DE102024111872A1 - NOZZLE ARRANGEMENT FOR AN INJECTION MOLD - Google Patents

Abstract

A nozzle assembly (1) for an injection mold is used to supply molten plastic material into a cavity of the injection mold. The nozzle assembly (1) comprises a nozzle housing (2) which includes a melt channel (5) with a valve opening (3). A valve needle (4) is arranged in the melt channel (5) and is displaceable in an axial direction (z) with respect to the nozzle housing (2) between a closed position and an open position. An actuator (6) comprises an actuator housing (7) operatively connected to the nozzle housing (2) and a drive rod (8) operatively connected to the valve needle (4) for displacing the valve needle (4) between the closed position and the open position. A first force sensor (9), which operatively connects the actuator housing (7) and the nozzle housing (2), is provided to determine the forces acting on the valve needle (4) via the actuator housing (7).

Description

AREA OF REVELATION

The present disclosure relates to nozzle arrangements for injection molds and hot runners for injection molds, comprising one or more such nozzle arrangements.

BACKGROUND OF THE REVELATION

Over the years, numerous advancements have been made in hot runner systems, which incorporate one or more injection nozzles and cavity sensors, improving productivity and capabilities for injection molders. The way a cavity in a mold fills has a significant impact on the quality of the injection-molded part. Even minor changes in timing, temperature, and pressure while the molten plastic fills the cavity can affect the part's dimensions, aesthetics, and functional strength. Cavity sensors play a crucial role in monitoring the injection molding process, providing valuable data on timing, temperature, and pressure as the molten plastic fills the cavity in the mold.

For larger injection-molded parts, more than one injection nozzle is often used to inject molten plastic material into the cavity where the part is formed. Typically, nozzles with valve control are used to fill the cavity in a cascade manner (i.e., sequentially), thus achieving high part quality. Automatic cascade control can be implemented by using sensors positioned within the cavity.

Known approaches typically involve arranging cavity sensors within the mold cavity near the respective injection point (i.e., next to the gate of the respective injection nozzle). However, this approach requires additional effort on the part of the mold maker to install sensors within the mold cavity.

Published in 2014 on behalf of Synventive Molding Solutions US2014210119A1 relates to a device for carrying out an injection molding cycle, comprising: a distributor that directs the injection fluid to two or more gates, an actuator connected to each gate, each gate having a downstream sensor that detects a selected state of the injection fluid material, a controller wherein the downstream sensors determine a standard residence time, the controller comprising commands that compare the standard residence time with a calculated residence time connected to each of the gates and that adjust the speed or position of each of the actuators

US2021078226A1 , published in 2021 on behalf of Synventive Molding Solutions, refers to an injection molding system comprising: a first selected valve, one or more downstream valves supplying a fluid to a mold cavity, at least one fluid property sensor, each valve being connected to a position sensor that reports the opening of a sprue to the controller at an actual time of sprue opening, the controller automatically adjusting the command time to open the sprue channels in a subsequent injection cycle by an adjustment time corresponding to a time delay between a predetermined target time for sprue opening and an actual time for sprue opening, wherein the system forms a first part or multiple first parts or objects, the user inspects or measures the first part or multiple first parts or objects and manually adjusts the predetermined target time for sprue opening.

GENERAL DESCRIPTION OF THE REVELATION

One of the biggest challenges associated with conventional injection molding systems is the need to place sensors directly within the cavity. First, installing cavity sensors requires additional effort and resources during the injection molding system setup. Integrating the sensors into the cavity necessitates complex machining processes to ensure correct positioning and alignment. This not only increases the complexity of mold manufacturing but also extends setup time, thus impacting production efficiency. Second, the complex installation of cavity sensors carries a significant risk of sensor damage.

A first aspect of the disclosure relates to a nozzle arrangement for an injection mold, for feeding a molten plastic material into a cavity of the injection mold, in order to improve at least some of the limitations of conventional injection molds.

