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 two or more melt conductor blocks (4a, 4b) and a multi-channel system (5), the multi-channel system (5) being arranged inside at least one of the melt conductor blocks (4a, 4b) 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 two or more melt conductor blocks and a multi-channel system, the multi-channel system being arranged with three-dimensional extension inside at least one of the melt conductor blocks 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 yth 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 at 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 the multi-channel system extends through at least two of the melt conductor blocks.
3. Melt conductor according to claim 2, characterized by a tensioning system by means of which the melt conductor blocks can be tensioned together to form one block unit.
4. Melt conductor according to claim 3, wherein the tensioning system comprises a retention device with a frame part which can be thermally activated and by means of which at least two of the melt conductor blocks can be tensioned with respect to one another.
5. Melt conductor according to claim 1, wherein the melt conductor blocks have positioning means by means of which the at least two melt conductor blocks can be mutually positioned.
6. Melt conductor according to claim 1, characterized by means for connecting, in particular threading and/or adhesive bonding, the melt conductor blocks.
7. Melt conductor according to claim 6, characterized by a tie rod which is guided through at least two of the melt conductor blocks and tensions at least two of the melt conductor blocks with respect to one another.
8. Melt conductor according to claim 1, wherein a seal is arranged at a contacting surface between two contacting melt conductor blocks.
9. Melt conductor according to claim 1, wherein two or more multi-channel systems extend through at least two melt conductor blocks, a channel output of a k.sup.th multi-channel system of the first melt conductor block being uniquely allocated to a channel input of a k.sup.th multi-channel system of the second melt conductor block and vice versa.
10. Melt conductor according to claim 1, wherein at least one of the melt conductor blocks 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.
11. Melt conductor according to claim 1, wherein at least one of the melt conductor blocks has a static functional element for influencing the designated polymer melt at least indirectly.
12. Melt conductor according to claim 11, wherein the static functional element is a static mixing element.
13. Extruding die for an extrusion facility for manufacturing extrusion products, comprising a melt conductor according to claim 1, the melt conductor being adapted to distribute and/or mix at least one designated polymer melt.
14. Extruding die according to claim 13, characterized by an extrusion nozzle output having a width of more than 5,000 mm, preferably more than 6,000 mm or more than 8,000 mm.
15. Extrusion facility for manufacturing extrusion products, comprising an extruding die according to claim 13.
16. Method of operating an extrusion facility according to claim 15, the extrusion facility being fed with at least one extrudable 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
[0133] In the drawings:
[0134] FIG. 1A is a schematic view of a possible structure of an extrusion facility having a melt conductor comprising several melt conductor blocks and a multi-channel system according to a first alternative;
[0135] FIG. 1B is schematic view of the melt conductor according to FIG. 1A;
[0136] FIG. 1C is a simplified detailed view of an interface between two melt conductor blocks according to FIG. 1A and FIG. 1B;
[0137] FIG. 2 is a schematic view of an output side of the melt conductor according to a second alternative example of embodiment;
[0138] FIG. 3 is a schematic perspective view of the multi-channel system according to FIGS. 1A through 1C, the melt conductor being embodied as a melt distributor;
[0139] FIG. 4 is a schematic perspective view of a third alternative embodiment of the multi-channel system, the melt conductor being embodied as a melt mixer;
[0140] 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 distributor and partly as a melt mixer;
[0141] FIG. 6 is a schematic perspective view of a fifth alternative embodiment of the multi-channel system, the melt conductor being partly embodied as a melt mixer and partly as a melt distributor;
[0142] FIG. 7A is a schematic perspective view of a sixth alternative embodiment of the multi-channel system, the melt conductor being embodied as a melt distributor;
[0143] FIG. 7B is another schematic perspective view of the sixth alternative embodiment according to FIG. 7A;
[0144] FIG. 8A 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;
[0145] FIG. 8B is a schematic perspective view of the seventh alternative embodiment according to FIG. 8A;
[0146] FIG. 8C is another schematic perspective view of the seventh alternative embodiment according to FIGS. 8A and 8B;
[0147] FIG. 8D is another schematic perspective view of the seventh alternative embodiment according to FIGS. 8A through 8C;
[0148] FIG. 9 is a schematic perspective view of an eighth alternative embodiment of the multi-channel system, the melt conductor being embodied as a melt distributor;
[0149] FIG. 10A is a schematic perspective view of a ninth alternative embodiment of the multi-channel system, the melt conductor being embodied as a melt distributor;
[0150] FIG. 10B is a schematic top view of the ninth alternative embodiment according to FIG. 10A; and
[0151] FIG. 10C is another schematic perspective view of the ninth alternative embodiment according to FIGS. 10A and 10B.
