material signals indicative of material properties of the plasticizable material.

[0038] The torque applied to the plasticizing screw could, for example, be measured via the current consumption of a rotary drive for the plasticizing screw.

[0039] Of course, the material signal can also consist of combinations or mixed forms of the mentioned quantities or other quantities.

[0040] In a particularly simple embodiment, a torque measurement, in particular the current consumption of the drive, could be used to establish a correlation with the bulk density, which is used to position the screw.

[0041] A sensor for detecting the material signal may be provided, which is signal-connected to the machine control and / or the computer server for transmitting the material signal.

[0042] Examples of sensors for detecting the material signal would be: - optical sensors, such as cameras (these can detect grain boundaries, whereby the area of ​​the “gaps” can be a measure of the bulk density) - capacitive sensors - a device with weighing cells (bulk density scale) in the material feed, which is preferably designed for discontinuous measuring of the bulk density

[0043] Alternatively or additionally, the machine control and / or the computer server may have an interface with a device for automatically providing and / or feeding the plasticizable material and be designed to receive the material signal via the interface.

[0044] The device for automatically providing and / or feeding the plasticizable material may, for example, include a dosing screw and / or a cutter-compactor.

[0045] Alternatively or additionally, the machine control and / or the computer server can be signal-connected to a human-machine interface, wherein the human-machine interface is designed to generate the material signal based on inputs from an operator and to forward it to the machine control.

[0046] It can be provided that a first relationship between the material signal and the at least one geometric parameter of the screw flight of the plasticizing screw and a second relationship between the at least one geometric parameter of the screw flight of the plasticizing screw in the region of the feed opening and the longitudinal position of the plasticizing screw is stored in the machine control and / or in the computer server, wherein the machine control and / or the computer server is designed to determine the longitudinal position on the basis of the first relationship and the second relationship.

[0047] The plasticizing screw can have at least two first regions, preferably within a feed zone, wherein the at least one geometric parameter of the screw flight of the plasticizing screw is constant in each of the at least two first regions—preferably viewed from a side or sectional view—and different from other first regions. If two first regions adjoin one another, "discrete" changes to the at least one geometric parameter of the screw flight can be realized. The plasticizing screw and the plasticizing unit can thus be optimized for (for example, precisely) two different types of plasticizable mass.

[0048] The machine control system can be configured to control the screw drive during a dosing process such that, at the start of the dosing process, a drive-side end region of one of the first sections is located in the area of ​​the feed opening. In other words, a starting position for the dosing process can be selected such that the plasticizing screw is as far forward as possible, while the desired first section is located in the area of ​​the feed opening.

[0049] During dosing, the plasticizing screw is then moved backwards because plasticized material accumulates in the screw antechamber.

[0050] Embodiments may be particularly preferred in which the first regions in which the at least one geometric parameter of the plasticizing screw is constant extend at least over a minimum length of the plasticizing screw along its longitudinal axis.

[0051] The minimum length can be given by: - a working stroke during an injection and / or dosing process and / or - an n-fold multiple of a screw diameter of the plasticizing screw, where n is equal to 1 or 2 or a natural number greater than 2

[0052] Alternatively or additionally, the plasticizing screw can have, preferably within a feed zone, at least one second region in which the at least one geometric parameter of the screw flight of the plasticizing screw changes continuously, in particular linearly or non-linearly, preferably as seen from a side or sectional view.

[0053] Preferably, the depth of the screw flight decreases toward the screw tip. The screw tip is the side of the plasticizing screw facing away from the screw drive.

[0054] Preferably, the pitch decreases towards the screw tip.

[0055] A greater flight depth and / or a higher flight pitch increases the flight volume per revolution, which favors the conveying of lower bulk densities.

[0056] Protection is also sought for the use of a plasticizing unit according to the invention and / or a system according to the invention in a dosing process and / or a plasticizing process and / or an injection process.

[0057] A plasticizing unit according to the invention or a system according to the invention can be used particularly preferably if a length along the longitudinal axis of the plasticizing screw of at least a first region - preferably all first regions - is greater than or equal to a working stroke of the plasticizing screw.

[0058] Dosing processes and / or plasticizing processes and / or injection processes can be part of molding processes. Molding processes can include injection molding processes, transfer molding processes, compression molding processes, and the like.

