Effects of injection pressure and post-curing on the behavior of woven carbon fiber/epoxy composites produced by rtm (resin transfer molding)

Download
2002
Kaş, Yusuf Onur
RTM (Resin Transfer Molding) is a closed mold process in which matrix resin is injected into a mold filled with a fiber preform. There are many RTM process parameters influencing the quality of the final product. The objective of this work was to study two of these variables: resin injection pressure and post-curing conditions. For this purpose, an amine curing epoxy resin was injected, by using a small laboratory size RTM machine, into a flat mold filled with woven carbon fiber layers. Various combinations of resin injection pressure levels and post-cure conditions were applied. inIn order to evaluate the influences of these parameters, ultrasonic (C-scan) inspection, mechanical (flexural and impact) tests, and microscopic (optic and SEM) analysis were conducted on the composite samples produced under different conditions. Generally, it was observed that an injection pressure level of 2 atm resulted in the best mechanical performance in the specimens, mainly due to the better fiber impregnation by the uniform resin flow leading to no void formation. Use of post-cure for the samples had no beneficial effect leading to some decreases in the mechanical properties. This should be mainly due to the standard curing applied in the mold which might have caused attainable crosslink density. Post-curing should have resulted in some kind of chemical deteriorations, especially in the matrix leading to decreases in the mechanical performance of the samples.
Citation Formats
Y. O. Kaş, “Effects of injection pressure and post-curing on the behavior of woven carbon fiber/epoxy composites produced by rtm (resin transfer molding),” Middle East Technical University, 2002.