[0152] FIG. 1A 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 for manufacturing and processing an extrusion product 30 or an intermediate product. The provision unit 23 is presently the extruder (not presented in detail here) which plasticizes at least one extrudable polymer 29 to form the polymer melt 24. The polymer can be, for instance, a plastic. 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.
[0153] The melt conductor 1 which in this first example of embodiment is formed as a melt distributor has five separate melt conductor blocks 4a-4e, a multi-channel system 5 extending three-dimensionally inside the melt conductor blocks 4a-4e after assembly of the melt conductor 1. The subdivision of the melt conductor blocks 4a-4e is represented by dashed lines. The melt conductor blocks 4a-4e are manufactured by an additive manufacturing method and arranged stationary with respect to each other and fixed into place. In this manner, a modular structure of the melt conductor 1 is achieved, for the melt conductor blocks 4a-4e can be combined or replaced as desired, depending on requirements on the extrusion product 30 or in case of maintenance or repair. Therefore, the melt conductor blocks 4a-4e can be integrated in the continuously operating extrusion facility 3 as replaceable components of the melt conductor 1. The melt conductor block 4a-4e can be formed massively as a block or delicately with supporting structures. In this case, the multi-channel system 5 is supported by supporting structures arranged spatially around the multi-channel system 5, which are not shown here in detail.
[0154] The provision unit 23 is flanged to an input side 26 of the melt conductor 1 or to the first melt conductor block 4a. The second, third, fourth and fifth melt conductor blocks 4b, 4c, 4d, 4e are arranged downstream of the first melt conductor block 4a and have the same width as the first melt conductor block 4a. The extrusion nozzle 14 is flanged to the output side 27 of the melt conductor block 1 or to the second, third, fourth and fifth melt conductor blocks 4a-4e. Alternatively, also the extrusion nozzle 14 can be manufactured with an additive manufacturing method, namely in extrusion nozzle segmentsnot shown herewhich are each integral with one of the second to fifth melt conductor blocks 4b-4e. Downstream, the extrusion nozzle 14 has an extrusion nozzle output 22 which here achieves an atomization of the polymer melt 24 to form the extrusion product 30. The extrusion nozzle 14 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 3, which in FIG. 1A is embodied as a film. Atomization to filaments is possible as well by means of the present extrusion facility 3, in particular by means of the present extruding die 2.
[0155] On the output side 27 of the melt conductor 1 a collection chamber 15 is arranged the multi-channel system 5 opens into, the collection chamber 15 being adapted to receive the polymer melt 24 distributed by the melt conductor 1 formed as melt distributor and continuously feed it to the extrusion nozzle 14. Here, in an assembled state of the melt conductor 1, the collection chamber 15 is formed on the output side by the second, third, fourth and fifth melt conductor blocks 4a-4e.
[0156] In its entirety, the multi-channel system 5 is only formed during assembly of the melt conductor 1, i.e. with mutual tensioning of the melt conductor blocks 4a-4e. For as can be seen in FIG. 1B in combination with FIG. 1C, the multi-channel system 5 extends through all melt conductor blocks 4a-4e, each of the melt conductor blocks 4a-4e having a partial channel system with a plurality of melt channels 11 which in the assembled state of the melt conductor 1 form the multi-channel system 5. In other words, the melt channels 11 of all melt conductor blocks 4a-4e are fluidically interconnected, forming the multi-channel system 5.
