MANIFOLD PLATE, MANIFOLD COMPRISING A MANIFOLD PLATE, EXTRUSION ASSEMBLY COMPRISING A MANIFOLD, AND METHOD OF MAKING A MANIFOLD PLATE

Abstract

A manifold plate for a manifold for supplying thermoplastic plastic melt to at least one extrusion head for producing a preform is disclosed. The manifold plate includes: a first plate side and a second plate side, a distribution groove incorporated in the first plate side and extending in a plate plane of the first plate side, and at least one connecting channel adjoining the distribution groove, which is worked into the manifold plate and ends at an outlet opening in the second plate side. The manifold plate is characterized in that the at least one connecting channel is milled into the manifold plate and, in the flow direction, has a course which is curved at least in sections towards the second plate side. A manifold, an extrusion assembly and a method for manufacturing a manifold plate are also disclosed.

Claims

1. A manifold plate for a manifold for supplying thermoplastic plastic melt to at least one extrusion head for producing a preform, the manifold plate comprising: a first plate side and a second plate side; a distribution groove formed in the first plate side and extending in a plate plane of the first plate side; and at least one connecting channel adjoining the distribution groove, said at least one connecting channel is incorporated in the manifold plate and ends at an outlet opening in the second plate side, and said at least one connecting channel is milled into the manifold plate and, in the flow direction, has a course which is curved at least partially towards the second plate side.

2. The manifold plate according to claim 1, wherein the at least one connecting channel defines a course line and has a curved section, the course line in the curved section being curved in the flow direction towards the second plate side.

3. The manifold plate according to claim 2, wherein the curved section of the at least one connecting channel is formed on an inlet side as a groove open perpendicular to the course line and on an outlet side as a conduit closed in the circumferential direction around the course line.

4. The manifold plate according to claim 2, wherein the at least one connecting channel has, upstream of the curved section, an inlet section extending in the plate plane of the first plate side, the inlet section being designed as a groove open to the plate plane of the first plate side.

5. The manifold plate according to claim 2, wherein a tangent to the course line in the curved section encloses an angle of greater than 0 degrees and less than 60 degrees with the plate plane of the first plate side.

6. The manifold plate according to claim 2, wherein the at least one connecting channel has, downstream of the curved section, a further curved section in which the course line is curved in the flow direction towards the second plate side.

7. The manifold plate according to claim 6, wherein the at least one connecting channel has a transition section between the curved section and the further curved section, in which the course line is straight.

8. The manifold plate according claim 2, wherein the at least one connecting channel has an outlet section ending at the outlet opening, the course line in the outlet section being straight and extending transversely to the first plate side.

9. The manifold plate according to claim 1, wherein the first plate side and the second plate side are outer sides of the manifold plate facing away from each other.

10. The manifold plate according to claim 1, wherein the distribution groove divides into exactly one or two of the connecting channels.

11. The manifold plate according to claim 1, wherein the manifold plate has one of the distribution grooves per extrusion head.

12. A manifold for supplying thermoplastic plastic melt to at least one extrusion head for producing a preform, the manifold comprising at least one manifold plate according to claim 1 and a cover plate.

13. An extrusion assembly comprising a manifold according to claim 12 and at least one extrusion head for producing a preform.

14. A method of manufacturing a manifold plate according to claim 1, the method comprising the steps of: working a distribution groove in a first plate side of a workpiece; and working at least one connecting channel into the workpiece by path-controlled form milling, a milling head being moved, starting from the first plate side, at least partially on a path curved towards a second plate side.

15. The method according to claim 14, wherein a first section of the at least one connecting channel starting from the first plate side and a second section of the at least one connecting channel starting from the second plate side are worked into the workpiece by path-controlled form milling.