[0059] Further advantages and details are shown in the figures and the accompanying figure descriptions. They show: Fig. 1a a plasticizing unit according to the state of the art, Fig. 1b a plasticizing unit according to the invention as part of a forming machine, Fig. 2a and Fig. 2b Detailed representations of the embodiment from Fig. 1b in the area of ​​the feed opening, Fig. 3a and Fig. 3b Detailed representations analogous to the Fig. 2a and Fig. 2b of a further embodiment according to the invention, Fig. 4 a detailed representation analogous to Fig. 2b of a further embodiment according to the invention, Fig. 5a and Fig. 5b further illustrations of the embodiment according to Fig. 4 and Fig. 6 a detailed representation analogous to Fig. 4 of a further embodiment of the invention.

[0060] Fig. 1a shows a plasticizing unit 1 according to the prior art.

[0061] This plasticizing unit has a mass cylinder 3 in which a plasticizing screw 4 is arranged.

[0062] By means of the screw drive 5, the plasticizing screw can be moved axially, i.e., along the longitudinal axis X of the plasticizing screw 4. In this case, for example, it is an electrically driven spindle drive (with a double-bearing spindle nut).

[0063] By means of the additional screw drive 14, the plasticizing screw 4 can also be rotated about the longitudinal axis X. In this embodiment, this is an electric drive, specifically a servo motor.

[0064] For feeding plasticizable material 2, a feed opening 7 is provided in the mass cylinder 3, which is arranged here in the outer surface of the mass cylinder 3.

[0065] A funnel is provided which serves to fill the plasticizable material 2 into the feed opening 7.

[0066] In this embodiment, there is also a device (not shown) that allows the feed quantity per unit of time to be controlled or regulated.

[0067] Fig. 1b shows the plasticizing unit 1 as part of a forming machine 10 or a system 20. The in connection with Fig. 1a may also be used in relation to the execution in accordance with Fig. 1b should be provided.

[0068] It should be noted that the plasticizing screw 4 in Fig. 1b is symbolically shown, variable geometric parameters of the screw flight 8 therefore do not appear. In this regard, reference is made to the Fig. 2a and Fig. 2b.

[0069] The forming machine 10 has a central machine control 6, which is designed to receive the material signal according to the invention, for which three exemplary variants are shown in Fig. 1b are shown.

[0070] First, a sensor 9 can be provided, which, for example, detects an average granule size of the plasticizable material 2 located in the hopper as a material signal. The sensor 9 can transmit the material signal to the machine control 6 via a signal connection shown in dashed lines.

[0071] Alternatively or additionally, the torque of the screw drive 5 can be used as a material signal.

[0072] In principle, it would be conceivable that the torque is used as a reference variable (for example within the framework of a control system) for the axial positioning (longitudinal position) of the plasticizing screw 4.

[0073] Alternatively or additionally, a device 15 for automatically providing and / or feeding the plasticizable material can be provided, which transmits the material signal to the machine control 6 via a signal connection shown in dashed lines.

[0074] Alternatively or additionally, a human-machine interface 12 can be provided on the machine control 6, via which operators can, for example, enter the average granulate size of the plasticizable material 2. The human-machine interface 12 then generates the material signal based on the operator's input and forwards it to the actual machine control 6.

[0075] The human-machine interface 12 does not necessarily have to be arranged on the machine control 6 itself, but could, for example, be implemented by an external computer that is signal-connected to the machine control 6 via a signal connection.

[0076] Based on the material signal, the machine control 6 can determine the longitudinal position of the plasticizing screw 4, which is appropriate for the plasticizable material currently present.

[0077] As mentioned, this can be done through stored relationships, for example: - between the material signal, for example the average granulate size, and at least one geometry parameter, for example the flight depth, on the one hand (i.e. answering the question: “Which part of the plasticising screw 4 is optimal for the given granulate size?”) and - between the at least one geometry parameter and the longitudinal position on the other hand (ie answering the question: “At which longitudinal position does the specific flight depth in the area of ​​the feed opening 7 occur?”).

[0078] Regarding the determination of the longitudinal position, reference should be made to the Fig. 2a and Fig. 2b.

[0079] The determination of the longitudinal position according to the invention can be carried out in a variant of the embodiment of Fig. 1b can also be taken over by a computer server 13 instead of by the machine control.

[0080] For this purpose, the computer server 13 can be in signal connection with: - the machine control 6 and / or - the human-machine interface 12 and / or - the sensor 9 and / or - the device 15 for automatically providing and / or feeding the plasticizable material

[0081] That is, the computer server 13 can receive the material signal directly from the sensor 9, from the human-machine interface 12 and / or from the device 15 for automatically providing and / or feeding the plasticizable material, or the computer server 13 can receive the material signal via the machine control 6.

