FILTER DEVICE

Abstract

Filter device for a molding machine with at least one filter element for filtering plasticized material, in particular plasticized plastic, wherein, in a fluidically parallel arrangement relative to the at least one filter element, at least one valve element is provided, which is formed to prevent the plasticized material from flowing through the at least one valve element during an injection process in a closed position and to allow the plasticized material to flow through the at least one valve element in an open position, in order to make it possible to relieve the pressure on the at least one filter element after the injection process.

Claims

1. A filter device for a molding machine with at least one filter element for filtering plasticized material, in particular plasticized plastic, wherein, in a fluidically parallel arrangement relative to the at least one filter element, at least one valve element is provided, which is formed to prevent the plasticized material from flowing through the at least one valve element during an injection process in a closed position and to allow the plasticized material to flow through the at least one valve element in an open position, in order to make it possible to relieve the pressure on the at least one filter element after the injection process.

2. The filter device according to claim 1, wherein the at least one valve element is formed as a check valve, preferably as a nonreturn valve.

3. The filter device according to claim 1, wherein the at least one filter element is arranged centrally in the flow direction of the plasticized material.

4. The filter device according to claim 1, wherein the at least one filter element at least partially, preferably completely, surrounds the at least one valve element preferably in a plane transverse to a flow direction of the plasticized material.

5. A plasticizing unit for a molding machine with a filter device according to claim 1.

6. The plasticizing unit according to claim 5, wherein the plasticizing unit has an injection cylinder and a plasticizing screw rotationally and linearly movable in the injection cylinder.

7. The plasticizing unit according to claim 5, wherein the filter device is downstream of the plasticizing screw and is formed to filter a material plasticized by the plasticizing screw.

8. A plasticizing unit according to claim 5, wherein the at least one filter device is arranged in the injection cylinder and/or forms a part of the injection cylinder.

9. A plasticizing for a molding machine with an injection cylinder, wherein the injection cylinder has a front nozzle-side structural component and a rear structural component and in that a filter device, in particular a filter device according to claim 1, for filtering plasticized material, in particular plasticized plastic, is arranged, preferably clamped, between the front structural component and the rear structural component.

10. The plasticizing unit according to claim 9, wherein the front structural component and the rear structural component are braced by means of at least one tension means, preferably tension bolt, which is arranged alongside the injection cylinder and transverse to the connection point between front structural component and rear structural component.

11. The plasticizing unit according to claim 10, wherein the filter device is braced directly with the front structural component and the rear structural component by means of the at least one tension means at the connection point between the front structural component and rear structural component.

12. The plasticizing unit according to claim 10, wherein at least one expansion element is provided, which at least one expansion element is formed to establish and/or increase a spacing between the front structural component and the rear structural component, wherein the at least one tension means is extended under deformation, preferably under at least partially elastic deformation.

13. The plasticizing unit according to claim 12, wherein the at least one expansion element has a, preferably hydraulic and/or pneumatic, drive unit.

14. The plasticizing unit according to claim 12, wherein the at least one expansion element has at least one pressure and/or tension rod, which is formed to establish and/or increase the spacing between the front structural component and the rear structural component by exerting a pressure and/or tension on the front structural component and/or the rear structural component.

15. The plasticizing unit according to claim 9, wherein the front structural component and/or the rear structural component has a connection element, preferably a flange point, particularly preferably a clamping flange.

16. The plasticizing unit according to claim 9, wherein the front structural component and the rear structural component are connected by means of at least one clamping ring, preferably a flange clamping ring.

17. The plasticizing unit according to claim 9, wherein the filter device is arranged in a, preferably pipe-shaped, filter component of the injection cylinder, which filter component represents a component of the injection cylinder that is separate from the front structural component and the rear structural component and together with the front structural component and the rear structural component forms the injection cylinder.

18. The plasticizing unit according to claim 9, wherein a separate clamping componentpreferably the filter componentis provided, the front structural component is braced with the separate clamping component and the separate structural component is braced with the rear structural component.

