Jerrys Intelligent Spraying RobotCommon Spraying Processes in Coating

JERRYS ROBOT

1. Roller Coating

Roller coating uses a rotating roller as the carrier for the coating material. A wet film of a certain thickness forms on the surface of the roller, and as the roller rotates and comes into contact with the object being coated, the coating is applied to the surface. Roller coating is suitable for flat objects and is widely used for coating metal sheets, plywood, fabric, and paper. It is particularly applicable for coating metal coils.

2. Air Spraying (Spray Gun with Compressed Air)

Air spraying is currently one of the most widely used coating processes in paint application. It utilizes a stream of compressed air flowing through the nozzle of the spray gun to create negative pressure. This negative pressure draws the paint from the suction tube and ejects it through the nozzle, forming a paint mist that sprays onto the surface of the object being coated, resulting in a uniform paint film.

3. Electrostatic Spraying

Electrostatic spraying includes liquid electrostatic spraying and powder electrostatic spraying. The principle involves using a high-voltage electrostatic field to direct negatively charged paint particles along the opposite direction of the electric field, adsorbing them onto the workpiece surface. Electrostatic spraying equipment consists of a spray gun, spray cup, and high-voltage power supply. Liquid electrostatic spray guns are divided into manual water-based and oil-based electrostatic spray guns, automatic water-based and oil-based electrostatic spray guns, and water-based and oil-based automatic electrostatic rotary cup atomizers. The paint supply system generally includes low-pressure paint delivery pressure tanks or diaphragm pumps, high-pressure plunger pump paint supply systems, automatic paint ratio mixing systems, automatic color change control systems, cup head automatic cleaning control systems, precision flow closed-loop control systems, gear pump precision flow control systems, and other spraying components.

4. Electrophoretic Coating

Electrophoretic coating (electro-coating) uses an external electric field to directionally migrate and deposit pigments, resins, and other particles suspended in the electrophoretic solution onto the surface of one of the electrodes. The principle of electrophoretic coating was invented in the late 1930s, but its development and industrial application began after 1963. Electrophoretic coating is a special film-forming method developed over the past 30 years and is the most practical application process for water-based coatings. Electrophoretic processes are divided into anodic electrophoretic coating and cathodic electrophoretic coating. If the paint particles are negatively charged and the workpiece is the anode, the deposition of paint particles on the workpiece under the action of the electric field is called anodic electrophoretic coating. Conversely, if the paint particles are positively charged and the workpiece is the cathode, the deposition is called cathodic electrophoretic coating. Electrophoretic coating is generally used for the pre-treatment primer and anti-rust primer of automobile bodies. It is an omnidirectional, dead-angle-free electrophoretic process with characteristics such as water solubility, non-toxicity, and ease of automation control. It has rapidly gained widespread application in industries such as automotive, construction materials, hardware, and home appliances.

5. High-Pressure Airless Spraying

Also known as airless spraying, this method uses a high-pressure plunger pump to directly pressurize the paint, forming high-pressure paint that is ejected through a manual or automatic spray gun nozzle to create atomized airflow applied to the object surface (such as walls or wood surfaces). Compared to air spraying, it results in a uniform paint film without granular texture. Since it is isolated from air, the paint dries cleanly. Airless spraying can be used for high-viscosity paints and provides sharp edges, making it suitable for噴涂 projects with boundary requirements, such as anti-corrosion painting for steel box bridges, ships, engineering machinery, bridge railway pads, or shock absorber supports. Depending on the machinery type, it is categorized into pneumatic airless sprayers, electric airless sprayers, and internal combustion airless sprayers. Different spraying methods are selected based on the specific process requirements, and the application of intelligent spraying robots is a future development trend.