Spray booth function and classification

The spray booth is a non-standard equipment and must be properly selected and carefully designed to achieve the best economic and technical results. The most basic task of the spray booth is to remove the paint mist, paint dust, solvent, etc. from the spraying process.
The paint mist is sprayed paint particles, which are still dry and remain adhesive; and the paint dust is sprayed paint particles, which are powdery and lose adhesiveness as the solvent evaporates, and float in the spray booth, then Adhesion is one of the causes of poor coating.

The spray booth should have the following two functions (functions for its representative purpose)
(1) It can promptly and quickly eliminate the paint mist and solvent vapor generated during the spraying process to prevent it from polluting the working environment and the coated surface, ensuring safe production, and maximally capturing the paint mist without discharging it to the outside. Make the exhaust fan and exhaust pipe do not accumulate paint. ,
(2) It can create the best coating conditions and working environment according to the requirements of the coating decoration of the coating process of the coating used, such as providing temperature adjustment, humidity control and purifying dust-free air, good lighting, so that The spraying operation is not affected by the external environment (climate conditions such as temperature and humidity). The temperature and humidity in the spraying operation area are always within the range required by the process to ensure the constant spraying quality.
The first function is the essential function of the spray booth; the second item can be selected according to the quality requirements of the paint layer, site conditions, investment and operating costs, etc. In the case of high decorative painting (such as car body painting), The second item is also a must-have feature of the spray booth system equipment. In the case of protective coating and general coating (the decorative requirements of the coating is not high), the configuration can be reduced. If the air supply system is not configured, the spray booth is open, the air is directly drawn from the workshop or the quality of the air supply can be reduced.
The spray booth can be classified as follows:
(1) Classification of the presence or absence of the air supply system. It is divided into a non-supply type spray booth (ie open type) and a wind supply type spray booth. The former directly draws air from the workshop, has no independent air supply system, and is suitable for general coating; the latter is equipped with an independent air supply system to absorb fresh air from outside the plant. Generally, the purified air-conditioning air is supplied to the spray booth from the top or the upper side of the spray booth, so that the spray booth has a separate air supply and exhaust system, which does not interfere with the ventilation and heating system in the paint shop, and is suitable for decorative painting.
(2) Classified by exhaust ventilation. It is divided into the lower exhaust type spray booth of the side exhaust type spray booth. The side exhaust vents are generally arranged at the lower part of the side, corresponding to the painting station, and are suitable for spraying operations where the medium or small coated parts or workpieces can be rotated in the painting work; the lower exhaust vents are arranged under the grill floor of the spray booth, suitable for For large and double-sided applications where simultaneous spraying is required.
(3) Classified according to the way of collecting paint mist. It is divided into dry spray booth and wet chamber spray booth. The former is to use the paint strip to collect the paint mist with the filter layer, which is suitable for the spraying operation with small amount of paint in small batches and unit time; the latter is to clean the spray chamber of the spray booth by circulating water with paint coagulant. Capture paint mist. According to the structure of the wet paint mist collecting device, the wet spray booth is divided into venturi type, water rotary type (power tube type), vortex type, spray type, water curtain type and water curtain type raft, etc. Spraying operations with a large amount of running water and a large amount of paint per unit time.
(4) Classified according to the purpose of the spray booth. Divided into primer spray booth, medium spray spray booth, electrostatic spray booth and topcoat spray booth, touch paint spray booth, spray paint base (PVC) chamber, protective wax spray chamber, electrostatic automatic painting spray booth and electrostatic powder coating Room and so on. Due to the different uses, there is a big difference in the functional configuration of the spray booth. There is also a spray drying room, which is only suitable for single piece, small batch (painting and drying of a paint production cycle 2H painting operation), such as car service station repair coating.
In the case of spraying organic solvent-based paints, according to the regulations for preventing organic solvent poisoning, the operator should control the wind speed in the working place, and the minimum wind speed is specified depending on the spray booth.
In the design and selection of the maintenance spray booth, the following basic principles should be followed to solve the problems encountered:
(1) The paint mist is 1000 times heavier than the air;
(2) The paint mist is affected by the inertial force;
(3) The organic solvent is heavier than air after gasification;
(4) The organic solvent evaporates and the gasification temperature decreases during spraying;
(5) The paint mist of the organic solvent type coating is not dissolved in water, and is wrapped by water. The waterborne paint mist can be dissolved in water; it is regenerated or agglomerated with a special coagulant;
(6) After the paint is dried, it becomes paint dust. Halve the weight;
(7) Blowing can extinguish the fire of the candle, but inhaling but not;
(8) The air flow can vortex in some cases.