Filter device

Abstract

A filter device for plasticized molding material includes a filter housing and a filter element arranged in the filter housing. The filter housing has at least two housing elements movable relative to each other. A drive is provided, via which the housing elements are movable between an open position and a closed position. The filter element is at least partially released in the open position of the housing elements and can preferably be taken out of the filter housing.

Claims

1. A filter device for a plasticized molding material, comprising: a filter housing formed by first and second housing elements, at least one of the first and second housing elements being movable relative to the other of the first and second housing elements; at least one filter element arranged in the filter housing; and at least one drive via which the at least one of the first and second housing elements is movable between an open position and a closed position, wherein the at least one filter element is at least partially released by a movement of the at least one of the first and second housing elements into the open position, and wherein the at least one filter element is releasably arranged between the first and second housing elements.

2. The filter device according to claim 1, wherein a separating plane is formed by the first and second housing elements, wherein a cavity is enclosed by the first and second housing elements in the closed position, and wherein the cavity is released on the separating plane in the open position of the first and second housing elements.

3. The filter device according to claim 1, wherein the first housing element is a fixed housing element and the second housing element is movable relative to the fixed first housing element by the at least one drive.

4. The filter device according to claim 3, further comprising at least one guide element which is formed to guide the first and second housing elements relative to each other during a transition from the open position to the closed position, and during a transition from the closed position to the open position.

5. The filter device according to claim 1, wherein: the first housing element has at least one supply opening; and the second housing element has at least one discharge opening, wherein in the closed position the plasticized material can be supplied to the filter device via the at least one supply opening and can be discharged via the at least one discharge opening.

6. The filter device according to claim 5, further comprising at least one nozzle, wherein the at least one nozzle is connected to the at least one supply opening or the at least one discharge opening for respectively supplying or discharging the plasticized material.

7. The filter device according to claim 1, wherein the filter housing is equipped with at least one temperature control element, wherein the at least one temperature control element is configured to make the plasticized molding material in the filter housing solidify.

8. The filter device according to claim 7, wherein the at least one filter element can be taken out of the filter housing together with the solidified molding material in the open position of the first and second housing elements.

9. The filter device according to claim 1, further comprising at least one ejector device configured to eject the at least one filter element in the open position.

10. A molding machine comprising the filter device according to claim 1.

11. The molding machine according to claim 10, wherein the filter device is connected to a clamping unit of the molding machine, wherein the at least one of the first and second housing elements of the filter device is movable between the open position and the closed position through an opening movement or closing movement of a movable platen relative to a fixed platen.

12. The molding machine according to claim 10, further comprising an injection unit, wherein plasticized material from a plasticizing unit of the molding machine can be supplied to the filter device, and the filtered, plasticized material can be transferred to the injection unit of the molding machine, or plasticized material from the injection unit of the molding machine can be supplied to the filter device, and the filtered, plasticized material can be supplied directly to a mold cavity of a mold.

13. A method for operating a filter device for a plasticized molding material, the filter device comprising: a filter housing formed by first and second housing elements, at least one of the first and second housing elements being movable relative to the other of the first and second housing elements; a first filter element arranged in the filter housing; and at least one drive via which the at least one of the first and second housing elements is movable between an open position and a closed position, wherein the first filter element is at least partially released by a movement of the at least one of the first and second housing elements into the open position, and wherein the first filter element is releasably arranged between the first and second housing elements, the method comprising: filtering the plasticized molding material in the filter device with the first filter element; and to clean or change the first filter element, opening the filter housing of the filter device by the at least one drive so as to release the first filter element.

14. The method according to claim 13, wherein the filter device is a first filter device, and a second filter device is provided, wherein the method further comprises selectively supplying the plasticized molding material at least partially to the second filter device.

15. The filter according to claim 1, wherein the plasticized molding material is plasticized plastic, wherein the at least one filter element is removable from the filter housing in the open position of the first and second housing elements, and wherein the at least one filter element is releasably braced between the first and second housing elements.

16. The filter device according to claim 6, wherein the at least one nozzle is a hot runner nozzle.

17. The filter device according to claim 16, wherein the hot runner nozzle is a hot runner shut-off nozzle.

18. The filter device according to claim 7, wherein the at least one temperature control element comprises temperature control channels for a temperature control medium.

19. The filter device according to claim 9, wherein the at least one ejector device is configured to eject the at least one filter element together with solidified molding material in the open position.

20. The molding machine according to claim 10, wherein the molding machine is an injection-molding machine.

21. The method according to claim 13, wherein the plasticized molding material is plasticized plastic.

22. The method according to claim 14, wherein the selective supplying of the plasticized molding material is performed while the first filter device is being cleaned or changed.

