Extrusion device having at least one perforated plate

Abstract

An extrusion device including at least one extruder having a screw cylinder, a screw shaft rotatably supported in the screw cylinder and an extruder outlet, an injection mould having an outlet nozzle determining the cross-sectional contour of the extruder, and an extrusion head arranged between the extruder outlet of the at least one extruder and the outlet nozzle of the injection mould, wherein at least one perforated plate arranged in the extruder head is provided, which has a plurality of passage openings, wherein the passage openings are designed to dam up extrusion material conveyed from the at least one extruder through the passage openings of the perforated plate differently into at least one first region of the perforated plate and at least one second region of the perforated plate, in such a way that the extrusion material is partly diverted from its preferential direction within a central section of the perforated plate, specifically increasingly into at least one edge section of the perforated plate.

Claims

1. An extrusion device comprising at least one extruder (2, 2.1, 2.2, 2.3) having a screw cylinder (3.1, 3.2, 3.3), a screw shaft (4.1, 4.2, 4.3) rotatably supported in the screw cylinder (3.1, 3.2, 3.3) and an extruder outlet (5.1, 5.2, 5.3), an injection mould (7) having an outlet nozzle (8) determining the cross-sectional contour of the extrudate, and an extrusion head (6) arranged between the extruder outlet (5.1, 5.2, 5.3) of the at least one extruder (2, 2.1, 2.2, 2.3) and the outlet nozzle (8) of the injection mould (7), with at least one perforated plate (12.1, 12.2, 12.3) arranged in the extrusion head (6), which has passage openings (18), wherein the passage openings (18) are designed to dam up an extrusion material conveyed from the at least one extruder (2, 2.1, 2.2, 2.3) through the passage openings (18) of the perforated plate (12.1, 12.2, 12.3) differently in at least one first region (B1) of the perforated plate (12.1, 12.2, 12.3) and at least one second region (B2) of the perforated plate (12.1, 12.2, 12.3), in such a way that the extrusion material is partly diverted from its preferential direction within a central section of the perforated plate (12.1, 12.2, 12.3), specifically increasingly into at least one edge section of the perforated plate (12.1, 12.2, 12.3), wherein the perforated plate (12.1, 12.2, 12.3) has a substantially rectangular basic shape, wherein an upper edge (K1) co-determining the height of the perforated plate (12.1, 12.2, 12.3) is configured to be straight, a lower edge (K2) co-determining the height of the perforated plate (12.1, 12.2, 12.3) is configured to be straight, and the two lateral edges (K3, K4), which determine the width of the perforated plate (12.1, 12.2, 12.3) are configured respectively to be semi-circular, wherein the cross-sectional contour of the extrudate has a maximum width which is greater than the maximum height of the cross-sectional contour of the extrudate, and the perforated plate (12.1, 12.2, 12.3) in a central section of the width has the first region (B1), which has the several first passage openings (18.1), and the perforated plate (12.1, 12.2, 12.3) in the two opposite edge sections of the width, which border the central section, has respectively a second region (B2), which have the several second passage openings (18.2).

2. The extrusion device according to claim 1, wherein the perforated plate (12.1, 12.2, 12.3) is designed to divert the extrusion material into two opposite edge sections at a central section of the flow channel, into a width of the flow channel and/or into a width of the outlet nozzle (8) of the injection mould (7), which exceeds an extruder diameter of the at least one extruder (2, 2.1, 2.2, 2.3) associated with the flow channel.

3. The extrusion device according to claim 1, wherein through the passage openings (18) of the perforated plate (12.1, 12.2, 12.3) within the at least one first region (B1) a plurality of first dam channels are formed, which with regard to their channel lengths and/or with regard to their channel cross-sectional areas are coordinated with one another in such a way that they have a greater flow resistance than second dam channels of the at least one second region (B2), and within the at least one second region (B2) a plurality of the second dam channels are formed through the passage openings (18), which with regard to their channel lengths and/or with regard to their channel cross-sectional areas are coordinated with one another in such a way that they have a smaller flow resistance than the first dam channels of the at least one first region (B1).

4. The extrusion device according to claim 1, the at least one first region (B1) has several first passage openings (18.1), which in relation to the area of the first region (B1) in total have a shared first relative passage cross-sectional area and the at least one second region (B2; B3) has several second passage openings (18.2, 18.3), which in relation to the area of the second region (B2, B3) in total have a shared second relative passage cross-sectional area, which is greater compared to the first relative passage cross-sectional area.

