No abstract

No abstract

No abstract

The viscosity of polymer melts is an important parameter for many applications. Several possibilities can be used to determine the viscosity parameters, but most of them are suitable for laboratory use only. A fast information about the viscosity parameters is necessary to ensure the quality in high volume productions of polymers, blends and compounds. In this case all of the laboratory methods are not qualified due to their feedback time. To address this problem a real-time determination of the viscosity parameters can be established using a soft sensor. Our work is focused on the development of a robust soft sensor based on models designed with artificial neural networks. In order to simulate slight material variations e.g. caused by batch changes we have manipulated the material properties by adding small amounts of material with a slightly altered molecular structure. This offers the possibility to observe the influence of batch changes on the modeling which reflects the quality of the soft sensor. Using representative data for modeling the prediction quality in slightly changing systems can be improved. Moreover, also the quality and usability of the soft sensors can be enhanced.

Abstract. The inline determination of process and product parameters is of great help for the evaluation and optimization of new procedures. Therefore, an ultrasound process tomography system has been developed, which enables the imaging of the local filler distribution in plastic melts. The objects investigated were extruded rods made of polypropylene (PP) with radial filler gradients. During extrusion, sound velocity and attenuation of the plastic melt were determined and processed via a modified reconstruction algorithm according to Radon transform into 2-D sectional images. Despite the challenges of higher attenuation and impedance mismatch of 60 mm filled PP melt compared to water, the resulting images are of good quality. An important factor for the image quality after tomographic reconstruction is the opening angle of the used ultrasound transducers. Furthermore, a simulation environment was developed in Matlab, which serves as a testing platform for the measurement system.