23. The method according to claim 14, wherein the plasticized molding material is supplied completely to the second filter device.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further advantages and details of the invention are revealed by the figures and the associated description of the figures, in which:

(2) FIG. 1 shows a first embodiment of a filter device,

(3) FIGS. 2a-2c is a schematic representation of a filter element change device,

(4) FIGS. 3a-3c shows an embodiment of a filter element change device,

(5) FIG. 4 shows an embodiment of a molding machine,

(6) FIG. 5 shows a further embodiment of a molding machine, and

(7) FIG. 6 shows a third embodiment of a molding machine.

DETAILED DESCRIPTION OF THE INVENTION

(8) FIG. 1 shows a first embodiment of a filter device 1, which has a filter housing 3 and a filter element 4 arranged in the filter housing 3.

(9) The filter housing 3 of this embodiment is implemented by the two housing elements 5, 6.

(10) In this embodiment the first housing element 5 is implemented as a fixed housing element 5 and the second housing element 6 is formed as a housing element 6 movable relative to the first housing element 5.

(11) A separating plane 7 between the housing elements 5, 6 is formed by the two housing elements 5, 6, wherein in the open position a cavity 8 is released on the separating plane 7, which cavity 8 is enclosed by the at least two housing elements 5, 6 in a closed position.

(12) With the aid of a drive 18, the movable housing element 6 can be displaced linearly relative to the fixed housing element 5, with the result that the inside (the cavity 8) of the filter housing 3 is released in an open position, with the result that the filter element 4 is also released.

(13) In a closed position (as represented in FIG. 1) the movable housing element 6 is placed and preferably pressed against the fixed housing element 5, whereby the filter element 4 is mounted and in particular braced between the fixed housing element 5 and the movable housing element 6.

(14) Furthermore, the filter housing 3 has a supply opening 9 and a discharge opening 10. In detail, the supply opening 9 is provided in the movable housing element 6 and the discharge opening 10 is provided in the fixed housing element 5.

(15) The filter device 1 moreover has a hot runner shut-off nozzle 11, which is arranged at the supply opening 9 and is formed to close a supply line 22 off from the cavity 8 as required.

(16) In the same way, a hot runner shut-off nozzle 11 is arranged at the discharge opening 10 in order to separate the cavity 8 off from a discharge line 23 as required.

(17) During operation of the filter device 1, plasticized molding material is supplied, via the supply line 22, to the cavity 8 of the filter housing 3 via the hot runner shut-off nozzle 11 and the supply opening 9.

(18) After being supplied via the supply opening 9, the plasticized molding material is conducted through the filter element 4, whereby the plasticized molding material is filtered by the filter element 4, with the result that only filtered, plasticized molding material passes through the filter element 4 and impurities or contaminants remain on or in the filter element 4.

(19) After filtration of the plasticized molding material by the filter element 4, the filtered, plasticized molding material is in turn discharged from the filter housing 3 via the discharge opening 10 and supplied to the discharge line 23 via the hot runner shut-off nozzle 11.

(20) In order to support the filter element 4 in the flow direction of the plasticized molding material and to protect it from damage by the volume flow, a supporting plate 24, which supports the filter element 4 in the direction of the volume flow of the plasticized molding material, is moreover provided in the mold cavity 8 between the fixed housing element 5 and the movable housing element 6.

(21) Before and after the filter housing 3 in the area of the hot runner shut-off nozzle 11, pressure sensors 25 are arranged which are formed to determine a prevailing pressure of the plasticized molding material or a signal characteristic of the pressure of the plasticized molding material before and after the filter housing 3.

(22) Through these pressures of the plasticized molding material before and after the filter housing 3more precisely: with the aid of a pressure gradient before and after the filter housing 3a value characteristic of the filter blocking, filter coating and/or filter contamination can be defined, wherein a filter change and/or a filter cleaning can be carried out when a predefined limit value is exceeded or reached.

(23) If a corresponding value is reached and/or a filter change and/or filter cleaning becomes necessary, the hot runner shut-off nozzles 11 of this embodiment are closed, whereby the cavity 8 is separated off from the supply line 22 and the discharge line 23 without there being the danger of plasticized molding material present in the supply line 22 and/or the discharge line 23 curing.

(24) The plasticized molding material present in the cavity 8, together with the residues and contaminants as well as deposits, is then cooled and thus cured with the aid of the temperature control element 12 of the filter housing 3.

