WO2008119559A2

WO2008119559A2 - Multi-shaft extruder device and method for operating said device

Info

Publication number: WO2008119559A2
Application number: PCT/EP2008/002629
Authority: WO
Inventors: Josef Blach; Markus Blach; Michael Blach
Original assignee: Blach Verwaltungs Gmbh & Co. Kg
Priority date: 2007-04-03
Filing date: 2008-04-02
Publication date: 2008-10-09
Also published as: WO2008119559A3; DE102007016346A1

Abstract

According to the invention, a fiber strand supply unit (32a, 32b, 32c, 32e, 32f, 32g) comprises at least one fibre strand introduction opening (80a, 80b, 80c, 80f, 80g) that leads to a process chamber (76, 136), said process chamber (76, 136) comprising a transfer zone (30a, 30b) that is provided, in at least one operating mode, to be filled to between 30 % and 80 % with a fibre strand additive mixture (92), and at least one first compression area (36) arranged after the fibre strand introduction opening (80a, 80b, 80c, 80f, 80g) and provided to reduce a conveyed gas volume (94) to about at least one quarter of the volume thereof.

Description

Multi-shaft extruder apparatus and method of operating the same

State of the art

The invention is based on a multi-screw extruder device according to the preamble of claim 1. The invention is further based on a method for operating a multi-shaft extruder device according to the preamble of claim 28.

From the document DE 40 16 784 Al an extruder device with a fiber strand feed is known, in which at one point of a housing, a fiber strand is fed via an insertion channel, wherein the fiber strand is preimpregnated in a impregnation before being fed into a mixing zone.

The invention is in particular the object of providing a multi-shaft extruder device, which allows a homogeneous coating result. It is achieved according to the invention by the features of claim 1. Further Embodiments result from the dependent claims and claims.

Advantages of the invention

The invention is based on a multi-shaft extruder device with at least two conveying elements which are arranged in meshing and can be operated in the same direction of rotation, with an additive supply unit for supplying an additive and with a fiber strand feed unit, by means of which at least one fiber strand is added to a viscous one Workspace is done.

It is proposed that the fiber strand feed unit has at least one fiber strand feed opening which opens into a process space, wherein a feed zone is provided in the process space which is intended to be filled with a fiber strand additive mixture in at least one operating mode between 30% and 80% and with at least one first compression zone arranged downstream of the fiber strand addition opening, which is intended to reduce an entrained gas volume by at least a quarter of its volume. As a result, a particularly good wetting of the fiber strand can be achieved.

Under a multi-screw extruder device is here a

Extruder device with two and / or more conveyor elements are understood. Under a conveyor element is to be understood in particular an element with a compression and / or relaxation function with conveying task. A Combing arrangement describes an arrangement of conveying elements which engage with their screw flights such as a toothing. In this case, a distance between a screw crest of a conveying element and a screw base of a further conveying element is greater and / or equal to 4 mm. Particularly preferably, the conveying elements are arranged tightly combing, wherein a backlash of the screws is performed with ≤ 10% of the distance. In this case, a fiber strand represents either a single fiber, such as a short glass fiber, a ring or an endless fiber strand and / or another fiber strand which appears expedient to the person skilled in the art. An additive here is either a thermosetting or thermoplastic plastic, a resin and / or another, considered appropriate to the expert additive. A viscous work area describes an area in which the additive is or has become viscous. This viscous component preferably constitutes a molten plastic and / or another component which has been prepared as required, such as a liquid. A conveying zone is a region which has a maximum length of 6 times the length of a conveying element outer diameter and in which Components, such as fiber strands and / or an additive to be transported or promoted in a preferred direction, axially of the multi-shaft extruder. A process space is to be understood as the space of the multi-shaft extruder device in which the fiber strands and / or an additive are filled and / or mixed. If the fiber strand and the additive are introduced into the process space for a wetting process, a fiber strand additive mixture results. Depending on the degree of filling of the process chamber, which occurs after the supply of the fiber strand and / or the additive At a value of between 30% and 80%, a remaining volume of the process space is filled with a gas volume, which preferably represents air and is introduced mainly by the fiber strand. Furthermore, a compression zone represents a zone which is intended to shift a volume ratio of fiber strand additive mixture to gas volume in favor of the fiber strand additive mixture by pressing off the gas. It is advantageous if the compression zone reduces the gas volume by at least a quarter of its volume, preferably by one half of its volume and particularly advantageously by at least 90% of its volume. For this purpose, a conveying element of the compression zone can be designed with a special geometry of the screw webs, such as a smaller pitch of the screw web. This takes a degree of filling in the

Multi-screw extruder over the conveyor zone, which has a direct effect on the wetting of the fibers.

Furthermore, it is advantageous if a unit is designed such that it is intended to have a volume ratio of fiber strand additive mixture to gas volume of at least 80% to 20%, preferably of at least 60% to 40% and particularly advantageously of at least 50% 50%. As a result, it is particularly easy to set an optimum filling level in the process area for a large working width. The unit may be a metering device that regulates the supply of fiber strand and / or additive and thus inevitably entrainment of the gas.