[0082] The device 15 for automatically spreading and / or feeding the plasticizable material may, for example, include a dosing screw 16 (see Fig. 6).

[0083] In the Fig. The signal connection shown in dashed lines in Figure 1b may be a wired and / or wireless data connection, possibly in the form of remote data transmission connections.

[0084] In the Fig. 2a and Fig. 2b schematically shows details of the plasticizing unit 1 according to the invention in the area of ​​the feed opening 7 in a sectional view.

[0085] It can be seen that the plasticizing screw 1 in this embodiment has two first regions with different flight depths h1 and h2 as geometric parameters.

[0086] Both in Fig. 2a as well as in Fig. 2b, the plasticizable material 2 is in the form of plastic granules, with the average granule size in Fig. 2a is larger than that in Fig. 2b. This can be detected, for example, with sensor 9.

[0087] According to the invention, the longitudinal position X1 in the first case of the Fig. 2a so that the area of ​​the plasticizing screw 4 with the greater flight depth h1 is located below the feed opening 7. In the second case from Fig. 2b, where the granulate size is smaller, the longitudinal position X2 is selected such that the area of ​​the plasticizing screw 4, which has the smaller flight depth h2, is located below the feed opening 7.

[0088] As a result, the mass conveyed per revolution can be adjusted, for example, for different bulk densities by adjusting the flight depth in the feeder. This adapts the throughput to the plasticizing performance of the screw geometry in such a way that only the required specific energy is applied.

[0089] Fig. 3a and Fig. 3b show a further embodiment, wherein alternatively or in addition to the different flight depths, different flight pitches S1 and S2 are present.

[0090] In this embodiment, the screw flights 8 with the larger pitch S2 are arranged behind the screw flights 8 with the smaller pitch S1, ie the screw flights 8 with the larger pitch S2 are closer to the worm drive 5 and / or the further worm drive 14.

[0091] If the material 2 to be plasticized has even greater bulk densities than those which are associated with the Fig. 2a and Fig. 2b, could be implemented according to the Fig. 3a and Fig. 3b, the screw can be moved even further forward so that the screw flights 8 with the larger pitch S2 are in the area of ​​the feed opening 7. Then, this material 2 can also be plasticized with an even higher bulk density.

[0092] In the example according to the Fig. 3a and Fig. 3b shows three first areas in which the geometric parameters of the plasticizing screw 4 are constant, namely: - front area with gear depth h1 and gear pitch S1 - middle range with larger flight depth h2 and flight pitch S1 - rear area with greater gear depth h2 and greater gear pitch S2

[0093] Alternatively or additionally, second regions could be provided, wherein at least one geometric parameter of the plasticizing screw 4 changes continuously.

[0094] Of course, mixed forms are also conceivable, whereby one geometric parameter changes continuously and another geometric parameter of the plasticizing screw 4 changes discontinuously.

[0095] Embodiments may be particularly preferred in which first regions in which geometric parameters of the plasticizing screw 4 are constant extend at least over a minimum length of the plasticizing screw 4 along its longitudinal axis X.

[0096] The minimum length can be given by: - a working stroke Y during an injection and / or dosing process and / or - an n-fold multiple of the screw diameter of the plasticizing screw 4, where n is equal to 1 or 2 or a natural number greater than 2

[0097] This is in Fig. 4, whereby in this embodiment the working stroke Y corresponds to twice the screw diameter D.

[0098] In Fig. 4 also indicates a starting position for a dosing process. During a dosing process, plasticizable material 2 is continuously fed through the feed opening 7 and plasticized in the mass cylinder 3 by means of the plasticizing screw 4. Therefore, the plasticizing screw 4 moves back accordingly, with the plasticized material collecting in the screw antechamber (not shown).

[0099] By means of first regions which have constant geometric parameters over a working stroke, it can be achieved that constant geometric parameters of the plasticising screw 4 are present in the region of the feed opening 7 during a dosing process and thus constant feed and plasticising conditions are present during a dosing process.

[0100] In particularly preferred embodiments, the following may be provided independently of one another or in combination: - In the longitudinal position X1 there is a low flight depth of h1 (for example 10mm), which is suitable for processing high bulk densities (such as lens, spherical or cylindrical granules from new material or regranulate) (see Fig. 5a). - At a further position X2, a larger flight depth h2 of e.g. 15 mm is available. Bulk densities 30% lower, for example large granules (such as ground material from thick-walled components), are conveyed at the same throughput per revolution (see Fig. 5b). - For even lower bulk densities, e.g. 50% lower, an increased aisle volume is provided in position X3 due to a change in gradient of +20%, which allows even very low bulk densities (either coarse ground material or fluffy material) to be processed.

