DE102011116152B4 - Arrangement with a plasticizing screw with temperature control device, injection molding machine with this arrangement and method for temperature control of the plasticizing screw - Google Patents

Abstract

Arrangement with a plasticizing screw (1), a plasticizing unit (2) of an injection molding machine and a temperature control device for controlling the temperature of the plasticizing screw (1), the temperature control device having an inlet line (5), a temperature control channel (6) in the plasticizing screw (1) and an outlet line (7 ) through which a temperature control medium flows, and wherein a heating and/or cooling unit (4) for heating and/or cooling the temperature control medium is arranged between the outflow line (7) and the inflow line (5) and the inflow line (5), the temperature control channel (6) and the drain line (7) to form a closed temperature control circuit (3), characterized in that the temperature control device
- a quantity sensor (10) for measuring the flow quantity (D) of temperature control medium through the temperature control circuit (3),
- a volume regulator (11) for regulating the amount of tempering medium introduced into the tempering circuit (3),
- A data memory (12) in which at least the measured temperatures (T _z , T _A ) of the tempering medium in the inlet line (5) or in the heating and/or cooling unit (4) and in the outlet line (7) and the measured flow rate (D) can be stored as current actual values (W _akt ), and
- A control or regulating unit (13) through which, depending on the measured actual values (W _act ) and _stored target values (W target ) or read out documented actual values (W _dok ) of previous injection molding cycles by outputting control signals (L) to the heating and/or cooling unit (4) and/or to the volume controller (11) the temperature of the temperature control medium in the temperature control channel (6) of the plasticizing screw (1) Can be controlled or regulated.

Description

The invention relates to an arrangement with a plasticizing screw of a plasticizing unit of an injection molding machine and a temperature control device for controlling the temperature of the plasticizing screw, the temperature control device having an inlet line, a temperature control channel in the plasticizing screw and an outlet line through which a temperature control medium flows. In addition, the invention relates to an injection molding machine with such an arrangement and a method for controlling the temperature of a plasticizing screw of a plasticizing unit of an injection molding machine using a temperature control device.

During the plasticizing process in a plasticizing cylinder, a plastic is heated from an initial temperature, usually room temperature, to the necessary melt or processing temperature. The temperature input takes place both via the heat conduction from the heating of the mass cylinder surrounding the screw into the plastic and via the drive of the plasticizing screw. The torque transmitted to the screw via the screw drive is converted into frictional energy (dissipation) and thus into heat and thus heats the plastic in the barrel. How high this dissipative energy component is essentially depends on the plastic. The higher the viscosity of the plastic, the higher the energy input via dissipation. If this energy input is too high, this leads to high melt temperatures. In the case of thermally sensitive plastics, this can lead to material damage and thus to streaks or poor mechanical properties.

For these thermally sensitive plastics such as PVC or PVC-C or for very difficult-to-flow plastics such as PE-HD with MVR (190°C/2.16kg) of less than 1g/10min, cooled screws are used to reduce the melt temperature and thus the temperature load of the plastic.

It is difficult to achieve an optimum process engineering setting with continuous temperature control of the screw. If the cooling effect is too low, the thermal load can only be reduced slightly. Dosing time fluctuations can also occur due to excessive feed zone temperatures. If the cooling effect is too strong, the

Torque requirements, poor melt quality, dosing time fluctuations and the risk of screw breakage are the consequences.

A significant improvement for process management is not having to switch on the cooling or temperature control permanently. It makes sense to switch on the temperature control or cooling depending on the dosing time and to switch off the temperature control or cooling in the standstill phase when no dissipation energy is being supplied.

A simple solution is to connect a temperature control unit to the screw cooling system via a valve. During dosing, the screw cooling or temperature control is activated, in the standstill phase the valve switches to a bypass position and the screw is not temperature-controlled.

As mentioned, energy is supplied both via thermal conduction from the heaters of the mass cylinder and via frictional energy (dissipation) via the dosing drive. If the dissipative portion of the supplied energy is very high, temperature-sensitive plastics such as PVC, for example, are not only heated but also cooled in order to keep the mass temperature as low as possible. Cooling can take place both at the barrel and in the screw.

