A study on the erosive wear of spray tip nozzle by epoxy primer paint impingement and the spraying characteristics

에폭시 프라이머 도료의 에어리스 스프레이 분사 시간에 따른 팁 노즐 침식마모경향과 분사특성 연구

Airless spray which is widely used for painting to ship blocks and hull sides is the coating method for attaching atomized paint material to the substrate using spray tip nozzle with compressed air. When the paint material which has high solid contents such as epoxy primer paint is atomized by passing through spray tip nozzle with high pressure, the nozzle composed of tungsten carbide(WC) undergoes the erosive wear, leading to widening of nozzle hole. The deformation of nozzle hole induces improper spray pattern and coating failures such as finger pattern and sagging because the conditions of spray pump pressure and paint flow rate for developing full spray pattern are changed. In this study, an appropriate replacement cycle of spray tip was predicted by measuring the erosive wear tendency as increasing the spraying time of epoxy primer paint.