Application instructions for high-pressure airless spraying in the construction of epoxy floor coatings

In the construction of epoxy flooring, the use of high-pressure airless spraying can achieve better apparent effects than rolling coating. Higher glossiness, higher wear resistance (airless spray floor paint with almost no diluent added). When spraying, the spray gun should be perpendicular to the surface of the workpiece being sprayed, with a distance of 30-40cm from the surface.

The spray gun should move uniformly at a suitable speed and be parallel to the floor surface to avoid accumulation and uneven coating. The spraying distance and vertical angle between the spray gun and the object surface are controlled by the body, and the movement of the spray gun also requires the assistance of the body to move the arms. The wrist cannot be moved, but it must be flexible.

Each spray painting operation overlaps about 20-30% on the previous spray painting operation to obtain a complete and uniform coating. When spraying corners, the spray gun can be aimed at the center of the corner to ensure even spraying on both sides.

The spray gun trigger should be turned on when the spray gun is moving during each spraying process, and the spray gun trigger should also be turned off when the spray gun is moving to avoid excessive accumulation of paint on the surface.

The same spray width, the larger the aperture, the thicker the film formation.

The same nozzle aperture results in thinner film formation as the spray width increases.

Precautions for high-pressure airless spraying

(1) Spray pressure and flow rate

For a certain model of airless spraying equipment, when the viscosity of the coating used remains constant and the input compressed air pressure is constant, the relationship between the spraying pressure and flow rate is: as the flow rate increases, the spraying pressure decreases. When the pressure of the input compressed air increases, the spraying pressure and flow rate correspondingly increase.

(2) Coating viscosity and spray pressure

The viscosity of different types of coatings varies, with high solid content coatings having particularly high viscosity, such as solvent-free high solid content epoxy resin coatings. The higher the viscosity, the greater the spraying pressure required during construction. The pressure ratio for low viscosity coatings is generally 23:1 and 32:1, while the construction pressure ratio for high viscosity coatings is generally around 45:1. But we cannot simply increase the spraying pressure. When spraying high viscosity coatings, we should also consider replacing the large-diameter nozzle.

(3) Selection of nozzle

Before high-pressure airless spraying, a nozzle with a certain aperture and shape should be selected according to the coating and spraying object used. The diameter of the nozzle determines the flow rate, and the shape of the nozzle determines the range of spray. For coatings with high temperature and large application area, you should choose nozzles with larger aperture.