Description

DRAWINGS

[0047] In order that the disclosure may be well understood, there will now be described various forms thereof, given by way of example, reference being made to the accompanying drawings, in which:

[0048] FIG. 1 shows a manifold plate according to one embodiment of the present invention in a top perspective view from oblique above;

[0049] FIG. 2 shows a top perspective view of the manifold plate from FIG. 1, with hidden body edges shown;

[0050] FIG. 3 is a sectional view of the manifold plate of FIG. 1 along line Ill-Ill shown in FIG. 1;

[0051] FIG. 4 shows a partial step of a method for manufacturing the manifold plate of FIG. 1 according to an embodiment of the present invention, in which a milling tool works a connecting channel into the manifold plate;

[0052] FIG. 5 shows the partial step from FIG. 4 in enlarged partial representation, whereby different working positions are shown to illustrate the relative movement between the milling tool and the manifold plate;

[0053] FIG. 6 shows a manifold according to one embodiment of the present invention in a top perspective view from oblique above, with hidden body edges shown;

[0054] FIG. 7 is a sectional view of the manifold shown in FIG. 6 along lines VII-VII of FIG. 6;

[0055] FIG. 8 is a top perspective view of the manifold shown in FIG. 6, with the outer edges of the manifold plates not shown to illustrate distribution networks extending across the manifold plates;

[0056] FIG. 9 is a perspective view from below of the distribution networks of FIG. 8 extending over the manifold plates;

[0057] FIG. 10 is a perspective view of an extrusion assembly according to one embodiment of the present invention, viewed obliquely from below; and

[0058] FIG. 11 is a sectional view of the extrusion assembly of FIG. 10 along the line XI-XI shown in FIG. 10.

[0059] The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.

DETAILED DESCRIPTION

[0060] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.

[0061] FIGS. 1 to 3 show a manifold plate 1 for a manifold for supplying thermoplastic plastic melt to at least one extrusion head for producing a preform for a melt distributor according to one embodiment.

[0062] To clarify the orientation of the manifold plate 1 in space, spatial axes X, Y, Z are defined in terms of a Cartesian coordinate system associated with the manifold plate 1 and indicated by corresponding arrows. The manifold plate 1 extends with its width along a spatial axis X, its depth along a spatial axis Y, and its height along a spatial axis Z.

[0063] The manifold plate 1, which is in particular metallic, can have an at least approximately cuboidal basic shape. The manifold plate 1 has a first plate side 2 and a second plate side 3 facing away from the first plate side 2. The two plate sides 2, 3 each define a plate plane E1, E2, which can be aligned parallel to each other. The plate planes E1, E2 are parallel to a plane spanned by the two spatial axes X, Y.

[0064] FIG. 1 shows that an inlet groove 4 is machined into the first plate side 2, through which a thermoplastic plastic melt can flow in a flow direction. The inlet groove 4 starts at a first mass inlet 5, to which a first extruder can be connected. The mass inlet 5 is formed in a front face 6 of the manifold plate 1, which may be oriented perpendicular to both plate sides 2, 3. In the flow direction, the inlet groove 4 in the first plate plane E1 branches in a tree-like structure into several, here exemplarily ten, distribution grooves 7, which are milled into the first plate side 2. The distribution grooves 7 each branch at a branch point 8 into two connecting channels 9, which are milled into the manifold plate 1. The connecting channels 9 begin in the first plate plane E1 and each end at an outlet opening 10, the outlet openings 10 being arranged in the second plate side 3.

[0065] The connecting channels 9 each define a course line L which is curved in the flow direction at least in sections towards the second plate side 3. FIG. 3 shows the course of one of the connecting channels 9, which is exemplary for the course of all connecting channels 9. The course of the connecting channels 9 is explained below with reference to FIG. 3.

[0066] The connecting channel 9 has an inlet section 11 into which the associated distribution groove 7 opens. It can be seen in FIG. 1 that the connecting channels 9 spread out from each other in pairs in the flow direction, starting from the respective branch point 8, so that the course line L in the inlet section 11 has a course L11 that is curved in the first plate plane E1. The inlet section 11 is designed as a groove open to the first plate plane E1, respectively perpendicular to the course line L11. The groove depth of the inlet section 11 corresponds to the groove depth of the distribution groove 7.

