# Berechnungsmodell für Temperaturerhöhungen während der Einspritzphase im Kautschukspritzguss

Translated title of the contribution: Mathematical model for the determination of temperature rises during the injection phase of rubber injection moulding

Michael Fasching

Research output: ThesisMaster's Thesis

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## Abstract

During the processing of rubber materials through injection moulding, the curing time, which is necessary for crosslinking, represents the largest portion of the complete cycle time. Within the FFG-Bridge-project "Heizzeitverkürzung", which this thesis is part of, dissipation heat is created through the injection process in using suitable die geometries. The focus of this thesis is put on the physical basics of heat creation. A model to calculate the increase of the temperature was developed and realized as Visual Basic programme. Thereby, material data viscosity, specific heat capacity, heat conductivity and density are used as well as the geometry of the die and process parameters (temperature of die, volume rate and material). Additionally, the heat exchange with the die through heat conduction as well as vortices, which do not contribute to the volumetric flow, are taken into account in the calculation. Afterwards, the calculated rise of the temperature was validated in practical experiments on a rubber injection moulding machine. Thereby, two rubber materials without crosslinking agent (SBR and EPDM) were analysed with 6 different die geometries. The results showed that with increasing volumetric flow rates, larger temperature rises could be achieved through higher shear rates. Furthermore, a lower starting temperature leads to a greater temperature rise due to the higher viscosity at lower temperatures.
Translated title of the contribution Mathematical model for the determination of temperature rises during the injection phase of rubber injection moulding German Dipl.-Ing. Friesenbichler, Walter, Supervisor (internal)Perko, Leonhard, Co-Supervisor (internal) 30 Mar 2012 Published - 2012

### Bibliographical note

embargoed until 26-03-2017

## Keywords

• rubber
• elastomer
• injection moulding
• shear dissipation
• curing time
• curing time reduction