The invention relates to a device for treating plastics material, in particular thermoplastic plastics material, having a receiving container, which has a base and lateral walls, and having tools, which are arranged in the receiving container and which are carried by a shaft which passes through the base of the receiving container in a sealed manner and which is driven by a motor so as to rotate about its axis, at least one tool being fastened on a tool carrier, designed in the form of a disc, on the top face of the disc, the disc being situated close to the base of the receiving container so that the plastics material present in the receiving container is set in a circulating movement about the axis of the shaft.
Devices of this type are known (e.g. AT 375 867 B, AT 407 970 B or WO 93/18902). On account of the rotating tool carriers or tools, the plastics material being treated is flung by the action of centrifugal force against the lateral wall of the container. A portion of this plastics material rises along the lateral wall of the container and circulates in the form of a mixing cone, but eventually drops back into the centre of the container again. This results in the desired dwell period of the treated particles of plastics material in the receiving container, so that the plastics material introduced into it is thoroughly mixed, is sufficiently heated by the frictional forces which occur, and, in the case of tools which have a comminuting effect upon the plastics material, is also sufficiently comminuted. It has been found, however, that the plastics material flung towards the lateral wall of the container does not all rise up on the said wall, but a portion goes down below the lowest tool or below the lowest disc forming a tool carrier. There this portion of plastics material can become fused on in an uncontrolled manner as a result of friction. Attempts have been made to avoid this drawback by the attachment of conveying ribs on the underside of the said disc, but this step is not entirely satisfactory.
The object of the invention is to avoid with little outlay the drawback described, so as thereby not only to reduce the susceptibility of the device to breakdown, but also to treat in a more uniform manner all the plastics material introduced into the receiving container, since the residue of plastics material in the region of the container base, i.e. below the lowest tool, is effectively counteracted. This object is attained according to the invention in that the disc carries, in addition to the tools, at least one blade which projects beyond the edge of the disc in the direction towards the lateral wall of the receiving container and is inclined with respect to the horizontal plane in such a way that the plastics material flung off from the disc by the tools is given an upwardly directed movement component during its circulation. Irrespectively of whether the circulation of the plastics material is now carried out only by the tools or, in addition, by tool carriers carrying the latter (individual tools or tool carriers could be formed by rods alone which project outwards from the shaft in the horizontal direction), the moved plastics material is deflected upwards by way of the blades, and this effectively prevents the material from dropping down. This effect can be utilized not only to prevent, to the greatest possible extent, the treated plastics material from dropping below the lowest tool carrier formed by the disc, but also in order that plastics material which has dropped down may be immediately returned to the revolving mixing cone again and is not fused on below the lowest tool carrier with friction during a prolonged dwell period in an uncontrolled manner. If a plurality of tool carriers are arranged one above the other in a plurality of planes, then the blades in the upper tool carriers result in a displacement of the circulating plastics material upwards and thus in a prolongation of the dwell period.
In accordance with a preferred embodiment of the invention, the blade also projects upwards and below beyond the disc, in order to make as large as possible the active area acting upon the plastics material.
Since, as already mentioned, discs arranged in the base region of the receiving container and forming [the] tool carriers are known, within the scope of the invention it is possible for already existing plants of this type to be re-fitted without difficulty.
Further characterizing features and advantages of the invention may be seen in the description of embodiments which are illustrated diagrammatically in the drawing.
The device as shown in
The receiving container 1 has vertical lateral walls 14 and a horizontal base 15. A tool carrier 16, which is formed by a horizontal circular disc 17 (see
In the horizontal projection (
The said blades 26 impart a preferred movement upwards to the plastics material flung off from the disc 17 by the tools 22 and thus effectively prevent portions of plastics material from being able to enter the space 25 below the disc 17 of the tool carrier 16 during the treatment of the material in the container 1. This can be assisted by ribs 37 which are arranged on the bottom face 36 of the disc 17 and which are arranged in such a way, radially for example, that the plastics material present in the space 25 is conveyed in the direction towards the lateral wall 14. The plastics material moved outwards in this way is then engaged by the blades 26 and is conveyed upwards again.
