Six sigma and design of experiments for improving the production of composite pipes

Abstract

Within the frames of this paper it was applied the six-sigma DMAIC methodology for improving the production process of composite pipes. The quality needs of the composite pipes were defined: resistance on high interior pressure and the important entries that influence on the improved solution. A designing was made for improving of the industrial process, i.e. planning of the experiments and on the basis of the plan matrix, 8 models of composite pipes were manufactured. During the process of designing three parameters were taken which influence the experiments the most: velocity, fiber tension and winding angle. Also, it was used three-factorial method for experimental planning with two levels of variation 2³. For all manufactured composite pipes the hoop tensile strength was tested in a lab. On the basis of the received experimental data it was created the regression equitation which the best describes the process.