19. The plasticizing unit according to claim 9, wherein the bracing of the front structural component with the rear structural component and/or the filter component and/or the separate clamping component has at least one clamping ring and/or a partially radial force component.

20. A molding machine, preferably injection-molding machine, comprising a filter device according to claim 1.

Description

[0083] Further advantages and details of the invention are revealed by the figures and the associated description of the figures. There are shown in:

[0084] FIGS. 1+2 a first embodiment example of a plasticizing unit,

[0085] FIG. 3 a flow diagram of a filter change,

[0086] FIGS. 4-7 a second embodiment example of a plasticizing unit,

[0087] FIGS. 8-13 a third embodiment example of a plasticizing unit,

[0088] FIGS. 14a-c a filter change device of a filter device, and

[0089] FIG. 15 a molding machine with a plasticizing unit.

[0090] FIG. 1 shows a first embodiment example of a plasticizing unit 6 with an injection cylinder 7 and a plasticizing screw 8 arranged in the injection cylinder 7.

[0091] The injection cylinder 7 of this embodiment example is designed in three parts and has a nozzle-side front structural component 9, a rear structural component 10 and a filter component 16 arranged between front structural component 9 and rear structural component 10.

[0092] In this embodiment example, the front structural component 9 is connected to the filter component 16 via the clamping ring 15 and the filter component 16 is connected to the rear structural component 10 via the clamping ring 15.

[0093] The clamping rings 15 grip onto the connection elements 14 (in this embodiment example formed as flange points) of the front component 9, of the filter component 16 and of the rear component 10.

[0094] The front structural component 9 furthermore has an injection nozzle opening 19.

[0095] The filter device 1 is provided in the filter component 16.

[0096] The filter device 1 has a filter element 3 and a valve element 4 arranged in a fluidically parallel arrangement relative to the filter element 3.

[0097] In this embodiment example, the valve element 4 is formed by a nonreturn valve 5.

[0098] During the plasticizing of a material to be plasticized, it is plasticized via the plasticizing screw 8 of the plasticizing unit 6 via shearing, shear heat and optionally by externally introduced heat energy and conveyed in the direction of the injection nozzle opening 19.

[0099] After the plasticizing by the plasticizing screw 8, the plasticized material flows via the backflow barrier 17 in the direction of the injection nozzle opening 19 and in the process passes through the filter element 3, wherein the plasticized material is filtered by the filter element 3 and contaminants, particles and foreign substances dissolved in the plasticized material thus remain in the filter element 3.

[0100] After passing through the filter element 3, the plasticized material accumulates in the space in front of the screw 18, which is formed in the front structural component 9, before the plasticized material is pushed out of the injection cylinder 7 via the injection nozzle opening 19.

[0101] This pushing of the plasticized material out of the space in front of the screw 18 can be performed by the plasticizing screw 8 because the latter is arranged axially and linearly movable in the injection cylinder 7.

[0102] In this way, material plasticized by the plasticizing screw 8 through a rotational movement is conveyed into the space in front of the screw 18, until a desired quantity of plasticized material is present in the space in front of the screw 18.

[0103] While the plasticized material is accumulating in the space in front of the screw 18, this accumulating material pushes the plasticizing screw 8 back in the direction of the rear structural component 10.

[0104] If the desired quantity of plasticized material is now present in the space in front of the screw 18 (as a result of which a melt cushion is formed), the plasticizing screw 8 is moved axially in the direction of the injection nozzle opening 19, whereby the backflow barrier 17 closes and a pressure can be exerted on the plasticized material present in the space in front of the screw 18.

[0105] If the injection nozzle opening 19 is now (actively or passively) opened, the plasticized material present in the space in front of the screw 18 is pushed out of the injection cylinder 7 via the injection nozzle opening 19 by the pressure exerted on the plasticized material and the axial movement of the plasticizing screw 8, which represents the injection process.

[0106] This plasticized material pushed out via the nozzle opening 19 can for example be supplied to a mold 25 of a molding machine 2.

[0107] In this embodiment example, the valve element 4 is arranged centrally in the injection cylinder 7 surrounded by the filter element 3, wherein particularly favorable flow properties through the valve element 4 form.