It is known to arrange temperature sensors along the mass cylinder, which measure a temperature for each heating zone. A target temperature is specified in the controller. If the temperature measured in each zone is below the target temperature, the heating is activated via a suitable control system. If the temperature is above the target temperature, this zone is cooled.

The disadvantage is that the screw temperature is largely unknown to the operator. The screw is a thermally short-circuited system, i.e. energy is supplied via dissipation and heat conduction and the screw is thus heated in the front area of the melting and metering zone. At the same time, the screw transfers energy from the hot, melt-carrying area to the cool feed area and screw shaft. The cold plastic trickling into the feed zone absorbs energy, cools the screw and is itself preheated.

In the DE 76 01 482 U describes an extruder screw in which a screw cooling system is provided, with a coolant being introduced into a central bore in order to control the temperature of the screw over its entire length in a targeted manner.

the DE 20 57 989 A relates to extruder worms in which cavities in the worm use heating or cooling means to achieve homogeneous heating, thereby enabling uniform plasticization of the plastic. What is essential in this invention is that the cooling bores or cooling chambers reach into the screw webs, whereby the distance to the surface is substantially chen is always constant along the entire surface. This is called differential cooling.

the DE 10 2007 009 027 A1 shows a snail with a heat transport device that can cool specific areas on the inside via a profile with ribbing. The exact control of the cooling is not mentioned.

the DE 12 46 222 A shows a screw injection molding of plastics, heating and/or cooling zones of any length or any volume being provided in the screw through a longitudinal bore. The work process or the influencing of the functional fulfillment is adapted to the rhythm of the screw axial movements and thus to the cycle. Any number of heating and/or cooling zones can be present in the screw. The temperature of the individual zones is advantageously monitored and controlled by thermostat measuring points, with control pulses being forwarded to a control box on the basis of this.

A disadvantage of the prior art as a whole is that although the precise temperatures in the screw can be set in some cases, the entire temperature change in the screw can never be observed. This results in the disadvantage that the controls known from the prior art are imprecise. In addition, measurements are only ever taken at certain points around or in the snail, so that the evaluation always lags behind the true temperature losses or temperature gains in the entire snail.

An arrangement with a plasticizing screw of a plasticizing unit of an injection molding machine and a temperature control device for controlling the temperature of the plasticizing screw according to the preamble of claim 1 is known from DE 40 14 347 C1 known.

the DE 44 44 092 C2 discloses a method for tempering an injection mold with at least one heated nozzle or one heating channel.

The object of the present invention is to specify an arrangement of plasticizing screw and temperature control device that is improved compared to the prior art, or an improved method for temperature control of a plasticizing screw. In particular, an easily controllable and manageable temperature control device is to be created that can carry out the entire temperature control process without external influence if possible. In addition, the temperature control should be able to be carried out as constantly as possible. Furthermore, the temperature control medium should be used as sparingly as possible.

This is achieved for an arrangement according to the invention in that a heating and/or cooling unit for heating and/or cooling the tempering medium is arranged between the outlet line and the inlet line and connects the inlet line, the temperature control channel and the outlet line to form a closed temperature control circuit. Compared to the prior art, this closed temperature control circuit means that the temperature control medium (service water) can be reused. In addition, temperature control can be better monitored and the temperature control device is no longer directly dependent on the temperature of the temperature control medium supplied (usually normal cool tap water), but can precisely control or regulate the temperature using the heating and/or cooling unit.

According to the invention, the temperature control device has a quantity sensor for measuring the flow rate of temperature control medium through the temperature control circuit. The quantity sensor is preferably arranged in the feed line.

