Device for producing preforms for containers made of a plasticized plastic material

Abstract

The invention relates to a device for producing preforms for containers made of a plasticized plastic material, which can be transported by means of a channel guide (10), forming a branching arrangement (14) having branching points (16) and connecting channels (18), within an extrusion head (12) from an inlet (20) along a supply direction (26) to multiple separate discharge points (22), which each supply a production device (24) for each preform in a discharge direction (28) which is different from the supply direction (26), characterized in that the mass throughput of the plastic material can be controlled by means of an adjusting device (34) at least in one part of the channel guide (10).

Description

[0001] Rommelag Engineering GmbH

[0002] Talstraße 22-30, 74429 Sulzbach-Laufen, Germany

[0003] device

[0004] The invention relates to a device for producing preforms for containers from a plasticized plastic material, which can be transported within an extrusion head from an inlet along a supply direction to several separate discharge points by means of a channel guide forming a branching arrangement with branching points and connecting channels, each of which supplies a production unit for each preform in a discharge direction that differs from the supply direction.

[0005] German patent DE 10 2007 030 677 B4 discloses a multiple extrusion head for extrusion blow molding machines, comprising several first extrusion heads arranged in a first row.

[0006] forming a plane, several second extrusion heads, which are arranged side by side in a second row, forming a second plane parallel to the first plane, are arranged side by side in a fixed position, a first distribution device with first distribution channels, which are arranged in a plane corresponding to the first plane and of which each is connected to a first extrusion head and all have a common first material inlet, a second distribution device with second distribution channels, which are arranged in a plane corresponding to the second plane and of which each is connected to one of the second extrusion heads and all have a common second material inlet, wherein the first distribution device is separated in the area of ​​the first plane and the second distribution device is separated in the area of ​​the second plane, a third distribution device with third distribution channels,which are arranged in a third plane perpendicular to the first and second planes, wherein the two third distribution channels originate from a common third ground input, one of the two third distribution channels is connected to the first ground input and the other of the two third distribution channels is connected to the second ground input, and the third distribution device is separated in the third plane.

[0007] Overall, the direction of extension of the distribution channels is chosen in such a way that the mass is evenly distributed onto the extrusion heads, whereby the division also simplifies cleaning and the design of the channels within the channel guide does not necessarily have to be limited to a cylindrical bore.

[0008] DE 10 2020 212 987 A1 discloses a melt distributor for polymer melts, comprising a melt distributor block with a multi-channel system, wherein the multi-channel system has an inlet for the polymer melt, then branches out by means of several successive branches and further branches over several generations of melt channels to a multitude of outlets, wherein the melt channels have smaller diameters from generation to generation and their cross-sectional shape and diameters are selected such that the flow resistance for the polymer melt through the multi-channel system remains at least essentially identical, so that two different polymer melts can be processed seamlessly one after the other with the melt distributor.by ensuring that the subsequent polymer melt flushes out the previous polymer melt without any dead zones and / or that, when switching from a first polymer melt to a second, different polymer melt, the flow resistance along the multi-channel system remains at least essentially identical, so that the melt distributor is suitable for several different melts.

[0009] This creates a melt distributor that provides a polymer melt downstream at the outlet side of the melt distributor with a larger total outlet cross-sectional area than was supplied upstream. This is intended to address any limitations in the design and dimensioning, particularly with regard to the extrusion die.

[0010] EP 3 684 695 B1 discloses a device for producing and filling containers, in which a single oval tube of plasticized plastic material, emerging from a simple extrusion head, can be extruded into an open mold, wherein, by means of a filling device, at least the filling material can be introduced into the respective container by means of filling mandrels which, at least during operation, extend through the extrusion head along at least a series of passages, wherein the extrusion head has a cuboid shell and wherein the height of the extrusion head, viewed parallel to the orientation of the respective filling mandrel, is less than the length of the extrusion head along the respective series of passages.Because the cuboid shell consists of a lower and an upper shell part, at least one of which has a channel for the plasticized material containing an annular space with a receiving rib in the center. This rib has individual longitudinal openings in the form of passages for the respective filling mandrels, enabling the extrusion of a plastic tube with a homogeneous wall thickness distribution, while simultaneously reducing the required installation space. Furthermore, the device ensures an unobstructed flow of sterile air.