In a further embodiment of the invention, at least one further compression zone is proposed. Thus, the Reduction of the gas volume gradually increased further. Conveying elements and compression zone work on the same principle as in the first compression zone.

It is also proposed that at least one degassing zone is provided. In this case, structurally simple additional degassing capability can be achieved by arranging a housing degassing opening in the extruder housing. Here, the degassing can be achieved, for example, by means of the externally acting atmospheric pressure.

Furthermore, it may be advantageous if the degassing zone is arranged after the first compression zone and the further compression zone is arranged after the degassing zone. By this arrangement, even better wetting of the fiber strand can be achieved.

In addition, it is proposed that the first compression zone, the degasification zone and / or the further compression zone each have a longitudinal extent of not more than three times a Förderelementaußendurchmesser, whereby a sufficiently long distance for degassing or wetting can be provided.

An additional reduction of a length of the multi-screw extruder can advantageously be achieved if the first compression zone, the degassing zone and / or the further compression zone each have a longitudinal extension of at most twice a Förderelementaußendurchmesser. As a result, installation space, assembly costs and / or costs can be saved. It is also proposed that the fiber strand addition opening has a longitudinal extent of not more than four times a Förderelementaußendurchmesser. Particularly advantageous is an embodiment of the fiber strand addition opening with a maximum of twice a delivery element outer diameter. This can

Space saving a sufficient length for feeding the fiber strand can be achieved. Particularly advantageous is the execution of the fiber strand addition opening with a longitudinal extent of a maximum of twice a Förderelementaußen- diameter.

A preferred development is that a vacuum source is provided, which serves to build and / or to maintain a vacuum. ^" By applying a vacuum, wetting can be done efficiently.

Furthermore, it is proposed that a homogenization zone is provided, in which at least two conveying elements have passage areas, so that a mass transfer between at least two device areas is possible. As a result, it is easy to achieve a mass transfer and also a mixing of components and / or fiber strand streams. This happens particularly effective under a built-up delivery pressure. Through passages should be understood here in particular breakthroughs and / or omissions in the Förderelementstegen the conveying elements. Advantageously, the conveying elements in the passage area at a distance greater than 4 mm. Here, "distance" defines, for example, a flight depth which results between a screw comb of one conveying element and a screw root of a further conveying element. Further, it is advantageous if the Faserstrangzuführeinheit has at least two arranged on a circumference of an extruder housing fiber strand feeders with Faserstrangzugabeöffnungen to a radial supply of fiber strands in the process space rensraum. As a result, the arrangement of the fiber strand feeders can be made particularly space-saving. Furthermore, the fiber strand feeds can be arranged structurally simple around the circumference of the extruder housing, since sufficient space is available. Furthermore, the entire length of the multi-screw extruder can be reduced. In general, however, the arrangement of the fiber strand feeds along an axial extent of the extruder housing would be possible. The feeding of the fiber strands is preferably carried out without pressure.

In a further embodiment of the invention, it is provided that the conveying elements of the first compression zone, the degassing zone and / or the further compression zone are executed in one, two and / or three courses. As a result, the geometry of the conveyor elements of the respective zone can be designed specifically and optimally for their function, since the number of conveyor lines is determined by the geometry of the conveyor elements.

It is also proposed that the conveyor elements are designed in at least one area opposite to at least one other area with a smaller Da / Di in order to achieve an enlarged housing conveyor element gap. Here "Da" represents the delivery element outer diameter and / or "Di" the delivery element inner diameter of the delivery elements. Furthermore, the delivery element gap defines the distance between the outer element ßendurchmesser the conveying element and an inner wall of the extruder housing. This results in a high variability to obtain an enlarged housing-Förderelementspalte, and it can be achieved a low installation cost, since the generation of the gap can be designed independently of the housing design.

Furthermore, it may be advantageous if at least one annular gap is provided which has a radial channel height of maximum (Da-Di) / 2. As a result, it is advantageously possible to realize a delivery element-free region which can be used for mass transfer. This is to be understood by channel height, the extent of the annular gap in the radial direction.

In addition, it is proposed that in the region of the fiber strand addition opening, a radial distance between a conveying element outer diameter of a conveying element of the conveying zone and an inner wall of an extruder housing be increased compared to at least one other region, whereby an enlarged wetting area for the supplied fiber strands with the additive can be achieved. Here, a "different area" defines in particular the remaining area of the multi-shaft extruder.

A preferred development consists in that in at least one extruder housing section of a conveying section a radial distance reduction is provided between at least one conveying element and the extruder housing section. As a result, a transition between two extruder housing sections can be achieved, which ensures a gentle transfer of a Nes fiber strand guaranteed. If the radial clearance reduction is in particular stepped and / or conical, the fiber strand can be selectively brought to a desired aspect ratio with the transition.

It is also proposed that a specific engine torque is at least 20 Nm / cm ³ , preferably at least 40 Nm / cm ³ and more preferably at least 60 Nm / cm ³ . As a result, a high output of the multi-shaft extruder and thus a high delivery volume can be achieved. In this case, a specific engine torque is to be understood as a torque to be introduced or a minimum power of a motor, which is related to the axial distance (indicated in cm) with the power 3 of two conveying elements.

