(1) Flow coating process parameters
In addition to the pre-coating treatment of the coated parts as required, the main process parameters of the flow coating are shown in Table 2_7_3.
project | Process parameters |
Paint viscosity (paint_4) /s | 25~60 |
Paint temperature/℃ | 20~ 25 |
Coating time/min | 1~3 |
Residence time/min | 8~30 |
Self-weight spray nozzle diameter/mm | 7~12 |
Pump pressure spray nozzle diameter/mm | 1. 5 ~ 2.5 |
Pump pressure spray pressure/MPa | 0.2~0.5 |
(2) Matters needing attention during operation
(1) Select the paint with slow drying coefficient and good leveling. Since the surface of the object to be coated by flow coating is covered by the paint, the time for leveling and removing the remaining paint is too long, so it is better to choose a thermosetting paint.
(2) According to the characteristics of the coating and the requirements for the thickness of the coating film, determine the viscosity of the coating coating. Since the paint is in the spray state during the flow coating, the solvent volatilizes quickly. The viscosity of the paint will thicken quickly, so it should be checked regularly, the solvent should be replenished, and the viscosity of the paint should be adjusted. In addition, due to changes in ambient temperature, attention should be paid to heating or cooling the paint to keep the viscosity of the paint in a stable state.
(3) According to the viscosity of the coating and the shape of the object to be coated during spraying construction, select the nozzle diameter and spraying pressure.
(4) The time of staying and removing residual paint and the size of the station should be determined according to the time of removing residual paint and the leveling effect of the coating film.
