The influence of particle size on surface glossiness, flowability, powder loading rate, and recovery

The particle size distribution of powder coatings directly affects the flowability, stability, electrification, coating film appearance, and spraying process parameters of powder coatings, which determines the quality of powder coating products.

PART 01

The effect of particle size on glossiness

The effect of powder coating particle size on glossiness is shown in Figure 1. From the figure, it can be seen that when the particle size of the powder coating decreases, the glossiness of the coating increases, and the particle size of the bright product is basically distributed at 45 μ Below m;

When the particle size of powder coating is too large, the appearance performance of the coating will deteriorate, and bubbles and orange peel phenomena will appear on the surface.

If the powder particle size is large, the powder loading rate is low, because its gravity is greater than aerodynamic and electrostatic forces, causing the powder particles to fall off before reaching the surface of the product, thereby reducing the powder loading rate. Choose a powder coating with a particle size of 45 μ At m, the glossiness of the powder coating reaches 80%.

PART 02

The Effect of Particle Size on Flatness

The larger the particle size of the powder coating, the less it will flow out within 30 seconds, which means that the smaller the particle size of the powder, the better its leveling performance. Powder coating with a particle size of 45 μ At m, the outflow of powder coating is 140g within 30 seconds.

PART 03

The effect of particle size on powder loading rate

The relationship between powder coating rate and powder particle size, and the particle size of powder coatings suitable for electrostatic spraying is best between 30-80 μ Between m.

In order to improve the quality of coated products, it is necessary to control the particle size and distribution of powder coatings. When producing powder coatings, it is important to avoid excessive particle size while minimizing particle size<10 μ Powder generation of m.

Therefore, controlling the particle size of powder coatings is one of the key factors affecting the powder loading rate. Powder coating with a particle size of 45 μ At m, the powder loading rate reaches 65%.

PART 04

The effect of particle size on recovery rate

Due to the fact that the particle size of powder coatings is not a single one, but a series of combinations of different particle sizes, with a specific particle size distribution.

For powder coatings, the narrower the differential distribution of particle size, the better. The filter element of the vibrating screen is not easily blocked during processing, and the high recycling efficiency is one of the advantages of powder coatings. The recycled powder coating can be mixed with new powder coating in a certain proportion and reused.

The relationship between recovery rate and particle size of powder coating, when the particle size of powder coating is less than 10 μ At m, the recovery rate is below 10%, with a lower value;

As the particle size of powder coatings continues to increase, the recovery rate of powder coatings also increases. From the data, the particle size ranges from 30 to 80 μ The recovery rate of m powder coating is good. Powder coating with a particle size of 45 μ At m, the recovery rate reaches 70%.