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Prepreg is the common term for a reinforcing fiber (fabric) which has been pre-impregnated with a resin system. This resin system (typically epoxy) already includes the proper curing agent. As a result, the prepreg is ready for composite parts. They provide great benefit in processing as the resin content is highly controlled, and the application is generally very clean, requiring little to no cleanup, unlike more commonly known "wet-layups". In manufacturing fiber-reinforced-plastic composite components, the use of prepregs reduces the work involved and provides stronger, stiffer and more reliable parts than equivalent components produced by wet lay-up processes like what is Filament winding technology. But these advantages will only be realized when prepregs with consistent properties are used. Prepregs consist of a layer of fiber or cloth impregnated with a partial mixture of monomers or oligomers, either in a solvent (solvent- type prepreg) or as a solvent-free medium (hot-melt type). In the case of a solvent-type prepreg, the impregnated reinforcement (prepreg) usually passes through a heating oven to decrease the solvent content. In this paper will be study the technological process of these impregnation for the production of unidirectional (UD) prepreg by a solvent procedure. This semi product as a UD tape will finds great application in advanced technological processes for the production of parts of aircraft or in the space industry by using automatic tape placement (ATP) machines. Because these materials are used in modern and automated composite machines, they should have excellent production properties. Therefore, in this paper, great attention will be paid to the technological parameters in the impregnation process that affect the final characteristics of UD prepregs. The width of UD prepreg is obtained as a function of the impregnation velocity, tensile of fiber, gap of rollers. Also and the heating length is also derived to give a possible combination of impregnation velocity and heating length to obtain a specific volatile content. This paper presents an experimental study of the impregnation of continuous glass fiber with thermosetting resin matrix materials. Results are obtained methodically through the separation of variables. It is found that the more technologies parameters are important in impregnation process. The model is valid for predicting width or surface weight (gr/m2) and % volatile content in the practical impregnation process for UD prepreg. |