(25) In this embodiment the temperature control element 12 is implemented by the temperature control channels 13, wherein a temperature control medium (for example water), which can be utilized to control the temperature of, preferably cool, the filter housing 3 and the components present in the filter housing 3 as well as the plasticized molding material, flows in the temperature control channels 13.

(26) After cooling and curing of the molding material present in the cavity 8, the movable housing element 6 is displaced linearly relative to the fixed housing element 5 and the cavity 8 and/or the filter element 4 is released on the separating plane 7.

(27) After release of the filter element 4, the filter element 4, together with the supporting plate 24 and the cured molding material as well as the contaminants and deposits present therein, can be taken out of the cavity 8.

(28) The ejector devices 14, which are movable, as represented by the arrows, relative to the fixed housing element 5 and the movable housing element 6, can serve to take this cured molding material out or eject it together with the filter element 4 and the supporting plate 24.

(29) To eject the cured molding material together with the supporting plate 24 and the filter element 4, the ejector devices 14 formed pin-shaped are thus displaced in the direction of the cavity 8 in order to expel the cured molding material together with the supporting plate 24 and the filter element 4 from the recesses, forming the cavity 8, of the housing elements 5, 6.

(30) After demolding and/or ejection of the solidified molding material together with the filter element 4 and the supporting plate 24, a new or cleaned supporting plate 24 with a new or cleaned filter element 4 can be positioned between the housing elements 5, 6 and via a drive 18 the movable housing element 6 can be placed against the fixed housing element 5 in order to clamp and/or brace the supporting plate 24 and the filter element 4 between the housing elements 5, 6.

(31) In turn, the hot runner shut-off nozzles 11 can then be opened in order to continue the process of the filtration by the filter element 4 and the filter device 1.

(32) A change of the filter element 4, where appropriate even together with the supporting plate 24, out of and into the filter device 1 can be effected in an automated manner via a filter change device 26, as illustrated schematically, for example, by FIGS. 2a to 2c.

(33) Here, FIGS. 2a to 2c show a schematically presented representation of a filter change device 26 and FIGS. 3a to 3c show a more specific embodiment of such a device.

(34) The embodiment represented of FIGS. 2a to 2c again has, according to an embodiment of the invention, a first and a second housing part 5, 6, wherein the filter element 4 is arranged between the housing parts.

(35) FIGS. 3a to 3c show an embodiment of a filter device 1 as known from FIG. 1 with a filter change device 26.

(36) The filter change device 26 of FIG. 3 is implemented by a supporting plate 24 linearly displaceable by a drive 18, which linearly displaceable supporting plate 24 has two receivers for filter elements 4, 27 and is movable between two positions, in which positions the receivers with filter element 4, 27 arranged therein are in engagement with the filter device 1.

(37) This filter change device 26 has a (first) filter element 4 and a (further) second filter element 27, which can be alternately added to a volume flow of plasticized molding material (illustrated here by the arrows) in order to filter the plasticized molding material and/or to remove impurities from it.

(38) Correspondingly (see FIG. 2a and FIG. 3a), first of all a first filter element 4 is located in the filter device 1 in order to filter the volume flow of plasticized molding material.

(39) If the first filter element 4 now has too great a coating (level of impurity), a filter change can be carried out.

(40) For the measurement of a coating, a pressure can for example (as already described previously) be measured before and after the filter element 4 and via the pressure difference between these two pressureswhen the pressure difference becomes too greatthe coating of the filter element 4 can be referred to indirectly.

(41) The cyclic filter change represents an alternative solution, wherein, according to empirical values, the filter elements 4 are changed after a certain number of plasticizing cycles have been carried out.

(42) During a filter change (such as is represented by FIG. 2b and FIG. 3b), the volume flow of plasticized molding material is briefly interrupted (for example by closing hot runner shut-off nozzles 11) andif the housing elements 5,6 are in an open positionthe first filter element 4 is taken out of the filter device 1 and replaced with the second filter element 27 via a change system 28.

(43) According to FIG. 3b it can also be provided that, even before the filter change (if the housing elements 5, 6 are in an open position), the contaminated filter element 4, together with the molding material solidified in the filter housing 3 before the housing parts 5, 6 are opened, is expelled from the housing parts 5, 6 via the ejector device 14.

(44) Then, after the change has been effected, the volume flow of plasticized molding material can be started again and supplied to the second filter element 27 (see FIG. 2c and FIG. 3c).

(45) The filter element 4 can then be cleaned while the second filter element 27 is being used and exchanged into the filter device 1 again once a coating of the second filter element 27 becomes too great.