An increase in the energy introduced into the plastics material present in the container 1 during the rotation of the tool carrier 16 can be achieved in that guide faces in the form of guide blades 38 (
In order to be able to adapt to different conditions, it is advantageous for at least one of the guide blades 38 to be made adjustable. This could be carried out by changing the active area of the guide blades 38, for example by insertion into the container to different degrees. What is structurally more advantageous is an adjustment of the angle of inclination of the guide blades 38 by means of a shaft 41 (
As a rule, it is advisable to monitor the temperature of the plastics material present in the receiving container 1, in order to keep its heating to the desired level or to control it in a suitable manner. To this end it is possible for at least one temperature probe 49 to be provided in the receiving container 1, the temperature probe 49 being advantageously arranged on the inner face of the lateral wall 14 and in a vertical region in which the mixing cone 23 is present. One or more of the said temperature probes 49 can be used to control the adjustment device 50 for at least one of the guide blades 38, and this is indicated by a line 51 in
As shown in the drawing, each blade 26 projects in the radial direction beyond the periphery of the disc 17 of the tool carrier 16. In addition, the blade also extends upwards and downwards beyond the top face 21 or the bottom face 36 of the disc 17, in order to increase the active area of each blade 26. The plate 27 of each blade 26 can be provided with a slot 55 in which the edge of the disc 17 engages. It is also possible, however, for the arrangement to be reversed, i.e. an arrangement with the slot in the disc 17, in which case the non-slotted plate 27 then engages in the said slot. This connexion can be secured by welding or in some other suitable manner. In many cases, however, it will be advisable for the plate 27 to be fastening to the disc 17 by screwing.
The plate 27 of each blade 26 need not be flat, and it would be possible for the plate 27 to be curved slightly, the concave side being arranged on the leading side of the plate. Such a curvature could have the effect that the particles of plastics material slide for a brief time on the plate 27 before they are deflected upwards. This would result in a gentle acceleration and treatment of the particles of plastics material.
It may be seen in
The above-mentioned arrangements of the blades 26 can also be made in designs in which a plurality of tool carriers 16 are arranged one above the other, in which case it is not necessary for all the tool carriers to be constructed in the form of discs and to be provided with blades, but only the tool carrier 16 situated closest to the base 15 of the container.
It would also be possible for the blades 26 to be provided, not on the disc-shaped tool carrier 16, but directly on the tools 22.
As a rule, the plastics material to be treated is introduced already comminuted beforehand into the receiving container 1. If comminution in the container 1 is necessary, the tools 22 can be formed accordingly, for example as cutters with cutting edges 57 (
Number | Date | Country | Kind |
---|---|---|---|
A 878/2002 | Jun 2002 | AT | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/AT03/00158 | 5/3/2003 | WO | 00 | 11/1/2004 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO03/103916 | 12/18/2003 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
2424679 | Cowles | Jul 1947 | A |
2665853 | Nicholson | Jan 1954 | A |
3155376 | Mollenbruck | Nov 1964 | A |
3638917 | Osten | Feb 1972 | A |
4222728 | Bacher et al. | Sep 1980 | A |
4460277 | Schulz et al. | Jul 1984 | A |
4548765 | Hultholm et al. | Oct 1985 | A |
4894001 | Petschner | Jan 1990 | A |
4979986 | Hill et al. | Dec 1990 | A |
5078505 | Nyman et al. | Jan 1992 | A |
5102326 | Bacher et al. | Apr 1992 | A |
5110055 | Teeny | May 1992 | A |
5240327 | Nyman et al. | Aug 1993 | A |
5409313 | Funk | Apr 1995 | A |
5783225 | Bacher et al. | Jul 1998 | A |
5947599 | Funk | Sep 1999 | A |
5988865 | Bacher et al. | Nov 1999 | A |
6619575 | Bacher et al. | Sep 2003 | B1 |
6719454 | Bacher et al. | Apr 2004 | B1 |
6883953 | Bacher et al. | Apr 2005 | B1 |
7070174 | Hultholm et al. | Jul 2006 | B2 |
7137802 | Bacher et al. | Nov 2006 | B2 |
20040202744 | Bacher et al. | Oct 2004 | A1 |
20050170029 | Bacher et al. | Aug 2005 | A1 |
20050287237 | Bacher et al. | Dec 2005 | A1 |
20060093696 | Bacher et al. | May 2006 | A1 |
Number | Date | Country |
---|---|---|
1144693 | Mar 1963 | DE |
2814958 | Nov 1978 | DE |
WO9318902 | Sep 1993 | WO |
WO 3103916 | Dec 2003 | WO |
Number | Date | Country | |
---|---|---|---|
20050170029 A1 | Aug 2005 | US |