Abstract
The invention relates to a melt conductor (1), in particular a melt distributor or melt mixer, for an extruding die (2) of an extrusion facility (3), comprising a melt conductor block (4) with a multi-channel system (5), the multi-channel system (5) being arranged inside the melt conductor block (4) with three-dimensional extension and having at least one input (6) and at least one output (7) for polymer melt, between one input (6) and one output (7) fluidically connected to the input (6) several branchings (8) arranged in series and several levels (9a) of sub-branches (10) being formed over several levels (12a, 12b) of divided melt channels (11a, 11b); with m melt channels (11a) of the a.sup.th level (12a) with X.sup.th local cross-sections and n melt channels (11b) of the b.sup.th level (12b) with y.sup.th local cross-sections being present, wherein n>m if b>a, the y.sup.th local cross-sections of the melt channels (11b) of the b.sup.th level (12b) being smaller than the X.sup.th local cross-sections of the melt channels (11a) of the a.sup.th level (12a). The invention further relates to an extruding die, an extrusion facility and to a method of operating the extrusion facility.
Claims
1. Melt conductor, in particular melt distributor or melt mixer, for an extruding die of an extrusion facility, comprising a melt conductor block with a multi-channel system, the multi-channel system being arranged with three-dimensional extension inside the melt conductor block and having at least one input and at least one output for polymer melt, where between an input and an output fluidically connected to the input, several branchings arranged in series and several levels of sub-branches are formed over several levels of divided melt channels, m melt channels of the a.sup.th level with x.sup.th local cross-sections and n melt channels of the b.sup.th level with y.sup.th local cross-sections being present, wherein n>m if b>a, the y.sup.th local cross-sections of the melt channels of the b.sup.th level being smaller than the x.sup.th local cross-sections of the melt channels of the a.sup.th level, and wherein in the designated direction of flow of the polymer melt, the melt channels of the a.sup.th level are oriented towards the input and the melt channels of the b.sup.th level towards the output such that the melt conductor acts as a melt distributor for a designated melt stream of the polymer melt, or in the designated direction of flow of the polymer melt, the melt channels of the a.sup.th level are oriented towards the output and the melt channels of the b.sup.th level towards the input, such that the melt conductor acts as a melt mixer for a designated melt stream of the polymer melt.
2. Melt conductor according to claim 1, wherein a circumference and a cross-sectional area of at least two melt channels originating from a common melt channel and separated are dimensioned in dependence on with U.sub.1 being the first circumference and A.sub.1 the first cross-sectional area of the common melt channel, U.sub.2 being the second circumference and A.sub.2 the second cross-sectional area of one of the divided melt channels, n.sub.k being the total number of divided melt channels and x being larger than or equal to ?0.5, preferably at least a value of 0.5, preferably at least a value of 0.75, and x being at the maximum a value of 4, preferably at the maximum a value of 2.5, further preferably at the maximum a value of 1.5.
3. Melt conductor according to claim 1, wherein a cross-section of at least two melt channels originating from one common melt channel and divided is dimensioned in dependence on
A.sub.2=A.sub.1*(1/n.sub.K).sup.2/y, with A.sub.1 being the first cross-sectional area of the common melt channel, A.sub.2 being the second cross-sectional area of one of the divided melt channels), n.sub.k being the total number of divided melt channels and y being at least a value of 2, preferably at least a value of 2.5, further preferably at least a value of 2.85, and y being at the maximum a value of 7, preferably at the maximum a value of 5, further preferably at the maximum a value of 3.35.
4. Melt conductor according to claim 1, wherein the melt channels of the multi-channel system have different local cross-sectional shapes which differ from a circular cross-sectional shape at least in portions.
5. Melt conductor according to claim 1, wherein the melt conductor block has a first multi-channel system and a second multi-channel system, in particular a third, fourth or fifth multi-channel system.
6. Melt conductor according to claim 5, wherein the multi-channel systems are formed so as to be mutually fluidically separated, each multi-channel system having at least one input for polymer melt and at least one output.
7. Melt conductor according to claim 5, wherein the first multi-channel system has a junction with at least the second multi-channel system.
8. Melt conductor according to claim 1, wherein the respective multi-channel system is formed with a plurality of outputs which are adapted to direct a polymer melt into a collection chamber to feed an extrusion nozzle.
9. Melt conductor according to claim 1, wherein the melt conductor, in particular the melt conductor block, has a hollow chamber system with at least one hollow chamber, spatially arranged between the melt channels of the respective multi-channel system.
10. Melt conductor according to claim 1, wherein the multi-channel system has a global machine direction through the melt conductor block which leads from the input to the output of a designated melt flow of the polymer melt, the melt channels extending in portions opposite to the global machine direction if a local machine direction is projected on the global machine direction.
11. Melt conductor according to claim 1, wherein the melt conductor block has a medium channel, in particular for a circulating fluid supply, especially for temperature control, and/or for an electric line and/or a measuring unit.
12. Melt conductor according to claim 1, wherein the melt conductor block has a static functional element for influencing the designated polymer melt at least indirectly.
13. Melt conductor according to claim 12, wherein the static functional element is a static mixing element.
14. Extruding die for an extrusion facility for manufacturing extrusion products, comprising the melt conductor according to claim 1, the melt conductor being adapted to distribute and/or mix at least one designated polymer melt.
15. Extruding die according to claim 14, characterized by an extrusion nozzle output having a width (B) of more than 5,000 mm, preferably more than 6,000 mm or more than 8,000 mm.
16. Extrusion facility for manufacturing extrusion products, comprising an extruding die according to claim 14.
17. Method of operating an extrusion facility according to claim 16, the extrusion facility being fed with at least one extrudible polymer, in particular at least one plastic, which is plasticized to form a respective polymer melt, the respective polymer melt being fed to the melt conductor which distributes and/or mixes the respective polymer melt.