In a preferred embodiment, the nozzle arrangement comprises a nozzle housing containing a melt channel with a valve opening. The nozzle housing comprises a valve opening. Depending on the design, the valve opening is configured as a needle valve at a downstream end of the nozzle housing. However, the valve opening can also be located downstream of the nozzle housing (i.e., within the melt channel at an intermediate position). A valve needle is arranged in the melt channel and is axially displaceable with respect to the nozzle housing between a closed position, in which the valve needle closes the valve opening and thus blocks the passage of molten plastic material from the melt channel through the valve opening, and an open position, in which the valve needle allows the passage of molten plastic material from the melt channel through the valve opening. If necessary, the needle can be moved to intermediate positions between the fully open and fully closed positions to regulate the material flow. An actuator, comprising an actuator housing, is operatively connected to the nozzle housing. A drive rod of the actuator is operatively connected to the valve needle in order to move the valve needle between the closed position and the open position.

Preferably, a first force sensor is operatively connected to the actuator housing and the nozzle housing in order to determine the forces acting on the valve needle via the actuator housing during operation.

In the assembled state and/or during operation, the first force sensor is mechanically connected to the actuator housing and the nozzle housing. In other words, the first force sensor is part of the needle's load path when the actuator moves the valve needle relative to the nozzle housing between the closed and open positions during operation.

If applicable, the signal from the first force sensor is an indicator of the forces acting on the valve needle in the axial direction during operation. In particular, the signal from the first force sensor is indicative of a pressure (or a change thereof) on the valve needle (i.e., a front face of the valve needle).

The forces acting on the valve needle can be differentiated as follows: The force acting on the front of the valve needle when, during operation, the injection mold and the valve needle are in a closed position after the melt has been injected into the cavity, particularly during the holding pressure phase. Forces from shear stresses resulting from the flow of the melt along the valve needle in the melt channel. Dynamic forces resulting from the inertia during the opening and closing of the valve opening due to the valve needle being driven by the actuator.

The nozzle arrangement according to the disclosure offers a "plug and play" solution for nozzle assemblies that can be used, for example, in pre-installed hot runner systems. The nozzle arrangements according to the disclosure eliminate the need to place sensors adjacent to or within the cavities of the injection mold. This reduces manufacturing costs and minimizes the risk of damage to the (cavity) sensors. Furthermore, nozzle arrangements according to the disclosure can be retrofitted into existing injection molds that previously had no sensors, without the need to retrofit sensors in the existing cavities.

Depending on the application, the actuator housing is mounted in a floating configuration and is axially displaceable relative to the nozzle housing by means of a linear bearing. The actuator can be hydraulic, pneumatic, or electric, depending on the application requirements. In the case of a hydraulic or pneumatic actuator, the drive rod is mechanically coupled to a piston of the actuator. Preferably, the drive rod is formed integrally with the piston. A rotation stop can be arranged between the drive rod and the actuator housing to prevent rotation of the drive rod relative to the actuator housing, particularly if a position sensor, configured to detect the axial position of the piston, is mounted on the actuator housing.

In an electric actuator, the drive rod can be multi-part, so that an electric motor of the electric actuator can be arranged offset from a central axis of the needle.

In some versions, the linear bearing comprises at least one column against which the actuator housing is slidably arranged. For a stable linear bearing, typically more than two, preferably four, columns are provided. This arrangement increases the overall stability of the linear bearing.

Preferably, the actuator housing includes a recess in which the at least one column extends. Typically, the actuator housing includes a separate recess for each column. The recess can be designed as a through-hole, with the column extending through the through-hole in the assembled state. extends so that the linear bearing is arranged to be displaceable between the recess and the column in relation to each other.

In some variants, the actuator housing is operatively connected to an adjustment device for adjusting the actuator housing in relation to the nozzle housing in the axial direction, for adjusting the axial position of the valve needle.

If necessary, at least one column is rigidly connected to the adjustment device. If four columns are provided, they can form a mounting cage for the actuator housing in combination with the adjustment device. In the assembled state, the actuator housing is suspended within this mounting cage. The adjustment device supports the actuator housing axially and is designed to adjust the axial position of the actuator housing relative to the mounting cage.

Good results can be achieved if the first force sensor is positioned between the actuator housing and the adjustment device. In particular, the first force sensor can be positioned between the actuator housing and the mounting cage.

Depending on the design, the adjusting device includes an adjusting screw for setting the axial position of the actuator housing relative to the nozzle housing. The adjusting device may include a plate with an opening that has an internal thread to receive the adjusting screw when assembled. This plate can serve as the upper plate of the mounting cage. Preferably, the columns are attached to the upper plate.