Furthermore, it is advantageous that the conveying elements are arranged in a closed pitch circle, whereby a high power density and a balanced load distribution can be achieved. By this arrangement, high speeds of the multi-shaft extruder device can be achieved, the arrangement structurally simple ensures a higher material throughput and a short residence time compared to a single screw. Advantageously, the arrangement of more than five and particularly advantageous arrangement of 12 conveyor elements, which also allow a maximum of four

Twin-screw extruder of e.g. four different products, additives, fiber strands and / or fiber strand contents to operate in parallel.

Furthermore, it is advantageous if the device has an outer and / or an inner process space which is characterized by a ne arrangement of the conveying elements are formed. As a result, structurally simple separate supply and / or separate transport of components are possible.

Advantageously, a return element is arranged, which is intended to transport via the additive feed unit supplied additive from the inner process space in the outer process space and vice versa. Here, a return element is to be understood as meaning a delivery element which has an opposite incline with respect to the delivery elements arranged, for example, in the delivery region.

In a further embodiment of the invention it is provided that the return element is arranged in the axial conveying direction in front of the fiber strand addition opening. As a result, structurally simple direct coating of the supplied fiber strands can be realized.

Furthermore, the invention is based on a method for operating a multi-shaft extruder device.

It is proposed that in at least one operating mode, a conveying zone in a process space of between 30% and 80% be filled with a fiber-strand additive mixture and an entrained gas volume be reduced by at least a quarter of its volume. As a result, good wetting of the fiber strand can be achieved particularly economically.

Further, a volume ratio of fiber additive mixture to gas volume of at least 80% to 20%, preferably from at least 60% to 40%, and more preferably at least 50% to 50%.

Further improvement in fiber strand wetting is accomplished by establishing and maintaining a vacuum at a degassing zone which is applied to reduce the volume of gas with a vacuum source.

Furthermore, it is advantageous if fiber strands are fed radially into the process space via at least two fiber strand addition openings arranged on a circumference of an extruder housing.

drawing

Further advantages emerge from the following description of the drawing. In the drawing, an embodiment of the invention is shown. The drawing, the description and the claims contain numerous features in combination.

The person skilled in the art will expediently also consider the features individually and combine them into meaningful further combinations.

Show it:

1 shows a longitudinal section through a multi-screw extruder according to the invention,

2 is a cross-sectional view II-II of FIG. 1, FIG. 3 is a schematic representation of a portion of the multi-screw extruder according to FIG. 1, 4 shows a cross section through a further multi-screw extruder according to the invention with 12 conveying elements,

6 shows a cross section through an alternative multi-screw extruder according to the invention with 4 fiber strand feeds, FIG.

7 shows a cross section through a further multi-shaft extruder according to the invention with empty positions,

8 is a schematic representation of a pre-impregnation device,

9 is a schematic representation of a portion of another multi-screw extruder with a conically executed Radialabstandsredu- ornamentation,

10 is a schematic representation of a portion of a further multi-shaft extruder with an endless fiber strand feed, and FIG. 11 is a detailed view of the Faserstrangzuführ- unit of Figure 10 in a plan view.

Description of the embodiment

FIG. 1 shows a multi-shaft extruder 10a in the design of a double-screw extruder. The twin-screw extruder has an extruder housing 12a, the two conveyor lines 44, 46 each having a plurality of along an axis 18 of the extruder housing 12a successively extending conveyor elements 14a, 48, 50, 52, 54, 56, 62, 218, or 16a, 64, 68, 98, 100, 106, 112, 220 and / or further conveying elements for melting, mixing, shearing, cutting and / or diverting conveying materials, such as a kneading block 58, 66. The conveying elements 14a, 16a, 48, 50, 52, 54, 56, 62, 64, 68, 98, 100, 106, 112, 218, 220 of the conveyor sections 44, 46 are arranged in pairs, so that, for example, the vertically superimposed Conveying elements 14a and 16a mesh with each other and with a same direction of rotation 60a of an unillustrated motor, which has a reduction and / or branching transmission, with a specific engine torque of at least 20 Nm / cm ³ , preferably 40 Nm / cm ³ and more preferably be operated from 60 Nm / cm ³ (see Figure 2). The conveying elements 14a and 16a are preferably designed to be tightly combing, the distance between a screw comb and a screw base being greater than and / or equal to 4 mm.

Along the axis 18, the conveying paths 44, 46 comprise at least one input area 20a, a wetting area 22a and a discharge and conveying area 24a.

An additive feed unit 26a is arranged at the input area 20a, via which an additive 28a, such as a plastic, is supplied to the conveying elements 48, 68 of the input area 20a. The additive 28a is transported by means of the conveying elements 48, 68 of the conveying paths 44, 46 in the direction of an axial conveying direction 74a to conveying elements 62, 64. These serve to build up pressure in the axial conveying direction 74a and ensure a transition into kneading blocks 58, 66, where the additive 28a is melted. In a viscous state, the additive 28a is now along The axis 18 transported in an area in which each conveying section 44, 46, a return element 70a, 72 is arranged. The return elements 70a, 72 guide the additive 28a in the axial conveying direction 74a into a process space 76 of a conveying zone 30a, which constitutes a viscous working area 78 and the beginning of the wetting area 22a.