Description
[0148] In the drawings:
[0149] FIG. 1 is a schematic view of a possible structure of an extrusion facility having a melt conductor comprising a melt conductor block and a multi-channel system according to a first alternative;
[0150] FIG. 2A is a schematic perspective view of the multi-channel system according to FIG. 1, the melt conductor being embodied as a melt distributor;
[0151] FIG. 2B is a schematic sectional view of two melt channels downstream in the direction of flow of a designated polymer melt;
[0152] FIG. 3 is a schematic perspective view of a second alternative embodiment of the multi-channel system, the melt conductor being embodied as a melt mixer;
[0153] FIG. 4 is a schematic perspective view of a third alternative embodiment of the multi-channel system, the conductor being partly embodied as a melt distributor and partly as a melt mixer;
[0154] FIG. 5 is a schematic perspective view of a fourth alternative embodiment of the multi-channel system, the melt conductor being partly embodied as a melt mixer and partly as a melt distributor;
[0155] FIG. 6A is a schematic perspective view of a fifth alternative embodiment of the multi-channel system, the melt conductor being embodied as a melt distributor;
[0156] FIG. 6B is another schematic perspective view of the fifth alternative embodiment according to FIG. 6A;
[0157] FIG. 7A is a schematic top view of a sixth alternative embodiment of the multi-channel system, the melt conductor being embodied as a melt distributor;
[0158] FIG. 7B is a schematic perspective view of the sixth alternative embodiment according to FIG. 7A;
[0159] FIG. 7C is another schematic perspective view of the sixth alternative embodiment according to FIGS. 7A through 7C;
[0160] FIG. 8 is a schematic top view of a seventh alternative embodiment of the multi-channel system, with the melt conductor being embodied as a melt distributor;
[0161] FIG. 9 is a schematic perspective view of an exemplary branching structure of an eighth alternative embodiment of the multi-channel system;
[0162] FIG. 10 is a schematic perspective view of an exemplary branching structure of a ninth alternative embodiment of the multi-channel system;
[0163] FIG. 11 is a schematic perspective view of a tenth alternative embodiment of the multi-channel system, the melt conductor being embodied as a melt distributor;
[0164] FIG. 12 is a schematic perspective view of an eleventh alternative embodiment of the multi-channel system, the melt conductor being embodied as a melt distributor;
[0165] FIG. 13A is a schematic perspective view of a twelfth alternative embodiment of the multi-channel system, the melt conductor being embodied as a melt distributor;
[0166] FIG. 13B is a schematic top view of the twelfth alternative embodiment according to FIG. 13A;
[0167] FIG. 13C is another schematic perspective view of the twelfth alternative embodiment according to FIG. 13A and FIG. 13B;
[0168] FIG. 13D is another schematic perspective view of the twelfth alternative embodiment according to FIGS. 13A through 13C;
[0169] FIG. 14A is a schematic perspective view of a thirteenth alternative embodiment of the multi-channel system, the melt conductor being embodied as a melt distributor;
[0170] FIG. 14B is a schematic top view of the thirteenth alternative embodiment according to FIG. 14A;
[0171] FIG. 14C is another schematic perspective view of the thirteenth alternative embodiment according to FIGS. 14A and 14B;
[0172] FIG. 15A is a schematic perspective view of a fourteenth alternative embodiment of the multi-channel system, the melt conductor being embodied as a melt distributor;
[0173] FIG. 15B is a schematic top view of the fourteenth alternative embodiment according to FIG. 15A;
[0174] FIG. 16A is a schematic view of a fifteenth alternative embodiment of the multi-channel system, the melt conductor being embodied as a melt distributor; and
[0175] FIG. 16B is a schematic lateral view of the fifteenth alternative embodiment according to FIG. 16A.
[0176] FIG. 1 is a strongly simplified presentation of an extrusion facility 3. The extrusion facility 3 comprises a provision unit 23 adapted to provide and process a polymer melt 24, in the present case a plastic material. The provision unit 23 is presently the extruder (not presented in detail here) which plasticizes at least one extrudible polymer 29 to form the polymer melt 24. The provision unit 23 can also be adapted for providing one or more different polymer melts 24 with the same or with different properties. The polymer melt 24 is continuously fed by the provision unit 23 into an extruding die 2, comprising a melt conductor 1 and an extrusion nozzle 14 downstream in the designated direction of flow 25 of the polymer melt 24. The extruding die 2 is integrated in the continuously operating extrusion facility 3 in which the polymer melt 24 is continuously conveyed through the melt conductor 1 in a global machine direction 18, the expressions downstream and upstream referring to this global machine direction 18.
[0177] The melt conductor 1 which is adapted as a melt distributor in this first example of embodiment has a melt conductor block 4 with a multi-channel system 5 which extends three-dimensionally inside the melt conductor block 4. The melt conductor block 4 is manufactured by means of an additive manufacturing method and can be integrated in the continuously operating extrusion facility 3 as a replaceable component of the melt conductor 1. The multi-channel system 5 according to the first embodiment is represented in detail in FIG. 2A.
[0178] The provision unit 23 is flanged to an input side 26 of the melt conductor block 4, the extrusion nozzle 14 being formed at the output side 27 of the melt conductor block 4 such that also the extrusion nozzle 14 is manufactured with an additive manufacturing method, namely together with the melt conductor block 4. On the output side 27 of the melt conductor block 4, a collection chamber 15 is formed into which the multi-channel system 5 opens, the collection chamber 15 being adapted to receive the polymer melt 24 distributed by the melt conductor 1 embodied as a melt distributor and to feed it continuously to the extrusion nozzle 14. As can be seen in FIGS. 2A through 16B, the multi-channel system 5 has outputs 7 adapted to direct the polymer melt 24 for feeding the extrusion nozzle 14 into the collection chamber 15. The extrusion nozzle 14 shown in FIG. 1 has an extrusion nozzle output 22 with a width B of more than 5,000 mm. The width B defines the width of an extrusion product 30 manufactured by the extrusion facility, which in FIG. 1 is embodied as a film.
