Summary of the invention
The invention provides a kind of static even-color painting method, by the enforcement of the method, can improve the surface quality of product spraying, and the utilization rate of paint reaches 70-80%, improve the quality of product, reduced greatly the fraction defective that sprays paint, made the production cost of enterprise reduce.
The technical scheme that the present invention adopts for achieving the above object is:
A kind of static even-color painting method, it comprises the following steps:
(1) paint spray booth's control module is set, is used for controlling the wind speed in this paint spray booth;
(2) a static auto spray painting unit is set, controls the duty of static functional automatic spray gun, make the effect of spraying paint that reaches setting;
(3) an automation hanger unit is set, makes that between workpiece hanger to be sprayed paint, the interval arranges rationally, be used for the outstanding chain speed that connects hanger reasonable;
(4) use the static functional automatic spray gun to carry out spray painting operation to the painting workpieces for the treatment of that is suspended on hanger in this paint spray booth, make coating well attached on workpiece by electrostatic efficiency.
As a further improvement on the present invention, in described step (1), it comprises a wind speed control module and a humidity controlling unit.
As a further improvement on the present invention, in described step (2), it is further comprising the steps of that this please calls the auto spray painting unit:
(21) dc static high voltage unit, when output supply voltage was too low, electrostatic effect and coating absorption variation affected transfer efficiency of coatings; During overtension, easily produce spark discharge.Therefore, in process of production, should note controlling well magnitude of voltage;
(22) atomization air pressure unit, the required compressed air pressure of static automatic spray gun is lower than common spray gun, and too high pressure will affect the shape of coating cloud, affect electrostatic efficiency, air pressure will be adjusted in an appropriate scope in spray painting operation;
(23) coating control module, this coating control module comprise paint viscosity control module and resistance of coating value control module.
As a further improvement on the present invention, in described step (3), it is further comprising the steps of:
(31) rack design unit arranges rational hanger spacing, guarantee the distance of workpiece and spray gun in the method standard, and workpiece lower end height overhead should be less than 1m, and the hanger spacing is 0.8m;
(32) carrier chain design cell, the transfer rate of this carrier chain is reasonable in design, guarantees that surface of the work is enough by the time in coating cloud, makes the coating energy well attached, and chain speed is 2m/min.
As a further improvement on the present invention, the air draft speed of described paint spray booth is to discharge that the solvent vapo(u)r, the coating cloud that produce in the electrostatic painting process splash or the key of solvent evaporates, be 0.5~0.6m/s with this air draft rate setting, this air draft speed can not affect the absorption affinity of coating cloud and the effect of spraying paint less than the speed of general aerial spraying.
As a further improvement on the present invention, prevent that humidity is excessive, thereby at the spray gun for paint surface condensation globule, order produces reverse current to spraying process affects painting effect.
As a further improvement on the present invention, described paint viscosity control module is along with paint viscosity is controlled in the variation of temperature, humidity, effectively improve atomizing effect, make the paint grain encircle deposition along the power line direction better, the coating relative density is 1.15g/cm3, and the coating discharge-amount is 138g/min.
As a further improvement on the present invention, described resistance of coating value control module is controlled at proper range with the resistance of coating value, prevents that electrostatic spraying is lower than aerial spraying with the resistance of coating value, the resistance value of coating should be controlled in standard when application.
Beneficial effect of the present invention is: the inventive method is reasonable in design, enforcement by the method, can improve the surface quality of product spraying, and the utilization rate of paint reaches 70-80%, improved the quality of product, reduced greatly the fraction defective that sprays paint, made the production cost of enterprise reduce, it has following characteristics:
(1) paint film is even, good leveling property, and the tangerine peel phenomenon is obviously improved.
(2) improve clarity and the glossiness of paint film, PGD (aquatic foods degree of reflecting) value can improve 0.1~0.3.
(3) adopt the static automatic coating, effectively reduce the discharge capacity of volatile organic solvent, alleviated the application public hazards.