In order to avoid enthalpy changes in the plastic produced with the plasticizing unit or to keep them constant over as long a production time as possible, it is provided that the temperature control device has a quantity controller for controlling the amount of temperature control medium introduced into the temperature control circuit, a data memory in which at least the measured temperatures of the temperature control medium in the inlet line or in the heating and/or cooling unit and in the outlet line and the measured flow rate can be stored as current actual values and a control or regulating unit, by which, depending on the measured actual values and stored target values or the temperature of the tempering medium in the tempering channel of the plasticizing screw can be controlled or regulated by outputting control signals to the heating and/or cooling unit and/or to the volume controller based on documented actual values that have been read out from previous injection molding cycles. With this design, the temperature in the entire screw can be precisely monitored and temperature control can be learned from previous injection molding cycles.

According to a preferred exemplary embodiment of the present invention, it can be provided that the temperature control device has a temperature sensor for measuring the temperature of the temperature control medium in the feed line or in the heating and/or cooling unit. Only when there is a water supply that supplies a constant temperature can a preferred inlet temperature sensor be dispensed with for the present invention.

In order to be able to draw even better conclusions about the energy loss or gain in the temperature control medium as it passes through the temperature control channel, it can preferably be provided that the temperature control device has a temperature sensor for measuring the temperature of the temperature control medium in the discharge line.

If you want to know the flow rate of temperature control medium through the temperature control circuit, it can be provided according to a variant of the invention that the
Temperature control device, preferably in the inlet line, has a flow stabilizer. This has a specific cross-section from which the flow rate can be deduced at a specific flow pressure.

A preferred embodiment of the arrangement can provide that at least a third temperature sensor is arranged in the plasticizing screw, preferably in the area of the screw tip. For this purpose, it can be provided that the screw is designed with a temperature measuring point, preferably in the critical area (i.e. in the area of the maximum temperature at the screw tip). The temperature information is passed on to the controller and can be used as a quality parameter for process monitoring or as a control parameter for screw temperature control.

The information on the screw temperature or, in general, on the stored thermal energy can also be obtained with this design. If, per cycle, the amount of cooling medium that corresponds to the volume of the bore in the screw is conveyed through the cooling bore of the screw and the flow and return temperature per unit of time are measured at the same time, an average screw temperature can be estimated. This temperature information can be used as a process parameter for process monitoring or as a control parameter. A complex measuring system in the screw can be avoided. With these temperature curves of flow and return temperature per unit of time and the volume flow of the cooling medium in the screw, the energy that is dissipated by the screw with the cooling medium per cycle can also be deduced. One goal could be to always dissipate the same amount of energy per cycle. In this case, a constant amount of energy dissipated would be achieved by varying the flow rate. Thus, the temperature control can in principle take place, for example, via the temperature of the temperature control medium, via the amount of water supplied, based on the temperature of the temperature control medium in the discharge line, due to a temperature difference or via the amount of heat removed.

An embodiment of the invention can provide that the temperature control channel in the plasticizing screw is formed by a tube in the plasticizing screw, this tube being arranged in a bore in the plasticizing screw, the length of the bore being at least 50% of the length of the plasticizing screw. However, it is preferably provided that the temperature control channel extends essentially to the tip of the plasticizing screw. This means that the temperature of each area of the surface of the plasticizing screw is influenced essentially uniformly by the temperature control medium guided in the temperature control channel, since the distance from the temperature control channel to the screw surface coming into contact with the plasticate is essentially constant over the entire length of the screw. It is not just the filling area of the screw that is tempered, for example, but the entire screw from the filling zone via the metering zone to the melting zone and the screw tip is tempered by the tempering medium in the tempering channel.

Although it should not be ruled out in principle that an arrangement according to the invention is used for an extruder, it is preferably provided that the plasticizing unit is also designed as an injection unit, the plasticizing screw being mounted in a plasticizing cylinder in an axially displaceable manner. The overall advantages of cycle-dependent temperature control are particularly useful with a common plasticizing and injection unit for an injection molding machine.