[0179] In manufacturing the melt conductor block 4 with an additive method, a hollow chamber system 16 with a plurality of honeycomb-shaped hollow chambers 17 is formed such that the hollow chamber system 16 forms the melt conductor block 4. The hollow chamber system 16 is only suggested here; it substantially extends through the entire melt conductor block 4. The hollow chamber system 16 accommodates the multi-channel system 5 which is manufactured with an additive manufacturing method as well. Thus, the multi-channel system 5 is supported by the hollow chamber system 16 arranged spatially around the multi-channel system 5.
[0180] The melt conductor 1 distributes the polymer melt 24 in FIG. 2A in the multi-channel system 5, with respect to its designated direction of flow 25, from an input 6 arranged on an input side 26 of the melt conductor block 4 which in this case is embodied as a melt distributor block, via several serially arranged branchings 8, several levels 9a, 9b of sub-branches 10 and several interposed levels of divided melt channels 11, to a plurality of outputs 7 fluidically connected to the input 6 and arranged on an output side 27 of the melt conductor block 4. Thus, the multi-channel system 5 has one input 6 and a plurality of outputs 7 fluidically connected to the input 6. The input 6 on the input side 26 of the melt conductor block 4 is consequently formed as an input opening through which the polymer melt 24 is fed into the multi-channel system 5 of the melt conductor block 4.
[0181] For simplification purposes, the multi-channel system 5 in FIG. 2A is only shown with one branching 8 and two levels 9a, 9b of sub-branches 10. The other sub-branches 10 and melt channels are substantially formed in an analogous manner to distribute the polymer melt 24 over the respective width B of the extrusion nozzle output 22. Thus, three or more levels of sub-branches 10 are possible as well. In the designated direction 25 of flow of the polymer melt 24, a melt channel 11a of the a.sup.th level 12a is arranged between the input 6 and the branching 8, sub-branches 10 of a b.sup.th level 12b of melt channels lib between the branching 8 and the first level 9a, and sub-branches 10 of a c.sup.th level 12c of melt channels 11c between the first level 9a of sub-branches 10 and the second level 9b of sub-branches 10. The second level 9b of sub-branches 10 is also followed by a d.sup.th level 12d of melt channels 11d. FIG. 2A also shows that the number of melt channels 11 increases with each level; that is, one melt channel 11a of the a.sup.th level divides into two melt channels lib of the b.sup.th level; the two melt channels lib of the b.sup.th level in turn each divide into two melt channels 11c of the c.sup.th level; i.e. in total four melt channels 11c are formed, etcetera. In other words, the number of melt channels 11 doubles from one level to the subsequent level in the direction 25 of flow. Therefore, also the multi-channel system 5 and its individual cavities in the form of melt channels 11, branching 8 and sub-branches 10 are manufactured by the additive manufacturing method. Furthermore, additional cavities can be provided in the form of a collection chamber 15, local expansions 28 or junctions 13 which will be explained in more detail in the further description of alternative embodiments. Also, the cavities can be embodied as distribution or mixing chambers (not shown here) or the like.
[0182] In this embodiment, the melt channel 11a of the a.sup.th level 12a has a first local cross-section smaller than the second local cross-section of the divided melt channels 11b of the b.sup.th level 12b. Every local cross-section of the divided melt channels 11b of the b.sup.th level 12b is again larger than the local cross-section of the divided melt channels 11c of the c.sup.th level 12c etcetera.
[0183] The relationship between the local cross-sections of one level of melt channels 11 and a level of melt channels 11 directly upstream or downstream of the same can be determined by means of the circumference and a cross-sectional area of the respective melt channel, especially in case of melt channels 11 of a simple structure. This is exemplarily shown in FIG. 2B. Here, a circumference U.sub.2 and a cross-sectional area A.sub.2 of at least two melt channels 11b originating from one common melt channel 11a and separating are dimensioned in dependence on
[00002]
[0184] where U.sub.1 is the first circumference and A.sub.1 the first cross-sectional area of the common melt channel 11a, U.sub.2 being the second circumference and A.sub.2 the second cross-sectional area of one of the divided melt channels 11b, n.sub.k being the total number of the divided melt channels 11b and x being larger than or equal to ?0.5, preferably a value of at least 0.5, preferably at least a value of 0.75, and x being at the maximum a value of 4, preferably at the maximum a value of 2.5, further preferably at the maximum a value of 1.5.
[0185] For cross-sectional geometries of the melt channels where in local cross-section of the respective melt channel, the narrowest and the widest place are close together, it may on the other hand be advantageous if only a relation between a first cross-sectional area A.sub.1 of a melt channel 11a to be divided and a second cross-sectional area A.sub.2 of a melt channel 11b to be divided is established in dependence on the number n.sub.k of divided melt channels. In case of circular cross-sections, for instance, the narrowest and the widest position of the local cross-section of the respective melt channel 11a, 11b are identical and correspond to the diameter.
