METHOD AND DEVICE FOR PRODUCING PROFILED PLASTIC SECTIONS

Abstract

The invention relates to a method for producing profiled plastic sections in an extrusion line consisting of multiple tools, wherein a starting material is plasticized and molded in an extruder and then cooled and calibrated in at least one drying calibration unit and at least one calibration tank. The material is then divided into individual profiled sections. The quality of the profiled sections is improved in that a central control unit is provided which is connected to the tools and obtains data from the tools for uniquely identifying the tool and data on the state of the tool and transmits back adjustment data for said tool and other tools.

Claims

1. A method for producing plastic profiles in an extrusion line consisting of a plurality of tools, the method comprising; plasticizing and forming a starting material in an extruder; cooling and calibrating the starting material in at least one dry calibration unit and at least one calibration tank; subdividing the starting material into individual plastic profiles; communicatively coupling a central control unit to the plurality of tools; receiving at the central control unit is data from the plurality of tools to uniquely identify the tool and data on the state of the plurality of tools; and adjusting the plurality of tools based on transmitted adjustment data from the central control unit.

2. The method according to claim 1, characterized in that the control device has a database in which a plurality of adjustment data are stored, and that this database is used in determining the adjustment data transmitted to the plurality of tools.

3. The method according to claim 2, characterized in that an extrusion model is produced from the data stored in the database, and the extrusion model is used for determining the adjustment data transmitted to the plurality of tools.

4. The method according to claim 1, characterized in that the adjustment data is output to the plurality of tools in the form of correction values.

5. The method according to claim 4, characterized in that a correction value relates to the extrusion speed.

6. The method according to claim 4, characterized in that a correction value relates to selective cooling of portions of a cross-section of the profile in a region of extrusion die.

7. The method according to claim 4, characterized in that a correction value relates to the control of a cooling water flow in at least a section of a calibration tank.

8. A system for producing plastic profiles in an extrusion line comprising: an extruder; a calibration table; a plurality of tools including, at least one dry calibration unit and at least one calibration tank, both the at least one dry calibration unit and the at least one calibration tank are positioned downstream of the extruder and are arranged on the calibration table; and a control unit communicatively connected to the plurality of tools.

9. The system of claim 8, characterized in that at least one of the plurality of tools is connected to the calibration table (2) via direct connections.

10. The system of claim 9, characterized in that the direct connection between the at least one of the plurality of tools and the calibration table includes both a supply with water and with vacuum as well as data communication.

11. The system of claim 9, characterized in that the at least one dry calibration unit includes a support surface with standardized connections corresponding to associated connections on the calibration table.

12. The system of claim 9, characterized in that the at least one calibration table has a detection device configured and arranged for detecting unused connections.

13. The system of claim 9, characterized in that the at least one dry calibration unit includes a plurality of water circuits separated from one another.

14. The system of claim 13, characterized in that the plurality of water circuits are configured and arranged to regulate the water to different temperatures.

15. The system of claim 13, wherein the calibration table further includes a cooling device configured and arranged to provide water with particularly low temperatures for at least one of the plurality of water circuits.

16. The system of claim 9, characterized in that the at least one calibration tank on the calibration table is configured and arranged to move in a longitudinal direction.

17. The system of claim 9, characterized in that the at least one calibration tank has a support surface with standardized connections which correspond to associated connections on the calibration table.

Description

[0022] In the following, the present invention will be explained in more detail on the basis of the embodiment variants depicted in the figures, wherein:

[0023] FIG. 1 schematically shows an extrusion line according to the invention;

[0024] FIG. 2 shows a detail of a calibration table including a dry calibration unit in an oblique view;

[0025] FIG. 3 shows a detail of an extrusion die;

[0026] FIG. 4 shows a front view of a dry calibration unit;

[0027] FIG. 5 shows a front view of an extrusion die;

[0028] FIG. 6 schematically shows a cooling unit installed in the calibration table; and

[0029] FIG. 7 schematically shows the water guidance in the calibration table and the calibration tools.

[0030] The extrusion line of FIG. 1 consists of an extruder 1 with an extrusion die 1a, a calibration table 2 arranged downstream thereof, on which several dry calibration units 3 and several calibration tanks 4 (the calibration tools) are arranged to cool and calibrate the plastic profile 100 ejected from the extruder 1.

[0031] The calibration tanks 4 can be moved longitudinally on the calibration table 2 to allow quick adaptation to a different number of dry calibration units 3, as it is desirable that the calibration tanks 4 adjoin the dry calibration units 3 directly.