A constant water supply is achieved with the closed temperature control circuit according to the invention, it being particularly preferred that the temperature of the temperature control medium can be adjusted to over 60° C., preferably over 75° C., by the heating and/or cooling unit. Particularly preferably, the water temperature can be above 80°C. The cooling or heating unit is preferably designed as a type of "air conditioning unit" which heats or cools the tempering medium flowing back from the discharge line to a desired temperature, as required. However, it should not be ruled out that this temperature control device is designed as a pure heating unit or as a pure cooling unit. This essentially depends on the positive or negative difference between the desired temperature and the supplied temperature.

In principle, the temperature control device can always have a specific total amount of temperature control medium. If there is too little medium (water) in the entire circuit, a corresponding warning can be issued. However, it is also possible for an operator to regularly check the filling level to let. If the level is too low (e.g. due to a small leak), the temperature control medium can be refilled in the closed circuit. However, it is preferably provided that the entire temperature control device (or the heating and/or cooling unit) is connected to a normal water supply line despite being designed as a closed circuit and supplies itself with fresh water if required (e.g. if the filling level is too low). .

With the present invention, protection is also sought for an injection molding machine with an arrangement of plasticizing screw and temperature control device according to the invention.

The object according to the invention is also achieved by a method having the features of claim 11.

• • Antriebsenergie (Dissipation) und
• • Wärmeleitung über die Heizbänder am Außendurchmesser des Zylinders.

The plasticizing process is a very complex process that can also be represented as an energy balance. On the one hand, energy is supplied, such as

• • Drive energy (dissipation) and
• • Heat conduction via the heating bands on the outer diameter of the cylinder.

• • Verlustenergie durch Konvektion, Wärmeleitung und Wärmestrahlung und
• • bewusst abgeführte Energie über Kühlmäntel am Außendurchmesser des Zylinders oder der Schneckenkühlung.

On the other hand, energy is also dissipated via

• • Loss of energy through convection, thermal conduction and thermal radiation and
• • Deliberately dissipated energy via cooling jackets on the outer diameter of the cylinder or the screw cooling.

The residual energy, i.e. the energy supplied minus the energy dissipated, is the proportion that is used to heat the plastic. These energy shares per cycle or generally per unit of time provide important information about the overall process in terms of energy consumption and process stability. These energy components or energy components per unit of time (power) are therefore documented in order to be able to analyze, optimize and monitor the process.

• • die Durchflussmenge eines bekannten Mediums und
• • der Temperaturunterschied zwischen Vorlauf und Rücklauf.

A suitable measurement sensor system can also be used to calculate and document the proportion of energy or performance introduced by screw temperature control. Required for this is according to the invention

• • the flow rate of a known medium and
• • the temperature difference between flow and return.

The higher the flow rate and the greater the temperature difference between the flow and return, the higher the amount of energy dissipated per unit of time. If the amount of energy is related to the cycle time, this parameter can be used for process analysis, process optimization and process monitoring. If this value changes, it can be assumed that the melt quality and thus the part quality will also change.

With the likewise measurable energy components of the drive energy and the heating energy, an energy analysis can be calculated and, if the loss component of the plasticizing unit is known, the enthalpy change of the plastic can also be deduced.

The parameters flow rate and flow temperature of the screw temperature control can be used to change the plasticizing process in a targeted manner, e.g. to reduce the required torque during dosing in order to prevent the screw from being overloaded. There is also the possibility of counteracting process changes that occur over a long period of time, e.g. due to batch fluctuations or differences in temperature or humidity in the environment. The process can be optimized through targeted changes to the flow temperature and/or the flow rate with the aim of keeping the enthalpy change in the plastic as constant as possible over a long production period.

In order to achieve a temperature in the plasticizing screw that is adapted to the current process, especially in the case of long injection molding cycles, it can preferably be provided that the temperature of the temperature control medium in the temperature control channel of the plasticizing screw is regulated as a function of the injection molding cycle, preferably based on the current screw position or the current injection molding cycle time. This means that the control unit is also provided with information that is specific to the current cycle time or the current screw position, as a result of which a change in the temperature control circuit is carried out.

