In the automotive painting process, in order to ensure a good topcoat spraying effect, what preparations should be made?

Painting process (typical): body inspection → high-flow rinsing 1 → high-flow rinsing 2 → pre-grease (spray) → degrease (dip + spray) → first water wash (dip + spray) → second water wash (spray) → surface adjustment (dip + spray) → phosphating (dip + spray) → third water wash (spray) → fourth water wash (dip + spray) → first pure water wash (spray) → second pure water wash (spray) → high-pressure spray (spray) → fresh Pure water washing (spraying) → cathodic electrophoresis (UF0 spraying) → UF1 water washing (spraying) → UF2 water washing (dipping+spraying) → UF3 water washing (spraying) → fresh UF water washing (spraying) → third pure water washing (spraying) → fourth pure water washing (dipping+spraying) → fresh pure water washing (spraying) → pouring and blowing water → transferring to the hangers → electrophoresis drying → strong cooling → electrophoresis checking → applying weld seam sealant and sound insulation pad → transferring to the hangers → sealant and spraying of bottom sealant PVC→transferring→spraying skirt anti-stoning coating→sealant drying→electrophoretic sanding→ostrich feather wiping machine→electrostatic dust removal→spraying mid-coating→mid-coating pre-drying and mid-coating drying→strong cold→mid-coating sanding→manual wiping→electrostatic dust removal→spraying primer→primer pre-drying→spraying varnish→flowing→drying→strong cold→checking→polishing, on-line repairing (repairing and reworking)→decorating→waxing→sending to general assembling.

In order to ensure a good finish coating effect, the following aspects should be paid attention to:

(1) Pre-treatment and electrophoresis adopt continuous spraying and dipping combination to carry out pre-treatment processes such as degreasing and phosphatization for the white body sent from the body shop, and then the cathodic electrophoresis primer, which is made of liquid degreasing agent, and the Pb-Free (lead-free) cathodic electrophoresis primer, to satisfy the requirement of clean production of coating.

(2) Weld rough/fine sealing, mounting anti-acoustic damping sheet, underbody sealing, underbody vibration damping and heat-insulating adhesive and RPP spraying, and finally drying, checking the bodywork, and grinding the defective parts.

The underbody PVC station adopts robot spraying; the skirt adopts the process of spraying anti-rock impact coating and robot spraying.

(3) The middle coating adopts water-based coating process, and wiping clean before middle coating adopts manual method, reserving ostrich feather wiping clean position and setting up ionized air curtain; the internal manual electrostatic spraying; the external spraying adopts robotic electrostatic spraying and manual paint refilling, and the robots adopt wall-mounted type; the middle coating drying adopts forced convection hot air circulating drying method, and the heat source is natural gas.

(4) The primer is a water-based paint process, and the overcoat is a one-component solvent-based paint. Before top coating spraying, the medium coating is polished by hand, and the workpieces with large grinding workload are transferred to offline grinding room for polishing; the wiping clean before top coating is done by hand, ostrich feathers are wiped clean in the position, and ionized air curtain is set up; the internal spraying is done by hand with electrostatic spraying; the external spraying is done by robotic electrostatic spraying and hand-painting, and the robots are wall-mounted; and the top coating drying is done by forced convection hot-air circulating drying, and the heat source is natural gas. The drying of the top coating adopts forced convection hot air circulation drying method, and the heat source is natural gas.

(5) The workpieces after top coating are checked and refined by hand; the unqualified workpieces are sanded and returned to the top coating line for re-spraying, and the workpieces that need local repair are sanded, repainted and dried in the small repair area. Design decoration and inner cavity waxing process.

(6) The large air volume industrial air conditioning blower unit is used to send air to the painting room and working area. The heating of the blower unit adopts direct-fired natural gas heater, and the humidification adopts spraying method. Warm air is sent to the working area in winter and cold air is sent to the working area in summer.

(7) The centralized paint supplying device adopts hydraulic paint conveying method, the medium paint, metal paint and overprint paint all adopt two-line circulation method, and the solvent adopts blind-end type, and there is a waste solvent recovery device; it adopts tube-in-tube temperature control system, and the medium paint and the color paint are painted in the way of water-based paint.

(8) The electric control of the equipment adopts decentralized control and centralized monitoring mode, and the electric control cabinet is arranged near the field equipment, which is convenient for operation and observation; the PLC, the core unit of the electric control cabinet, connects with the computer of the central control room through the field bus, and the central control room monitors the running condition of the production line and conducts the scheduling and management of the production; it sets up the car body identification system, which can carry out intelligent management on the car model, color, number of times of spraying, and the formation of groups etc. The system is equipped with a waste solvent recovery device. Intelligent management.

(9) In order to prevent dust from entering outside the workshop, an air shower channel is set up at the entrance of the workshop, the paint spraying room is centrally arranged and equipped with a clean area, and an air shower room is set up outside the clean area to improve the air purification level and ensure the high quality of the painting environment; an ionized air curtain is set up before spraying paint to ensure the high cleanliness of the base layer of the paint; a robotic spinning cup is used for electrostatic spraying, and the spinning cup adopts double-layer molding air to ensure the stable and high quality of the paint coating. High quality.

Whether or not robotic spraying is used in the above expression depends on the coating input.

I hope the above helps you.