What spray techniques do we need to use when we use shotcrete machines

Shotcrete machines are widely used in mines, tunnels, culverts, subways, hydropower projects, underground constructions and shotcrete construction operations in coal mine high marsh mine tunnels.
So what spray techniques do we need to use when we use a shotcrete machine?

1. Adjust the mortar or coating to a suitable spray viscosity with a matching blender or manually (this is based on what type of material consistency the builder needs).

2. The air pressure is best controlled at 0.3-0.4 MPa (3-4 kg force / square centimeter). If the pressure is too low, the material will be poorly atomized and the surface will form pits; if the pressure is too large and the paint mist is too large and the paint mist is too large, it will waste the material and affect the operator's health.

3. The distance between the nozzle and the object surface is generally 300-400 mm. Nearly easy to flow hanging; too long uneven material, the specific size of the distance, should be based on the type of coating, viscosity and pressure to adjust the size of the appropriate. Slow-drying materials can be sprayed a little further, faster-drying materials can be sprayed, and the distance can be closer; when the viscosity is thicker, it can be nearer, when the viscosity is thin, it can be farther; when the air pressure is high, the distance can be farther, and the pressure can be closer .

4. The spray gun can be used for up and down, left and right movement, it is best to run at a speed of 10-12 meters / minute, the nozzle should be flat on the surface of the spray gun, to minimize the oblique shot. When sprayed on both ends of the object, the trigger that deducts the trigger of the spray gun should be loosened quickly to reduce the atomization. Because the two ends of the object surface are often subjected to two or more shots, it is the most likely cause for sagging. .

5. Spray the next time to suppress the last one 1/3 or 1/4, so that there will be no leakage phenomenon. When spraying the quick-drying materials, they must be sprayed in sequence one at a time. Spraying effect is not ideal.