Coating manufacturers said that water-dilutable coatings refer to coatings prepared from emulsions as film-forming materials, in which solvent-based resins are dissolved in organic solvents, and then, with the help of emulsifiers, the resins are dispersed in water by strong mechanical stirring to form emulsions , called post-emulsion, can be diluted with water during construction.
A paint prepared by adding a small amount of emulsion to a water-soluble resin cannot be called a latex paint. Strictly speaking, water-thinning paint cannot be called latex paint, but it is also classified as latex paint by convention.
Advantages and disadvantages of water-based coatings
1. Using water as the solvent saves a lot of resources. Fire hazards during construction are avoided and air pollution is reduced. Only a small amount of low-toxic alcohol ether organic solvent is used, which improves the working environment conditions.
2. The organic solvent of ordinary water-based paint is between 10% and 15%, but the current cathodic electrophoretic paint has been reduced to less than 1.2%, which has an obvious effect on reducing pollution and saving resources.
3. The dispersion stability to strong mechanical force is relatively poor. When the flow velocity in the conveying pipeline varies greatly, the dispersed particles are compressed into solid particles, which will cause pitting on the coating film. It is required that the conveying pipeline is in good shape and the pipe wall is free of defects.
4. It is highly corrosive to coating equipment. Corrosion-resistant lining or stainless steel materials are required, and the equipment cost is relatively high. Corrosion and metal dissolution of the conveying pipeline can cause precipitation and pitting of dispersed particles on the coating film, so stainless steel pipes are also used.
Finishing application and construction method of paint manufacturers
1. Adjust the paint to a suitable spray viscosity with clean water, and measure the viscosity with a Tu-4 viscometer. A suitable viscosity is usually 2 to 30 seconds. The paint manufacturer said that if there is no viscometer, you can use the visual method to stir the paint with an iron rod, stir to a height of 20 cm and stop to observe.
2. The air pressure should be controlled at 0.3-0.4 MPa and 3-4 kgf/cm2. If the pressure is too low, the paint will not atomize well and the surface will be pitted. If the pressure is too large, it is easy to sag, and the paint mist is too large to waste materials and affect the health of construction workers.
3. The distance between the nozzle and the surface of the object is 300-400 mm, and it is easy to sag if it is too close. If it is too far, the paint mist will be uneven and there will be pitting. And if the nozzle is far away from the surface of the object, the paint mist will spread out on the way, causing waste. The paint manufacturer stated that the specific distance can be determined according to the type of paint, viscosity and air pressure.
4. The spray gun can move up and down, left and right, and can run evenly at a speed of 10-12 m/min. It should be straight and directly facing the surface of the object. When spraying on both sides of the surface of the object, the hand that pulls the trigger of the spray gun should be released quickly. On, this will reduce paint fog.
Post time: Jan-18-2024