[0108] Seen in a plane transverse to the flow direction of the plasticized material, the valve element 4 is completely surrounded by the filter element 3.

[0109] The valve element 4more precisely: the nonreturn valve 5 of this embodiment exampleis formed [0110] to prevent the plasticized material from flowing through the valve element 4 during the injection process in a closed position and [0111] to allow the plasticized material to flow through the valve element 4 in an open position, in order to make it possible to relieve the pressure on the filter element 3 after the injection process.

[0112] This has the marked advantage that after an injection process a pressure relief of the filter element 3 is always performed, which has an advantage to the effect that the pressure on the filter element 3 is relieved after the injection process in order to be able to carry out a cleaning and/or a change of the filter element 3.

[0113] Consequently, the pressure on the filter element 3 can be relieved quickly in every cycle of the plasticizing unit 6 in order for it to be cleaned and/or changed, which would require some time and expense if a filter element 3 without valve element 4 is provided.

[0114] With respect to a change and/or cleaning of the filter element 3 of this embodiment example, reference is made to FIG. 2, wherein an exploded representation of the embodiment example of FIG. 1 is schematically represented.

[0115] It can thus be seen that, for the cleaning and/or changing of the filter element 3, the clamping rings 15 are detached and lifted off the front structural component 9 and the rear structural component 10.

[0116] The front structural component 9 and the filter component 16 are then lifted off the rear structural component 10 axially, whereby the filter component 16 is released from the rest of the injection cylinder 7.

[0117] In this disassembled state, the filter element 3 of the filter device 6 which is arranged in the filter component 16 can now be cleaned and/or changed.

[0118] Embodiments in which the whole filter component 16 is replaced in order to make a cleaned filter element 3 available as quickly as possible are also entirely conceivable.

[0119] The named component parts can then be reassembled in order to be able to use the plasticizing unit 6 again for plasticizing a material.

[0120] This process can be fully automated and, due to its simple disassembly and assembly and due to the pressure relief of the filter element 3, represents a very quick possibility for changing and/or cleaning the filter element 3.

[0121] This possibility and embodiment variant allow the shortest possible downtimes of the molding machine 2 and/or the plasticizing unit 6 for the cleaning and/or changing of the filter element 3 to be realized.

[0122] FIG. 3 shows a flow diagram of a possible use of a plasticizing unit 6 from FIG. 1 or 2 in an injection-molding machine, wherein one or more injection cycles can first be run through until the filter has a certain level of blockage.

[0123] In order to be able to remove this filter blockage, or coating or contamination, of the filter element 3, which impairs the plasticizing cycle, the flange dismantling is performed and a changing and/or cleaning of the filter element 3 is made possible.

[0124] After the filter element 3 has been cleaned and/or changed, the flange assembling can again take place in order to make the plasticizing unit 6 usable again, whereby the plasticizing unit 6 is in turn prepared in order to run through further injection-molding cycles.

[0125] FIGS. 4 to 7 show a further embodiment example of a plasticizing unit 6 with a filter device 1.

[0126] Here, for better clarification an exploded representation of this plasticizing unit 6 is represented in FIG. 4.

[0127] The represented plasticizing unit 6 of this embodiment example of FIG. 4 has an injection cylinder 7 which is formed by a front, nozzle-side structural component 9 and a rear structural component 10 in which a plasticizing screw 8 is arranged.

[0128] A filter element 3 of the filter device 1 is arranged between the front structural component 9 and the rear structural component 10 and is braced with the front structural component 9 and the rear structural component 10 via the tension means 11 or, in other words, is clamped between the front structural component 9 and the rear structural component 10.

[0129] The represented tension means 11 of this embodiment example can be formed as tension bolts or screws.

[0130] An assembled state of this embodiment example of FIG. 4 is represented in FIG. 5, wherein in the usual manneras already described abovethe plasticizing unit 6 can run through a plasticizing cycle, wherein material to be plasticized is plasticized by the plasticizing screw 8 and is filtered by the filter device 1, before the plasticized, purified material leaves the injection cylinder 7 via the injection nozzle opening 19.