In this viscous working area 78 via a Faserstrangzuführeinheit 32a, the supply of a fiber strand 34a, wherein a fiber strand either a single fiber, such as a short glass fiber and / or an endless fiber, such as a roving, can be understood. Shown here is a Seitendo- sieraggregat with two screw elements to a supply of chopped fibers. In general, a supply of endless fiber strands by means of a Zuführgatters would be possible here. The fiber strand feed unit 32a has a fiber strand feed opening 80a having a longitudinal extent of about 1.5 times the length of the conveyor element outer diameter 82. In this case, the conveying element outer diameter 82 refers to a conveying element arranged in the respective region and, in the case of the fiber strand feed opening 80a, to the conveying elements 14a and 16a.

In the region 84 of the fiber strand feed opening 80a, a radial distance 86 between a conveying element outer diameter 82 of a conveying element 14a, 16b of the conveying zone 30a and an inner wall 88 of the extruder housing 12a is increased relative to at least one other region 90 (see FIGS. 2 and 3). In the process chamber 76 of the conveying zone 30a, the fiber strand 34a and the additive 28a are mixed to a fiber strand additive mixture 92, which is to 30% to 80%, preferably to 50% completes the process room 76. A remaining space is filled to 70% to 20%, preferably to 50%, with a gas volume 94, which is entrained in the fiber strand feed and preferably consists of air. In FIG. 2, the fiber-strand additive mixture 92 and the gas volume 94 are shown schematically for a partial section of the process chamber 76. A volume ratio of fiber strand additive mixture 92 to gas volume 94 is adjusted by means of a unit 96 which adjusts either the amount of fiber strands 34a supplied and / or the amount of additive 28a supplied.

In the direction of the axial conveying direction 74a, the conveying zone 30a is adjoined by a first compression zone 36 with two vertically arranged double-flighted conveying elements 50 and 98, which have a longitudinal extent of approximately 0.5 times the length of the conveying element outer diameter 82 and have a compression function. By means of the first compression zone 36, the gas volume 94 is squeezed out via a cross-sectional reduction by a small selected screw pitch and thus an increase in pressure from the process chamber 76 and the gas volume 94 is thus reduced by at least a quarter of its volume. Preferably, the gas volume 94 is reduced by half, and more preferably by its entire volume. Alternatively, the gas volume reduction can also be reduced by changing a pitch of a worm gear.

In the axial conveying direction 74a, the first compression zone 36 is adjoined by a degassing zone 38 with two vertically arranged double-flighted conveying elements 52 and 100, which have a longitudinal extent of about 2 times the length of the conveyor element outer diameter 82 and have a higher pitch of the screw threads compared to the conveyor elements 50 and 98 and thus have a relaxation function. At this degassing zone 38 is a Gehäuseentgasungsöffnung

102, via which a vacuum source 104 can be applied to the extruder housing 12a for establishing and / or maintaining a vacuum for reducing the gas molecules in the process chamber 76. It would also be possible only to apply an atmospheric pressure for degassing.

For a complete squeezing out of the gas volume 94, in the direction of the axial conveying direction 74a, a further compression zone 40 with two vertically arranged single-channel conveying elements 54 and 106 is arranged, which have a longitudinal extent of approximately 0.5 times the length of the conveying element outer diameter 82 Have compression function and also have an influence on the fiber length. Again, the squeezing of the gas volume 94 is achieved by a very strong cross-section reduction.

In the axial conveying direction 74a is followed by the further compression zone 40, a further degassing zone 222 with two vertically arranged zweigängigen conveying elements 218 and 220, which have a longitudinal extension of about 2 times the length of Förderelementaußendurchmessers 82 and compared to the conveying elements 54 and 106 a have higher pitch of the flights and thus have a relaxation function. At this further degassing zone 222, a housing degassing opening 224 is arranged, via which the vacuum source 104 can be applied to the extruder housing 12a In the direction of the axial conveying direction 74a after the further compression zone 40, a homogenization zone 42, which corresponds to 0.5 times the length of the conveying element outer diameter 82, is arranged. The homogenization zone 42 may correspond to a maximum length of 3 times the length of the conveyor element outer diameter 82. In conveying element regions 108, 110 of the homogenizing zone 42, which are arranged vertically one above the other, passage regions 114, 116 are formed which enable a mass transfer between at least two device regions 118, 120. In this case, the conveying element regions 108, 110 in the passage regions 114, 116 have a spacing between the screw crest and the screw root which is greater than and / or equal to 4 mm. The mass transfer enables a uniform wetting of the fiber strand 34a by the additive 28a.

The homogenization zone 42, which also represents the end of the wetting area 22a, is adjoined in the axial conveying direction 74a by the discharge and delivery area 24a into which delivery elements 56, 112 extend. The discharge and

Conveying area 24a may, however, still extend to a maximum length of 6 times the length of conveying element outer diameter 82.