[0011] Based on this prior art, the invention aims to create a multi-extrusion head with an integrated melt distributor that is improved compared to the prior art.

[0012] A device with the features of claim 1 in its entirety solves such a problem.

[0013] According to the characterizing part of claim 1, the mass flow rate of the plastic material can be controlled by means of an adjustment device, at least in a portion of the channel, thus enabling individual adjustment of the volume flow rate or the exit velocity of the plasticized plastic material for the individual tubes or preforms to be extruded in the area of ​​the respective discharge points. This is achieved by redirecting the flow direction of the plastic material from a supply direction within the extrusion head to a discharge direction for the production of the tubes by the manufacturing unit. If necessary, the adjustment device can also be used to completely block at least parts of the channel, for example, to allow cleaning and / or maintenance work to be carried out on the manufacturing unit downstream of the extrusion head.A multi-extrusion head for producing pressure-molded hollow plastic bodies is thus created, in which several tubular preforms are simultaneously extruded synchronously from several adjacent extrusion dies of a multi-extrusion head and fed directly, or after a section of tubing has been cut off, to blow mold cavities by means of a transport system. In these cavities, the tubular preforms are expanded into hollow plastic bodies by means of a pressure differential after the blow mold cavities have been closed. Subsequently, the respective mold is opened and the empty container is demolded, or, in the preferred application within the framework of a so-called BFS process (described in detail in DE 10 2020 002 077 A1, DE 10 2020 004 564 A1 and EP 2 909 000 B1), while still in the mold, it is filled with a predetermined fluid by means of a filling mandrel, sealed, and then discharged from the mold.As part of the manufacturing process, the mass throughput or exit velocity of the plastic tube to be produced from the respective dispensing nozzle can be adjusted very precisely using the adjustment device, which benefits the production process as a whole.

[0014] In a preferred embodiment of the device according to the invention, the adjusting device specifies the respective mass throughput from a central location, which is situated on a freely accessible side of the extrusion head; in this way, particularly simplified handling of the device is achieved.

[0015] In a further preferred embodiment of the device according to the invention, the adjustment device comprises a plurality of individual adjustment means, the number of which corresponds to the number of connecting channels and their sections that are to be controlled. It is particularly preferred that the number of individual adjustment means corresponds to the number of separate dispensing points. In this way, precise metering of the desired mass throughput of the plastic material is achieved for each dispensing point.

[0016] In a further preferred embodiment of the device according to the invention, the respective adjusting means is formed from a cartridge that extends through the free side of the extrusion head and is fixed to wall sections thereof. An adjusting means, which is longitudinally movable within the cartridge, defines the free opening cross-section of an associated channel section with one free end region and serves for operation with its other free end region. Thanks to the cartridge design, all adjusting means can be designed in a standardized manner, which increases reliability and reduces manufacturing costs. In particular, one free side of the extrusion head is easily accessible from the outside for the respective adjusting means, and manual operation is possible, including operation by means of a handling system.

[0017] Preferably, the cartridge is designed as a screw-in cartridge and has an external thread for fixing it in wall sections of the extrusion head, with a threaded section on the inside of the screw-in cartridge for longitudinal movement of the adjusting element. Preferably, the adjusting element also has a rounded, convex shell, particularly hemispherical, shape on its free end face. In this way, the adjustable shell, in conjunction with the opposite wall of the respective channel section of the channel guide, forms a type of variable orifice or throttle cross-section, resulting in a predefinable change in the free channel cross-section.Due to the increased flow resistance, the mass or volume flow rate changes depending on the generated pressure gradient, with flow rate and pressure drop fundamentally depending on the viscosity of the plastic material used. In any case, the mass flow rate within the channel can be controlled or regulated very precisely in this way.