[0186] Thus, a cross-section A.sub.2 of at least two melt channels 11b originating from a common melt channel 11a and divided can be dimensioned in dependence on
A.sub.2=A.sub.1*(1/1.sub.K).sup.2/y,
[0187] where A.sub.1 is the first cross-sectional area of the common melt channel 11a, A.sub.2 is the second cross-sectional area of one of the divided melt channels 11b, n.sub.k is the total number of divided melt channels 11b and y has a value 2, preferably at least a value of 2.5, further preferably at least a value of 2.85 and y having a maximum value of 7, preferably a maximum value of 5, further preferably a maximum value 3.35. This is especially advantageous if the melt channels 11 of the multi-channel system 5 have a local cross-sectional shape deviating from a circular cross-section over at least half the length of the respective melt channel 11, preferably at least ? the length of the respective melt channel 11, preferably at least ? the length of the respective melt channel 11. This geometric relation between the melt channels 11 can be applied to all embodiments described above.
[0188] Presently, the melt channel 11a of the a.sup.th level 12a is oriented towards the input 6 in the designated direction 25 of flow of the polymer melt 24 and the melt channels 11b of the b.sup.th level 12b are oriented towards the output 7 with respect to the melt channel 11a of the a.sup.th level 12a. The melt channels 11c of the c.sup.th level 12c are oriented towards the input 6 with respect to the melt channels 11d of the d.sup.th level 12d, the melt channels 11d of the d.sup.th level being oriented towards the respective output 7 with respect to the melt channels 11 of the a.sup.th, b.sup.th and c.sup.th level 12a, 12b, 12c. In this manner, the melt conductor 1 functions as a melt distributor.
[0189] In FIG. 3, a second alternative multi-channel system 5 of a second alternative melt conductor block 4, which is not shown here, the melt conductor 1 is, in contrast to FIG. 2A, arranged in reverse order in the extruding die 2 and the extrusion facility 3 and is consequently embodied as a melt mixer in this alternative example of embodiment. This is due to the fact that the melt conductor 1 has a plurality of inputs 6, eight in this case, on the input side 26 of the melt conductor bock 4 via which one or up to eight identical or at least partly different polymer melts 24 are combined into an output 7 fluidically connected to the inputs 6 and arranged on the output side 27 of the melt conductor bock 4. In the present case, the melt conductor block 4 is not shown but only, for better clarity, the multi-channel system 5. The multi-channel system 5 is formed substantially identical with the embodiment in FIG. 1 and FIG. 2A. The only difference is that the polymer melt 24 is not distributed through the multi-channel system 5 but that up to eight different polymer melts 24 can be combined by means of the multi-channel system 5. The multi-channel system 5 presently also has several branchings 8 arranged in series, several levels 9a, 9b of sub-branches 10 and several levels 12a, 12b, 12c, 12d of divided melt channels 11a, 11b, 11c, 11d arranged between them; however seen against the designated direction 25 of flow of the polymer melt 24, namely from the output side 27 to the input side 26.
[0190] In opposition to the designated direction 25 of flow of the polymer melt 24, a melt channel 11a of the a.sup.th level 12a is arranged between the respective output 7 and the branching 8; between the branching 8 and the first level 9a of sub-branches 10, a b.sup.th level 12b of melt channels 11b, and between the first level 9a of sub-branches 10 and the second level 9b of sub-branches 10, a c.sup.th level 12c of melt channels 11c. A d.sup.th level 12d of melt channels 11d is also arranged downstream of the second level 9b of sub-branches 10, which levels are fluidically connected to the inputs 6. Thus, in the designated direction 25 of flow of the polymer melt 24, the number of melt channels 11 decreases with each level from the inputs 6 to the output 7; that is, every two of the presently eight melt channels 11d of the d.sup.th level 12d are combined to one melt channel 11c of the c.sup.th level 12c, i.e. in total four melt channels 11c of the c.sup.th level 12c. Every two of the four melt channels 11c of the c.sup.th level 12c are again combined to one melt channel 11b of the b.sup.th level 12b, i.e. in total there are two melt channels 11b of the b.sup.th level 12b, and from the two melt channels 11b of the b.sup.th level 12b, a melt channel 11a of the a.sup.th level is formed which is directly fluidically connected to the output 7.
[0191] In reverse order to the embodiment in FIG. 1 and FIG. 2A, the local cross-section of the respective melt channel level increases in the designated direction 25 of flow of the polymer melt 24 with each lower level. The melt channels 11a of the a.sup.th level 12a are oriented towards the output 7 in the designated direction 25 of flow of the polymer melt 24 and the melt channels 11b of the b.sup.th level 12b are oriented towards the inputs 6 with respect to the melt channels 11a of the a.sup.th level 12a. The melt channels 11c of the c.sup.th level 12c are oriented towards the output 7 with respect to the melt channels 11d of the d.sup.th level 12d, the melt channels 11d of the d.sup.th level 12d being oriented towards the inputs 6 with respect to the melt channels 11a, 11b, 11c of the a.sup.th, b.sup.th and c.sup.th levels 12a, 12b, 12c. Accordingly, the melt conductor 1 acts as a melt mixer.
[0192] FIG. 4 shows a third alternative multi-channel system of a third alternative melt conductor block 4 not shown here. The present multi-channel system 5 is formed as a combination of a melt conductor 1 which is partly formed as a melt distributor and partly as a melt mixer. On the input side of the melt conductor block 4, first an input 6 into the multi-channel system 5 is provided, the melt channel 11a of the a.sup.th level 12a being separated into a plurality of melt channels 11d of the d.sup.th level 12d in analogy to the embodiment in FIG. 2A. Further downstream in the designated direction 25 of flow of the polymer melt, starting from the melt channels 11d of the d.sup.th level 12d, the melt channels 11 are again combined in a manner analogous to the embodiment in FIG. 3 via melt channels 11c, 11b of the C.sup.th level 12c and of the b .sup.th level 12b down to a melt channel of the a.sup.th level 12a or down to the output 7, respectively.