[0157] FIG. 1B shows the melt conductor 1 in top view. Mutual tensioning of the melt conductor blocks 4a-4e occurs by means of a tensioning system 13 spatially arranged around the melt conductor 1 or around all melt conductor blocks 4a-4e, which tensioning system mutually tensions the melt conductor blocks 4a-4e to form one block unit. The tensioning system 13 here comprises a retention device 16 with four frame parts 17 which can be thermally activated. A smaller or a larger number of frame parts 17 are conceivable as well, depending on the configuration of the melt conductor blocks 4a-4e. The frame parts 17 to be thermally activated are embodied such that a thermal expansion of the melt conductor blocks 4a-4e during operation, either by the polymer melt 24 conveyed through the multi-channel system and/or by supplementary temperature regulation of the melt conductor 1, achieves a tensioning effect. In this manner, no separate mechanical tensioning of the melt conductor blocks 4a-4e with respect to each other is required, for during operation of the extrusion facility 3, the melt conductor blocks 4a-4e are automatically tensioned with respect to one another. Independently thereof, the tensioning system 13 can nevertheless be adapted for at least partial mechanical tensioning of the melt conductor blocks 4a-4e.
[0158] The melt conductor blocks 4a-4e can be embodied and joined as desired. In particular, it is possible to manufacture, in addition to individually embodied melt conductor blocks, standard blocks so as to allow faster manufacture, assembly and allocation of the melt conductor blocks 4a-4e and to produce blocks which are less expensive. Here, the second to fifth melt conductor blocks 4b-4e are identical; in particular the partial channel systems formed in the respective melt conductor blocks 4b-4e are identical. Thus, the melt conductor 1 according to this embodiment has five melt conductor blocks 4a-4e; however, only two different melt conductor blocks 4a-4e are provided. The first melt conductor block 4a pre-distributes the polymer melt 24 to the melt conductor blocks 4b-4e which are downstream in the global machine direction 18 and switched in parallel.
[0159] FIG. 1C shows a detailed partial section between the first and the second melt conductor blocks 4a, 4b. Presently, the melt conductor blocks 4a, 4b have positioning means 31 in the form of a projection 37 and a recess 38, the projection 37 during assembly of the melt conductor blocks 4a, 4b protruding into the recess 38, thus preventing a relative movement of the melt conductor blocks 4a, 4b, in this case to the left and to the right on the leaf level. During additive manufacturing of the respective melt conductor block 4a, 4b, the projection 37 is formed integral therewith, the recess being formed as well directly during manufacturing of the respective melt conductor block 4a, 4b. In this manner, the arrangement of the projection 37 and of the recess 38 complementary therewith is predetermined. With the positioning means 31, the melt conductor blocks 4a, 4b can thus be directly positioned with respect to each other during assembly without supplementary orientation and positioning of the melt conductor blocks 4a, 4b being required.
[0160] In FIG. 1C, it can be seen that the multi-channel system 5 extends three-dimensionally through at least two of the melt conductor blocks 4a, 4b. The melt conductor blocks 4a, 4b are configured, mutually arranged and tensioned such that a channel output 36 of the melt channel 11 formed on the first melt conductor block 4a is uniquely allocated to the melt channel 11 formed at the second melt conductor block 4b and vice versa. In other words, the channel input 35 and the channel output 36 have the same shape and size at the point of intersection of the melt channels 11 and 11 such that unimpeded conveyance of the polymer melt 24 is possible and in particular deposits and/or defects in the polymer melt are prevented.
[0161] In addition, seals 34 are provided between a first contact surface 33a of the first melt conductor block 4a and a second contact surface 33b contacting the first contact surface 33a, which achieve a sealing effect of the multichannel system 5 with respect to an outer atmosphere. In addition, the polymer melt 24 is prevented from reacting with air. Here, the seals 34 are received on the first melt conductor block 4a.