The mounting cage can include a mounting plate which, in the assembled state, is arranged axially opposite the cover plate, with the columns connecting the cover plate and the mounting plate. The actuator housing is arranged between the cover plate and the mounting plate, with the columns extending through corresponding recesses in the actuator housing and being guided linearly.

In a preferred embodiment, the first force sensor is arranged concentrically around a mounting screw that firmly connects the actuator housing to the adjusting device. Optionally, the mounting screw also connects the adjusting screw and the actuator housing.

Alternatively or additionally, the first force sensor can be arranged concentrically around a mounting projection on the actuator housing, which firmly connects the actuator housing to the adjusting device. The mounting projection can include an internal and/or external thread for connection to the adjusting device. The actuator housing can be formed integrally with the mounting projection.

The mounting screw or mounting projection can form a single-point suspension for the actuator housing. Accordingly, forces acting axially on the actuator housing, e.g., caused by forces acting on the front of the valve needle, are transmitted to the adjusting device via this single-point suspension. It is advantageous if the mounting cage is fixed in position relative to the nozzle housing during operation.

Preferably, the first force sensor is arranged coaxially to the valve needle. However, an offset arrangement is also conceivable, with typically two or more first force sensors arranged symmetrically to a central axis of the needle or the drive rod.

Alternatively or additionally to the first force sensor, a second force sensor can be arranged between the actuator's drive rod and a rear end of the valve needle to determine the forces acting on the valve needle, particularly in the axial direction. Alternatively or additionally, the second force sensor can be integrated into the actuator's drive rod.

Good results can be achieved if the first force sensor is a piezoelectric sensor. Preferably, the first force sensor is pre-tensioned in the mounted state using the mounting screw. This allows both tensile and compressive forces in the axial direction of the valve needle to be measured. Alternatively or additionally, the first force sensor can also include a strain gauge. The same applies to the second force sensor, if present.

Depending on the application, the first force sensor is designed as a load cell that includes a strain gauge. In some versions, the adjusting screw of the setting device can function as the load cell.

In another aspect of the disclosure, the valve needle includes a front face on which a first temperature sensor is located. In combination with the first and/or second force sensor, significant technical advantages can be achieved by determining both the temperature of the molten plastic injected into the cavity and its pressure on the front face of the needle. A first temperature sensor located on a front face of the valve needle, However, this is fundamentally independent of the disclosure relating to the first (and/or second) force sensor. This aspect therefore constitutes an independent inventive concept.

The forces determined by means of the first and/or the second force sensor can be dynamic and/or static loads during operation, such as forces resulting from the inertia when the valve needle is moved axially by means of the actuator and/or forces resulting from the pressure within the cavity and/or within the melt channel acting on the valve needle, in particular on a front face of the valve needle, which is located, for example, adjacent to a cavity wall of a mold cavity in an injection mold.

Good results are possible if the first temperature sensor element is arranged for direct thermal contact with the molten plastic that is injected into the cavities during operation.

Preferably, the first temperature sensor is crimped from the front and welded to the front of the valve needle. Depending on the desired application, the front end of the valve needle is then machined (ground) to match the final geometry of the valve needle.

The first temperature sensor is preferably a type N thermocouple. The positive leg of the first temperature sensor can be made of NiCroSil and the negative leg of another nickel alloy, NiSil. The legs of the first temperature sensor can extend through a sleeve that partially encapsulates the first temperature sensor. This sleeve preferably forms part of the front of the valve needle, so that the first temperature sensor comes into direct contact with the molten plastic that is injected into the cavity during operation.

For connecting the first temperature sensor, the valve needle includes a longitudinally extending bore in which a cable is operatively connected to the first temperature sensor located at the front of the valve needle. The bore is preferably a through-bore in the axial direction, in the front end of which the first temperature sensor is inserted. The cable exits the valve needle at a rear end, which is located opposite the front end of the valve needle.

The drive rod preferably includes an axially extending recess for partially receiving the cable of the first temperature sensor, so that the cable cannot bend beyond its minimum bending radius when it is routed laterally away from the drive rod.