[0032] Subsequently, the plastic profile 100 is fed into a caterpillar pull-off 5, which provides the necessary tensile forces to pull the plastic profile 100 through the calibration tools. In a measuring station 6, the plastic profile 100 is measured and then cut in a saw 7 to plastic profiles 101, which are deposited on a tilting table 8.

[0033] The extrusion line is controlled by a control unit 10, which is connected to the individual components of the extrusion line via control lines 11, 12. Schematically, a scale 13 is indicated in the tilting table 8, which determines the weight of each plastic profile 101 and transmits it to the control unit 10.

[0034] In the same way, the data about the profile geometry and the like are output from the measuring station 6 to the control unit 10. With reference numeral 15, the nature of this data is indicated, namely geometric measurements, color, gloss and scratches. In addition, all relevant data of the other components are transmitted in a manner not described here, such as the pull-off force applied by the caterpillar pull-off 5, measured values of pressure and temperature from the calibration tools and the like, and above all identification data with which each tool can be uniquely identified.

[0035] During operation of the extrusion line, the control unit 10 not only accepts data and issues control commands in order to optimally manage the extrusion process, but also records them in a database in order to gain empirical values for subsequent extrusion processes.

[0036] FIG. 2 shows that the dry calibration units 3a, 3b can be easily mounted on the calibration table 2, since only a mechanical connection via quick-release fasteners 16 has to be established. All connections are provided on the contact surface on the underside of the dry calibration units 3a, 3b, which is not visible here. They interact with connections at the mounting positions of the calibration table 2 that are also not visible here. Therefore, no hoses are required to connect the calibration tools 3a, 3b, 4 to the calibration table 2, which minimizes the risk of mix-ups or errors.

[0037] It is also possible within the scope of the invention to continue to use existing calibration tools in an extrusion line designed in accordance with the invention. A base plate is firmly attached to the underside of these tools, which has the necessary connections on its underside and connects laterally to other connections via internal connecting lines. These additional connections are then connected via connecting hoses to the typically side-mounted connections of conventional calibration tools. The original tool then forms a unit with the base plate and the connecting hoses, which is also no longer separated during dismantling and assembly of the tool. For the purposes of this invention, this unit is regarded as a calibration tool. Again, there is no danger of mix-ups, as there is no further manipulation of the connecting hoses after the initial installation.

[0038] FIG. 3 shows a quick-change system for the extrusion die 1a, which can be folded away sideways. Quick-release fasteners combined with preheating of the extrusion die 1a allow an extremely short cycle time of less than 10 minutes when changing the extrusion die 1a.

[0039] FIG. 4 shows the end face of a dry calibration unit 3, wherein a die plate 18a, 18b is magnetically fixed on both sides of the opening 19, through which the plastic profile 100 passes. Several dies not visible here can be supplied with compressed air via connections 20 in order to selectively cool the plastic profile 100 entering the opening 19. The air volume is measured to create reproducible conditions. In this way, the wall thickness can be individually adjusted to the outer areas of the plastic profile 100, and the weight of the manufactured plastic profile can be precisely regulated (meter weight).

[0040] A similar solution is shown in FIG. 4, in which eight die plates 21a, 21b, 21c, 21d, 21e, 21f, 21g and 21h are also mounted magnetically on the face of an extruder die 1a. The die plates 21a and 21e are aimed at the visible surfaces of the plastic profile 100, while the die plates 21b, 21c, 21d, 21f and 21h are aimed at extremities, which are always a challenge in extrusion processes.

[0041] FIG. 6 shows a cooling device arranged in calibration table 2, which cools the general cooling water, which is made available to the extrusion line from the outside, to a lower temperature of 5 C. to 8 C., for example. A distributor 23 is supplied via a flow line 24 and a return line 25, which are used to supply special cooling circuits in the calibration tools.

[0042] FIG. 7 shows the general cooling water guidance for the dry calibration units 3a, 3b. The distributor 23 is supplied with general cooling water through a supply line 29 via a water tank 26. In addition, the cooling unit 22 supplies low-temperature water as shown above.

[0043] General cooling water at a first pressure level is fed to certain circuits in the dry calibration units 3a, 3b via a first supply line 26a with a small cross-section. A second supply line 26b with a small cross-section leads cooling water of low temperature to further circuits. General cooling water at a further pressure level is supplied via a third supply line 26c with a large cross section. Return lines 27, 28 return the used cooling water.