[0067] The inlet section 11 is followed in the flow direction by a first curved section 12 of the connecting channel 9, in which the course line L from the plate plane E1 has a course L12 that is continuously curved in the flow direction towards the second plate side E2. In the first curved section 12, the course line L follows an arc section at least in an idealized manner. This can be, as shown here as an example, an eighth circle, whose circle center M1 lies in the second plate plane E2. Accordingly, a tangent T1 at the course line L in the first curved section 12 can enclose a first tangent angle 1 of greater than 0 degrees and, here exemplarily, a maximum of 45 degrees, with the first plate plane E1. This applies along the first curved section 12 for each point on the course section L12 of the course line L. FIG. 3 also shows that a partial section 13 of the first curved section 12 on the inlet side is designed as a groove open towards the first plate plane E1, or perpendicular to the course line L, which has a groove bottom curved in the flow direction towards the second plate side 3. The groove-shaped section 13 joins the groove-shaped inlet section 11 without interruption. The inlet-side section 13 extends in the flow direction over at least approximately half of the first curved section 12. Downstream of the inlet section 13, the connecting channel 9 is continuously closed in the circumferential direction around the course line L, i.e., in the form of a pipe.

[0068] The first curved section 12 is followed by a transition section 14 in the flow direction, in which the course line L has a straight course L14. The transition section 14 may also be referred to as the intermediate section. An imaginary extension of the section L14 of the course line L, which extends in a straight line in the transition section 14, encloses a first angle 1 with the first plate plane E1. The first angle 1 is, here exemplarily, 45 degrees.

[0069] The transition section 14 is followed by a second curved section 15 in the flow direction, in which the course line L has a curved course L15 from the straight course L14 in the transition section 14 in the flow direction towards the second plate side E2. In FIG. 3, it is shown that the course line L in the second curved section 15 follows an arc section at least in an idealized manner. This can be, as shown here as an example, an eighth circle, whose circle center M2 lies in the second plate plane E2. Accordingly, a tangent T2 to the course line L in the second curved section 15 may enclose with the first plate plane E1 a second tangent angle 2 of, here exemplarily, greater than or equal to 45 degrees and less than 90 degrees. This applies along the second curved section 15 for each point on the course line L. For clarity, an auxiliary line is drawn to represent the second tangent angle 2, which extends parallel to the first plate plane E1. The second circle center M2 is located in the second plate plane E2 between the first circle center M1 and the outlet opening 10 of the connecting channel 9. The distance between the two circle centers M1, M2 corresponds at least approximately to the extension of the transition section 12 in the flow direction.

[0070] An outlet section 16 of the connecting channel 9 adjoins the second curved section 15 in the flow direction. The outlet section 16 ends at the outlet opening 10. In the outlet section 16, the course line L again has a rectilinear course L16 and encloses a second angle 2 of, here exemplarily, 90 degrees with the first plate plane E1. The outlet opening 10 is correspondingly circular. Due to the infinitesimally small extension of the outlet section 16 in the flow direction shown here, the two circle centers M1, M2 lie in the second plate plane E2. Especially if the second plate side 3 is to be mechanically reworked, it can be advantageous if the outlet section 16 has a greater rectilinear extension in the flow direction. Then the two circle centers M1, M2 can be offset by the length of the outlet section 16 from the second plate plane E2 toward the first plate plane E1.

[0071] The course of the connecting channels 9 branching off in pairs from the associated distribution groove 7 resembles the shape of a pair of seated trousers, as can be seen in FIG. 2, thus avoiding flow dead zones. In principle, however, it is also possible for only one connecting channel 9 to be connected to the respective distribution groove 7, which can correspond to the course shown in FIG. 3, in which case the course line L in the inlet section 11 can have a straight course in the first plate plane E1, thus avoiding flow dead zones.

[0072] The grooves 4, 7 machined into the first plate side 2 of the manifold plate 1 as well as the connecting channels 9 belong to a contiguous distribution network 17, which can be connected to an extruder on the inlet side via the mass inlet 5. Each distribution groove 7 supplies an extrusion head with a partial flow of the thermoplastic plastic melt via the connected connecting channels 9, here exemplarily two. In the embodiment shown here, the manifold plate 1 can thus divide the thermoplastic plastic melt flowing in during operation via the first mass inlet 5 into twenty strands, to which ten extrusion heads can be supplied here as an example. It goes without saying that the manifold plate 1 can also have fewer or more than ten of the distribution grooves 7, respectively fewer or more than twenty of the connecting channels 9.