[0018] It is advantageous if the respective adjusting device is arranged at an angle of 80° to 100°, preferably 90°, to the course of the associated connecting channel. This minimizes undesirable disturbances to the flow of the plastic material in the area of ​​the adjusting device, such as dead spaces.

[0019] In a further particularly preferred embodiment of the device according to the invention, the plastic material can be discharged into the annular discharge point in the extrusion head via a sequentially final connecting channel of the channel guide in the supply direction. This annular discharge point is accessible to a forming and / or filling unit of the manufacturing device. Preferably, the sequentially final connecting channel opens into the annular discharge point after a single or multiple, particularly double, deflection, and the adjusting means for adjusting the flow rate is arranged in the area of ​​the last deflection before the channel section enters the discharge point. In principle, it is also possible to control two adjacent discharge points with just one adjusting means, which reduces the number of adjusting means required.

[0020] In a further preferred embodiment of the device according to the invention, at least some, preferably all, of the adjusting means are arranged along a common actuation plane on the extrusion head. This makes it possible to observe all extruded tubes simultaneously from a central point on the extrusion head and to make and / or monitor the correspondingly fine adjustments to the adjusting means. The invention also relates to an extrusion head, in particular equipped with a device as described above, with a head housing in which a channel guide is arranged, which branches out and has a plurality of branching points and connecting channels, wherein at least parts of the channel guide, in the form of at least one connecting channel, have different cross-sectional shapes and / or cross-sectional areas.In particular, the cross-sectional area of ​​the channel at the inlet side is larger than the cross-sectional area of ​​the channel at a branch. Preferably, a circular channel cross-section is chosen at the inlet side and in the area of ​​the adjustment means, while non-circular, i.e., preferably superelliptical (also referred to as lamé ovals), and especially preferably longitudinally oval, cross-sectional shapes can be used in the intermediate sections. A longitudinal oval is characterized by two long, parallel, opposite straight sides and two identical, opposite semicircles. This results in an unobstructed and largely undisturbed flow pattern within the multi-extrusion head.

[0021] In a further particularly preferred embodiment of the extrusion head according to the invention, the respective connecting channel of the channel guide has a round (circular) distribution cross-section starting from its inlet or distribution side. After a predetermined distance, this cross-section transitions into a non-circular (e.g., longitudinally oval or superelliptical) discharge cross-section within the channel guide, which is preferably smaller than the inlet or distribution cross-section. It is further preferred that non-circular cross-sections are provided in the area between the inlet and the respective outlet of a section of the channel guide. Although this can lead to pressure losses within the melt flow path, such cross-sections have surprisingly proven to be particularly advantageous for the homogeneity of the overall flow path.A longitudinally oval cross-sectional shape (also known as a slot) of a channel can be produced much more easily, quickly and therefore more cost-effectively compared to elliptical or superelliptical cross-sectional shapes, for example by milling.

[0022] For a compact design, in a further preferred embodiment of the extrusion head according to the invention, the channel guide has a double deflection in the direction of the respective discharge point or, angled by 90°, a connecting channel branches off from the other channel guide in the direction of the discharge point.

[0023] It is particularly preferred that, starting from the entrance of the channel, it undergoes a deflection in the direction of the respective discharge point of between 90° and 180°, particularly preferably of about 170°.

[0024] The device according to the invention will now be explained in more detail with reference to an exemplary embodiment shown in the drawing. The drawing shows, in a general and not to scale, the following:

[0025] Figure 1 shows a perspective view of a cross-section through a multi-extrusion head;

[0026] Figure 2, in the form of a longitudinal section view, shows the

[0027] Multiple extrusion head according to Figure 1 with inserted filling mandrel device;

[0028] Figure 3 shows a top view of the multiple extrusion head according to Figure 1;

[0029] Figure 4 shows a modified embodiment of the multiple extrusion head according to Figures 1 and 3 in a comparable top view;