5. The extrusion device according to claim 4, wherein the several first passage openings (18.1) and the several second passage openings (18.2) with their individual cross-sections all have the same geometric shape, wherein each of the first passage openings (18.1) is configured smaller in the size of the shape than the size of the shape of each second passage opening (18.2).

6. The extrusion device according to claim 4, wherein the several first passage openings (18.1) are respectively circular in cross-section with a first diameter (D1) and the several second passage openings (18.2) are respectively circular in cross-section with a second diameter (D2), wherein the second diameters (D2) of the second passage openings (18.2) are greater than the first diameters (D1) of the first passage openings (18.1).

7. (canceled)

8. The extrusion device according claim 1, wherein the cross-sectional contour of the extrudate has a maximum width which is greater than the maximum height of the cross-sectional contour of the extrudate and the perforated plate (12.1, 12.2, 12.3) in all vertical positions has first passage openings (18.1) of equal size and/or second passage openings (18.2) of equal size.

9. (canceled)

10. The extrusion device according to claim 1, wherein the several first passage openings (18.1) and the several second passage openings (18.2) are distributed substantially uniformly over the perforated plate (12.1, 12.2, 12.3).

11. The extrusion device according to claim 1, wherein the at least one perforated plate (12.1, 12.2, 12.3) has a seat which is designed for supporting a screen.

12. The extrusion device according to claim 1, wherein the extrusion head (6) has a first head half (6.1), which has two or more inlet openings (9.1, 9.2, 9.3) to which respectively an extruder outlet (5.1, 5.2, 5.3) of an associated extruder (2, 2.1, 2.2, 2.3) of two or more extruders (2, 2.1, 2.2, 2.3) is connected, and which first head half (6.1) has a number of through-openings (10.1, 10.2, 10.3) corresponding to the number of inlet openings (9.1, 9.2, 9.3), wherein each through-opening (10.1, 10.2, 10.3) has a seat (11.1, 11.2, 11.3) for a perforated plate (12.1, 12.2, 12.3), and that the extrusion head (6) has a second head half (6.2) which has a number of exit openings (13.1, 13.2, 13.3) corresponding to the number of through-openings (10.1, 10.2, 10.3) of the first head half (6.1), wherein each exit opening (13.1, 13.2, 13.3) has a seat (14.1, 14.2, 14.3) for one of the perforated plates (12.1, 12.2, 12.3), and which second head half (6.2) has at least one outlet opening (15) to which the injection mould (7) adjoins.

13. The extrusion device according to claim 10, wherein the first head half (6.1) has a first clamping flange (17.1) and the second head half (6.2) has a second clamping flange (17.2), wherein the first clamping flange (17.1) and the second clamping flange (17.2) are designed to hold the first head half (6.1) with the second head half (6.2) together in a pressure-resistant manner by means of a mounted clamping clip, when at least one perforated plate (12.1, 12.2, 12.3) is inserted between the first head half (6.1) and the second head half (6.2).

14. The extrusion device according to claim 10, wherein the first head half (6.1) and the second head half (6.2) are mounted adjustably with respect to one another, in such a way that the first head half (6.1) and the second head half (6.2) are movable separably from one another for inserting the at least one perforated plate (12.1, 12.2, 12.3) and/or for removing the at least one perforated plate (12.1, 12.2, 12.3).

Description

[0024] There are shown:

[0025] FIG. 1 a schematic illustration of an extrusion device with for example three extruders and three perforated plates,

[0026] FIG. 2 a sectional illustration of an exemplary extrusion head with a first head half and a second head half, and the three perforated plates,

[0027] FIG. 3 a perspective illustration of the first head half according to FIG. 2 in a top view on three inlet openings, to which the three extruders are to be connected,

[0028] FIG. 4 a schematic illustration of the first head half according to FIG. 2 in a top view onto the rear side of the first head half, facing away from the three inlet openings, on which rear side three corresponding through-openings are arranged, with seats for the perforated plates,

[0029] FIG. 5 a perspective illustration of the second head half according to FIG. 2 in a top view onto three corresponding exit openings with seats for the perforated plates,

[0030] FIG. 6 a schematic illustration of the second head half according to FIG. 2 in a top view onto the rear side of the second head half, facing away from the three exit openings, on which outlet openings are arranged, to which the injection mould adjoins, and

[0031] FIG. 7 a perspective schematic illustration of a representative example of a perforated plate according to the invention.