Along a longitudinal extension of the multi-shaft extruder in the axial direction 74a, it is also possible to arrange a plurality of fiber strand feed units 32a for feeding different fiber strand types, such as ductile, tough and / or brittle fiber strands 34a. Here, the arrangement of the Faserstrangzuführeinheiten 32a can be tailored to the type of fiber strand 34a. Is a feeder of brittle cut fibers, a Seitendozagaggregat, as shown in Figure 1, are used. If ductile cut fibers are fed, a side-dosing unit can take place in the area of the kneading blocks 58, 66, since the ductile fiber strands 34a can withstand the loading of the kneading block 58, 66 and / or can be impregnated with equal efficiency. Furthermore, the supply of ductile fiber strands 34a as cut fibers in the kneading blocks 58, 66 can take place via a side metering unit and, in the axial conveying direction, the supply of a brittle fiber strand 34g in the form of a continuous strand via a fiber strand feed unit 32g to a gate 190 (see FIG 10).

FIG. 4 shows an alternative multi-shaft extruder 10b in a cross section in the form of a ring extruder 122 with 12 conveying elements 14b, 16b, 126 arranged distributed in the circumferential direction 124, of which only three have been provided with reference numerals for the sake of clarity. The conveying elements 14b, 16b, 126 arranged in a closed pitch circle are enclosed by an extruder housing 12b and all have the same direction of rotation 60b. With regard to features and functions that remain the same, reference is made to the description of the exemplary embodiment in FIGS. 1 to 3. The following description is essentially limited to the differences from the exemplary embodiment in FIGS. 1 to 3. The extruder housing 12b has a fiber strand feed unit 32b with two fiber strand feeders 128, 130 arranged in a circumferential direction 124 one after the other, at an angular distance of 180 °. The fiber strand feeders 128, 130 are arranged at the same axial height of the extruder housing 12b, but an axially offset arrangement would also be possible. borrowed. Each fiber strand feed 128, 130 has a fiber strand feed opening 80b and a transfer region 132, 134, in which fiber strands 34b fed through the fiber strand feeders 128, 130 are fed to an outer process space 136.

The process space 136 constitutes a guide clearance 138 for guiding at least one fiber strand 34b, wherein the guide clearance 138 is formed in a radial direction 140 between the conveying elements 14b, 16b, 126 and the extruder housing 12b.

The conveying elements 14b, 16b, 126 include a core 142b and in the radial direction 140 between the core 142b and the conveying elements 14b, 16b, 126, a filling gap 144 is arranged, which forms an inner process space 146. An additive 28b, such as a plastic, is introduced into this filling gap 144 via the additive feed unit 26b. The core 142b can have at least one cooling channel 210 for temperature control of the system, which extends at least in regions in the axial direction 74b.

FIG. 6 shows an alternative multi-shaft extruder 10c as a ring extruder 158 with a fiber strand feed unit 32c with four at an angular distance of 90 ° around the circumference of the fiber extruder

Extruder housing 12c distributed fiber strand feeders 160, 162, 164, 166, each with a fiber strand addition opening 80c shown. With regard to features and functions that remain the same, reference is made to the description of the exemplary embodiment in FIGS. 1 to 5. The following description is essentially limited to the differences between 1 to 5 on at least one fiber strand feed 160, 162, 164, 166, a feed unit 168 is arranged, the pre-coated cut fibers 170 before feeding a fiber strand 34c in the fiber strand feed 160 of the fiber strand 34c applies. The cut fibers 170 are introduced into the fiber strand feed 160 with the fiber strand 34c.

FIG. 7 shows a further multi-screw extruder 10d as a ring extruder 172. With regard to features and functions that remain the same, reference is made to the description of the exemplary embodiment in FIGS. 1 to 6. The following description is essentially limited to the differences from the exemplary embodiment in FIGS. 1 to 6. In the extruder housing 12d, conveying element positions 174 are arranged radially around a core 142d, of which ten are filled with conveying elements 14d, 16d and two empty positions as conveying elements 176, 178 are executed. However, any number, combination and / or sequence of conveying element-carrying and conveyor element-free conveying element positions 174 can also be provided. The empty positions 176, 178 extend at least from the area of the fiber feed unit 32d and preferably from the input area 20 to the discharge and conveying area 24 and are filled with separating filling pieces. By arranging the Trennfüllstücke from the input area 20, an input of various additives 28 can be made, which can be transported separated by the Trennfüllstücke. If the separating filling pieces are arranged only in the axial conveying direction 74 after the fiber strand adding unit 32d, the flow of the molten additive 28 is proportionally directed into regions, which are formed by the Trennfüllstücke. At least two conveying elements 14d, 16d can be combined as a functional unit or as a conveying element unit 180.

Further, a fiber strand 34d and the additive 28 can be transported in spaced-apart conveyor element units 180 by the arrangement of separation filler pieces in the empty positions 176, 178 in the circumferential direction 124.