[0162] The embodiment and arrangement of the seals 34 and the positioning means 31 are to be understood as merely exemplary. The shape, size and arrangement can be selected as desired and can be applied without any problems in particular to all contact surfaces 33a, 33b between the melt conductor blocks 4a-4e which contact each other.
[0163] FIG. 2 shows a second alternative embodiment of the melt conductor 1; the output side 27 of the melt conductor 1 is schematically shown. The melt conductor 1 has three melt conductor blocks 4a, 4b, 4c, the second and the third melt conductor block 4b, 4c together being just as wide as the first melt conductor block 4a. Here, the melt conductor 1 is assembled in two layers, the first melt conductor block 4a being arranged in the lower layer and the second and third melt conductor blocks 4b, 4c in the upper layer. It thus becomes clear that the melt conductor blocks 4a, 4b, 4c can be arranged and tensioned both next to each other and on top of each other.
[0164] In this embodiment, the melt conductor 1 has means for connection, or threaded connection, respectively, of the melt conductor blocks 4a, 4b, 4c. These means are configured as tie rods 32shown here in dashed lineswhich are guided and screwed through openings 39, shown here in dashed lines as well. By means of the tension rods 32, a tensioning effect is achieved which prevents relative movement of the melt conductor blocks 4a, 4b, 4c. A larger number of tie rods 32 than is shown here is possible as well; in particular, the first and the second melt conductor block 4a, 4b can be tensioned with respect to one another. On the sectional planes between the melt conductor blocks 4a, 4b, 4c an arrangement of seal elements 34 and/or positioning means 31 is possible, in the same way as in FIG. 1C. Alternatively or additionally, the melt conductor blocks 4a, 4b, 4c can after positioning be interconnected by material engagement, in particular by adhesive bonding, soldering, welding or the like.
[0165] Here the multi-channel system 5 is configured three-dimensionally such that a plurality of outputs 7 of the multi-channel system 5 are arranged on the output side 27 of the melt conductor 1, the outputs 7 being arranged transversely to the output direction of the designated melt stream, i.e. spaced on several planes or layers on the leaf level. Depending on the requirements on the extrusion product 30, the outputs 7 can be arranged in any configuration with respect to each other and in one or more layers. The outputs 7 are configured to convey the polymer melt 24 into the collection chamber 15 to feed the extrusion nozzle 14 according to FIG. 1A, i.e. to feed the extrusion nozzle 14. The configuration of the multi-channel system 5 according to this example of embodiment is exemplarily described for the first and the second melt conductor block 4a, 4b in FIGS. 7A and 7B and for the third melt conductor block 4c in FIGS. 10A through 10C.
[0166] In this example, the outputs 7 are arranged in six parallel layers. For the first two melt conductor blocks 4a, 4b four layers are provided, four outputs 7 each being vertically arranged on top of each other on the leaf level with equal spacing. In contrast, the third melt conductor block 4c has two layers of outputs 7, one output 7 each of one layer being arranged centrally between two outputs 7 of the respective other layer in the direction of flow of the polymer melt 24. Thus, it is possible to arrange outputs 7 transversely to the output direction of the designated melt stream on top of each other, misaligned with respect to each other and/or partly overlapping.
[0167] FIG. 3 shows the multi-channel system 5 according to the first embodiment in FIGS. 1A and 1B, where this multi-channel system 5 can be embodied as a partial channel system in one of the second to the fifth melt conductor blocks 4b-4e. By means of the multi-channel system 5, the polymer melt 24 is distributed from an input 6 arranged on an input side 26 of the melt conductor 1 embodied in this case as a melt distributor, via a branching 8, several levels 9a, 9b of sub-branches 10 arranged in series and several fluidically interposed levels of divided melt channels 11 to a plurality of outputs 7 fluidically connected to the input 6 and arranged on the output side 27 of the melt conductor 1. The designated direction 25 of flow of the polymer melt 24 thus is from the input side 26 to the output side 27.
