When the dosage of HB type suspending agent is 1 phr, the suspending property has reached 97%. The surface strength of the coating reached grade 1 by adding 2% NT binder at room temperature.
The coating with Guangdong zircon powder and Australia zircon powder is superior to Yulin zircon powder in technology and performance.
1. Effect of particle size and distribution of zircon powder on coating process performance
Coating is a kind of suspension system, and there are many factors affecting its viscosity, but there are three main aspects, namely, dispersion medium, dispersion phase and condition factors.
According to the research, the powder distribution in the range of 1-100 μ m is bimodal, which has high stacking density and good fluidity.
In refractory powder, with the refinement of particles, the specific surface energy and surface energy increase, so the interaction between particles increases.
With the increase of the number of particles in the same solution, the interface area and the interaction between polymers are increased, the chance of collision is increased, the connection points in the structure are more, the strength is improved, and the yield value and thixotropy are higher. The finer the average particle size is, the higher the content of particles (< 10 μ m) in the powder, the higher the yield value, and the higher the viscosity.
In the coating, the refractory powder is fine with large yield value and thixotropy; in the process of flow coating, the fluidity, leveling and coating uniformity are poor, resulting in serious drop marks, increasing coating thickness and reducing penetration depth.
The particle size and distribution of refractory powder in the coating have a great influence on the technological performance of the coating. When choosing refractory powder, do not blindly pursue the fineness of powder and mistakenly think that the finer the better, and the proportion of powder less than μ m should not be too high.
2. Effect of zircon powder flow coating density on process performance
With the increase of density, viscosity and density of the same kind of coating, the thickness of the coating increases sharply. With the increase of density, the penetration depth decreases, the density of the coating increases, the viscosity increases, the thickness of the coating increases, and the penetration depth decreases. For the coating with small viscosity, the fluidity is good; for the coating with large viscosity, the fluidity is poor. With the increase of coating density, the homogeneity of coating becomes worse, the viscosity of coating increases, and the homogeneity of coating becomes worse.
The leveling property of the coating becomes worse gradually. The viscosity of the coating increases, and the leveling property of the coating becomes worse. With the increase of viscosity, the drop mark resistance of the coating becomes worse.
As the density and viscosity of the coating increase, the thickness of the coating increases, and the penetration depth decreases, that is, the coating hanging becomes better, and the permeability becomes worse; as for the fluidity, coating uniformity, leveling and anti drop mark become worse, the viscosity of the coating cannot be large, but the viscosity of the coating is low, the density is small, the density of the coating becomes worse, and the anti stick sand ability is weakened, so the density change should be minimized In other words, the increase of coating density does not cause a significant increase of viscosity, and the increase or decrease of coating thickness, penetration depth, fluidity, coating homogeneity, leveling and anti drop mark are not significant. Z004 and z007 coatings have good flow coating performance.