Improvement of the Polyurethane Foam Molding by the DoE Method: Case Study

Design of Experiments is one of the tools for improvement and optimizing of products and manufacturing processes. Experiments conducted in industrial conditions should marginally interfere with the course of a studied process. The subject of the paper is the analysis of the impact of polyurethane foam-forming parameters on its strength properties, i.e., tensile strength and elongation at break. The tests were carried out on flexible foam molded for car seats. The measured parameters were: mixing pressure in the head, the volume of the mixing chamber, and time to prepare the pressure. The purpose of experiments was also to analyze the interactions of parameters on foam properties. A full factorial experiment was used for this. Eight combinations of parameters were developed, and on their basis, foams were prepared from which test samples were cut out. The foams were made using a one-step method. The results showed that both the elongation and strength have the greatest influence on the mixing pressure.