Abstract. The industrialization of the resin transfer molding process is a major objective in reducing production cost for FRPs thus making it more competitive for use in large scale applications. Normally, shorter cycle times run into the risk of quality inconsistencies. The creation of voids is influenced by various process parameters, such as mold temperature, resin flow rate and fiber volume content. With knowledge of the effects of these parameters on the process, a specific approach to reducing void content is made while reducing processing time. In order to achieve this objective, in particular, capillary forces and its influence on impregnation of the fiber bundle were examined. A DOE approach was chosen to lead to the determination of interactions. The results target at a pre-determination of required process parameter to obtain consistent part quality with reduced cycle time.

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Effects of aspect ratio and concentration on rheology of epoxyAbstract. The development of, in particular RTM, processes for fiber reinforced composite parts is driven by cost reduction that can be achieved by shorter cycle times. The main sub processes are the injection and the curing time of the resin. Both depend directly on resin properties. During the injection phase the viscosity of the resin is a main factor for the flow rate. Additionally, the wetting of fibers and within that the void formation is influenced. The cure of the resin is the most time intensive sub process. In this paper a new model for the description of the resin viscosity development during the injection phase using the cumulative Weibull distribution function is presented. A study of the isothermal viscosity development of numerous resins has been conducted in a wide temperature range ascertaining the applicability. New possibilities for advanced resin selection and a more accurate modeling of the void formation during an injection phase of the RTM process are shown to confirm the benefit of this model.

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