Validation of the Karrenberg/Wortberg Melting Model for Polyamide in Polymer Injection Molding

Description

Accurate simulation of the plasticizing process in injection molding is essential for a comprehensive understanding of the process and the development of optimized procedures. Modeling the melting mechanism plays a crucial role in improving plasticizing simulations accuracy. Originated in single-screw extrusion modeling, the Tadmor model is state-of-the-art for many polymer processing applications. However, the Karrenberg/Wortberg melting model, a recently developed approach, promises an improvement even in injection molding.
Previous studies have validated the Karrenberg/Wortberg model for high-density polyethylene using a high-speed-extruder. In this study, we assess its capability for an injection molding process, in detail, for a standard three-zone screw for polyamide. Therefore, the Karrenberg/Wortberg melting model is implemented in CFD-simulations and the results are compared to experimental data.
Both in ANSYS Fluent and in real experiments, a parametric design study is carried out, varying back pressure, circumferential screw velocity, and metering volume, as well as measuring the pressure and the melting profiles. The latter is obtained using ultrasonic sensors, while pressure data is acquired via in-barrel pressure sensors. Additional process parameters are recorded via the injection molding machine’s user interface.
The simulation model is validated by real melting performance, pressure build-up, and key process parameters such as drive power, torque, melt temperature, mass flow rate, and plasticizing time. Based on quality and model-stability of the results, an integration of the Karrenberg/Wortberg model into other simulation software tools will be discussed.

Period	16 Apr 2025
Event title	Polymers 2025: Polymers International Conference
Event type	Conference
Location	PortugalShow on map
Degree of Recognition	International