[0193] In FIG. 5, a fourth alternative multi-channel system 5 of a fourth alternative melt conductor block 4not shownis represented, a combination of a melt conductor 1 formed partly as a melt mixer and partly as a melt distributor being shown here as well. The method of functioning, however, is opposite to the one shown in the embodiment of FIG. 4. On its input side 26, the melt conductor block 4 has several inputs 6 to the multi-channel system 5, the melt channels 11d of the d.sup.th level 12 d, which are fluidically directly connected to the inputs 6, being combined along the designated direction 25 of flow of the polymer melt 24, in a manner analogous to the example of embodiment in FIG. 3, from one level to the other up to a melt channel 11a of the a.sup.th level 12a. Further downstream, this melt channel 11a of the a.sup.th level 12a is divided, in a manner analogous to the embodiment in FIGS. 2A and 2B, from one level to the other via a branching 8, several levels 9a, 9b of sub-branches 10 as well as interposed levels 12b, 12c, 12d of melt channels 11b, 11c, 11d until a plurality of outputs 7 are arranged on the output side 27 of the melt conductor block 4.
[0194] The multi-channel system 5 according to the embodiment in FIG. 4 and according to the embodiment in FIG. 5 is not limited to the shape and arrangement described herein. It is also possible to provide upstream and/or downstream of the respective multi-channel system 5 additional portions formed as melt distributors and/or melt mixers which can be embodied and combined as desired. It is of an advantage, however, if the polymer melt 24 always has the same melt history at the output(s) 7, independently of which melt channels 11 or melt channel sequence it flows through. In case of eight melt channels 11d of the d.sup.th level 12d, the polymer melt 24 is therefore divided into a maximum of eight different melt streams. A same history of the polymer melt 24 in this connection means that all melt streams of the polymer melt 24 have traversed the same path through the multi-channel system 5 when they arrive at the output(s) 7 and have flown through the same number of melt channels 11, branchings 8 and sub-branches 10.
[0195] The embodiments according to FIGS. 6A through 16B, which are described in the following, exclusively refer to melt conductors 1 formed as melt distributors, with the polymer melt 24 in the multi-channel system 5 being distributed from a respective input 6 to a plurality of outputs 7. Thus, the arrangement and numbering of the levels of melt channels 11 as well as of the branchings 8 and levels of sub-branches 10 are analogous to the first embodiment shown in FIGS. 1 and 2A. Naturally, the following embodiments are also suitable for implementing the melt conductor 1 as a melt mixer or as any combination of melt mixer and melt distributor.
[0196] In the embodiments according to FIGS. 1 through 5, the multi-channel system 5 is in each case substantially formed lying on one plane, the respective input 6 and output 7 as well as all melt channels 11, branchings 8 and sub-branches 10 being consequently arranged on one common plane. Therefore, at least three degrees of freedom are used for forming the multi-channel system 5.
[0197] In contrast, a fifth alternative multi-channel system 5 of a fifth alternative melt conductor block 4not shown hereis represented in FIGS. 6A and 6B, the multi-channel system 5 branching out three-dimensionally in space using five degrees of freedom. As shown clearly in FIG. 6B, the melt channels 11 extend in the direction of flow of the polymer melt 24, starting from the input 6 and distributed over several levels, at least partly downwards, to the left, to the right, into and out of the leaf level. The melt channels 11 fluidically connected to the input 6 thus branch out over the branchings 8 and sub-branches 10 down to the outputs 7 which in the present arrangement are distributed over two substantially parallel planes, the first level 9a of sub-branches 10 being formed such that the melt channels 11c of the c.sup.th level 12b substantially extend rotated by 90? with respect to the melt channels 11b of the b.sup.th level, such that starting from each melt channel 11c of the c.sup.th level, a separate distribution system 29a-29d is formed. The first and the second distribution system 29a, 29b are arranged on one plane and the third and the fourth distribution system 29c, 29d are arranged on a second plane, the two planes being substantially arranged in parallel.
[0198] By means of such a melt conductor 1, it is possible in an easy manner to distribute the polymer melt 24 not only evenly in width in a manner analogous to FIG. 2A but also homogeneously in a direction transverse thereto, that is, in height or in depth, depending on the direction of view, so that the polymer melt 24 can exit from the melt conductor block 4 on a comparably large surface. This is especially suitable for manufacturing filaments or endless filaments and in particular for producing spunbonded fabrics by means of multirow nozzle dies.
[0199] Independently of the arrangement of the branching 8 and the sub-branches 10 in relation to the melt channels 11 and their arrangement in three-dimensional space, the local cross-section of the melt channels 11 decreases from one level to the next down to the outputs 7, the melt channels 11 of each level 12a-12e being always formed symmetrical in all distribution systems 29a-29d and the separated melt streams of the polymer melt 24 having the same melt history.
[0200] The outputs 7 of the first and second distribution systems 29a, 29b or of the first plane, respectively, are thus located on a theoretical straight first line and the outputs 7 of the third and the fourth distribution system 29c, 29d or of the second plane on a theoretical straight second line. Both lines and both planes are arranged in parallel to one another. Since all melt channels 11 are connected to a single input 6, all melt streams have the same material properties at the respective output 7 due to conveying the same polymer melt 24.
[0201] In FIGS. 7A through 7D, a sixth alternative multi-channel system 5 of a sixth alternative melt conductor block 4, not shown here, is represented, the multi-channel system 5 presently dividing three-dimensionally into space using six degrees of freedom. In this embodiment, it is shown that the two melt channels 11b of the b.sup.th level 12b partly extend in opposition to a global machine direction 18. The global machine direction 18 leads from the input 6 to the output 7 of a designated melt stream of the polymer melt 24. Every melt channel 11b of the b.sup.th level 12b has a local machine direction 19 which can always have, in dependence on the embodiment and extension of the respective melt channel 11, the same or a changing orientation in the longitudinal direction of the melt channel 11. It can be of an advantage if the local machine direction 19 runs at least partly in opposition to the global machine direction 18. This is in particular shown in FIG. 7A.
