Multistage Extrusion Line
Design Features/Advantages
- Individual pressure depending regulation of screw speed for constant material output separately for each extruder
- Automatic line speed control depending on profile dimensions and continuous weight
- Special control data filters for individual recognition and separation of different disturbance variables
- Different control activities and feed back for compensation of product variations depending on variations of compound properties or feeding deviations
- Reduction of dimensional and continuous weight variations
- Improvement of product quality and process capability
- Constant component distribution in multi-component extrusion profiles
- Improvement of productivity by long time profile constancy even during emptying process
To fulfill these requirements when extruding tire components such as treads, sidewalls, etc., not only the characteristic features of the production line must be taken into account. To a considerable extent, the quality of the extruded profiles is determined by the characteristics of the processed rubber compounds, upon which suppliers normally have little influence.
Considerable effects on dimensions and continuous weight of the extruded profile must be taken into account due to permanent variations in process characteristics, especially when processing rubber compounds with large content of natural rubber. The same is true of irregularities in material feeding e.g. to irregular slab dimensions or other faults related to material feeding.
Harburg-Freudenberger has developed a multistage control system for multi-component extrusion lines which compensates the lack of uniformity in material feeding and process characteristics resulting from irregularities in the quality characteristics of the extruded material and which increases the product quality and the process capability of entire extrusion lines.
Comparable influence on extrusion parameters with / without pressure control