[0168] The multi-channel system 5 thus has an input 6 and a plurality of outputs 7 fluidically connected to the input 6. The input 6 on the input side 26 is an input opening through which the polymer melt 24 is fed into the multi-channel system 5. The outputs 7 can therefore be understood as output openings out of which the polymer melt 24 is evenly distributed and fed to the collection chamber 15not shown herewith a same melt history.
[0169] For simplification purposes, the limits between the melt conductor blocks 4a-4e are not shown in FIG. 3 and in the subsequent Figures. Furthermore, the multi-channel system 5 is shown exemplarily and simplified; the multi-channel system 5 here only comprises one branching 8 and two levels 9a, 9b of sub-branches 10, with naturally three or more levels of sub-branches 10 being 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, a b.sup.th level 12b of melt channels 11b between the branching 8 and the first level 9a of sub-branches 10 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.
[0170] FIG. 3 further 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 11b of the b.sup.th level; the two melt channels 11b 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 according to FIG. 1, local expansions or junctions. Also, the cavities can be embodied as distribution or mixing chambers (not shown here) or the like.
[0171] 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.
[0172] When smaller or larger local cross-sections of the respective melt channel 11 are mentioned, this means that the melt channel 11 has a larger or smaller cross-section, respectively, 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.
[0173] Here, 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 11b of the b.sup.th level 12b. 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 12d being oriented towards the output 7 with respect to the melt channels 11 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 distributor.
[0174] In FIG. 4, a third alternative multi-channel system 5 of a third alternative melt conductor 1, which is not shown here, the melt conductor 1 is, in contrast to FIG. 3, 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 1 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 1. The multi-channel system 5 is formed substantially identical with the embodiment in FIG. 3. 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 comprises a branching 8, several levels 9a, 9b of sub-branches 10 arranged in series and several levels of divided melt channels 11 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.
[0175] 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 channels are fluidically directly 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.
[0176] In reverse order to the embodiment in FIGS. 1A, 1B and 3, 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 11 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.
[0177] FIG. 5 shows a fourth alternative multi-channel system of a fourth alternative melt conductor block 4 not shown here. The 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 1 or of the multi-channel system 5, respectively, 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. 3. 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. 4 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 11a of the a.sup.th level 12a or down to the output 7, respectively.
[0178] In FIG. 6, a fifth alternative multi-channel system 5 of a fifth alternative embodiment is represented, a combination of a melt conductor 1 formed partly as a melt mixer and partly as a melt distributor being shown here. The method of functioning, however, is opposite to the one shown in the embodiment of FIG. 5. On its input side 26, the multi-channel system 5 has several inputs 6, the melt channels 11d of the d.sup.th level 12d, 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. 4, 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 FIG. 3, 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 1 or the multi-channel system 5, respectively.
[0179] The multi-channel system 5 according to the embodiment in FIG. 5 and according to the embodiment in FIG. 6 is not limited to the shape and arrangement described herein. It is also possible to provide upstream or downstream of the respective partial channel system 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, 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 of the multi-channel system 5 and have flown through the same number of melt channels, branchings 8 and sub-branches 10.
[0180] The embodiments according to FIGS. 7A through 10C, 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 FIG. 3, that is, ascending in the designated direction 25 of flow of the polymer melt 24. 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.
[0181] In the embodiments according to FIG. 1A, FIG. 1B and FIG. 3 through FIG. 6, 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.
[0182] In contrast, a sixth alternative multi-channel system 5 is represented in FIGS. 7A and 7B, the multi-channel system 5 branching out three-dimensionally in space using five degrees of freedom. As clearly shown in FIG. 7B, the melt channels 11 extend in the direction of flow of the polymer melt 24, starting from the input 6 and distributed 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 12b, such that starting from each melt channel 11c of the c.sup.th level, a separate distribution system 29a, 29b, 29c, 29d is formed, such that the first and the second distribution system 29a, 29b as well as the third and the fourth distribution system 29c, 29d are arranged on one plane, the planes being substantially arranged in parallel.
[0183] 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. 3 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 4a-4e on a comparatively 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.
