OVERTURNING DEVICE FOR OVERTURNING MOLTEN MATERIAL AND RINSING METHOD

Abstract

The present invention relates to an overturning device (10) for overturning a molten material (200) in a melt channel (110) comprising a melt inlet (20) and a melt outlet (30), wherein between the melt inlet (20) and the melt outlet (30) at least a melt guidance means (40) is assembled for a rearrangement of molten material (200) from the centre (22) of the melt inlet (20) to the edge (34) of the melt outlet (30) and for a rearrangement of molten material (200) from the edge (24) of the melt inlet (20) into the centre (32) of the melt outlet (30).

Claims

1. An overturning device for overturning a molten material in a melt channel comprising a melt inlet and a melt outlet, wherein between the melt inlet and the melt outlet at least a melt guidance means is assembled for a rearrangement of molten material from the centre of the melt inlet to the edge of the melt outlet and for a rearrangement of molten material from the edge of the melt inlet into the centre of the melt outlet

2. The overturning device according to claim 1, wherein at least the at least one melt guidance means comprises a first guidance channel with a guidance opening in the centre of the melt inlet and at least one guidance outlet at the edge of the melt outlet or at least a melt guidance means comprises a second guidance channel with a guidance outlet in the centre of the melt outlet and at least one guidance openin at the edge of the melt inlet.

3. The overturning device according to claim 1, wherein the at least one melt guidance means comprises a separation section with a first separation channel and a second separation channel, wherein in front of the separation section a division section for dividing the molten material to the separation channels and at least after the separation section a combination section for merging the molten material from the separation channels is assembled or the combination section is configured for a central merging of the edge sections of the molten material.

4. The overturning device according to claim 1, wherein a shifting device is provided for a shifting of the overturning device between a first position in which the melt inlet and the melt outlet are in a fluid communicating connection with the melt channel and a second position in which the melt inlet and the melt outlet are separated from the melt channel.

5. The overturning device according to claim 4, wherein the shifting device comprises a melt channel piece with a length which corresponds or mainly corresponds to the distance between the melt inlet and the melt outlet.

6. The overturning device according to claim 4, wherein the shifting device comprises a guidance section for guiding of the shifting movement between the first position and the second position.

7. The overturning device according to one of claim 4, wherein the shifting deviceis configured for shifting the overturning device between the first position and the second position along a translational path.

8. The overturning device according to one of claim 4, wherein the shifting device comprises a drive device for performing the shifting between the first position and the second position.

9. A Blow head for performing a blow head extrusion method comprising at least a melt channel for conveying molten material to a blow outlet of the blow head wherein in the at least one melt channel at least one overturning device for overturning a molten material in a melt channel comprising a melt inlet and a melt outlet, wherein between the melt inlet and the melt outlet at least a melt guidance means is assembled for a rearrangement of molten material from the centre of the melt inlet to the edge of the melt outlet and for a rearrangement of molten material from the edge of the melt inlet into the centre of the melt outlet is assembled.

10. The Blow head according to claim 9, wherein the overturning device is assembled in the middle or mainly in the middle of the melt channel related to the length of the melt channel.

11. The Blow head according to claim 9, wherein the shifting device is provided with at least two overturning devices for a common shifting of two overturning devices between the first position in which the first overturning device is in a fluid communication with the melt channel and a second position in which the second overturning device is in a fluid communicating connection with the melt channel.

12. A Method for performing a purge process in an extrusion device, comprising: introducing a molten material in a melt inlet in an overturning device rearranging molten material from the centre of the melt inlet to the edge of a melt outlet of the overturning device and rearranging molten material from the edge of the melt inlet into the centre of the melt outlet.

13. The Method according to claim 12, wherein previous to performing the purge process via a shifting device the overturning device is shifted into a fluid communicating position with the melt channel.

14. The Method according to claim 12, wherein after performing the purge process via a shifting device the overturning device is shifted into a position without fluid communicating connection to the melt channel.

15. The Overturning device according to claim 7, wherein the translational path is a straight line.

16. The Overturning device according to claim 8, wherein the shifting device comprises a drive device in form of an electric motor for performing the shifting between the first position and the second.

Description

[0037] Further advantages, features and details of the invention result from the subsequent description in which embodiments of the invention are described in detail in relation to the drawings. Thereby, the features described in the claims and in the description can be essential for the invention each single for themselves or in any combination. It is shown schematically:

[0038] FIG. 1 a schematic representation during a purge process with known extrusion devices,

[0039] FIG. 2 a situation according to FIG. 1 with the use of an overturning device according to the invention,

[0040] FIG. 3 an embodiment of an overturning device according to the invention,

[0041] FIG. 4 the embodiment of FIG. 3 with a further representation of flow conditions of the molten material,

[0042] FIG. 5 a further embodiment of an overturning device according to the invention,

[0043] FIG. 6 a schematic representation of the effect of an overturning device according to the invention,

[0044] FIG. 7 a further embodiment of an overturning device according to the invention,

[0045] FIG. 8 a further embodiment of an overturning device according to the invention,

[0046] FIG. 9 an embodiment of a blow head according to the invention, and

[0047] FIG. 10 a further embodiment of a blow head according to the invention.

[0048] In FIG. 1 a melt channel 110 with a flow direction from the left to the right is shown, like it is represented during the purge process. Within the melt channel 110 a free flow area 70 is intended through which molten material 200 flows. Here, it has to be differentiated between the old molten material 220 and new molten material 210. It can be recognized that via the longitudinal course of the melt channel 110 during the purge process a ramp-like or cone-like configuration between the old molten material 220 and the new molten material 210 is configured. This cone moves during the purge time in the course to the right until finally the greatest part of the old molten material 220 is put out and it can be further proceeded with the active production.