In order to improve the overall learning effect, so to speak, it can preferably be provided that the measured actual values of temperature of the temperature control medium in the inlet line, temperature of the temperature control medium in the outlet line, flow rate and, if applicable, flow time are documented in the data memory as actual values of previous injection molding cycles, depending on the injection molding cycle. That is, the individual, each measured The data is stored linked to injection cycle times, which means that the documentation is available for specific cycle times.

Particularly preferably, this can result in the control or regulation unit calculating process parameters for the temperature control process as a function of documented actual values read out, which, as time- or cycle-dependent control signals, determine the flow rate of the volume controller, the temperature control output of the heating and/or cooling unit and /or regulate the switch-on time of the heating and/or cooling unit.

• 1 schematisch die Bestandteile einer Plastifiziereinheit und
• 2 schematisch einen gesamten Temperierkreislauf.

Further details and advantages of the present invention are explained in more detail below on the basis of the description of the figures with reference to the exemplary embodiments illustrated in the drawings. Show in it:

• 1 schematically the components of a plasticizing unit and
• 2 schematic of an entire temperature control circuit.

1 shows - greatly simplified - a plasticizing unit 2 with a rotatably mounted and axially displaceable screw 1, which is mounted in a screw receiving shaft 24 and surrounded by a plasticizing cylinder 23. This plasticizing cylinder 23 has an injection nozzle 22 in the front area, pointing in the direction of the molds (not shown), and a funnel-shaped filling opening 21 in the rear area. The plasticizing cylinder 23 surround heating bands 25.

2 shows the essential components of a temperature control device with a temperature control circuit 3 comprising the temperature control channel 6 in the plasticizing screw 1, the discharge line 7, the heating and/or cooling unit 4 and the feed line 3, whereby it is irrelevant in which specific components of the plasticizing unit 2 or the entire injection molding machine, the heating and/or cooling unit 4 and thus parts of the lines 7 and 5 are formed. The heating and/or cooling unit 4 basically serves to cool or heat the temperature control medium circulating in the temperature control circuit 3 of the temperature control device and also to circulate it by means of a suitable pump (not shown). The plasticizing screw 1 has the temperature control channel 6 essentially over its entire length. Of course, only the foremost area in the area of the screw tip has to be closed, so that the temperature control channel 6 does not reach the screw tip
through the screw tip. This guarantees that the screw surface temperature is evenly influenced by the temperature of the temperature medium in the temperature control channel 6.

After the tempering medium has left the heating and/or cooling unit 4, it reaches a quantity controller 11, which controls the flow rate. The tempering medium then flows through the volume sensor 10, which measures the flow rate D, and then reaches the temperature sensor 8 in the inlet line 5. Instead of the volume regulator 11 and the volume sensor 10, a flow stabilizer can also be provided in principle. From the feed line 5, the temperature control medium finally reaches the temperature control channel 6 in the plasticizing screw 1. While flowing through the feed line 5, the current actual values W _act are measured by the sensors 10 and 8 and recorded as concrete values in degrees Celsius or in liters in a tabular data memory 12 is entered, with the flow rate D and flow time D _t values coming from the quantity sensor 10 and the temperature T _Z in the inlet line 5 coming from the temperature sensor 8 . The temperature sensor 8 can also be arranged in the cooling and/or heating unit 4 .

The temperature control channel 6 is formed in a tube 15 which itself is in turn arranged in a hollow bore 16 in the plasticizing screw 1 . A third temperature sensor 14 is provided in the area of the screw tip 1a of the plasticizing screw 1 and is connected to the transmission unit 18 via a signal line 17 . The measured temperature T _Z of the third temperature sensor 14 is also forwarded to the data memory 12 by this transmission unit 18 . This temperature sensor 14 does not necessarily have to be provided for the present invention, but it can provide helpful process parameters for the entire control.