[0030] Figures 5 and 6 show, in elevation and sectional views respectively, an adjusting element of an adjusting device as used in Figures 1, 3, and 4. Figure 1 shows parts of a device for producing tubular preforms (not shown) for container products, including ampoules and / or bottles, from a plasticized plastic material. For this purpose, the device has a channel guide, designated as a whole by 10, within an extrusion head 12. The channel guide 10 is formed from a branching arrangement 14 with individual branch points 16 and connecting channels 18 (not shown in Figure 1) located between them. Furthermore, the channel guide 10 extends from a central inlet 20 (not shown in Figure 1) to several spatially separated dispensing points 22 (not shown in Figure 1), each of which supplies a manufacturing unit 24, as shown in Figure 2, for each preform.In total, with the device shown, including the eight dispensing points 22, eight tubular preforms for container products can be produced using the manufacturing device 24 according to Figure 2, wherein a manufacturing device 24 according to Figure 2 is provided for each dispensing point 22.

[0031] The horizontal supply direction, indicated by arrow 26 in Figure 1, is perpendicular to a vertically extending discharge direction, indicated by arrow 28 in Figure 1. Figure 1 illustrates a structurally simple, plate-shaped assembly for a multi-extrusion head 12 with a total of eight discharge nozzles 29, which connect downwards to the eight discharge points 22 (not shown in Figure 1). Figures 1, 3, and 4 each show only the lower head section 30 for the extrusion head 12. It is understood that an upper head section 32 with a corresponding channel completes the device, as can be seen by way of example in Figure 2. This results in a largely closed or encapsulated channel 10 for the polymer melt.As shown in particular in Figure 3, the channel 10 for supplying eight dispensing points 22 requires only a small number of branching points 16; in this case, a total of seven branching points 16. Furthermore, a total of fourteen connecting channels 18 extend between the aforementioned branching points 16 as part of the overall channel 10. Due to its modular design, the extrusion head 12 with its channel 10 can be easily adapted to changing conditions, for example, to the fact that, depending on the number of preforms to be produced, there are more or fewer than eight dispensing points 22 that need to be supplied with plastic material during the production of the preforms.However, with regard to flow guidance and the efficiency of the manufacturing process, it is always advantageous to provide the discharge points 22 in pairs opposite each other, although an odd number of discharge points is also possible.

[0032] The device further comprises an adjustment device, designated as a whole by 34, which serves to control or regulate the mass flow rate of the plastic material within the channel 10. In an embodiment of the device not shown, the adjustment device 34 may control only parts of the channel and not, as in the present case, in such a way that all discharge points 22 in the feed direction can be controlled simultaneously. The adjustment device 34 specifies the respective mass flow rate from a central location and is arranged on a freely accessible, front end face 36 of the extrusion head 12. Furthermore, the adjustment device 34 comprises a plurality of individual adjustment means 38, the number of which corresponds to the number of connecting channels 18 and their sections 48, each of which must be controlled during material discharge to the individual discharge points 22.In the present case, each dispensing point 22 is assigned a single adjusting element 38 in the inflow. As shown in particular in Figures 5 and 6, the respective adjusting element 38 is formed from a type of cartridge 40, which extends through the free end face 36 of the extrusion head 12 and is fixed to wall sections 42 thereof. An adjusting element 44, which is longitudinally movable within the cartridge 40, defines the free opening cross-section of an associated channel section 48 of the channel guide 10 with one free end region 46 and serves for operation with its other free end region 50. In the exemplary embodiments, the adjusting element 44 of the respective cartridge 40 is shown in a forward extended position and can thus reduce the free cross-section of the associated channel section 48 of the channel guide 10, so that less plastic material can reach the dispensing points 22 via this channel guide 10.In an extremely retracted position of the adjusting element 38, the associated connecting channel 18 or channel section 48 is as open as possible and thus has the largest free channel cross-section, ensuring the highest mass flow rate. The cartridge 40 shown in Figures 5 and 6 is designed as a screw-in cartridge and accordingly has an external thread 52 for securing it in the wall sections 42 of the extrusion head 12. A threaded section 56 on the inside of the cartridge housing 54 serves for the longitudinal movement of the pin-like adjusting element 38 within the cartridge housing 54.