To support the cable of the first temperature sensor, particularly when the drive rod moves the associated valve needle between the closed and open positions during operation, a cable support element is arranged on the drive rod to guide the cable laterally away from the drive rod. The support element preferably includes a guide surface with a curvature equal to or greater than the minimum bending radius of the cable. This prevents damage to the cable, as bending beyond its minimum bending radius is prevented.

For easy setup, the drive rod is operatively connected to a rear end of the valve needle by means of a quick-release coupling.

Alternatively or in addition to the first temperature sensor, a second temperature sensor is arranged at a front end of the nozzle housing. Preferably, the nozzle housing comprises a front face on which the second temperature sensor is arranged.

For connecting the second temperature sensor, the nozzle housing includes a channel extending at least partially along the surface of the nozzle housing, in which a cable operatively connected to the second temperature sensor is arranged.

Depending on the design, the nozzle housing is multi-part and comprises a substantially tubular body and a tip bushing. The tip bushing can be attached to the body by means of a threaded connection. The second temperature sensor element can be arranged in the tip bushing. Preferably, a front face of the tip bushing is designed to be embedded in a cavity of an injection mold. Good results are achieved when the second temperature sensor is embedded in the front face of the tip bushing in order to directly determine the temperature of the molten plastic injected into the cavity.

The valve needle can essentially be tubular. The front end of the valve needle can have different geometries depending on the application, such as cylindrical or conical.

In some versions, centering devices are arranged in the nozzle housing to guide the valve needle. The needle centering means preferably comprise at least one radially extending rib with an inner guide surface that centers the needle radially during operation.

Another aspect of the disclosure relates to a hot runner arrangement for an injection mold. The hot runner arrangement typically comprises at least one, preferably two or more nozzle arrangements according to the disclosure, which are attached to a common manifold and distribute molten plastic material into the respective melt channels during operation.

Such hot runner systems can be installed in an injection mold without the need for additional sensors within the mold. Consequently, no additional wiring for cavity sensors is required, resulting in cost reductions for the mold manufacturer and a lower risk of damage to (cavity) sensors. A hot runner system according to the disclosure can be considered "plug-and-play" because it can be inserted into a prepared injection mold without the need for additional sensors in the cavity (or cavities), while providing the same level of process control (i.e., cascaded nozzle opening).

Preferably, the hot runner system includes a junction box connected to the sensors of at least one nozzle assembly to receive signals from them. Typically, the junction box is connected to the sensors of two or more nozzle assemblies. The junction box preferably provides an interface, such as one or more electrical connectors, for connection to a controller (e.g., a cascade controller configured to control the actuators). The interface is configured to transmit the sensor signals to the controller.

It is understood that both the preceding general description and the following detailed description represent embodiments and serve to provide an overview or framework for understanding the nature and features of the disclosure. The accompanying drawings provide further understanding and form part of this description. The drawings illustrate various embodiments and, together with the description, serve to explain the principles and operation of the disclosed concepts.

BRIEF DESCRIPTION OF THE DRAWINGS

• 1 eine perspektivische Ansicht einer teilweise zerlegten Heißkanalanordnung, die eine erste Variante einer Düsenanordnung gemäß der Offenbarung umfasst;
• 2 eine Explosionsdarstellung der ersten Variante von 1;
• 3 eine perspektivische Ansicht einer teilweise zerschnittenen Heißkanalanordnung, die eine zweite Variante einer Düsenanordnung gemäß der Offenbarung umfasst;
• 4 eine perspektivische Ansicht einer teilweise zerschnittenen Heißkanalanordnung, die eine dritte Variante einer Düsenanordnung gemäß der Offenbarung umfasst;
• 5 eine perspektivische Ansicht einer teilweise zerschnittenen Antriebsstange einer Düsenanordnung gemäß der Offenbarung;
• 6 die Antriebsstange aus 5 in einer anderen perspektivischen und geschnittenen Ansicht;
• 7 eine perspektivische Ansicht eines vorderen Endes einer ersten Variante einer Ventilnadel gemäß der Offenbarung, sowie eine durch die Schnittlinie BB angedeutete Schnittansicht; und
• 8 eine perspektivische Ansicht eines vorderen Endes einer zweiten Variante einer Ventilnadel gemäß der Offenbarung, sowie eine durch die Schnittlinie CC angedeutete Schnittansicht.