(46) The molding machine 2 represented by way of example in FIG. 4 is an injection-molding machine and has an injection unit 20 and a clamping unit 15, which are arranged together on a machine frame 29.

(47) The machine frame 29 could alternatively also be formed multi-part.

(48) The clamping unit 15 has a fixed platen 16, a movable platen 17 and an end plate 30.

(49) The movable platen 17 is movable relative to the machine frame 29 via a symbolically represented drive 18 (for example a knuckle joint mechanism).

(50) In this embodiment the drive 18 of the clamping unit 15 also serves as the drive 18 of the filter device 1 (which will be discussed in even more detail later).

(51) Mold halves of a mold 21 can be clamped or fitted (represented dashed) on the fixed platen 16 and the movable platen 17.

(52) The fixed platen 16, the movable platen 17 and the end plate 30 are mounted and guided relative to each other by the rails 31.

(53) The mold 21 represented closed in FIG. 4 has at least one cavity. An injection channel, via which a plasticized material can be supplied to the plasticizing unit 19, leads to the cavity.

(54) FIG. 4 shows a molding machine 2 with an injection unit 20, which in this embodiment has an injection screw and is thus also used for plasticizing a material to be plasticized.

(55) The injection unit 20 of this embodiment has a barrel 35 and a plasticizing screw arranged in the barrel 35. This plasticizing screw is rotatable about an axis of rotation as well as movable axially along the axis of rotation in the conveying direction.

(56) 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.

(57) The plasticizing unit 19 (and thus the injection unit 20) is in signaling connection with a control or regulating unit 33. Control commands are for example output to the plasticizing unit 19 and/or the drive unit 32 by the control or regulating unit 33.

(58) 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.

(59) It can be provided that the control or regulating unit 33 of the molding machine 2 at least partly undertakes the function of the control or regulating device 33 of the plasticizing unit 19, is formed as the latter or alternatively even is implemented independently and/or separately from the latter.

(60) In this embodiment of FIG. 3 the filter device 1 is formed as part of the mold 21, wherein the mold 21 has several separating planes. Such molds 21 are also often called stack molds or three-plate molds.

(61) The filter device 1, with the fixed housing element 5 and the movable housing element 6, forms a first separating plane 7 of the three-plate mold.

(62) The movable housing element 6 of the filter device is connected in a movement-locking manner to the fixed mold part of the mold 21 (precisely: formed in a single part with the fixed mold part of the mold 21), wherein the second separating plane of the mold is formed by the fixed mold part and the movable mold part of the mold 21.

(63) The structure represented in FIG. 4 is to be understood purely schematically, wherein dimensions and design details of a corresponding three-plate mold with a filter device would be to be adapted and can vary.

(64) Thus, from the plasticizing unit 19 and/or injection unit 20, the plasticized molding material is introduced directly into the filter device 1 in order to filter the plasticized molding material, wherein, after filtration, the filtered, plasticized molding material is transferred directly into a mold cavity of the mold 24, where it solidifies to form a molded part and can then be ejected.

(65) In a manufacturing process, the procedure can be such that during the manufacturing cycles it is always only the mold 21 that is opened in order to eject the finished products and additionally the separating plane 7 of the filter device 1 is additionally also opened by the drive 18 and the movement of the movable platen 17 after a predefinable number of cycles or if a filter change becomes necessary.

(66) The transferring of the filter device 1 between a closed position and an open position can be controlled or regulated for example by the closure mechanism 37 shown in FIG. 4, wherein either an opening between movable housing element 6 and fixed housing element 5 or an opening between fixed mold part and the movable mold part of the mold 21 via the drive 18 is allowed.

(67) This closure mechanism 37 can be formed for example as a locking device and can hold the filter device 1 closed when the clamping unit 15 is opened, with the result that the filter device 1 is not also opened every time the clamping unit 15 is opened.

(68) If a filter change becomes necessary, the closure mechanism 37 can release or actively drive the movable housing element 6 relative to the fixed housing element 5 during an opening of the clamping unit 15, in order to transfer the filter device 1 into an open position.

(69) During this opening of the movable housing element 6 relative to the fixed housing element 5, the closure mechanism 37 can be formed to fix the movable mold part relative to the fixed mold part in order to prevent the movable mold part from opening relative to the fixed mold part.

(70) The closure mechanism 37 can be connected for example to the control or regulating unit 33 and can be controlled and/or regulated by the control or regulating unit 33.

(71) Such a procedure or such a structure has the striking advantage that no additional drive 18 needs to be provided, but rather the already existing drive 18 of the clamping unit 15 (implemented here for example as a knuckle joint mechanism 38) can be utilized.