(4) improve transfer efficiency of coatings, save coating.Owing to adopting the high-voltage electrophoresis coatings method, vehicle frame, fuel tank are suspended on the carrier chain of ground connection (positive pole), the discharge electrode of flush coater leads to negative pole, thereby forms very high electrostatic field between coated article and discharge electrode, makes the coating after atomizing have the good effect of encircling under the effect of electric field force.
The specific embodiment
Embodiment: a kind of static even-color painting method of the present invention, it comprises the following steps:
(1) paint spray booth's control module is set, is used for controlling the wind speed in this paint spray booth;
(2) a static auto spray painting unit is set, controls the duty of static functional automatic spray gun, make the effect of spraying paint that reaches setting;
(3) an automation hanger unit is set, makes that between workpiece hanger to be sprayed paint, the interval arranges rationally, be used for the outstanding chain speed that connects hanger reasonable;
(4) use the static functional automatic spray gun to carry out spray painting operation to the painting workpieces for the treatment of that is suspended on hanger in this paint spray booth, make coating well attached on workpiece by electrostatic efficiency.
In described step (1), it comprises a wind speed control module and a humidity controlling unit.
In described step (2), it is further comprising the steps of that this please calls the auto spray painting unit:
(21) dc static high voltage unit, when output supply voltage was too low, electrostatic effect and coating absorption variation affected transfer efficiency of coatings; During overtension, easily produce spark discharge.Therefore, in process of production, should note controlling well magnitude of voltage;
(22) atomization air pressure unit, the required compressed air pressure of static automatic spray gun is lower than common spray gun, and too high pressure will affect the shape of coating cloud, affect electrostatic efficiency, air pressure will be adjusted in an appropriate scope in spray painting operation;
(23) coating control module, this coating control module comprise paint viscosity control module and resistance of coating value control module.
In described step (3), it is further comprising the steps of:
(31) rack design unit arranges rational hanger spacing, guarantee the distance of workpiece and spray gun in the method standard, and workpiece lower end height overhead should be less than 1m, and the hanger spacing is 0.8m;
(32) carrier chain design cell, the transfer rate of this carrier chain is reasonable in design, guarantees that surface of the work is enough by the time in coating cloud, makes the coating energy well attached, and chain speed is 2m/min.
The air draft speed of described paint spray booth is to discharge that the solvent vapo(u)r, the coating cloud that produce in the electrostatic painting process splash or the key of solvent evaporates, be 0.5~0.6m/s with this air draft rate setting, this air draft speed can not affect the absorption affinity of coating cloud and the effect of spraying paint less than the speed of general aerial spraying.
Prevent that humidity is excessive, thereby at the spray gun for paint surface condensation globule, order produces reverse current to spraying process affects painting effect.
Described paint viscosity control module along with paint viscosity is controlled in the variation of temperature, humidity, improves atomizing effect effectively, makes the paint grain encircle deposition along the power line direction better, and the coating relative density is 1.15g/cm3, and the coating discharge-amount is 138g/min.
Described resistance of coating value control module is controlled at proper range with the resistance of coating value, prevents that electrostatic spraying is lower than aerial spraying with the resistance of coating value, the resistance value of coating should be controlled in standard when application.
During the work of static automatic spray gun, by allowing oil pump partly connect power cathode, workpiece connects positive source and ground connection, under the action of high voltage of high voltage source, just forms an electrostatic field between the end of spray gun and workpiece.The suffered electric field force of paint particles in oil pump is directly proportional to the voltage of electrostatic field and the carried charge of paint particles, and and the distance between spray gun and workpiece be inversely proportional to, when voltage is enough high, near zone formation air ionization district, spray gun end, air is ionization and heating intensely, form a bolarious haloing around making spray gun end sharp edge or utmost point pin, can obviously see in the dark, at this moment air produces strong corona discharge.Coating sprays after nozzle atomization, and is charged because of contact during the electrode needle edge of the paint particles that is atomized by muzzle, when the gas ionization zone that produces through corona discharge, will increase again its surface charge density.Under the electrostatic field of the paint particles that these are electronegative, the surface of the work of guide polarity motion, and be deposited over to form on surface of the work and film uniformly.
As described in the embodiment of the present invention, with same or analogous other static even-color painting methods of the present invention, all in protection domain of the present invention.