[0131] If the filter element 3 now has too great a coating and/or contamination after a number of plasticizing cycles (as indicated by FIG. 6 by the crossed-dashed filter element 3), the tension means 11 can be detached again in order to release the filter element 3 in order to change and/or clean it.

[0132] This position in which the filter element 3 is released from the front structural component 9 and the rear structural component 10 is in turn represented in FIG. 7.

[0133] After the filter element 3 has been cleaned and/or changed, it can again be braced between the front structural component 9 and the rear structural component 10 via the tension means 11 and the plasticizing cycles of the plasticizing unit 6 can be continued.

[0134] FIGS. 8 to 13 show a third embodiment example of a plasticizing unit 6.

[0135] An exploded representation of this third embodiment example is represented again for clarity in FIG. 8, wherein, in comparison with the embodiment example of FIGS. 4 to 7, the third embodiment example of FIGS. 8 to 13 has an expansion element 12.

[0136] This expansion element 12 is formed via the two pressure or tension rods 13. The remaining features for the most part correspond to the embodiments already explained in relation to FIGS. 4 to 7.

[0137] An assembly of the third embodiment example of FIGS. 8 to 13 is represented in FIG. 9, wherein it can be seen how the expansion elementmore precisely: the pressure or tension rods 13are mounted on the rear structural component 10 and pierce through it, wherein pressure or tension rods 13 contact the side of the front component 9 facing the rear structural component 10.

[0138] As already described in relation to the preceding embodiment examples, the third embodiment example of FIGS. 8 and 9 can also be added to the plasticizing cycle, wherein a material to be plasticized is plasticized via the plasticizing screw 8 and the plasticized material is then conveyed in the direction of the front component 9 via the filter element 3 of the filter device 1, until the plasticized material leaves the plasticizing unit 6 via the injection nozzle opening 19.

[0139] After a certain number of plasticizing cycles, the filter element 3 is again loaded with contaminants and coatings, which impair the plasticizing cycle, as is indicated by FIG. 10 and the crossed-dashed filter element 3.

[0140] In order now to be able to exchange or change the coated and/or contaminated filter element 3, in this embodiment example a spacing between the rear structural component 10 and the front structural component 9 can be increased with the aid of the expansion element 13 by exerting a pressure on the front structural component 9 via the pressure or tension rods 13.

[0141] Due to the pressure exerted on the front structural component 9 and the fact that the rear structural component 10 is fixedly braced, the tension means 11 arepreferably primarily elasticallydeformed (or more precisely: extended), whereby the spacing between the front structural component 9 and the rear structural component 10 increases (as can be seen through FIG. 11).

[0142] Due to the increase in the spacing between the front structural component 9 and the rear structural component 10, the filter element 3 of the filter device 1 is released, whereby the filter element 3 can be removed from the spacing between front structural component 9 and rear structural component 10 in order to clean and/or change the filter element 3.

[0143] Then the cleaned filter element 3 or another filter element 3 can again be inserted into the gap between front structural component 9 and rear structural component 10, as can be seen through FIG. 12.

[0144] As soon as the cleaned or new filter element 3 is arranged in the gap between front structural component 9 and rear structural component 10, the pressure on the front structural component 9 can be dissipated via the pressure or tension rods 13, whereby the tension means 11 pull the front structural component 9 back against the rear structural component 10 and again brace the filter element 3 between the front structural component 9 and the rear structural component 10.

[0145] This state in which the filter element 3 is again braced between front structural component 9 and rear structural component 10 can be seen through FIG. 13, wherein in this state the plasticizing process can be started again and plasticized material can be filtered by the filter element 3.

[0146] FIGS. 14a to 14c show, purely schematically, a filter device 1 which has a filter change device 20.

[0147] This filter change device 20 has a first filter element 3 and a (further) second filter element 21, which can be alternately added to a fluid stream 22 consisting of plasticized material in order to filter the plasticized material and/or to remove contaminants from it.

[0148] Correspondingly (see FIG. 14a), first of all a first filter element 3 is located in the fluid stream 22 of plasticized material for the filtration.