FIG. 8 shows a preimpregnation device 182 with a

Coating unit 184 for preimpregnating at least one fiber strand 34e by means of an additive feed unit 26e with an additive 28e and a feed unit 186 which feeds the fiber strand 34e to a fiber strand feed unit 32e of an extruder device (not shown). Here, the coating takes place before feeding the fiber strand 34e into the extruder device. The additive 28e, preferably a plastic, is applied to the fiber strand 34e as a film by means of at least one application device in the form of a nozzle 188. To improve the coating, at least one movement device in the form of a gate 190 is arranged on the coating unit 184, via which the fiber strand 34e is guided before passing the nozzle 188. The gate 190 oscillates the supplied fiber strand (s) 34e in the process of application of the additive. The feed unit 186 includes a first guide member 192 and a second guide member 194, both of which guide the fiber strand 34e. Since the fiber strand 34e is guided past the guide elements 192, 194 under tension by means of a tension generated by the extruder device, and the additive 28e is moved past the guide elements 192, 194 second guide element 194 between the fiber strand 34e and a working surface 196 of the second guide element 194, the second guide element 194 additionally operates the additive 28e into the fiber strand 34e. Further, by this passing and the exercise of a sliding pressure on the fiber strand 34e, on the fiber strand adhering or in the additive 28e befindliches gas is squeezed out. After the second guide element 194, a deflection unit 216 is arranged, which feeds the fiber strand 34e via a further guide element 228 of the fiber strand feed unit 32e. On all guide elements 194, 196, 228 or on the leading part 230 of the deflecting a tear-off edge 226 is formed, which ensures that the additive film is transported to the fiber strand 34e. Furthermore, a heat source 198, for example in the form of at least one heating jet introduced into the guide elements 194, 196, 228, 230, is arranged, which heats the supplied and coated fiber strand 34e before it is fed into the fiber strand feed unit 32e.

FIG. 9 shows a schematic section of a conveying path 200 with at least two conveying elements 202, 204 of a further multi-screw extruder 10f. With regard to features and functions that remain the same, reference is made to the description of the exemplary embodiment in FIGS. 1 to 7. The following description is essentially limited to the differences from the embodiment in FIGS. 1 to 7. An extruder barrel 12f has an extruder barrel portion 206 disposed after the fiber strand feeding unit 32f and its fiber strand adding port 8Of and extending by a distance 3 times a conveyor element ßendurchmesser 82 corresponds, in an axial conveying direction 74 f extends. Following this extruder housing section 206, a further extruder housing portion 208 is arranged, which has a transition 212 with a Radialabstandsredu- ornamentation 256, which is conical. The further extruder housing region 208, in turn, merges into a discharge and delivery region 24f in which the one separation unit 214 in the form of the conveying element 204 is arranged, which splits the fiber strands 34f into predetermined lengths.

FIG. 10 shows a schematic section of another multi-shaft extruder 10 g in the form of a ring extruder 232. With regard to features and functions that remain the same, reference is made to the description of the exemplary embodiment in FIGS. 1 to 9. The following description is essentially limited to the differences from the exemplary embodiment in FIGS. 1 to 9.

Along an axial conveying direction 74g, a conveying element 234 is arranged in an input region 20g, which is a conveying element 234

Promotion of an introduced via an additive supply unit 26g additive 28g is used. The conveyor element 234 is adjoined by a region which forms a filling gap 144 and an inner process region 146. From this filling gap 144, the additive 28g is transported in the radial direction 140 to the extruder housing 12g into an outer process space 136 or guide clearance 138 by means of a return conveying element 70g, which is arranged in the axial conveying direction 74g downstream of the conveying element 234. In order to achieve a sufficient fiber strand feed, in the region of a fiber strand feed unit 32g, which is a fiber strand feed 252 and a Transfer portion 254, a widened housing portion provided through which an extruder housing conveying element gap 152 is formed.

This extruder housing conveying element gap 152 may additionally and / or alternatively be formed by a design of a conveying element 148. For this purpose, the conveying element 148 has a smaller ratio of the conveying element outer diameter 82 (Da) to a conveying element inner diameter 150 (Di) in one area, for example the fiber strand feed area, compared to another area, such as the wetting area 22g (see FIG. 5) ).

Furthermore, a core segment 240 may be provided, which has a widened diameter with respect to the remaining part of the core 142g.

Furthermore, an annular gap 154, for example arranged in the homogenization zone 42g and / or between two conveying elements 236, 238, which is designed without conveying elements, extends at least by a length of one third of the length of the conveying element outer diameter 82 and a radial channel height 156 of maximum (Da-Di) / 2.