After the temperature control medium has released and/or absorbed energy in the plasticizing screw 1 , it reaches the temperature sensor 9 via the discharge line 7 , which measures the temperature T _A in the discharge line 7 and delivers a corresponding value to the data memory 12 . Subsequently, the temperature control medium reaches the valve 19, which - depending on the filling level of the temperature control circuit 3 or depending on the measured temperature T _A - the temperature control medium

into the heating and/or cooling unit 4 or diverts it back into the inlet line 5 via a bypass line 20 . The bypass line 20 can be used in particular when the temperature T _A in the outflow line 7 already corresponds to a temperature desired in the inflow line 5 .

The current actual values W _act are stored in the data memory 12 at the current point in time t ₀ . In order to bring about corresponding changes in the temperature control circuit 3 from this information, the control or regulating unit 13 uses either documented actual values W _dok from previous injection molding cycles or other _stored setpoint values W setpoint . Of course, a combination of these values W _dok and W set can also _be used for the control. The control or regulating unit 13 uses the collected or stored data to determine control signals L, which regulate either the heat output of the heating and/or cooling unit 4 or the volumetric throughput of the volume regulator 11 or the pure switch-on time of the heating and/or cooling unit 4. Taxes. By appropriately monitoring and taking into account all values, the energy balance of the entire plasticizing process can be simulated as precisely as possible and a constant amount of energy dissipated in the area of the plasticizing screw 1 can be achieved by varying the flow rate parameters in the volume controller 11 or the heating output or switch-on time of the heating and/or cooling unit 4 be reached.

With regard to the schematic representation of the data memory 12 and the control or regulation unit 13, it should be pointed out that these can be arranged on a single circuit board or on different computers. It is essential that a logical combination of the individual values W _act and W _dok or W set _is made possible. The fact that the data memory 12 is partially dashed also shows that the values W _dok are supplied by the current actual values W _akt and so to speak represent a continuation over time. For this reason, the documented values W _dok are also linked to the injection molding cycle times t ₁ to t _n .

For an exact calculation of the energy balance, the temperature of tempering belts 25 surrounding the plasticizing cylinder 23 (not shown here) can be included in the overall regulation by means of appropriate sensors.

It is generally possible for the quantity sensor 10 and the quantity regulator 11 to be designed as one component. In principle, any fluid can be used as the temperature control medium, water being preferably used.

Particularly preferably, the temperature control circuit 3 can function as a kind of learning cycle, in which case, according to the respective cycle time t, heat must be dissipated by the temperature control medium during dosing and cooling, for example, while the screw must not be too cold during the injection process or heating, which means that heat is supplied via the tempering medium. For the learning cycle, it can be provided that the enthalpy change in the plastic being produced can flow into the control system as an additional parameter by an operator or by sensors.

Claims (14)