[0202] In the present case, the input 6 and the outputs 7 of the multi-channel system 5 are substantially arranged on a first plane, the melt channels 11b of the b.sup.th level 12b extending partly transversely to this first plane such that the first level 9a of sub-branches 10 is arranged on a second plane parallel to the first plane. The attached melt channels 11c of the c.sup.th level 12c extend partly on the second plane and are guided back to the first plane for further distribution of the polymer melt 24. By guiding the melt channels 11 three-dimensionally in space, and in particular by guiding the local machine direction 19 of the melt channels 11 partly against the global machine direction 18, the polymer melt 24 is distributed over a smaller axial construction space, that is, in the global machine direction 18 of the melt conductor 1. In this manner, the melt conductor 1 can be constructed to be more compact.
[0203] FIG. 8 shows a seventh alternative melt conductor block 4 of the melt conductor 1 having a seventh alternative multi-channel system 5, the three-dimensionally extending multi-channel system 5 being embodied in a manner analogous to the multi-channel system 5 in FIG. 7 in terms of arrangement, structuring and guiding of the melt channels 11. What is shown is a possible arrangement of the multi-channel system 5 in the melt conductor block 4 which is here only shown schematically as a cuboid, where the melt conductor block 4 can be constructed with a comparatively large width and at the same time a low constructive height and low axial length in the global machine direction 18 due to three-dimensional guiding of the melt channels 11 in space. With such a melt conductor block 4, it is possible to distribute the polymer melt 24 such that in particular non-woven fabrics with 20 to 10,000 individual filaments per meter of width can be produced.
[0204] FIG. 9 shows an exemplary embodiment of a branching 8 or sub-branch 10 of the multi-channel system 5 in an eighth alternative embodiment of an eighth alternative multi-channel system 5. It is shown that in case of a melt conductor 1 at least partly embodied as a melt distributor, a melt channel 11a of an a.sup.th level 12a can be divided into three melt channels 11b of a b.sup.th level 12b via the branching 8. The three melt channels 11b of a b.sup.th level 12b are arranged evenly distributed around the melt channel 11a of the a.sup.th level 12a. An irregular arrangement around the melt channel 11a of the a.sup.th level 12a is conceivable as well. Conversely, in a melt conductor 1 at least partly formed as a melt mixer, three melt channels 11b can be combined to one melt channel 11a.
[0205] FIG. 10 shows an exemplary embodiment of a branching 8 or a sub-branch 10 of the multi-channel system 5 in a ninth alternative embodiment of a ninth alternative multi-channel system 5. It is shown that in case of a melt conductor 1 at least partly embodied as a melt distributor, a melt channel 11a of an a.sup.th level 12a can be divided into four melt channels 11b of a b.sup.th level 12b via the branching 8. The four melt channels 11b of a b.sup.th level 12b are arranged evenly distributed around the melt channel 11a of the a.sup.th level 12a. Here as well, an irregular arrangement around the melt channel 11a of the a.sup.th level 12a is also conceivable. Vice versa, with a melt conductor at least partly embodied as a melt mixer 1, four melt channels 11b can be combined to one common melt channel 11a.
[0206] FIG. 11 shows a tenth example of embodiment with a tenth alternative multi-channel system 5. The multi-channel system 5 is substantially identical with the multi-channel system 5 in FIG. 1. The main difference is that the melt distributor block 4, here in the area of the melt channels 11c of the c.sup.th level 12c, each has a static functional element 21 in the form of a static mixing element for influencing the designated polymer melt 24. The respective functional element 21 is arranged within a local broadening 28 of the melt channels 11c of the c.sup.th level 12c and implements mixing of the polymer melt 24 guided and distributed inside the melt channels 11c of the c.sup.th level 12c. In this manner, homogeneous distribution of the melt strand of the polymer melt 24 guided in the respective melt channel 11, in particular its flow and material properties, can be guaranteed. Thus, the respective functional element 21 is arranged in one of the melt channels 11c of the c.sup.th level 12c between a sub-branch 10 of the first level 9a and a sub-branch 10 of the second level 9b. Before and after the local broadening 28, the cross-sectional dimension and shape of the respective melt channel 11c of the c.sup.th level 12c is substantially equal. Alternatively, the static mixing element can also be arranged directly in the respective melt channel 11 and not in a local expansion.
[0207] FIG. 12 shows an eleventh example of embodiment with an eleventh alternative multi-channel system 5. The multi-channel system 5 is identical with the multi-channel system 5 in FIGS. 6A and 6B. In addition, the melt conductor block 4 has a medium channel 20 extending spatially between the melt channels 11 of the multi-channel system 5, here between the two levels of the distribution systems 29a, 29b, 29c, 29d, and implements a fluid guidance. The fluid guidance is used for temperature control of the melt conductor block 4 and therefore of the polymer melt 24 guided in the multi-channel system 5. The medium channel 20 is not fluidically connected to the melt channels 11 of the multi-channel system 5 and implements temperature control of the melt conductor 1 and in particular of the melt conductor blocks 4a-4e during operation of the extrusion facility 3. Furthermore, any number of additional medium channels of any structure can be provided which are arranged fluidically separated from the melt channels 11 of the multi-channel system 5 in the melt distributor block 4. The additional medium channels can also be embodied as drying shafts which are adapted, for instance, for accommodating an electric line and/or a measuring unit.