The disclosure described herein will be better understood from the detailed description below and the accompanying drawings, which should not be considered as limiting the disclosure described in the accompanying claims. The drawings show:

• 1 a perspective view of a partially disassembled hot runner arrangement comprising a first variant of a nozzle arrangement according to the disclosure;
• 2 an exploded view of the first variant of 1 ;
• 3 a perspective view of a partially cut-away hot runner arrangement comprising a second variant of a nozzle arrangement according to the disclosure;
• 4 a perspective view of a partially cut-away hot runner arrangement comprising a third variant of a nozzle arrangement according to the disclosure;
• 5 a perspective view of a partially cut drive rod of a nozzle assembly according to the disclosure;
• 6 the drive rod 5 in a different perspective and sectioned view;
• 7 a perspective view of a front end of a first variant of a valve needle according to the disclosure, as well as a sectional view indicated by the section line BB; and
• 8 a perspective view of a front end of a second variant of a valve needle according to the disclosure, as well as a sectional view indicated by the section line CC.

DESCRIPTION OF THE EXECUTION FORMS

The following section refers in detail to specific embodiments, examples of which are shown in the accompanying drawings, which illustrate some, but not all, of their features. Indeed, the embodiments disclosed herein can be embodied in many different forms and should not be interpreted as being limited to those presented here; rather, these embodiments are made available so that this disclosure meets applicable legal requirements. Wherever possible, the same reference numerals are used to refer to identical components or parts.

1 shows a hot runner arrangement 26, which includes a first variant of a nozzle arrangement 1 according to the disclosure. 2 shows the first variant of the nozzle arrangement 1. 1 in an exploded view.

The nozzle assembly 1 comprises a nozzle housing 2, which is attached to a distributor 27. In the illustrated embodiment, the nozzle housing 2 is sealed to the distributor 27 by means of a screw connection. The nozzle housing 2 includes a melting channel 5, which receives molten plastic material from the distributor 27 during operation. A valve needle 4 is arranged in the melting channel 5 and is slidable between a closed and an open position. In the closed position, the valve needle closes a valve opening 3, preventing any molten plastic material from flowing through it. In the open position, the valve needle 4 allows molten plastic material to flow through. In the first embodiment, the valve opening 3 is located at a front end 23 of the nozzle housing 2.

Opposite the nozzle housing 2, relative to the distributor 27, an actuator 6 is arranged. The actuator 6 comprises an actuator housing 7 and a drive rod 8. In the assembled state, the drive rod 8 is detachably connected to a rear end 17 of the valve needle 4 in order to move the valve needle 4 between the open and closed positions during operation. The actuator 6 shown is, for example, a pneumatic or hydraulic actuator that includes a piston 37 which is axially displaceable in the z-direction within the actuator housing 7. A rotation stop 31 is arranged between the piston 37 and the actuator housing 7, which prevents rotation of the drive rod 8 relative to the actuator housing 7.

A first force sensor 9 is arranged on the upper side of the actuator housing 7. This first force sensor 9 is arranged in a load path from the valve needle 4 via the drive rod 8, the piston 37 and the actuator housing 7 to the nozzle housing 2 in order to determine the forces acting on the valve needle 4.

In the illustrated variants, the actuator housing 7 is arranged in a mounting cage comprising a cover plate 28, a mounting plate 29, and four columns 11 extending axially z between the cover plate 28 and the mounting plate 29. The actuator housing 7 has four recesses, each to receive a column, which forms a linear bearing 9 of the actuator housing 7 in the mounting cage in the axial z direction. The actuator housing 7 is attached to the cover plate 28 of the mounting cage. The mounting plate 29 of the mounting cage is associated with the distributor 27 and is thus fixed in position relative to the nozzle housing 2, completing the load path.