Arrangement with a plasticizing screw (1), a plasticizing unit (2) of an injection molding machine and a temperature control device for controlling the temperature of the plasticizing screw (1), the temperature control device having an inlet line (5), a temperature control channel (6) in the plasticizing screw (1) and an outlet line (7 ) through which a temperature control medium flows, and wherein a heating and/or cooling unit (4) for heating and/or cooling the temperature control medium is arranged between the outflow line (7) and the inflow line (5) and the inflow line (5), the temperature control channel (6) and the drain line (7) to form a closed temperature control circuit (3), characterized in that the temperature control device - a quantity sensor (10) for measuring the flow rate (D) of temperature control medium through the temperature control circuit (3), - a quantity controller ( 11) for controlling the introduction amount of temperature control medium in the temperature control circuit (3), - a data memory (12), in which at least the measured Temperatures (T _z , T _A ) of the temperature control medium in the inlet line (5) or in the heating and/or cooling unit (4) and in the outlet line (7) and the measured flow rate (D) as current actual values (W _akt ) can be stored, and - a control or regulating unit (13) by which, depending on the measured actual values (W _akt ) and _stored target values (W set ) or read out documented actual values (W _dok ) of previous injection molding cycles the temperature of the tempering medium in the tempering channel (6) of the plasticizing screw (1) can be controlled or regulated by outputting control signals (L) to the heating and/or cooling unit (4) and/or to the quantity controller (11). arrangement according to claim 1 , characterized in that the temperature control device has a temperature sensor (8) for measuring the temperature (T _Z ) of the temperature control medium in the supply line (5) or in the heating and/or cooling unit (4). arrangement according to claim 1 or 2 , characterized in that the temperature control device has a temperature sensor (9) for measuring the temperature (T _A ) of the tempering medium in the discharge line (7). Arrangement according to one of Claims 1 until 3 , characterized in that the temperature control device, preferably in the inlet line (5), has a flow stabilizer. Arrangement according to one of Claims 1 until 4 , characterized in that at least a third temperature sensor (14) is arranged in the plasticizing screw (1), preferably in the area of the screw tip (1a). Arrangement according to one of Claims 1 until 5 , characterized in that the temperature control channel (6) in the plasticizing screw (1) is formed by a tube (15) in the plasticizing screw (1), this tube (15) being arranged in a bore (16) in the plasticizing screw (1). is, the length of the bore (16) being at least 50% of the length of the plasticizing screw (1). Arrangement according to one of Claims 1 until 6 , characterized in that the plasticizing screw (1) is part of a plasticizing unit (2) which is also designed as an injection unit, the plasticizing screw (1) being mounted so as to be axially displaceable in a plasticizing cylinder (23). Arrangement according to one of Claims 1 until 7 , characterized in that the temperature of the tempering medium can be adjusted to over 60°C, preferably over 75°C, by the heating and/or cooling unit (4). Arrangement according to one of Claims 1 until 8th , characterized in that the tempering channel 6 extends substantially to the tip of the plasticizing screw (1). Injection molding machine with an arrangement according to one of Claims 1 until 9 . Method for tempering the plasticizing screw (1) of an arrangement according to one of Claims 1 until 9 , characterized by - a temperature sensor (8) for measuring the temperature (T _Z ) of the tempering medium in the supply line (5) or in the heating and/or cooling unit (4), - a temperature sensor (9) for measuring the temperature (T _A ) of the temperature control medium in the outlet line (7), - a quantity sensor (10) arranged in the temperature control circuit (3), preferably in the inlet line (5), for measuring the flow rate (D) of temperature control medium through the temperature control circuit (3) or a flow stabilizer , - a volume controller (11) for regulating the amount of temperature control medium introduced into the temperature control circuit (3), - a data memory (12), in which at least the measured temperatures (T _A , T _Z ) of the temperature control medium in the inlet line (5) or in the heating and / or cooling unit (4) and in the drain line (7) and the measured flow rate (D) are stored as current actual values (W _akt ) and - a control or regulating unit (13), depending on which the gem These actual values (W _act ) and _stored target values (W set ) or read out documented actual values (W _act ) of previous injection molding cycles by outputting control signals (L) to the temperature control device (4) and/or to the volume controller (11 ) the temperature of the tempering medium in the tempering channel (6) of the plasticizing screw (1) is controlled or regulated. procedure after claim 11 , characterized in that the temperature of the tempering medium in the tempering channel (6) of the plasticizing screw (1) depending on the injection molding cycle, preferably based on the current screw position or the current injection molding cycle time (t ₀ ), is regulated. procedure after claim 11 or 12 , characterized in that the measured actual values (W _akt ) temperature (T _Z ) of the temperature control medium in the inlet line (5), temperature (T _A ) of the temperature control medium in the outlet line (7), flow rate (D) and optionally flow time ( D _t ) are documented as actual values (W _dok ) of previous injection molding cycles (t ₁ , t _n ) depending on the injection molding cycle in the data memory (12). procedure after claim 12 or 13 , characterized in that the control or regulating unit (13) calculates process parameters for the tempering process as a function of documented actual values (W _dok ) that have been read out and which, as time- or cycle-dependent control signals (L), determine the flow rate (D) of the volume regulator ( 11), control or regulate the temperature control performance of the temperature control device (4) and/or the switch-on time of the temperature control device (4).

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