Dust in Lacquer, Evidence of Deviation of Process in Production Lines for Spray Painting

This paper concerns work carried with a view to reduce defect occurrence rate in the spray painting lines of MDF (medium density fibre cluster-medium density fibreboard) parts of a multinational mobile manufacturing. The determination of the causes for the excessive rejection values is elusive for the multiplicity of factors and parameters involved and the dispersion of application times, not always sufficiently or properly documented. A process analysis methodology was applied to diagnose possible causes of defect occurrences. Considering that the highest defect rate concerned impurities, data collected over a six months' period was analysed using SPSS to find the correlation between parameters, to find optimal limits of some parameters and evidence of their influence. Kaizen-Lean actions were discussed and implemented conducing to an effective reduction of the existing impurities defect rate, which decreased ninefold related with initial work values.