In-line control of the extrusion process using a new measurement system for pellet moisture content of < 0.05%

Project background

The project focuses on the development of an innovative microwave resonance measurement system for the precise online measurement of very low residual moisture levels in plastic pellets during the injection molding process. Even the slightest deviations in moisture content can lead to quality defects, scrap, and increased resource consumption. The goal is therefore to continuously and directly monitor granule moisture content during the production process to enable stable and resource-efficient manufacturing. The project thus addresses a critical need in the plastics processing industry for fast, precise, and cost-effective moisture measurement.

Project objective

As part of the project, a novel microwave measurement system is to be developed for the noncontact, in-line measurement of residual moisture levels below 0.05%. In addition, an interface between the moisture sensor and the injection molding machine will be created to enable automatic adjustment of process parameters during operation. The goal is to reduce scrap, improve part quality, and increase energy and resource efficiency in plastics processing.

Project procedure

The project is being carried out in collaboration between industry and research institutions. The first step involves developing and investigating highly sensitive resonators and suitable microwave techniques for measuring very low moisture content. Subsequently, relationships between granule moisture content, process parameters, and component quality will be experimentally investigated and statistically evaluated. Based on this, an automated process control system and a digital interface to the injection molding machine will be developed. Finally, the entire system will be tested, validated, and optimized under real-world conditions.

Innovation

The innovation of this project lies in the first-ever development of a microwave resonance measurement system for the non-destructive, inline measurement of extremely low residual moisture levels in plastic pellets. Furthermore, the relationships between granule moisture content, process parameters, and component quality are being systematically investigated for the first time and utilized for automatic process control. Successful implementation can significantly reduce scrap, material consumption, and energy consumption, while improving product quality and process stability. The technologies developed also offer potential for other industries, such as the pharmaceutical, electronics, and materials industries.