[0073] In FIG. 2, it can be seen that further grooves are machined, or milled, in the second plate side 3 of the manifold plate 1, which can be used as channel upper parts to cover the grooves 4, 7 formed in a first plate side 2 of a further manifold plate 1 which can be arranged thereunder, as well as the groove-shaped sections 11, 13 of the connecting channels 9. The slots, which are in the form of grooves and are open towards the second plate plane E2, may belong to a further distribution network 18 which is coherent in itself, the further distribution network 18 existing independently of the distribution network 17 and being correspondingly spatially separated from the latter. In order to be able to connect the manifold plate 1 to upstream components, such as extruders, and downstream components, such as further manifold plates or extrusion heads, due to structural, spatial conditions, the distribution networks 17, 18 can be arranged, respectively aligned differently, especially in the area of the mass inlets and in the area of the outlet channels.

[0074] The manifold plate 1 has its own mass inlet 19 for the further distribution network 18, which here can also be arranged in the front face 6 of the manifold plate 1, adjacent to the mass inlet 5. An inlet groove 20 is machined into the second plate side 3, through which a thermoplastic plastic melt can flow in one flow direction. The inlet groove 20 starts at the further mass inlet 19, to which another extruder can be connected. In the flow direction, the inlet groove 20 branches in the second plate plane E2 in the manner of a tree structure into several, here exemplarily ten, distribution grooves 21, which are machined into the second plate side 3. The distribution grooves 21 in the second plate side 3 and the distribution grooves 7 in the first plate side 2 are, here exemplarily, congruent.

[0075] The distribution grooves 21 each branch at a branch point 22 into two connection grooves 23, which are milled into the second plate side 3. The connection grooves 23 are designed to cover the section of the distribution grooves 7, which is designed as a groove, of a further manifold plate 1 which can be arranged underneath. That is, the connection grooves 23 may cover, from the distribution grooves 7, the respective inlet section 11 and the inlet-side section 13 of the first curved section 12 of the in the first plate side 2 of the adjacent manifold plate 1. In FIG. 2, it can be seen that the groove-shaped sections 11, 13 of the connecting channels 9 incorporated in the first plate side 2 spread further apart from one another than the connection grooves 23 incorporated in the second plate side 3, which cover the groove-shaped sections 11, 13 of a further manifold plate 1 that can be arranged thereunder. In FIG. 2, for reasons of clarity, only a subset of the reference signs 7, 8, 9, 10, 21, 22, 23 are shown as representative of the total set of these reference signs.

[0076] FIGS. 1 and 2 further show that a portion of a third inlet groove 24 may be machined, or milled, into the manifold plate 1. The inlet groove 24 begins, in the flow direction, at still another mass inlet 25, which may be located in the front face 6 of the manifold plate 1, and ends in the second plate side 3. The inlet groove 24 may be continued in another manifold plate 1 which may be arranged therebelow. A separate extruder can be connected via the additional mass inlet 25, so that thermoplastic plastic melt can be fed to an additional, here third, distribution network 26.

[0077] For the manufacture of the manifold plate 1, a workpiece 27, in particular a metallic workpiece, can be provided which may already have the basic shape of the manifold plate 1. The workpiece 27 may be a quenched and tempered tool steel. A CNC machining center 28, in particular a 5-axis CNC machining center, of which only a partial section is shown in FIGS. 4 and 5, can be used to machine the grooves 4, 7, 20, 21, 23 and the connecting channels 9 into the manifold plate 1.

[0078] In a manner known per se, the CNC machining center 28 can have a unit carrier with, among other things, a milling spindle 29 as well as a machine table (not shown) on which the workpiece 27 can be clamped. The milling spindle 29 drives a milling tool 30 in rotation around a spindle axis S. The milling tool 30 has a clamping shaft 31 and a working area, respectively a milling head 32. The clamping shaft 31 can be clamped in a receptacle of the spindle 29. The milling head 32 can be used to subject the workpiece 27 to a milling operation. The milling head 32 can be spherical. A diameter of the milling head 32 is to be selected smaller than a channel diameter of the connecting channel 9 to be produced, so that the milling head 32 can cut itself free.