(72) Existing molding machines 2 and/or injection-molding machines from the state of the art can thus also be retrofitted with a filter device 1.

(73) The embodiment of FIG. 5, in comparison with FIG. 4, shows an arrangement of the filter device 1 on a side of the fixed platen 16 facing away from the mold 21.

(74) Here, the filter device 1 is again downstream of the plasticizing unit 19 and the injection unit 20 in the flow direction of the plasticized molding material, wherein, after filtration by the filter element 4, the plasticized molding material is supplied to the mold 21.

(75) In this embodiment of FIG. 5 the filter device 1 has a filter closing unit 41, which can move the movable housing part 6 relative to the fixed housing part 5 via rails and a closure plate between a closed position and an open position using a drive 18 not represented here.

(76) Through a corresponding design, the possibility of a filter device 1 to be activated independently and separately from the clamping unit 15 is created, wherein for example during an opening movement of the clamping unit 15 a filter change can simultaneously be carried out via the filter closing unit 41.

(77) The remaining features of the embodiment of FIG. 5 substantially correspond to that of FIG. 4.

(78) An embodiment like that shown by FIG. 4 or 5, in which the plasticizing unit 19 is combined with the injection unit 20 through an injection screw, is also called a single-stage injection-molding machine.

(79) The embodiment of a molding machine 2 according to FIG. 6, on the other hand, shows a two-stage process, in which the plasticizing unit 19 is formed separate from the injection unit 20.

(80) As can be seen in FIG. 6, the molding machine 2 depictedmore precisely: this injection-molding machinehas a plasticizing unit 19, which plasticizes a material to be plasticized via a plasticizing screw.

(81) This plasticizing screw is arranged in the barrel 35 drivable rotationally by the drive unit 32, in order to plasticize the material to be plasticized by shearing, shear heat and optionally externally introduced heat.

(82) The plasticized molding material is then supplied from the plasticizing unit 19 via the supply line 22 of the filter device 1 to the filter device 1.

(83) In the filter device 1, the plasticized molding material is again filtered and transferred to the injection unit 20 via the discharge line 23 of the filter device 1.

(84) The injection unit 20 formed by an injection plunger in the injection cylinder 36 then injects the plasticized material into a cavity of the mold 21.

(85) The injection plunger is arranged linearly over the drive unit 32 in the injection cylinder 36.

(86) In this embodiment the filter device 1, more precisely: the movable housing element 6, is drivable relative to the fixed housing element 5 by means of a drive 18 formed separate from the clamping unit 15.

(87) This drive 18 of the embodiment of FIG. 6 is implemented similarly to a small clamping unit, wherein the fixed housing element 5 is connected to a filter end plate 39 via a filter frame 40.

(88) The drive 18, which is implemented as a linear drive, preferably a piston-cylinder unit or a knuckle joint mechanism, and is formed to move the movable housing element 6 relative to the fixed housing element 5 between an open position and a closed position, is provided between the filter end plate 39 and the movable housing element 6.

(89) The drive 18 can be connected to the control or regulating unit 33 and can be controlled and/or regulated by the control or regulating unit 33.

(90) It could also be provided that, in an embodiment of FIG. 6, a filter change device 26 (as represented for example by FIGS. 2a-2c or FIGS. 3a-3c) is used in order to minimize downtimes during the filter change.

(91) Such an embodiment is preferably advantageous in the case of materials to be plasticized with particularly high levels of contamination, wherein a change and/or a cleaning of the filter element 4 can be performed independently of a movement of the clamping unit 15.

(92) The remaining features of the embodiment of FIG. 6 substantially correspond to that of FIG. 4.

LIST OF REFERENCE NUMBERS

(93) 1 filter device 2 molding machine 3 filter housing 4 filter element 5 first (fixed) housing element 6 second (movable) housing element 7 separating plane 8 cavity 9 supply opening 10 discharge opening 11 hot runner shut-off nozzle 12 temperature control element 13 temperature control channel 14 ejector device 15 clamping unit 16 fixed platen 17 movable platen 18 drive 19 plasticizing unit 20 injection unit 21 mold 22 supply line 23 discharge line 24 supporting plate 25 pressure sensor 26 filter change device 27 further filter element 28 change system 29 machine frame 30 end plate 31 rail 32 drive unit 33 control or regulating unit 34 operating unit and/or display device 35 barrel 36 injection cylinder 37 closure mechanism 38 knuckle joint mechanism 39 filter frame 40 filter end plate 41 filter closing unit