Análise dos fatores relacionados ao defeito de fervura em tinta aplicada em motor industrial por meio de planejamento de experimentos

Abstract

The solvent-pop defect is related to the solvent evaporation in the applied paint coat during the curing process. There are several factors related to this process which can be controlled in a way to reduce the occurrence of this problem. This study aimed to reduce this defect through Design of Experiments (DOE). The company where the study was performed manufactures components made of steel plate, which are likely to present this defect due to their high temperature ramp in the curing oven. During the initial planning of the study, several factors were considered critical. Those could be experimentally controlled with the objective to identify what are the most-related to the solvent-pop occurrence. As a start of this sequential work, a replicated fractioned factorial experiment was performed, seeking to eliminate some of the previously selected factors and better understand their levels and their contributions to the studied defect. Six factors were selected in this first experiment, resulting on sixteen treatments with a total of forty-eight sample specimens. The factor related to the paint-film thickness was the one that most contributed for the solvent-pop occurrence. Following a sequential approach, other experiment was performed with the objective to analyze the influence of the temperature in the curing process. Through this experiment, it was concluded that with the current paint and paint process, and in the studied component, it is not possible to produce components with only one paint finish coat that present both good coverage and absence of the solvent-pop defect.