[0079] In path-controlled form milling, the connecting channels 9 are milled into the workpiece 27 with a controlled engagement path. The milling spindle 29 with the milling tool 30 and the workpiece 27 clamped on the machine table are moved relative to each other, as shown in FIG. 5. Therein, one relative working position of the milling tool 30 and the workpiece 27 is shown with solid lines and three other relative working positions are shown with dashed lines. Relative to the workpiece 27, the spindle axis S traverses the lateral surface of a cone in order to be able to traverse the curved contact path past interfering edges 33. To ensure radial infeed of the milling head 32, the milling cutter center path can be helical, as shown in FIG. 5. The spiral movement prevents the front face of the milling head 32 from touching the workpiece 27. In the case of steep adjustment, as shown in FIG. 3 with the solid line of the milling spindle 29, the milling tool 30 abuts with the clamping shaft 31 against the interfering edges 33. In this respect, a first section of the respective connecting channel 9 can first be milled into the workpiece 27 starting from the first plate side 2. The first section may include a section of the transition section 14 in addition to the inlet section 11 and the first curved section 12.

[0080] After the grooves 4, 7 and the first sections of the connecting channels 9 have been milled into the manifold plate 1 starting from the first plate side 2, the second plate side 3 can be machined. For this purpose, the workpiece 27 can be reclamped on the machine table. In an analogous manner, the grooves 20, 21 and the second sections of the connecting channels 9 can be machined into the manifold plate 1 starting from the second plate side 3. In addition to the outlet section 16 and the second curved section 15, the second section of the respective connecting channel 9 may also comprise a section of the transition section 14.

[0081] FIGS. 6 to 9 show a manifold 40 according to one embodiment. The manifold 40 is designed for feeding thermoplastic plastic melt to, here exemplarily ten, extrusion heads for producing a, here exemplarily three-layer, preform.

[0082] The manifold 40 comprises a plate pack with, here exemplarily four, manifold plates arranged one above the other, each of which rests against the other along a parting plane A1, A2, A3. Looking at FIG. 6, the uppermost plate is a cover plate 41, which has grooves on an inner plate side 42 through which the thermoplastic plastic melt can flow. An outer plate side 43 is flat or smooth. The basic shape of the cover plate 41 corresponds to that of the three manifold plates 1. A first manifold plate 1.1, a second manifold plate 1.2 and a third manifold plate 1.3 are arranged below the cover plate 41. The first and second manifold plates 1.1, 1.2 have the grooves through which the thermoplastic plastic melt can flow both on their first plate side 2.1, 2.2 and on their second plate side 3.1, 3.2. The manifold plates 1.1 and 1.2 are designed as described above, so that reference is made to the above description in this respect. The same or modified details are marked with the same reference signs as in FIGS. 1 to 5. The third manifold plate 1.3 closes off the plate pack at the bottom and accordingly has the grooves through which the thermoplastic plastic melt can flow only on its first plate side 2.3. In this respect, the third manifold plate 1.3 is designed as described above, with the exception that no grooves through which the thermoplastic plastic melt can flow are formed in the second plate side 3.3.

[0083] To illustrate the orientation of the manifold 40 in space, spatial axes X, Y, Z are defined in terms of a Cartesian coordinate system associated with the manifold 40 and indicated by corresponding arrows. The manifold 40 extends with its width along a spatial axis X, its depth along a spatial axis Y, and its height along a spatial axis Z.

[0084] Grooves 44, 45 are machined, respectively, into the inner plate side 42 of the cover plate 41, which grooves coincide with the grooves 4, 7 machined into the first plate side 2.1 of the first manifold plate 1.1 as well as the machined groove-shaped sections 11, 13 of the connecting channels 9.1. The grooves 44 of the cover plate 41 and the grooves 4, 7 of the first manifold plate 1.1 thus together form a circumferentially closed inlet channel 46.1 and circumferentially closed distribution channels 47.1, as shown in particular in FIGS. 8 and 9. Their channel axes, around which the channels 46.1, 47.1 are circumferentially closed, extend in the parting plane A1. The inlet channel 46.1 can be connected to the first extruder via the first mass inlet 5. The distribution channels 47.1 are each adjoined by two of the connecting channels 9.1, which divert the thermoplastic plastic melt flowing through the distribution channels 47.1 out of the parting plane A1 by 90 degrees towards the second parting plane A2. For clarity, only a subset of the reference signs are shown in FIGS. 6 and 7.