[0049] In FIG. 2 the mode of action of an overturning device 10 according to the invention is shown. Here, a rearrangement occurs from the edge of the molten material 200 into the centre of the molten material 200 and vice versa. At the melt inlet 20 of the overturning device 10 accordingly material is received from the edge of the molten material 200 and is provided into the centre at the melt outlet 30. In an inverse manner fresh or new molten material 210 is guided from the centre of the melt inlet 20 to the edge of the melt outlet 30. Like it can be recognized, therewith the adjusted amount of the old molten material 220 is reduced at the right edge of the melt channel 110. The representation of FIG. 2 occurs at the same point of time during the purge process like FIG. 1.

[0050] FIGS. 3 and 4 show a first embodiment of an overturning device 10 according to the invention. This overturning device 10 is configured with two guidance channels 42 and 44 as melt guidance means 40. By a not further described ring collector a guidance opening 44a is provided at the edge 24 of the melt inlet 20 such that corresponding molten material 200 can flow into the second guidance channel 44. This is shown with arrows in FIG. 4. Via a guidance outlet 44b in the centre 32 of the melt outlet 30 now the rearrangement occurs from the edge into the centre for this molten material 200.

[0051] In the same manner in the centre 22 of the melt inlet 20 a guidance opening 42a of the first guidance channel 42 is provided which allows rearranging the molten material 200 at the edge 34 of the melt outlet 30 and the corresponding guidance outlet 42b along the arrows of FIG. 3. Hereby, this is about a technical solution by an active rearrangement, wherein the overturning device 10 is part of the melt channel 110.

[0052] FIG. 5 shows a reduced complexity concerning the embodiment of FIGS. 3 and 4. Here, a closed second melt guidance means 40 is intended with the corresponding guidance opening 44a and guidance outlet 44b . The remaining material of the molten material 200 is untouched by the melt inlet 20, guided at the upper edge through the melt guidance means 40 or guided to the lower edge. The corresponding sections A-A and B-B are shown in the lower area of FIG. 5 wherein likewise the arrows represent the corresponding rearrangement movements.

[0053] FIGS. 6 and 7 show the possibility to provide a rearrangement by a separation functionality. Starting from a melt channel 110 according to FIG. 7 via a division section 47 a division of the molten material 200 to two separation channels 46a and 46b of the separation section 46 occurs. This schematically leads to a separation according to FIG. 6. Starting from the melt channel 110 completely circumferentially old molten material 220 encloses the new molten material 210 during separation in the separation channels 46a and 46b only approximately half of the extent is covered with old molten material 220. The other half in the separation channels 46a and 46b is already equipped with new molten material 210 at the edge. In case by a clever combining a central merging of both separation channels 46 for the edge areas is performed with old molten material 220, thus a complete or at least partial rearrangement according to the invention occurs by this separation function.

[0054] FIG. 8 schematically shows a possible further embodiment of an overturning device 10 with this separation functionality. Here, a division to in total four separation channels 46a and 46b and a recombining in a combination section 48 occurs. Schematically, further a corresponding distribution of old molten material 220 and new molten material 210 is shown in the corresponding channels. After combining or merging at the combination section 48 the edge sections with the old molten material 220 are completely in the centre such that the surrounding edge in the melt channel 110 is configured mainly completely with new molten material 210.

[0055] In FIG. 9 it is shown how in a melt channel 110 in a blow head 100 an overturning device 10 can be assembled. Thereby, here it can be the described embodiment of the overturning device 10. Thereby, the overturning device 10 comprises a shifting device 60. According to FIG. 9 the overturning device 10 is in the second position and therewith outside a fluid communicating engagement with the melt channel 110. Hereby, this is the operation position. For the purge situation the overturning device 10 is inserted into the melt channel 10 via the shifting device 60 and therewith can provide the functionality according to the invention for the reduction of the purge time. For the movement of the shifting a drive device 64 is intended which comprises an electric motor. The shifting occurs along a straight line and is guided through a guidance section 62 of the shifting device 62. Further, in the shifting device 60 a melt channel piece 114 is intended which completes the melt channel 110 in the second position according to FIG. 9. The blow head of this embodiment is configured with a ring-like blow outlet 112.

[0056] In FIG. 10 a variation of the embodiment of FIG. 9 for a blow head 100 is shown. Here, the shifting device is configured with two separate and especially different overturning devices 10. Thus, here the shifting device can take over three different positions. Besides the operation function in FIG. 10 two different purge positions with the different overturning devices can be taken over such that an adjustment to the different requirements can occur during the purge process.

[0057] The previous description of the embodiments describes the present invention only within the scope of examples. Naturally, single features of the embodiments as far as technically meaningful can be freely combined with one another without leaving the scope of the present invention.

LIST OF REFERENCE SIGNS0 Overturning device

[0058] 10 Melt inlet

[0059] 22 Centre of melt inlet

[0060] 24 Edge of melt inlet

[0061] 30 Melt outlet

[0062] 32 Centre of melt outlet

[0063] 34 Edge of melt outlet

[0064] 40 Melt guidance means

[0065] 42 First guidance channel

[0066] 42a Guidance opening

[0067] 42b Guidance outlet

[0068] 44 Second guidance channel

[0069] 44a Guidance opening

[0070] 44b Guidance outlet

[0071] 46 Separation section

[0072] 46a First separation channel

[0073] 46b Second separation channel

[0074] 47 Division section

[0075] 48 Combination section

[0076] 60 Shifting device

[0077] 62 Guidance section

[0078] 64 Drive device

[0079] 70 Free flow area

[0080] 100 Blow head

[0081] 110 Melt channel

[0082] 112 Blow outlet

[0083] 114 Melt channel piece

[0084] 200 Molten material

[0085] 210 New molten material

[0086] 220 Old molten material