In the first variant, the first force sensor 9 is arranged axially z between the top of the actuator housing 7 and the cover plate 28 of the mounting cage. This first variant includes an adjustment device 13 located on the cover plate 28. The adjustment device 13 comprises an adjusting screw 14 and a fastening screw 15. The adjusting screw 14 has an external thread and is located in an opening in the cover plate 28, which has an internal thread for engaging the adjusting screw 14, so that the axial position of the adjusting screw 14 can be adjusted by turning the adjusting screw 14. The fastening screw 15 firmly connects the adjusting screw 14 and the actuator housing 7. As shown in 2 As can be seen, the first force sensor 9 is essentially ring-shaped and arranged concentrically around the fastening screw 15. In this arrangement, the first force sensor 9 is also coaxial with the valve needle 4.

In the first variant, as in 1 As shown, the first force sensor 9 is a piezoelectric force sensor, wherein the fastening screw 15 clamps the first force sensor 9 between the actuator housing 7 and the adjusting screw 14, thereby pre-tensioning the sensor.

In addition to the first force sensor 9, a first temperature sensor 19 is provided. The valve needle 4 includes a front surface 19 on which the first temperature sensor 19 is located. As shown in the 7 and 8 As can be seen most clearly, the first temperature sensor 19 is arranged in a bore 20 (through bore) that extends in the axial direction z. The first temperature sensor 19 comprises two legs 35 (one positive and one negative) that extend in the axial direction z to the front face 18 of the valve needle 4. The front face 18 of the valve needle 4 is partially formed by a sleeve 36 of the first temperature sensor 19, which is inserted into the bore 20. A cable 21 of the first temperature sensor 19 extends along the bore 20 and exits the bore 20 at a rear end 17 of the valve needle 4. The first variant of the valve needle 4, as shown in 7 The one shown has a conical front section. In contrast, the second variant of the valve needle 4, as shown in 8 depicted, a cylindrical front section.

The rear end 17 of the needle is attached to the drive rod 8 of the actuator 6. This is shown in the 5 and 6 The drive rod includes a detachable quick-release coupling 25 for detachable connection to the rear end 17 of the valve. needle 4. Inserting the rear end 17 into the quick coupling 25 is in 6 The drive rod 8 includes an axially extending recess 30 for partially receiving the cable 21. Additionally, a cable support element 32 is arranged on the drive rod 8 to guide the cable 21 laterally away from the drive rod 8 and away from the recess 30. The cable 21 is guided by a guide surface 38 of the cable support element 32, which has a curvature greater than or equal to the minimum bending radius of the cable 21.

In 3 A second variant of a nozzle arrangement 1 according to the disclosure is shown. The second variant differs from the first variant in that a second temperature sensor 22 is arranged at a front end 23 of the nozzle housing 2 and a second force sensor 16 is arranged on the drive rod 8. The second temperature sensor 22 is embedded in a front face of a tip bushing 39 of the nozzle housing 2. The second force sensor 16 rests against the rear end 17 of the valve needle.

In 4 A third variant of a nozzle arrangement 1 according to the disclosure is shown. The third variant differs from the first and second variants in that the first force sensor 9 is designed as a load cell 33, which includes a strain gauge 34. In the variant shown, the load cell 33 acts like the adjusting screw 14 of the first and second variants, with which the axial position of the actuator housing 7 relative to the distributor 27 and thus to the nozzle housing 2 can be adjusted.

It is assumed that various changes can be made without exceeding the scope of the revelation.

REFERENCE MARK LIST

1

Nozzle arrangement

2

Nozzle housing

3

Valve opening

4

Valve needle

5

Melt channel

6

actuator

7

actuator housing

8

Drive rod (actuator)

9

First force sensor

10

Linear bearings

11

Column (linear bearing)

12

Recess (actuator housing)

13

Adjustment device

14

Adjusting screw (adjusting device)

15

Mounting screw (adjusting device)

16

Second force sensor

17

Rear end (valve needle)

18

Front (valve needle)

19

First temperature sensor

20

Bore (valve needle)

21

Cable (first temperature sensor)

22

Second temperature sensor

23

Front end (nozzle housing)

24

Front (nozzle housing)

25

quick coupling

26

Hot runner system

27

Distribution

28

Upper plate

29

Mounting plate

30

Recess (drive rod)

31

Rotation stop

32

Cable support element

33

load cell

34

strain gauges

35

Leg (temperature sensor)

36

Sleeve (temperature sensor)

37

Piston (actuator)

38

Guide surface (cable support element)

39

Tip bushing (nozzle housing)

QUOTES CONTAINED IN THE DESCRIPTION

This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions.