[0184] 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 12e down to the outputs 7, the melt channels 11 of each level 12a, 12b, 12c, 12d, 12e being always formed symmetrical in all distribution systems 29a, 29b, 29c, 29d and the separated melt streams of the polymer melt 24 having the same melt history.
[0185] The outputs 7 of the first and second distribution systems 29a, 29b are thus located on a theoretical first straight line and the outputs 7 of the third and the fourth distribution system 29c, 29d on a theoretical straight second line. Both lines are arranged in parallel to one another so that all melt streams have the same material properties at the respective output 7 due to conveying the same polymer melt 24. Such an arrangement of the outputs 7 along straight, parallel lines is exemplarily shown in FIG. 2, in this case the melt channels 11 on the first and the second melt distributor block 4a, 4b not being distributed over two levels but over four.
[0186] In addition, in FIGS. 7A and 7B, a medium channel 20 is arranged inside the melt conductor 1 extending spatially between the melt channels 11 of the multi-channel system 5 and implementing in particular a circulating fluid supply, in this case for temperature control of the polymer melt 24. The medium channel 20 is not fluidically connected to the melt channels 11 of the multi-channel system 5 and causes 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, additional medium channels of any type can be provided which are arranged fluidically separated from the melt channels 11 of the multi-channel system 5 in one or more melt conductor blocks 4a-4e. 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.
[0187] In FIGS. 8A through 8D, a seventh alternative multi-channel system 5 is represented, the multi-channel system 5 here branching out three-dimensionally in space using six degrees of freedom. In this embodiment, it is shown that the two melt channels 11b of the b.sup.th level 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 flow of the polymer melt 24. Each melt channel 11b of the b.sup.th level 12b has a local machine direction 19 which can always be the same in the longitudinal direction of the melt channel 11 or which may change in the longitudinal direction of the melt channel 11, depending on the configuration and extension of the respective melt channel 11. It may be of an advantage if the local machine direction 19 extends at least partially against the global machine direction 18. This can especially be seen in FIG. 8A. 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.
[0188] FIG. 9 shows an eighth alternative example of embodiment with an eighth alternative multi-channel system 5. The multi-channel system 5 is substantially identical with the multi-channel system 5 in FIG. 3. The main difference is that the melt conductor 1, 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 achieves mixing of the polymer melt 24 conducted and distributed within the melt channels 11c of the c.sup.th level 12c. In this manner homogenization of the melt strand conducted inside the respective melt channel 11, in particular of its flow and material properties, can be ensured. 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 respective melt channel 11c of the c.sup.th level 12c has substantially identical cross-sectional sizes and shapes. Alternatively, the static mixing element can also be arranged directly within the respective melt channel 11 and not in a local broadening.
[0189] In a ninth alternative embodiment according to FIGS. 10A through 10C, the melt conductor 1 has a first multi-channel system 5a and a second multi-channel system 5b fluidically separated therefrom, three or more multi-channel systems easily being conceivable as well. 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 24 may 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 polymer melt 24 into an extrusion nozzle (not shown here). The first multi-channel system 5a is formed in a manner substantially analogous to the multi-channel system 5 in FIG. 3. We therefore refer to the corresponding description, where for reasons of better clarity, identical reference numbers are not repeated, unless where this is absolutely necessary.
[0190] The melt channel 11a of the a.sup.th level 12a of the second multi-channel system 5b extends at first, starting from the input 6a of the second multi-channel system 5b, 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, which are downstream of the branching 8, are however rotated by 45?, namely 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 with each increasing level continuously approach the melt channels 11 of the first multi-channel system 5a. This results in the outputs 7b of the second multi-channel system 5b to be comparatively close to the outputs 7a of the first multi-channel system 5a so that the melt stream of the polymer melt 24 distributed with the second multi-channel system 5b exits in the region of the outputs 7a, 7b at a comparatively small distance from the melt stream of the polymer melt 24 distributed with the first multi-channel system 5a.
[0191] 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 substantially parallel to each other. In other words, the outputs 7a, 7b of the respective multi-channel system 5a, 5b are arranged on two parallel planes. In this manner, two-layered film webs can be produced whose layers can have identical or different material properties.
