the “automatic pretreatment machine of steel door production line” adopt complete program-controlled, quick process to cold-rolled steel sheets (degreasing, roughening, passivation and drying). Space occupied is less than trasitional phosphating equipment. The powder adhesiveness is improved greatly. The follow-up process can be finished mechanically. The quality of surface finish is stable and under control. Running cost is decreased, and no pollutant emissions.                                                                   External size: LxW=12000x1800mmWork piece size: δ=0.3-2.5mm,  W≤1100mm sheet metal;Labor required: 2-3 workers;Capacity: δ=0.7mm  LxW=2000x1000mm sheet. 120-200pieces per hour  We are professional providing A to Z project service for steel door production line.We provide entire steel door production line, includ door manufacture machine, steel door surface finish machineyWe developed our advanced method of manufacturing steel door instead of traditional way. Our new method is adopted by big Chinese steel door factories.