[0032] In FIG. 1 an exemplary extrusion device 1 is shown. The extrusion device 1 has at least one extruder 2, in the case of the present example embodiment three extruders 2.1, 2.2, 2.3, each of which is provided with a screw cylinder 3.1, 3.2, 3.3, a screw shaft 4.1, 4.2, 4.3, rotatably supported in the screw cylinder 3.1, 3.2, 3.3, and an extruder outlet 5.1., 5.2, 5.3. The three extruders 2.1, 2.2, 2.3 or respectively their extruder outlets 5.1, 5.2, 5.3 are connected at the input side to an extrusion head 6. The extrusion head 6 comprises a first head half 6.1 and a second head half 6.2.

[0033] The extrusion device 1 comprises in addition an injection mould 7 with an outlet nozzle 8 (FIG. 2) determining the cross-sectional contour of the extrudate. The extrusion head 6 is arranged between the extruder outlets 5.1, 5.2, 5.3 and the outlet nozzle 8 of the injection mould 7.

[0034] As can be seen in particular in FIG. 1 and FIG. 2, the extrusion head 6 has the first head half 6.1, which has two or more, in the case of the present example embodiment three inlet openings 9.1, 9.2, 9.3, to which respectively one of the extruder outlets 5.1, 5.2, 5.3 is connected. Accordingly, the first head half 6.1 has a number of through-openings 10.1, 10.2, 10.3 corresponding to the number of inlet openings 9.1, 9.2, 9.3. Each through-opening 10.1, 10.2, 10.3 has a seat 11.1, 11.2, 11.3 for a perforated plate 12.1, 12.2, 12.3.

[0035] The extrusion head 6 has in addition the second head half 6.2, which has a number of exit openings 13.1, 13.2, 13.3 corresponding to the number of through-openings 10.1, 10.2, 10.3 of the first head half 6.1, wherein each exit opening 13.1, 13.2, 13.3 has a seat 14.1, 14.2, 14.3 for one of the perforated plates 12.1, 12.2, 12.3. The second head half 6.2 has in addition at least one outlet opening 15, to which the injection mould 7 adjoins. Accordingly, the second head half 6.2 has a mount 16, which is configured to receive the injection mould 7 in a form-fitting manner.

[0036] The first head half 6.1 can have a first clamping flange 17.1 and the second head half 6.2 can have a second clamping flange 17.2, wherein the first clamping flange 17.1 and the second clamping flange 17.2 are designed to hold the first head half 6.1 with the second head half 6.2 together in a pressure-resistant manner by means of a mounted clamping clip (not illustrated), when at least one perforated plate 12.1, 12.2, 12.3 is inserted between the first head half 6.1 and the second head half 6.2.

[0037] The first head half 6.1 and the second head half 6.2 can be mounted adjustably with respect to one another, as indicated by the arrows P, in such a way that the first head half 6.1 and the second head half 6.2 are movable separably from one another for the inserting of the at least one perforated plate 12.1, 12.2, 12.3 and/or for removing the at least one perforated plate 12.1, 12.2, 12.3.

[0038] The first head half 6.1 is illustrated in FIG. 3 in a top view onto the three inlet openings 9.1, 9.2, 9.3, to which the three extruders 2.1, 2.2, 2.3 are to be connected.

[0039] The first head half 6.1 is illustrated in FIG. 4 in a top view onto the rear side of the first head half 6.1 facing away from the three inlet openings 9.1, 9.2, 9.3, on which rear side the three corresponding through-openings 10.1, 10.2, 10.3 are arranged, with the seats 11.1, 11.2, 11.3 for the perforated plates 12.1, 12.2, 12.3.

[0040] The second head half 6.2 is illustrated in FIG. 5 in a top view onto the three corresponding exit openings 13.1, 13.2, 13.3 with the seats 14.1, 14.2, 14.3 for the perforated plates 12.1, 12.2 12.3.