[0192] The outputs 7a, 7b of the multi-channel systems 5a, 5b are arranged misaligned with respect to each other transversely to the designated direction 25 of flow or to the global machine direction 18 of the respective polymer melt 24, respectively. 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 spatially misaligned with respect to each other. Such an arrangement of the outputs 7 can be envisaged for the third melt conductor block 4c according to FIG. 2, the melt channels 11 on the third melt conductor block 4c not exiting on two parallel planes from the third melt conductor block 4c.
[0193] The two multi-channel system 5a, 5b extend through at least two of the melt conductor blocks 4a-4e in a manner analogous to FIG. 1B and FIG. 1C. We therefore refer to FIG. 1C, where a channel output 36 of a first partial channel system of e.g. the first melt conductor block 4a is uniquely assigned to a channel input 35 of a second partial channel system of e.g. the second melt conductor block 4a. The first multi-channel system 5a is formed at least from the first and the second partial channel system after assembly of the melt conductor 1. Similarly, a channel output 36 of a third partial channel system of e.g. the first melt conductor block 4a is uniquely assigned to a channel input 35 of a fourth partial channel system of e.g. the second melt conductor block 4a. The second multi-channel system 5a is formed from at least the third and the fourth partial channel system after assembly of the melt conductor 1. Of course, this can also be applied to more than two partial channel systems and to the third, fourth and/or fifth melt conductor blocks 4c, 4d, 4e.
[0194] 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 9 can also be implemented with two or more multi-channel systems. For these as well as for the embodiment in FIGS. 10A through 10C, it is also to be said that the melt conductor 1 can also be embodied with three multi-channel systems, with four multi-channel systems, with five or more multi-channel systems.
[0195] 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.
[0196] 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.
[0197] 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
[0198] 1 melt conductor [0199] 2 extruding die [0200] 3 extrusion facility [0201] 4a first melt conductor block [0202] 4b second melt conductor block [0203] 4c third melt conductor block [0204] 4d fourth melt conductor block [0205] 4e fifth melt conductor block [0206] 5 multi-channel system [0207] 6 input of multi-channel system [0208] 7 output of multi-channel system [0209] 8 branching [0210] 9a first level of a sub-branch [0211] 9b second level of a sub-branch [0212] 10 sub-branch [0213] 11 melt channel [0214] 11 melt channel [0215] 11a melt channel to be divided of a first level [0216] 11b divided melt channel of a second level [0217] 11c divided melt channel of a third level [0218] 11d divided melt channel to be divided of a fourth level [0219] 11e divided melt channel of a fifth level [0220] 12a a.sup.th level of a melt channel [0221] 12b b.sup.th level of a melt channel [0222] 12a a.sup.th level of a melt channel [0223] 12b b.sup.th level of a melt channel [0224] 12c c.sup.th level of a melt channel [0225] 12c c.sup.th level of a melt channel [0226] 12d d.sup.th level of a melt channel [0227] 12d d.sup.th level of a melt channel [0228] 12e e.sup.th level of a melt channel [0229] 13 tensioning system [0230] 14 extrusion nozzle [0231] 15 collection chamber [0232] 16 retention device [0233] 17 frame part [0234] 18 global machine direction [0235] 19 local machine direction [0236] 20 medium channel [0237] 21 static functional element [0238] 22 extrusion nozzle output [0239] 23 provision unit [0240] 24 polymer melt [0241] 25 flow direction of polymer melt [0242] 26 input side of melt conductor block [0243] 27 output side of melt conductor block [0244] 28 local expansion of melt channel [0245] 29 polymer [0246] 30 extrusion product [0247] 31 positioning means [0248] 32 tie rod [0249] 33a first contact surface of a melt conductor block [0250] 33b second contact surface of a melt conductor block [0251] 34 seal [0252] 35 channel input [0253] 36 channel output [0254] 37 projection [0255] 38 recess [0256] 39 through hole [0257] B width of extrusion nozzle output
