The method of supplementing steel shot during shot blasting cleaning has a significant impact on the quality of cleaning. A good steel shot will peel off layer by layer on the surface during the cleaning process, and the casting of the steel shot will become smaller. The composition of the steel shot will gradually reduce the particle size of the entire system. If the material is not replenished for a long time, the particle size of the system will become very small, and the surface roughness and cleaning efficiency will decrease. If too much material is added at once, the surface roughness of the casting will immediately increase.
So, it is recommended to continuously supplement the steel shot as much as possible to ensure that the quantity and particle size composition remain unchanged, in order to ensure stable cleaning quality. Usually, production is achieved by regularly replenishing steel shot (once per shift). When the feeding control is not good, the particle size composition of the steel shot will undergo significant changes.
During the shot blasting process, changes in replenishment methods and particle size can also have a significant impact on cleaning efficiency. On the one hand, when the steel shot accelerates on the blade, the large particle steel shot leaves the blade first, and the small particle steel shot leaves the blade later. If the particle size composition of the steel shot remains unchanged, the main concentration area where the hot spot steel shot of the throwing head is thrown will remain unchanged. If the particle size of the steel shot changes and the hot spot leaves the workpiece, the cleaning efficiency will decrease.
On the other hand, cleaning efficiency is not only related to impact, but also to coverage. The impact force of large particle steel balls is strong and effective, but the number of particles per kilogram is limited, the coverage rate is low, and the cleaning efficiency is not very high. Causing rough surface, low impact force of small particle steel balls, and poor cleaning effect of each steel ball. But there are many particles per kilogram of steel shot, so the coverage is high and can be cleaned to small points, thereby reducing surface roughness.
Editor: Lena