Colloquia

Summary

For the production of passenger car tires, rubber strips produced on an extruder setup are sometimes used. To create those strips, rubber extrusion is used. A rubber extruder typically consists of four main components: the hopper, the barrel with the screw inside, the external gear pump and the head which contains the die. The gear pump used in this process introduces a pulsating flow resulting in a strip with oscillating dimensions. Strip dimension oscillations have a negative effect on the strip quality, stability and applicability. Therefore, the topic of this research is to reduce these oscillations in the strip dimensions.

By analyzing the process and doing research in the literature, three solution areas were defined. The first area is in the head of the extruder directly behind the gear pump. In this area, a dampener device could be added to dampen out the pulsation. The second area is inside the gear pump. Literature provides several solutions in which the internal geometry of the gear pump is modified to dampen out the pulsation. The third area is the drive of the gear pump. By varying the rotational speed of the gear pump, the pulsation effect could be reduced or removed. For these three areas, multiple concepts are created which are graded based on a Kesselring analysis.

After grading the concepts, one final concept is selected and worked out in detail. Detailed analytical calculations and simulations were done to in the end develop a functioning prototype. This prototype is tested to validate the design choices and assumptions that were done during the detailed design phase.