Cited patent literature

• US 2014210119A1 [0005]
• US 2021078226A1 [0006]

Claims (16)

Nozzle assembly (1) for an injection mold, for supplying molten plastic material into a cavity of the injection mold, wherein the nozzle assembly (1) comprises: a. a nozzle housing (2) comprising a melt channel (5) arranged therein with a valve opening (3); b. a valve needle (4) arranged in the melt channel (5) and displaceable in an axial direction (z) with respect to the nozzle housing (2) between i. a closed position in which the valve needle (4) closes the valve opening (3) and thereby blocks the passage of molten plastic material from the melt channel (5) through the valve opening (3), and ii. an open position in which the valve needle (4) allows the passage of molten plastic material from the melt channel (5) through the valve opening (3); c. an actuator (6) comprising i. an actuator housing (7) operatively connected to the nozzle housing (2), and ii. a drive rod (8) operatively connected to the valve needle (4) to move the valve needle (4) between the closed position and the open position; d. a first force sensor (9) operatively connecting the actuator housing (7) and the nozzle housing (2) to determine the force acting on the valve needle (4) via the actuator housing (7) during operation. Nozzle arrangement (1) according to Claim 1 , wherein the actuator housing (7) is arranged to be displaceable in the axial direction (z) relative to the nozzle housing (2) by means of a linear bearing (10). Nozzle arrangement (1) according to Claim 2 , wherein the linear bearing (10) comprises at least one column (11) against which the actuator housing is arranged to be displaceable. Nozzle arrangement (1) according to Claim 3 , wherein the actuator housing (7) includes a recess (12) in which the column (11) extends. Nozzle arrangement (1) according to one of the preceding claims, wherein the actuator housing (7) is operatively connected to an adjusting device (13) for adjusting the actuator housing (7) in relation to the nozzle housing (2) in the axial direction (z) for adjusting the axial position of the valve needle (4), in particular by means of an adjusting screw (14) of the adjusting device (13). Nozzle arrangement (1) according to Claim 5 , wherein the first force sensor (9) is arranged between the actuator housing (7) and the adjusting device (13). Nozzle arrangement (1) according to Claim 5 or 6 , wherein the first force sensor (9) is arranged concentrically around a fastening screw (15) which firmly connects the actuator housing (7) to the adjusting device (13). Nozzle arrangement (1) according to one of the preceding claims, wherein the first force sensor (9) is arranged coaxially to the valve needle (4). Nozzle arrangement (1) according to one of the preceding claims, wherein alternatively or additionally to the first force sensor (9) a second force sensor (16) is arranged between the drive rod (8) of the actuator (6) and a rear end (17) of the valve needle (4) to determine the forces acting on the valve needle (4) and/or the second force sensor (16) is integrated into the drive rod (8) of the actuator (6). Nozzle arrangement (1) according to one of the preceding claims, wherein the first force sensor (9) is a piezoelectric sensor which is pre-tensioned in particular in the mounted state by means of the fastening screw (15). Nozzle arrangement (1) according to one of the preceding claims, wherein the valve needle (4) comprises a front face (18) on which a first temperature sensor (19) is arranged. Nozzle arrangement (1) according to Claim 11 , wherein the valve needle (4) comprises a longitudinally extending (z) bore (10) in which a cable (21) is operatively connected to the first temperature sensor (19) which is located on the front (18) of the valve needle (4). Nozzle arrangement (1) according to one of the preceding claims, wherein a second temperature sensor (22) is arranged at a front end (23) of the nozzle housing (2). Nozzle arrangement (1) according to Claim 13 , wherein the nozzle housing (2) comprises a front (24) on which the second temperature sensor (22) is arranged. Nozzle arrangement (1) according to Claim 13 or 14 , wherein the nozzle housing (2) comprises a channel (5) which extends at least partially along the surface of the nozzle housing (2) in which a cable operatively connected to the second temperature sensor (22) is arranged. Nozzle arrangement (1) according to one of the preceding claims, wherein the drive rod (8) is operatively connected to a rear end (17) of the valve needle (4) by means of a quick coupling (25).