Shot blasting is a process of cleaning and scouring that uses a high-powered stream of abrasive materials propelled by a mechanical device or an air stream. It is an efficient method of cleaning or scouring surfaces or parts, including molds, dies, and castings, prior to painting or other finishing applications. Additionally, the process can be used to remove excess coating or rust on existing parts.
Shot blasting is the ideal choice for surface conditioning and preparation because it can produce uniform finishes on parts of almost any complexity. The process removes burrs and sharp edges, minimizing rejects and improving quality control. As a result, shot blasting can increase productivity and reduce the cost of surface preparation.
Shot blasting differs from sand blasting, in that it uses finer abrasive materials like glass beads, steel shot, or plastic beads. These materials usually range in size from 40 to 60 grit, resulting in a finish that is rougher than sand blasting and smoother than tumbling.
The process begins by placing the part inside a shot blast machine or chamber. The chamber has a series of rotating blades with special cups for holding the shot blasting material. When the machine is activated, the abrasive is propelled by centrifugal force at very high speeds against the part. This scouring action not only strips away dirt and debris, but also levitates the surface of the part and fractures into small pieces. This causes a uniform layer of material to be frozen to the surface which helps to protect it from oxidation and corrosion.
The most common use of shot blasting is to remove paint, rust, or other deposits from metal parts. This process helps to prepare the part for reuse or repainting, as the shot blast removes any old sealants or adhesives that could cause the paint to chip. It is also used to prepare the surface of a new part before painting or coating, as the uniform layer of particles aids in the adhesion of paint or coatings.
Shot blasting is also commonly used to clean plastic parts. This process helps to remove dirt, dust, oils, and other contaminants which can interfere with the manufacturing process of plastic parts.
In addition to being a largely automated process, shot blasting is cost-effective and time-efficient. It generates high-quality results in much less time than traditional methods of surface preparation, and can be used on a variety of different materials, from steel to rubber. However, it is important to note that shot blasting is not recommended for delicate materials, as it can cause micro-elements to be removed from the surface. Consequently, it is important to select the most suitable media and technique for your application in order to achieve the desired surface finish.
