Problems in powder coating shot blasting machine

Problems in powder coating shot blasting machine
The quality of the shot blasting machine not only affects the corrosion resistance of the steel component itself, but also affects the adhesion of the coating, the quality of the coating appearance and the economic cost of coating. Unlike liquid coating, the overall quality of powder coating is closer to the quality of shot blasting. Because powder coatings are different from liquid coatings, thick coatings are formed at one time. If affected by factors such as substrates and construction conditions, powder coatings have no room for remediation, so pretreatment is particularly important to ensure the best coating effect . In the construction of powder coating composite coating on corrugated beam steel fence products, it was found that the main factors affecting the coating quality and cost in the shot blasting process are the cleanliness and roughness of the workpiece surface, and the key factor is roughness.
Adopt Q6910 type 8-throwing-head hanging chain shot blasting machine to perform surface treatment on corrugated beam board. During powder coating, it is found that the leveling effect of the surface of the composite coating is poor, and there is an obvious orange peel. The coating must be very thick (total thickness 150-200 μm) to have the appearance and leveling effect under normal coating conditions, which not only difficult to meet customer quality requirements, but also significantly increased processing costs.
On-site analysis and experiments found that the corrugated beam and slab use spherical abrasives with a projectile velocity of 60-70 m / s, while the column uses steel wire abrasives and a projected velocity of 80 m / s. The surface cleanliness and roughness obtained by the two are significantly different . The corrugated beam surface, especially the part parallel to the blasting direction, has visible oxide scale with a roughness of about 30-40 μm; while the surface of the column is clean and rough, with a roughness of more than 70 μm, but there is a significant surface deformation , The formation of significant pits or bump coating and corrosion protection, deformation point powder coating on the surface of the column is difficult to dewetting, leveling and covering in a short gel time (generally 60-120 s) Finally, pits, pinholes, bubbles or particles are formed on the surface of the coating, which seriously damages the surface decoration effect of the powder coating. Insufficient cleaning of corrugated beam plates affects the powder.