The fiber strand feed unit serves to feed endless fiber strands and has at the fiber strand feed opening 80g a cylindrical insert 236 with a feed mold part 244 and a holding edge 246, wherein the feed mold part 244 extends against the radial direction 140 into the housing 12g. The insert 242 further includes a longitudinal slot 248 into which the fiber strands 34g are inserted. the. The insert 236 can be arranged rotatably offset at an angle of 0 ° to 45 ° to the conveying direction 74g. Vertically above the insert, a gate 190g is arranged, which feeds the fiber strands 34g, separated by gate webs 250, to the fiber feed unit 32g. The gate 190 may be rotatably staggered at an angle of 0 ° to 45 ° with respect to the direction of conveyance 74g, with rotation of the gate 190 being independent of rotation of the insert 242 (see FIG. 11). Furthermore, the gate 190 can be adjusted in the vertical direction continuously relative to the insert 242.

reference numeral

10 multi-screw extruder 60 turning sense

12 extruder housing 62 conveying element

14 conveying element 64 conveying element

16 conveying element 66 kneading block

18 axis 68 conveying element

20 Input area 70 Return element

22 wetting area 72 return conveyor element

24 Discharge and conveying chamber axial conveying direction rich 76 Process room

26 additive feed unit 78 viscous work area

28 Additive 80 Fiber feed addition port

30 conveying zone 82 conveying element outside

32 fiber strand feed unit knife

34 fiber strand 84 area

36 first compression zone 86 radial distance

38 degassing zone 88 inner wall

40 more compression zone 90 other area

42 homogenization zone 92 fiber strand

44 conveying section additive mixture

46 conveying section 94 gas volume

48 conveying element 96 unit

50 conveying element 98 conveying element

52 conveying element 100 conveying element

54 conveying element 102 housing degassing opening

56 conveying element 104 vacuum source

58 kneading block 106 conveying element 108 conveying element region 166 fiber strand feed

110 conveying element area 168 loading unit

112 conveying element 170 cut fiber

114 passage area 172 ring extruder

116 passage area 174 conveyor element position

118 Device area 176 Empty position

120 Device area 178 Empty position

122 ring extruder 180 conveying element unit

124 circumferential direction 182 preimpregnating device

126 conveying element 184 coating unit

128 fiber strand feed 186 feed unit

130 fiber strand feed 188 nozzle

132 transfer area 190 oscillating gate

134 transfer area 192 first guide element

136 outer process space 194 second guide element

138 Guide clearance 196 Work surface

140 radial direction 198 heat source

142 core 200 conveyor line

144 filling gap 202 conveying element

146 inner process space 204 conveying element

148 conveying element 206 extruder housing section

150 Inline element through208 Extruder housing range Knife 210 Cooling channel

152 extruder housing 212 transition conveyor element gap 214 division unit

154 Annular gap 216 deflecting element

156 Channel height 218 conveying element

158 ring extruder 220 conveying element

160 fiber strand feed 222 degassing zone

162 fiber strand feed 224 housing vent

164 fiber strand feed 226 trailing edge 228 guide element 244 feed molding

230 leading part 246 retaining edge

232 ring extruder 248 longitudinal slot

234 conveyor element 250 gate web

236 conveying element 252 fiber strand feed

238 conveying element 254 transfer area

240 core segment 256 Radial Distance Reduction

242 use

Claims

claims

1. multi-shaft extruder device with at least two conveying elements (14a, 14b, 14d, 16a, 16b, 16d, 48-56, 62, 64, 68, 98, 100, 106, 112, 126, 148, 202, 204, 234 - 238) intermeshing and operable in a same direction of rotation (60a, 60b) with an additive supply unit (26a, 26b, 26e) for supplying an additive (28a, 28b, 28e) and a fiber strand feeding unit (32a, 32b, 32c , 32e, 32f, 32g), by means of which at least one fiber strand (34a, 34b, 34c, 34e, 34f, 34g) is added in a viscous working area (78), characterized in that the fiber strand feed unit (32a, 32b, 32c , 32e, 32f, 32g) at least one fiber strand addition opening (80a, 80b, 80c, 8Of, 80g), which in a process chamber (76, 136) opens, wherein in the process space (76, 136) a conveying zone (30a, 30b) arranged which is intended to be filled with a fiber-strand additive mixture (92) in at least one operating mode between 30% and 80% and at least one first compression zone (36) located downstream of the fiber strand feed opening (80a, 80b, 80c, 80f, 80g), which is designed to reduce an entrained gas volume (94) by at least a quarter of its volume.

2. Multi-screw extruder device according to claim 1, characterized in that the compression zone (36) is provided to reduce the gas volume (94) by at least one half of its volume.

3. Multi-screw extruder device according to claim 1 or 2, characterized in that the compression zone (36) is provided to reduce the gas volume (94) by at least 90% of its volume.

4. multi-shaft extruder apparatus according to claim 1, characterized by a unit (96), which is intended to set a volume ratio of fiber strand additive mixture (92) to gas volume (94) of at least 80% to 20%.

5. multi-screw extruder device according to claim 4, characterized in that the unit (96) adjusts a volume ratio of fiber strand additive mixture (92) to gas volume (94) of at least 60% to 40%.

6. multi-shaft extruder device according to claim 5, characterized in that the unit (96) adjusts a volume ratio of fiber strand additive mixture (92) to gas volume (94) of at least 50% to 50%

7. multi-shaft extruder device according to one of the preceding claims, characterized by at least one further compression zone (40).

8. multi-shaft extruder device according to one of the preceding claims, characterized by at least one degassing zone (38).

9. multi-screw extruder device according to claim 7 and 8, characterized in that after the first compression zone (36) the degassing zone (38) and after the degassing zone (38) the further compression zone (40) is arranged.