[0208] According to the following examples of embodiment in FIGS. 13A to 15B, the melt conductor block 4 has a first multi-channel system 5a and a second multi-channel system 5b fluidically separated therefrom, three or more multi-channel systems also being conceivable without any problems.
[0209] FIG. 13A through 13D show a twelfth alternative embodiment in which the two multi-channel systems 5a, 5b are embodied so as to be fluidically separated from each other. In other words, a first polymer melt 24 is conducted into a first input 6a of the first multi-channel system 5a and a second polymer melt 24 is directed into a second input 6b of the second multi-channel system 5b, where the two polymer melts 24 can have identical or different properties. Each multi-channel system 5a, 5b has a respective input 6a, 6b for feeding the respective polymer melt 24 and a plurality of outputs 7a, 7b for feeding the polymer melt 24 to an extrusion nozzle (not shown here). The first multi-channel system 5a is embodied in a manner substantially analogous to the multi-channel system 5 in FIG. 2A. We therefore refer to the respective description, where a repetition of identical reference numbers is omitted for the purpose of simplicity.
[0210] The melt channel 11a of the a.sup.th level 12a of the second multi-channel system 5b extends, starting from the input 6a of the second multi-channel system 5b, first in parallel to the melt channel 11a of the a.sup.th level 12a of the first multi-channel system 5a. The melt channels 11b of the b.sup.th level 12b, however, subsequent to the branching 8, are here rotated by 45? with respect to the first multi-channel system 5a so that the melt channels 11 of the b.sup.th, c.sup.th and d.sup.th levels 12b, 12c, 12d of the second multi-channel system 5b extend towards the first multi-channel system 5a and continuously approach the melt channels 11 of the first multi-channel system 5a with each rising level. This causes the outputs 7b of the second multi-channel system 5b to be approached comparatively closely to the outputs 7a of the first multi-channel system 5a so that the melt stream of the polymer melt distributed by the second multi-channel system 5b exits in the area of the outputs 7a, 7b at a comparatively low distance from the melt stream of the polymer melt 24 distributed by the first multi-channel system 5a.
[0211] In the front view in FIG. 13A, an output 7a of the first multi-channel system 5a and an output 7b of the second multi-channel system 5b are arranged in series mutually spaced. Additionally, the first outputs 7a of the first multi-channel system 5a are arranged on a first straight line and the second outputs 7b of the second multi-channel system 5b on a second straight line, the lines being arranged substantially in parallel. In other words, the outputs 7a, 7b of the respective multi-channel system 5a, 5b are arranged on two planes arranged in parallel to one another. In this manner, two-layered film webs can be produced whose layers can have identical or different material properties.
[0212] A thirteenth alternative embodiment according to FIGS. 14A to 14C shows a thirteenth alternative embodiment identical with the previously described embodiment according to FIGS. 13A to 13D. The main difference is simply that the outputs 7a, 7b of the multi-channel systems 5a, 5b are not arranged in front of and behind one another but transversely to the designated direction 25 of flow or to the global machine direction 18 of the respective polymer melt 24, offset with respect to one another.
[0213] This can be seen particularly well in FIG. 14C. Each output 7a of the first multi-channel system 5a is arranged between two outputs 7b of the second multi-channel system 5b. The two multi-channel systems 5a, 5b are arranged mutually spatially offset. This allows an even closer mutual approach of the outputs 7a, 7b of the multi-channel systems 5a, 5b than in the embodiment in FIGS. 13A through 13D.
[0214] FIGS. 15A and 15B show a fourteenth alternative embodiment in which the two multi-channel systems 5a, 5b are fluidically separated from one another. A first polymer melt 24 is fed into a first input 6a of the first multi-channel system 5a and a second polymer melt 24 into a second input 6b of the second multi-channel system 5b, where the polymer melts can have the same or different properties. Thus, each multi-channel system 5a, 5b has a respective input 6a, 6b for feeding in the respective polymer melt 24 and a plurality of outputs 7a, 7b for feeding the extrusion nozzle 14 with the respective polymer melt 24. The first multi-channel system 5a is formed in a manner substantially analogous to the multi-channel system 5 in FIGS. 6A and 6B in which the melt channels lib of the b.sup.th level 12b each branch out into a separate distribution system 29a, 29b, 29c, 29d. For the arrangement of the melt channels 11 of the first multi-channel system 5a, we therefore refer to the description of FIGS. 6A and 6B. For reasons of simplicity, a repetition of identical reference numbers, unless absolutely necessary, is omitted.
[0215] The second multi-channel system 5b is formed substantially identical with the embodiment in FIG. 2A. The only difference is that the melt channel 11a of the a.sup.th level 12a of the second multi-channel system 5b is offset in relation to the melt channels 11c, 11d of the c.sup.th and d.sup.th levels 12c, 12d of the second multi-channel system 5b. Here the first multi-channel system 5a has five levels 12a-12e of melt channels 11a-11e (analogous to FIGS. 6A and 6B) and the second multi-channel system 5b has four levels 12a-12d of melt channels 11a-11d.
[0216] The first input 6a of the first multi-channel system 5a is arranged centrally, the second input 6b of the second multi-channel system 5b being arranged parallel thereto and therefore eccentrically for fluidic separation of the multi-channel systems 5a, 5b. The melt channel 11a of the a.sup.th level 12a of the first multi-channel system 5a is parallel to a central axis M, the melt channels 11c, 11d of the c.sup.th and d.sup.th levels 12c, 12d and the outputs 7b of the second multi-channel system 5b being arranged on the central axis M as well as the input 6a of the first multi-channel system 5a. Thus, the melt channels 11b of the b.sup.th level 12b of the second multi-channel system 5b are embodied such that the polymer melt 24 is directed from the melt channel 11a of the a.sup.th level 12a of the first multi-channel system 5a to the central axis M. In this manner, it is achieved that the outputs 7a of the first and of the second distribution system 29a, 29b as well as of the third and fourth distribution systems 29c, 29d are arranged at equal distances from the outputs 7b of the second multi-channel system 5b.
