The objective of this work is to obtain proper and educated values of thermal conductivity of the composite material, study which phenomena appear during the manufacturing process and which setting parameters affect to the final manufactured plate. It is necessary to obtain proper and educated values of thermo physical parameters of the resin and the glass fiber and study phenomena during the manufacturing process. To achieve this goal, some experiments were run at the laboratory in order to generate profile temperature data along the throughthickness of the manufactured plate and volume fraction of the resin (Matrix Volume Fraction) and fibre (Fibre Volume Fraction). The work carried out at the laboratory is going to be focused on the RTM experiment. Problems related to the manufacturing process also need to be solved, in order to achieve valid experiments and useful data. With values obtained with the experimental work, simulations are taken over to study the behavior of the plate. Solutions given by the model of cure kinetics and experimental work need to be compared, in order to generate a value of thermal conductivity, which gives the best agreement between them. With MATLAB software the simulation of RTM curing process were run, and its verification with experiments at the laboratory. The goal is to obtain an average value of thermal conductivity, and use it in future simulations. Also, those simulations behave as a design tool, which helps to establish the best process strategy to manufacture thick-walled composites. The simulation tool COMSOL Multiphysics is going to be used as a tool to simulate the behavior of composite parts during the manufacturing process. The goal of this part of the work is to generate knowledge about phenomena occurring during the process, keys of the manufacture, values of peak temperature and times of the overshoots. Models of one, two and three dimensions are going to be evaluated, and models of real life structures like T-shaped structures and curved shapes.------------------------------------------------------------------------------------------------------------------------------------------------------------------------------