10. multi-shaft extruder device at least according to claim 7 and 8, characterized in that the first compression zone (36), the degassing zone (38) and / or the further compression zone (40) each have a longitudinal extension of a maximum of three times a Förderele- ment outer diameter (82).

11. multi-screw extruder device according to claim 10, characterized in that the first compression zone (36), the degassing zone (38) and / or the further compression zone (40) each have a longitudinal extent of at most twice a Förderele- ment outer diameter (82).

12. Multi-screw extruder device according to one of the preceding claims, characterized in that the fiber strand addition opening (80a, 80b, 80c, 8Of) has a longitudinal extent of not more than four times a delivery element outer diameter (82).

13. Multi-shaft extruder device according to one of the preceding claims, characterized by a vacuum source (104), which serves to build and / or to maintain a vacuum.

14. Multi-shaft extruder device according to one of the preceding claims, characterized by a homogenization zone (42) in which at least two conveying elements (56, 112) have passage regions (114, 116), so that a mass transfer between at least two device regions (118, 120). is possible.

15. Multi-screw extruder device according to at least one of the preceding claims, characterized in that the fiber strand feed unit (32b, 32c, 32g) has at least two fiber strand feeders (128, 130, 160-166, 252) arranged on a circumference of an extruder housing (12b, 12c, 12g). with fiber strand feed openings (80b, 80c, 80g) for radially feeding fiber strands (34b, 34c, 34g) into the process space (136).

16 multi-screw extruder device at least according to claim 7 and δ, characterized in that the conveying elements (50-54, 98, 100, 106) of the first compression zone (36), the degassing zone (38) and / or the further compression zone (40) a , two- and / or Dreigängig are executed.

17. A multi-shaft extruder apparatus according to at least one of the preceding claims, characterized in that the conveyor element (148) is designed in at least one area opposite to at least one other area (22g) with a smaller Da / Di to accommodate an enlarged extruder housing conveyor element gap (152) achieve.

18. multi-shaft extruder device according to at least one of the preceding claims, characterized by, at least one annular gap (154) having a radial channel height (156) of a maximum (Da-Di) / 2.

19. Multi-shaft extruder device according to claim 1, characterized in that in the area (84) of the fiber strand addition opening (80a) a radial distance (86) between a delivery element outer diameter (82) of a conveying element (14a, 16a) of the conveying zone (30a) and an inner wall (88) of an extruder housing (12a) is enlarged relative to at least one other area (90).

20. multi-shaft extruder device according to at least one of the preceding claims, characterized in that in at least one extruder housing portion (208) of a conveying path (200) a Radialabstandreduzierung between at least one conveying element (204) and the extruder housing portion (208) is provided.

21. Multi-shaft extruder device according to at least one of the preceding claims, characterized in that a specific engine torque is at least 20 Nm / cm ³ .

22. Multi-shaft extruder device according to claim 21, characterized in that the specific engine torque is at least 40 Nm / cm ³ .

23. Multi-shaft extruder device according to claim 22, characterized in that the specific engine torque is at least 60 Nm / cm ³ .

24. multi-screw extruder device according to at least one of the preceding claims, characterized in that the conveying elements (14b, 14d, 16b, 16d, 126, 148, 202, 204, 234 - 238) are arranged in a closed pitch circle.

25. Multi-shaft extruder device according to at least one of the preceding claims, characterized by an outer and / or an inner process space (136, 146), which is arranged by an arrangement of the conveying elements (14b, 14d, 16b, 16d, 126, 148, 202, 204, 234 - 238) are formed.

26. Multi-shaft extruder apparatus according to claim 25, characterized by a return element (70g), which is provided to transport via the additive feed unit (26g) supplied additive (28g) from the inner process chamber (146) in the outer process space (136).

27. The multi-shaft extruder device according to claim 26, characterized in that the return element (70g) is arranged in the axial conveying direction (74g) in front of the fiber strand addition opening (80g).

28. A method for operating a multi-screw extruder device according to at least one of the preceding claims, characterized in that in at least one operating mode, a conveying zone (30a, 30b) is filled in a process space (76, 136) between 30% and 80% with a fiber strand additive mixture and an entrained gas volume (94) is reduced by at least a quarter of its volume.

29. The method according to claim 28, characterized in that a volume ratio of fiber additive mixture to gas volume of at least 80% to 20% is set.

30. The method according to claim 29, characterized in that a volume ratio of fiber-additive mixture (92) to gas volume (94) of at least 60% to 40% is set.

31. The method according to claim 30, characterized in that a volume ratio of fiber-additive mixture (92) to gas volume (94) of at least 50% to 50% is set.

32. Method according to one of the preceding claims, characterized in that a vacuum source (104) is applied to a structure and to maintain a vacuum at a degassing zone (38) in order to reduce the gas volume (94).

33. The method according to any one of the preceding claims, characterized in that

Fiber strands (34b, 34c, 34g) are fed radially into the process space (136) at at least two fiber strand feed openings (80b, 80c, 80g) arranged on a circumference of an extruder housing (12b, 12c, 12g).