[0217] In other words, the first outputs 7a of the first multi-channel system 5a are partly arranged on a first straight line and partly on a second straight line, the second outputs 7b of the second multi-channel system 5b being arranged on a third straight line. The three lines are substantially parallel. In other words, the outputs 7a, 7b of the respective multi-channel system 5a, 5b are arranged on planes which are mutually parallel. In this manner, three-layered film webs can be produced, with the outer layers having first material properties and the inner layer enclosed by the outer layers having second material properties. This can be advantageous, for instance, for sustainably produced extrusion products when the polymer melt 24, which is distributed on the inner plane by the second multi-channel system 5b, consists of a recycled material and the polymer melt 24 distributed by the first multi-channel system 5a over the two outer planes is made of a material as yet unused. This helps to save unused material and at the same time reuse recycled material.
[0218] FIGS. 16A and 16B show a fifteenth embodiment in which two multi-channel systems 5a, 5b are formed as well, in a manner substantially analogous to the embodiment in FIGS. 13A through 13D. The two multi-channel systems 5a, 5b are at first fluidically separated, with a first polymer melt 24 being fed into a first input 6a of the first multi-channel system 5a and a second polymer melt 24 into a second input 6b of the second multi-channel system 5a. The difference to the embodiment in FIGS. 13A through 13D substantially consists in the fact that not every one of the multi-channel systems 5a, 5b has separate outputs 7a, 7b but that the first multi-channel system 5a has a junction 13 with the second multi-channel system 5b such that commonly used outputs 7 are provided on the output side of the multi-channel system 5a, 5b. Here, the polymer melts 24 of both multi-channel systems 5a, 5b are only joined briefly before exiting the melt conductor block 4. In this manner, the properties of the two polymer melts 24 are largely maintained, subsequent atomization merely leading to mutual adhesion of the polymer melts 24. Thus, the properties of the different polymer melts 24 can be optimally adjusted depending on the requirements on the extrusion product. As an alternative, it is possible to join the polymer melts 24 from the first and the second multi-channel system 5a, 5b earlier to achieve in particular better mixing of the polymer melts.
[0219] At this point, it is explicitly pointed out that features of the solutions described above, in the Claims or in the Figures can also be combined, if desired, so as to cumulatively achieve the features, effects and advantages. It is also explicitly mentioned that the embodiments in FIGS. 1 through 10 can also be implemented with two or more multi-channel systems. For these as well as for the other embodiments up to FIG. 16B, it is also to be said that the melt conductor block 4 can also be embodied with three multi-channel systems, with four multi-channel systems, with five or more multi-channel systems.
[0220] It is understood that the embodiments explained above are only first embodiments of the invention, in particular of the melt conductor, the extruding die and the extrusion facility according to the invention. Thus, the implementation of the invention is not limited to these embodiments. All features disclosed in the application documents are claimed as essential to the invention provided that they are novel individually or in combination with respect to the state of the art.
[0221] The embodiments shown here are only examples of the present invention and are therefore not to be understood as limiting. Alternative embodiments considered by the person skilled in the art are equally comprised by the scope of protection of the present invention.
LIST OF REFERENCE NUMBERS
[0222] 1 melt conductor [0223] 2 extruding die [0224] 3 extrusion facility [0225] 4 melt conductor block [0226] 5 multi-channel system [0227] 5a first multi-channel system [0228] 5b second multi-channel system [0229] 6 input of multi-channel system [0230] 6a input of first multi-channel system [0231] 6b input of second multi-channel system [0232] 7 output of multi-channel system [0233] 7a output of first multi-channel system [0234] 7b output of second multi-channel system [0235] 8 branching [0236] 9a first level of a branching [0237] 9b second level of a branching [0238] 9c third level of a branching [0239] 10 sub-branch [0240] 11 melt channel [0241] 11a divided melt channel of a first level [0242] 11b divided melt channel of a second level [0243] 11c divided melt channel of a third level [0244] 11d divided melt channel of a fourth level [0245] 11e divided melt channel of a fifth level [0246] 12a a.sup.th level of a melt channel [0247] 12a a.sup.th level of a melt channel [0248] 12b b.sup.th level of a melt channel [0249] 12b b.sup.th level of a melt channel [0250] 12c c.sup.th level of a melt channel [0251] 12c C.sup.th level of a melt channel [0252] 12d d.sup.th level of a melt channel [0253] 12d d .sup.th level of a melt channel [0254] 12e e.sup.th level of a melt channel [0255] 13 junction [0256] 14 extrusion nozzle [0257] 15 collection chamber [0258] 16 hollow chamber system [0259] 17 hollow chamber [0260] 18 global machine direction [0261] 19 local machine direction [0262] 20 medium channel [0263] 21 static functional element [0264] 22 extrusion nozzle output [0265] 23 provision unit [0266] 24 polymer melt [0267] 25 flow direction of polymer melt [0268] 26 input side of melt conductor block [0269] 27 output side of melt conductor block [0270] 28 local expansion of melt channel [0271] 29 polymer [0272] 30 extrusion product [0273] A.sub.1 first cross-sectional area of melt channel to be divided [0274] A.sub.2 second cross-sectional area of divided melt channel [0275] B width of extrusion nozzle output [0276] n.sub.k total number of divided melt channels [0277] U.sub.1 first circumference of melt channel to be divided [0278] U.sub.2 second circumference of divided melt channel [0279] M center axis