[0149] If the first filter element 3 now has too great a coating (contamination), a filter change can be carried out.

[0150] For the measurement of a coating, a pressure can for example be measured before and after the filter element 3, 21 and via the pressure difference between these two pressureswhen the pressure difference becomes too greatthe coating of the filter element 3, 21 can be referred to indirectly.

[0151] The cyclic filter change represents an alternative solution, wherein, according to empirical values, the filter elements 3, 21 are changed after a certain number of plasticizing cycles have been carried out.

[0152] During a filter change (such as is represented by FIG. 14b), the fluid stream 22 of plasticized material is briefly interrupted and the first filter element 3 is taken out of the injection cylinder 7 and replaced with the second filter element 21 via a change system 23.

[0153] After the change has been effected, the fluid stream 22 of plasticized material can be started again and supplied to the second filter element 21 (see FIG. 14c).

[0154] The filter element 3 can then be cleaned while the second filter element 21 is being used and exchanged into the fluid stream 22 of plasticized material again once a coating of the second filter element 21 becomes too great.

[0155] The molding machine 2 represented by way of example in FIG. 15 is an injection-molding machine and has a plasticizing unit 6 and a clamping unit 24, which are arranged together on a machine frame 26. The machine frame 26 could alternatively also be formed multi-part.

[0156] The clamping unit 24 has a fixed platen 27, a movable platen 28 and an end plate 29.

[0157] The movable platen 28 is movable relative to the machine frame 26 via a symbolically represented knuckle joint mechanism 30.

[0158] Mold halves of a mold 25 can be clamped or fitted (represented dashed) on the fixed platen 27 and the movable platen 28.

[0159] The fixed platen 27, the movable platen 28 and the end plate 29 are mounted and guided relative to each other by the rails 31.

[0160] The mold 25 represented closed in FIG. 15 has at least one cavity. An injection channel, via which a plasticized material can be supplied to the plasticizing unit 6, leads to the cavity.

[0161] FIG. 15 shows a molding machine 2 with a plasticizing unit 6, wherein the plasticizing unit 6 shown in this embodiment example also serves as an injection unit and has a plasticizing screw 8 formed as an injection screw, which is also used for plasticizing a material to be plasticized.

[0162] The plasticizing unit 6 of this embodiment example has an injection cylinder 7 and a plasticizing screw 8 arranged in the injection cylinder 7. This plasticizing screw 8 is rotatable about an axis of rotation as well as movable axially along the axis of rotation in the conveying direction.

[0163] These movements are driven via a schematically represented drive unit 32. This drive unit 32 preferably comprises a rotary drive for the rotational movement and a linear drive for the axial injection movement.

[0164] The plasticizing unit 6 (and thus the injection unit) is in signaling connection with a control or regulating unit 33.

[0165] Control commands are for example output to the plasticizing unit 6 and/or the drive unit 32 by the control or regulating unit 33.

[0166] The control or regulating unit 33 can be connected to an operating unit and/or a display device 34 or can be an integral constituent of such an operating unit.

LIST OF REFERENCE NUMBERS

[0167] 1 filter device [0168] 2 molding machine [0169] 3 filter element [0170] 4 valve element [0171] 5 nonreturn valve [0172] 6 plasticizing unit [0173] 7 injection cylinder [0174] 8 plasticizing screw [0175] 9 front structural component [0176] 10 rear structural component [0177] 11 tension means [0178] 12 expansion element [0179] 13 pressure or tension rod [0180] 14 connection element [0181] 15 clamping ring [0182] 16 filter component [0183] 17 backflow barrier [0184] 18 space in front of the screw [0185] 19 injection nozzle opening [0186] 20 filter change device [0187] 21 second filter element [0188] 22 fluid stream [0189] 23 change system [0190] 24 clamping unit [0191] 25 mold [0192] 26 machine frame [0193] 27 fixed platen [0194] 28 movable platen [0195] 29 end plate [0196] 30 knuckle joint mechanism [0197] 31 rail [0198] 32 drive unit [0199] 33 control or regulating unit [0200] 34 display device