ABSTRACT
Pellet size can also be varied by selecting a smooth bore or rough (convoluted) bore blast hose. The rough inside surface of convoluted hose can break up the larger 3 mm diameter pellets into very fine particle sizes. 4.3.3. Thermal shock It can always be enhanced by heating the substrate surface or the entire mass of the substrate. Rubber and tire molds, and baking oven molds are good examples of starting with a hot substrate. 4.3.4. Thermal shock and kinetic energy These can be varied also by adjusting the flow rate of the pellets in the blast stream. In the single-hose system, the radial airlock feeder speed can be precisely controlled to meter out just the right amount of pellets. Sometimes too much pellet flow can cool the coating and substrate too quickly, resulting in a performance drop. Sometimes a higher pellet flow is needed if the application requires more kinetic energy than the thermal effect, like removing heavily built-up oil, grease, and grime from machinery.