[0085] In FIG. 7, it can be seen that the respective groove 45 machined in the inner plate side 42 of the cover plate 41 covers the groove-shaped section 11, 13 of the respective connecting channel 9.1. Along the groove-shaped inlet section 11 of the respective connecting channel 9.1, the groove 45 extends parallel to the parting plane A1 and approaches the first parting plane A1 in a continuously curved manner along the groove-shaped partial section 13 in the flow direction. The radius of curvature corresponds to that of the course line L in the first curved section 12. The groove-shaped section 11, 13 of the respective connecting channel 9.1 is thus formed closed by the respective groove 45 in the circumferential direction around the course line L. The course line L of the respective connecting channel 9.1 thus extends in the inlet section 11 in the parting plane A1 (straight course L11) and changes in the first curved section 12 into the curved course L12 towards the second parting plane A2. After a 90 degree deflection, which is reached at the end of the second curved section 15, the course line L in the outlet section 16 extends perpendicular to the parting planes A1, A2 (straight course L16).

[0086] Bores 48, 49 are formed in the subsequent manifold plates 1.2, 1.3 in alignment with the outlet openings 10.1 of the first manifold plate 1.1, which extend perpendicular to the plate sides 2, 3. The extrusion heads can be connected to the manifold 40 at the, here exemplarily twenty, holes 49 in the third manifold plate 1.3. For example, if each extrusion head is to be supplied with thermoplastic plastic melt via two of the bores 49, which can open in pairs, for example, into a heart curve of the respective extrusion head, ten extrusion heads can be connected to the first distribution network 17 in this way. In particular, it can be seen in FIGS. 8 and 9 that the first distribution network 17 starts in the first parting plane A1 and extends from the first mass inlet 5 through the inlet channel 46.1, the distribution channels 47.1, the connecting channels 9.1 and the holes 48, 49 and ends in twenty connection points 50 formed in the second plate side 3.3 of the third manifold plate 1.3. The first distribution network 17 thus divides the thermoplastic plastic melt that can be conveyed by the first extruder into, here exemplarily, twenty melt streams of equal size, which can be fed to, here exemplarily, ten extrusion heads.

[0087] In an analogous manner, circumferentially closed channels 46.2, 47.2 are formed between the second plate side 3.1 of the first manifold plate 1.1 and the first plate side 2.2 of the second manifold plate 1.2, which extend in the parting plane A2 and merge downstream into the connecting channels 9.2 of the second manifold plate 1.2. In the following manifold plate 1.3, bores 51 are formed in alignment with the outlet openings 10.2 of the second manifold plate 1.2, which extend perpendicular to the plate sides 2, 3. In particular, it can be seen in FIGS. 8 and 9 that the second distribution network 18 starts in the second parting plane A2 and extends from the second mass inlet 19 through the inlet channel 46.2, the distribution channels 47.2, the connecting channels 9.2 and the holes 51, and ends in twenty connection points 52 in the second plate side 3.3 of the third manifold plate 1.3. The second distribution network 18 thus divides the thermoplastic plastic melt that can be conveyed by the second extruder into, here exemplarily, twenty melt streams of equal size that can be fed, here exemplarily, to the ten extrusion heads.

