Entwicklung des Prototyps eines Systems zur Heizzeitverkürzung im Kautschukspritzguss

Research output: ThesisMaster's Thesis

Abstract

The curing time represents the biggest part of the whole cycle time during injection molding of rubber parts. This thesis deals with the reduction of the curing time by dissipative heating of the material during the injection phase. The increase of temperature during the injection phase is accomplished by the use of conical dies with different diameters and cone angels. Using these geometries, shear and strain dissipation should be created. Within the scope of this work practical experiments on a rubber injection moulding machine were performed. Rubber parts were injection moulded by means of five different conical dies and tested on their properties (compression set and hardness Shore A). Furthermore this thesis deals with the prediction of the curing time that is needed to produce a rubber part. Therefore a visual basic program for the calculation of the temperature and the state of cure over the thickness of a rubber part as function of time was developed. To verify the calculation isothermal and non isothermal measurements on a curemeter had been performed. The results were compared with the calculations of the program. The deviation was very small, indicating a good correlation between theory and experiments. Thus using the developed program a prognosis of the needed curing time of rubber part is possible. The experiments on a rubber injection moulding machine showed that the curing time is mainly influenced by the injection work. To shorten this time a high pressure loss is needed, which is built-up by a high injection speed and a small diameter of the die. Therefore a short curing time is only achieved by the combination of a narrow die geometry and a high injection speed.

Details

Translated title of the contributionDeveloping a prototype for cure time reduction in the rubber injection moulding process
Original languageGerman
QualificationDipl.-Ing.
Supervisors/Advisors
Award date13 Dec 2013
Publication statusPublished - 2013