[0033] Furthermore, the respective adjusting element 44 has a rounded end face, in the form of the end region 46, shaped like a bowl, particularly a hemispherical shape. A channel section 48, which has a round cross-section, can be completely closed in the fully blocked area by an adjusting element and its rounded end face 58, as can be seen in the figures. According to the invention, this is achieved if the radius of the hemispherical rounded end face 58 is only slightly smaller than the radius of the channel section in the area of ​​the adjusting element; preferably, the difference between the radius of the channel section and the radius of the rounded end face is less than 0.06 mm, and particularly preferably less than 0.04 mm. As the adjusting element 44 is increasingly retracted, a cross-section is progressively opened, similar to a throttle or orifice, which serves for the harmonic and continuous flow of the plastic material to supply the dispensing points 22.To facilitate the screwing of the cartridge 40 into the wall sections 42 of the extrusion head 12, a polygon 60, particularly in the form of a hexagon, is provided for the engagement of a conventional actuating tool, such as a wrench. The actuating end section 50 of the cartridge 40 is also provided with a further polygon 62, which both facilitates manual actuation and simplifies engagement by a handling system (not shown), thus enabling automatic actuation of the adjusting device 34 with all its adjusting means 38. The respective adjusting means 44 engages at an angle of preferably 90° to the course of the associated connecting channel 18 in the form of the channel section 48, which simplifies actuation and allows for rapid positioning of the respective adjusting means 44.This also applies to the modified embodiment according to Figure 4, in which, after the last branching point 16 and before the subsequent discharge point 22 in the river, the channel section 48 opens at a right angle into the respective annular discharge point 22. Otherwise, the modified embodiment according to Figure 4 largely corresponds to the solution according to Figure 1. Accordingly, the same reference numerals are used for the solution according to Figure 4 as in Figure 1, and the statements made regarding this apply analogously to the solution according to Figure 4.

[0034] In contrast to the embodiment shown in Figure 4, in the solution shown in Figures 1 and 3, the subsequent connecting channel 18, with its respective channel section 48, is deflected twice before entering the annular discharge point 22, resulting in a U-shaped bend. The adjusting element 38 engages in the lower leg of this bend. This achieves a particularly space-saving and harmonious channel flow for the plasticized material before it is discharged into the annular discharge point 22, which is penetrated by the mandrel-shaped manufacturing or filling device 24 shown in Figure 2. Other flow guidance options are possible. In any case, in the solution shown in Figures 1 and 3, the plastic melt is fed at a total angle of 180° from the inlet 20 to just before the discharge point 22.

[0035] The extrusion head 12 shown in the figures comprises a head housing 64 in which the channel guide 10 is arranged. As shown particularly in Figures 3 and 4, starting with the inlet 20 with a round cross-section 66 at the first branching point 16, two connecting channels 18 are arranged, which are designed in the form of a longitudinal oval 66. Instead of longitudinal oval, these can also have an elliptical or superelliptical cross-section.

[0036] At the first branch point 16 after the inlet 20, the two connecting channels 18 subsequently form an angle of approximately 120 to 130° with each other, relative to their central longitudinal axes. A corresponding angle is observed at the next branch point 16 before, after two U-shaped bends, the final channel section, starting from the last branch point 16, transitions into the two adjacent discharge points 22. The embodiment according to Figure 4 differs from the solution described above according to Figures 1 and 3 in that, using only one bend, the last channel section 48 branches off at a right angle from the branch point 16 upstream in the fluid direction before entering the annular discharge point 22.In the solution according to Figures 1 and 3, if one considers the inflow of the fluid plastic material at the inlet 20 in a vertical direction from top to bottom, the flow direction from bottom to top is deflected by 180° at the last deflection point of the channel section 48 before entering the associated discharge point 22. Contrary to established expectations from fluid mechanics, which state that such pronounced changes in the direction of a melt flow should be avoided, for example to prevent inhomogeneous flow resistances, surprisingly, a strong deflection according to the invention (Figure 4 once by 90°, Figures 1 and 3 twice by 90°) does not adversely affect the overall flow behavior in a small space.