[0041] The second head half 6.2 is illustrated in FIG. 6 in a top view onto the rear side of the second head half 6.2, facing away from the three exit openings 13.1, 13.2, 13.3, on which rear side outlet openings 15 are arranged, to which the injection mould 7 adjoins.

[0042] In FIG. 7 a representative perforated plate 12.1, 12.2, 12.3 is shown in isolation. The perforated plate 12.1, 12.2, 12.3 comprises a plurality of passage openings 18.

[0043] In the case of the present example embodiment, the perforated plate 12.1, 12.2, 12.3 has a first region B1 which has several first passage openings 18.1, which in relation to the area of the first region B1 in total have a shared first relative passage cross-sectional area. The perforated plate 12.1, 12.2, 12.3 has in addition a second region B2 which comprises several second passage openings 18.2, which in relation to the area of the second region B2 in total have a shared second relative passage cross-sectional area which is greater compared to the first relative passage cross-sectional area. Furthermore, the perforated plate 12.1, 12.2, 12.3 in the case of the present example embodiment has a third region B3 which comprises several third passage openings 18.3, which in relation to the area of the second region B2 and of the first region B1 in total have a shared third relative passage cross-sectional area, which is greater compared to the first relative passage cross-sectional area and to the second relative passage cross-sectional area.

[0044] The several first passage openings 18.1 are respectively configured circular in cross-section with a first diameter D1, the several second passage openings 18.2 are respectively configured circular in cross-section with a second diameter D2, and the several third passage openings 18.3 are respectively configured circular in cross-section with a third diameter D3, wherein the second diameters D2 of the second passage openings 18.2 are greater than the first diameters D1 of the first passage openings 18.1, and wherein the third diameters D3 of the third passage openings 18.3 are greater than the second diameters D2 of the second passage openings 18.2.

[0045] In particular when the cross-sectional contour of the extrudate has a maximum width which is greater than the maximum height of the cross-sectional contour of the extrudate, the perforated plate 12.1, 12.2, 12.3, as illustrated in FIG. 7, can have in a central section of the width the first region B1, which has the several first passage openings 18.1, and the perforated plate 12.1, 12.2, 12.3 in the two opposite edge sections of the width, which border the central section, can respectively have a second region B2, which have the several second passage openings 18.2, and additionally at the edge regions of the region B2 have the further third passage openings 18.3. Here, the perforated plate 12.1, 12.2, 12.3, as illustrated in FIG. 7, can have in all vertical positions respectively first passage openings 18.1 of equal size, and second passage openings 18.2 of equal side, and third passage openings 18.3 of equal size.

[0046] The perforated plate 12.1, 12.2, 12.3 in the case of the present example embodiment has a substantially rectangular basic shape, wherein an upper edge K1, co-determining the height of the perforated plate 12.1, 12.2, 12.3 is configured to be straight, a lower edge K2 co-determining the height of the perforated plate 12.1, 12.2, 12.3 is configured to be straight, and the two lateral edges K3, K4, which determine the width of the perforated plate 12.1, 12.2, 12.3 are respectively configured to be semi-circular.

LIST OF REFERENCE NUMBERS

[0047] 1 extrusion device [0048] 2, 2.1, 2.2, 2.3 extruder [0049] 3.1, 3.2, 3.3 screw cylinder [0050] 4.1, 4.2, 4.3 screw shaft [0051] 5.1, 5.2, 5.3 extruder outlet [0052] 6 extrusion head [0053] 6.1 first head half [0054] 6.2 second head half [0055] 7 injection mould [0056] 8 outlet nozzle [0057] 9.1, 9.2, 9.3 inlet openings [0058] 10.1, 10.2, 10.3 through-openings [0059] 11.1, 11.2, 11.3 seat [0060] 12.1, 12.2, 12.3 perforated plate [0061] 13.1, 13.2, 13.3 exit openings [0062] 14.1, 14.2, 14.3 seat [0063] 15 outlet opening [0064] 16 mount [0065] 17.1 first clamping flange [0066] 17.2 second clamping flange [0067] 18 passage openings [0068] B1 first region [0069] B2 second region [0070] B3 third region [0071] 18.1 first passage openings [0072] 18.2 second passage openings [0073] 18.3 third passage openings [0074] D1 first diameters [0075] D2 second diameters [0076] D3 third diameters [0077] K1 upper edge [0078] K2 lower edge [0079] K3, K4 lateral edges