[0101] The aim may be to keep the mass flow rate (kg / revolutions) largely constant.

[0102] In other words, by sequentially adjusting X1, X2, X3 of the duct volume (V1, V2, V3) the mass m present in the snail chamber is kept approximately constant.

[0103] In addition, the used screw length is increased, which allows for better melting of large granules. The flight depth change (h1 to h2) or pitch change (to S2) is preferably constant over one or more revolutions, thus achieving constant feed conditions over a working stroke Y.

[0104] Fig. 6 shows a further embodiment, wherein a device 15 for automatically providing and / or feeding the plasticizable material 2 is provided in the form of a metering screw 16. By means of the metering screw 16, the material 2 to be plasticized can be metered in via the feed opening 7.

[0105] The device 15 for automatically providing and / or feeding the plasticizable material 2 can be used for underfilling, wherein less plasticizable material 2 is fed through the feed opening 7 than would be space in the screw flights 8 of the plasticizing screw 4, so that air or other gases can also be present in part in the mass cylinder 3.

[0106] The underfilling can be used to plasticize the plasticizable material 2 particularly gently because a shorter residence time at high temperatures in the melt cylinder 3 is achieved. The invention further improves this effect of the underfilling because the partially filled screw flights 8 can have a larger volume, thereby further reducing the thermal effect on the plasticizable material 2.

[0107] Overall, the invention allows the plasticization of the plasticizable material 2 to be optimized or at least tailored to the material at hand, even though only a single plasticizing screw 4 is used. According to the invention, different compression ratios can be realized, thus taking into account the conveying behavior of ground materials depending on grain size, bulk density, and shape. Reference symbol: 1 plasticizing unit 2 Plasticizable material 3 mass cylinders 4 plasticizing screw 5 Worm drive 6 Machine control 7 Feed opening 8 worm gear 9 Sensor 10 forming machine 11 Interface 12 Human-machine interface 13 computer servers 14 Additional worm drive 15 Device for automatically providing and / or feeding the plasticizable material 16 Dosing screw 20 systems X Longitudinal axis of the plasticizing screw h1, h2 aisle depths (generally hX) S1, S2 gear pitches (generally SX) Y working stroke V1, V2, V3 gait volume (generally VX) BD1, BD2 bulk densities (generally BDX)