[0037] The longitudinal section shown in Figure 2 depicts the annular dispensing point 22 between the two head sections 30 and 32. Viewed in the direction of Figure 2, the vertical extent of the annular dispensing point 22 is smaller upwards than downwards. Furthermore, the annular dispensing point 22 is connected to the annular dispensing nozzle 29 on the underside of the extrusion head 12, and the annular dispensing channel 68 leading to the extrusion point 70 on the respective dispensing nozzle 29 opens to the outside for the purpose of dispensing the plastic material. The dispensing channel 68 is also penetrated by a central filling tube 72, which is shown in a lower dispensing position in Figure 2. The height of the filling mandrel or the filling tube 72 relative to the dispensing channel 68 can be adjusted by means of an adjusting device 74.This type of construction is common and is shown, for example, in DE 10 201 7 008 803 A1 and DE 10 201 7 008 802 A1, so that it will not be discussed in detail here. In any case, the plastic material is dispensed at the lower end of the respective dispensing nozzle 29 along the vertical dispensing direction, which is indicated by arrow 28 in Figure 2.

[0038] In summary, a device for producing and filling containers is proposed in which several tubes of plasticized plastic material, which can be extruded from the extrusion head 12, can be inserted directly or by means of a transport system into an open mold, wherein the extrusion head 12 has an inlet opening in the form of the inlet 20 and several outlet openings in the form of the discharge points 22 for molten plastic material, as well as a cuboid shell with a lower and an upper head part 30 and 32 respectively, with several adjusting means 38 of an adjusting device 34 for adjusting the mass flow at the corresponding outlet points 70 on the outlet side.The cuboid shell, which essentially forms the extrusion head 12, consists, as already described, of at least one lower shell or head part 30 and an upper shell or head part 32, of which at least the lower shell or head part 30 has a multiply branched channel 10 for the plasticized plastic material, which terminates in several annular spaces as part of the discharge points 22, from which the plastic material can exit at a lower discharge point 70, wherein an angle formed by the flow direction of the plasticized plastic material, starting from the inlet 20 and the flow direction of the plasticized plastic material before entering the respective annular discharge point is 180°, but preferably also 170°, as shown in the embodiment according to Figures 1 and 3.In the embodiment according to Figure 4, however, the angle between the inlet 20 and the outlet before the associated delivery point, as indicated above, is 90° or substantially 90°.

[0039] Since all dispensing points 22 are identically shaped, the extent to which each dispensing point 22 delivers plastic material for container forming via its outlet 70 depends solely on the individual adjusting means 38. In this way, a precise supply of a predetermined quantity to the respective dispensing point 22 is achieved.

[0040] Another characteristic of the invention is that all adjusting means 38, in particular in the form of cartridges 40, for adjusting the mass flow rate of the plastic material are arranged on a free end face or on a front end face 36 of the extrusion head 12, which is opposite the inlet opening or the inlet 20, so that very good accessibility for the adjusting device 34 as a whole with its individual adjusting means 38 is achieved.

Claims

Patent claims 1. Device for producing preforms for containers from a plasticized plastic material, which can be transported within an extrusion head (12) from an inlet (20) along a supply direction (26) to several separate discharge points (22) by means of a channel guide (10) forming a branching arrangement (14) with branching points (16) and connecting channels (18), each of which supplies a production unit (24) for each preform in a discharge direction (28) that is different from the supply direction (26), characterized in that the mass flow rate of the plastic material can be controlled by means of an adjustment device (34) at least in part of the channel guide (10).