[0088] In an analogous manner, circumferentially closed channels 46.3, 47.3 are formed between the second plate side 3.2 of the second manifold plate 1.2 and the first plate side 2.3 of the third manifold plate 1.3, which extend in the third parting plane A3 and merge downstream into the connecting channels 9.3 of the third manifold plate 1.3. The third distribution network 26 differs from the other two distribution networks 17, 18, exemplified here, in that one connecting channel 9.3 is provided for each extrusion head. FIG. 9 shows that four of the distribution channels 47.3 branch into two of the connecting channels 9.3 each and two of the distribution channels 7.3 branch into exactly one of the connecting channels 9.3 each. Accordingly, the connecting channels 9.3 in the second plate side 3.3 of the third manifold plate 1.3 end at ten connection points 53. In addition, the connecting channels 9.3 do not perform a 90 degree deflection, but a deflection of, in this case, about 20 degrees from the parting plane A3 to the second plate side 3.3 of the third manifold plate 1.3. In principle, however, deflections through the connecting channels 9.3 between 1 degree and 89 degrees are conceivable and possible. In this way, the interfaces of the ten extruders for the third distribution network 26 can be positioned at an angle to the second plate plane E2 of the third manifold plate 1.3 at the connection points 53, as shown in connection with the extrusion assembly according to the invention in FIG. 11. In FIG. 9 it can be seen that the connection points 50, 52 are arranged on an imaginary first straight line, whereas the connection points 53 are arranged at a distance from the first straight line on an imaginary second straight line which is parallel to the first straight line.

[0089] The third distribution network 26 begins, here exemplarily, in the first parting plane A1, in which the third mass inlet 25 is located. This is arranged here only as an example in the first parting plane A1. In principle, at least one of the mass inlets 5, 17, 25 can also be arranged at a different location of the manifold 40 if the structural specifications, positioning of the interfaces to the extruders, or space conditions of the extrusion assembly require it. In particular, it can be seen in FIGS. 8 and 9 that the third distribution network 26 extends from the third mass inlet 25 via the inlet channel 46.3, which here extends through the second manifold plate 1.2 into the third parting plane A3, the distribution channels 47.3 extending in the third parting plane A3, and the connecting channels 9.3, and ends in the, here, ten connection points 53 in the second plate side 3.2 of the third manifold plate 1.3. The third distribution network 25 thus divides the thermoplastic plastic melt that can be supplied by the third extruder into, here exemplarily, ten melt streams of equal size, which can be fed, here exemplarily, to the ten extrusion heads.

[0090] By means of the manifold 40 shown as an example, which, in this case, has three manifold plates 1.1, 1.2, 1.3 and the cover plate 41, a total of ten extrusion heads can thus be connected to the manifold 40 for the production of three-layer preforms. If the preforms to be produced are to be extruded with more than three layers, the manifold 40 can be supplemented with additional manifold plates 1. Likewise, the manifold 40 can extrude preforms with two layers or only one layer, for which the manifold 40 then accordingly has only two of the manifold plates 1 or only one of the manifold plates 1 and the cover plate 41.

[0091] FIGS. 10 and 11 show an extrusion assembly 60 according to one embodiment. The extrusion assembly 60 includes the manifold 40 and ten extrusion heads 61. In FIG. 10, only one of the extrusion heads 61 is shown in order to show the connection points 50, 52, 53 formed in the second plate side 3.3 of the third manifold plate 1.3. Each of the extrusion heads 61 is connectable to the first extruder (not shown) via two of the connection points 50 of the first distribution network 17, to the second extruder (not shown) via two of the connection points 52 of the second distribution network 18, and to the third extruder (not shown) via one of the connection points 53 of the third distribution network 26, in order to be able to extrude, in this case, three-layer preforms.

[0092] To illustrate the orientation of the extrusion assembly 60 in space, spatial axes X, Y, Z are defined in terms of a Cartesian coordinate system associated with the extrusion assembly 60 and indicated by corresponding arrows. The extrusion assembly 60 extends with its width along a spatial axis X, its depth along a spatial axis Y, and its height along a spatial axis Z. When installed in the extrusion assembly 60, the parting planes A1, A2, A3 between the manifold plates 1 are preferably horizontally oriented.

[0093] Unless otherwise expressly indicated herein, all numerical values indicating mechanical/thermal properties, compositional percentages, dimensions and/or tolerances, or other characteristics are to be understood as modified by the word about or approximately in describing the scope of the present disclosure. This modification is desired for various reasons including industrial practice, material, manufacturing, and assembly tolerances, and testing capability.

[0094] As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A OR B OR C), using a non-exclusive logical OR, and should not be construed to mean at least one of A, at least one of B, and at least one of C.

[0095] The description of the disclosure is merely exemplary in nature and, thus, variations that do not depart from the substance of the disclosure are intended to be within the scope of the disclosure. Such variations are not to be regarded as a departure from the spirit and scope of the disclosure.