Claims

[1] Plasticizing unit for plasticizing a plasticizable material (2) with a mass cylinder (3), a plasticizing screw (4) arranged in the mass cylinder (3), a screw drive (5) for driving longitudinal movements of the plasticizing screw (4) relative to the mass cylinder (3) and a machine control (6) for controlling the screw drive (5), wherein the mass cylinder (3) has a feed opening (7) for feeding the plasticizable material (2) and wherein the plasticizing screw (4) has a screw flight (8) with at least one geometric parameter that can be changed along a length of the plasticizing screw (4), in particular a variable flight depth (h1, h2) and / or a variable flight pitch (S1, S2), characterized by that the machine control (6) is designed to - to receive a material signal which is indicative of a material property of the plasticisable material (2) and / or a resistance exerted by the plasticisable material (2) on the plasticising screw, - to determine a longitudinal position of the plasticising screw (4) on the basis of the material signal, which longitudinal position (X1, X2) correlates with the material signal on the one hand and the at least one geometric parameter in the region of the feed opening (7) on the other hand, and - to control the screw drive (5) for positioning the plasticizing screw (4) according to the determined longitudinal position (X1,X2). [2] Plasticizing unit according to claim 1, characterized bythat the material signal includes at least one of the following: a density of the plasticizable material (2) and / or a characteristic particulate size of the plasticizable material (2) and / or a flowability of the plasticizable material (2) and / or a torque applied to the plasticizing screw (4). [3] Plasticizing unit according to one of the preceding claims, characterized by that a sensor (9) is provided for detecting the material signal, which is signal-connected to the machine control (6) for transmitting the material signal. [4] Plasticizing unit according to one of the preceding claims, characterized by that the machine control (6) has an interface (11) with a device (15) for automatically providing and / or feeding the plasticizable material (2) and is designed to receive the material signal via the interface (11). [5] Plasticizing unit according to one of the preceding claims, characterized by in that the machine control (6) is signal-connected to a human-machine interface (12), wherein the human-machine interface (12) is designed to generate the material signal based on inputs from an operator and to forward it to the machine control (6). [6] Plasticizing unit according to one of the preceding claims, characterized byin that a first relationship between the material signal and the at least one geometric parameter of the screw flight (8) of the plasticizing screw (4) and a second relationship between the at least one geometric parameter of the screw flight (8) of the plasticizing screw (4) in the region of the feed opening (7) and the longitudinal position (X1, X2) of the plasticizing screw (4) is stored in the machine control (6), wherein the machine control is designed to determine the longitudinal position (X1, X2) on the basis of the first relationship and the second relationship. [7] Plasticizing unit according to one of the preceding claims, characterized by that the plasticizing screw (4), preferably within a feed zone, has at least two first regions, wherein the at least one geometric parameter of the screw flight (8) of the plasticizing screw (4) is constant in the at least two regions and different from other first regions. [8] Plasticizing unit according to claim 7, characterized by that the machine control (6) is designed to control the screw drive (5) during a dosing process in such a way that at the start of the dosing process a drive-side end region of one of the first regions is arranged in the region of the feed opening. [9] Plasticizing unit according to one of the preceding claims, characterized by that the plasticizing screw (4), preferably within a feed zone, has at least one second region in which the at least one geometric parameter of the screw flight (8) of the plasticizing screw (4) changes continuously, in particular linearly or non-linearly. [10] Forming machine with a plasticizing unit according to one of the preceding claims. [11] System for plasticizing a plasticizable material (2) with a plasticizing unit (1) and at least one computer server (13), wherein the plasticizing unit (1) includes a mass cylinder (3) with a feed opening (7) for feeding the plasticizable material (2), a plasticizing screw (4) arranged in the mass cylinder (3), a screw drive (5) for driving longitudinal movements of the plasticizing screw (4) relative to the mass cylinder (3) and a machine control (6) for controlling the screw drive (5), wherein the plasticizing screw (4) has a screw flight (8) with at least one geometric parameter that can be changed along a length of the plasticizing screw (4), in particular a changeable flight depth (h1, h2) and / or a changeable flight pitch (S1, S2), and wherein the machine control (6) is signal-connected to the at least one computer server (13) is, characterized bythat the at least one computer server (13) is designed to - to receive a material signal which is indicative of a material property of the plasticisable material (2) and / or a resistance exerted by the plasticisable material (2) on the plasticising screw, - to determine a longitudinal position (X1, X2) of the plasticising screw (4) on the basis of the material signal, which longitudinal position (X1, X2) correlates with the material signal on the one hand and the at least one geometric parameter in the region of the feed opening (7) on the other hand, and - to transmit the determined longitudinal position (X1,X2) to the machine control (6), and that the machine control (6) is designed to control the screw drive (5) for positioning the plasticizing screw (4) according to the transmitted longitudinal position (X1,X2). [12] Method for plasticizing a plasticizable material, in particular for operating a plasticizing unit (1) according to one of claims 1 to 9 and / or a system (20) according to claim 11, wherein - a plasticizable material (2) is plasticized by means of a plasticizing screw (4) which has a screw flight (8) with at least one geometric parameter that can be varied along a length of the plasticizing screw (4), in particular a variable flight depth (h1, h2) and / or a variable flight pitch (S1, S2), - a material signal is detected which is indicative of a material property of the plasticisable material (2) and / or a resistance exerted by the plasticisable material (2) on the plasticising screw, - on the basis of the material signal, a longitudinal position (X1, X2) of the plasticising screw (4) is determined, which longitudinal position (X1, X2) correlates with the material signal on the one hand and the at least one geometric parameter in the region of the feed opening (7) on the other hand, and - the plasticizing screw (4) is positioned according to the determined longitudinal position (X1,X2). [13] Computer program product for plasticizing a plasticizable material, in particular for carrying out a method according to claim 12, with instructions which cause an executing computer to - to receive a material signal which is indicative of a material property of the plasticisable material (2) and / or a resistance exerted by the plasticisable material (2) on the plasticising screw, - to determine a longitudinal position (X1, X2) of the plasticising screw (4) on the basis of the material signal, which longitudinal position (X1, X2) correlates with the material signal on the one hand and the at least one geometric parameter in the region of the feed opening (7) on the other hand, and - to control the screw drive (5) for positioning the plasticizing screw (4) according to the transmitted longitudinal position (X1,X2) and / or to transmit the longitudinal position (X1,X2) to a machine control (6). [14] A computer-readable storage medium on which a computer program product according to claim 13 is stored. [15] Use of a plasticizing unit according to one of claims 1 to 9 and / or a system according to claim 11 in a dosing process and / or a plasticizing process and / or an injection process.

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