2. Device according to claim 1, characterized in that the adjusting device (34) specifies the respective mass throughput from a central location, which is located on a freely accessible side (36) of the extrusion head (12).

3. Device according to claim 1 or 2, characterized in that the adjusting device (34) has a plurality of individual adjusting means (38), the number of which is based on the number of connecting channels (18) together with their sections (48) which are to be controlled.

4. Device according to one of the preceding claims, characterized in that the respective adjusting means (38) is formed from a cartridge (40) which extends through the free side (36) of the extrusion head (12) and is fixed to wall parts (42) thereof, and that an adjusting means (44) which is guided longitudinally within the cartridge (40) has one free end region (46) specifies the free opening cross-section of an attributable channel section (48) and serves for operation with its other free end area (50).

5. Device according to one of the preceding claims, characterized in that the cartridge (40) is designed as a screw-in cartridge for fixing in wall parts (42) of the extrusion head (12) and has an external thread (52) and that a threaded section (56) is provided on the inside of the screw-in cartridge for the longitudinal movement of the adjusting means (38).

6. Device according to one of the preceding claims, characterized in that the respective adjusting means (44) has a rounding (58) in the form of a bowl, in particular in hemispherical form, on its free end face.

7. Device according to one of the preceding claims, characterized in that the channel section (58) attributable to an adjusting means (44) has a circular cross-section at least in the engagement area of ​​the adjusting means (44).

8. Device according to one of the preceding claims, characterized in that the radius of the hemispherical rounding of the adjusting means (44) corresponds to the radius of the circular channel section (58) attributable to the adjusting means (44) to less than 0.06 mm, preferably less than 0.04 mm.

9. Device according to one of the preceding claims, characterized in that the respective actuating means is arranged at an angle of 80 to 100°, preferably 90°, to the course of the associated connecting channel (18).

10. Device according to one of the preceding claims, characterized in that the plastic material can be discharged into the annular discharge point (22) in the extrusion head (12) via a successive last connecting channel (18) of the channel guide (10) in the supply direction (26), which is accessible to a forming and / or filling unit of the manufacturing device (24).

11. Device according to one of the preceding claims, characterized in that the subsequent last connecting channel (18) opens into the annular discharge point (22) after single or multiple, in particular double, deflection and that the adjusting means (38) is arranged in the area of ​​the last deflection before the channel section (48) enters the discharge point (27) for adjusting the flow rate.

12. Device according to one of the preceding claims, characterized in that at least a part of the, preferably all, adjusting means (38) are arranged parallel to each other along a common actuation plane on the extrusion head (12).

13. Extrusion head, in particular equipped with a device according to one of the preceding claims, with a head housing (64) in which a channel guide (10) is arranged, which has a branched plurality of branching points (16) and connecting channels (18), wherein at least parts of the channel guide (10) in the form of at least one connecting channel (18) have different cross-sectional shapes at the inlet (20) and outlet (28) and / or a cross-sectional shape (66) present on the inlet side (20), in particular circular, decreases continuously over at least a part of the channel length towards the outlet side with the discharge points (22). 21 14. Extrusion head according to claim 13, characterized in that the respective connecting channel (18) of the channel guide (10) has a round channel cross-section starting from its inlet side (20), which transitions into a longitudinally oval channel cross-section after a predefinable distance.

15. Extrusion head according to claim 13 or 14, characterized in that non-circular cross-sections are provided in the area between the inlet (20) and the respective discharge point (22) of the channel guide (10), in particular in the form of a longitudinal oval or superelliptical cross-section (66).

16. Extrusion head according to one of claims 13 to 15, characterized in that the channel guide (10) has a double deflection in the direction of the respective discharge point (22) or, angled by 90°, a connecting channel (18) branches off from the other channel guide (10) in the direction of the discharge point (22).

17. Extrusion head according to one of claims 13 to 16, characterized in that, starting from the inlet (20) of the channel guide (10), the channel guide undergoes a deflection in the direction of the respective discharge point (22) of between 90° and 180°, particularly preferably of about 170°.

Images