General Introduction to Shot Blasting
Shot Blasting is a surface treatment process using high velocity steel abrasive. Shot blasting is method through which it is possible to obtain excellent cleaning and surface preparation for secondary finishing operations.
Shot blasting is commonly used for:
· The cleaning of iron, steel, non-cast parts, forgings, etc.
· Mechanical cleaning of sheets, rods, coils, wire, etc.
· Shot peening to alter mechanical properties (increasing resistance to fatigue for springs, gears, etc.)
· Preparing surfaces to be painted, coated, etc.
In general shot blasting concentrates abrasive particles at high speed (65-110 m/second) in a controlled manner at the material thereby removing surface contaminates due to the abrasive impact.
Initially in the 1930’s the shotblasting process used compressed air for propelling the steel shot. This method remains in use today for cleaning metal frames and weldments.
Shot blast production lines, both manual and automated systems, became possible with the introduction of centrifugal wheel blast machines. The system of shot blasting by centrifugal wheel is more productive than by compressed air and achieves a better more uniform surface finish.
The criteria used for selecting the type of shot blasting system depends on the size and shape of the parts, the condition of the surface to be cleaned, final surface finish specification and overall process required.
Shot blasting systems are comprised of 6 basic subsystems:
1. Abrasive delivery method:
o By Compressed Air.
o By Centrifugal turbines.
2. Abrasive recovery and cleaning.
3. Dust collection.
4. Blast Cabinet.
5. Part movement and support system.
6. Controls and instrumentation.
Blast Cleaning and Shot peening machines are widely used in different industries such as:
o Cleaning and preparation of profiles and sheets surfaces before painting
o Portable machines for the maintenance of ship hulls
· Automotive components:
o Cleaning of gearboxes, mechanical transmissions, connecting rods, etc.
o Shot peening of stabilizing bars, springs and elastics, gearboxes, pistons, connecting rods, etc for increasing fatigue resistance.
o Cleaning and preparation of car and truck tires before painting.
o Break shoes and clutches blasting
o Cleaning of rectified engines components (blocks, pistons, etc).
o Screw mechanical descaling from metric 3 before coating application
o Portable machines for rubber elimination and roughness restitution in airport tracks
o Shot peening of airplane components tincrease fatigue resistance.
o Airplane painting removal
· Bicycles and motor bikes:
o Cleaning and preparation of bicycle frames, motorbikes and tires surface before painting.
o Cleaning and preparation of steel part surfaces before rubber application.
· Concrete, ceramics, marbles:
o Blast for making non-slipping floors.
o Artistic blasting.
· Coach builders:
o Cleaning and preparation of truck coaches surfaces before painting.
· Denin Jeans:
o Erosion of clothes (jeans).
· Metallic structures and profiles:
o Cleaning and preparation of steel sheets and profiles before painting.
· Iron foundry:
o Remove foils from the framework.
o Surface homogenization.
o Melting of steel, iron, aluminum and bronze.
o Cleaning and grit removal of melted parts.
o Surface homogenization.
· Milk, Refrigerating and Nutritional Industries:
o Limpieza y preparación de superficies previal metalizad.
o Cleaning and preparation of surfaces of stainless steel parts for surface homogenization.
· Cleaning of painting systems (hooks):
o Painting removal of part load hooks of painting systems.
· Metal working:
o Cleaning and preparation of surfaces before being metalized.
o Cleaning of rubber, glass, aluminum extrusion moulds, etc.
· Metallic furniture:
o Cleaning and preparation of metallic furniture surfaces before painting.
o Cleaning and preparation of industrial machines before painting.
· Petroleum and gas:
o Cleaning and preparation of surfaces of GLP, GNC gas cylinder and gas and petroleum stationary tanks before painting.
o Cleaning and preparation of gas and petroleum bottles before painting.
o Blasting and shot peening of petroleum pump rods.
o Blasting of coupling union of pump rods before metal working.
· Concrete floors:
o Portable machines for the preparation of concrete industrial floors before coating.
· Iron and steel industries:
o Mechanic descaling of round, hexagonal and square bars for wire drawing operation.
o Mechanic descaling of coil rod.
o Mechanic descaling of steel sheets and iron hoops.
o Mechanic descaling of tubes with and without rims.
o Descaling of laminated levers by heating.
o Blasting of lamination cylinders.
o Cleaning and preparation of trains and wagons surfaces before painting.
· Metallic drums:
o Cleaning and preparation of internal and external surfaces of metallic drums before painting.
· Heat treatments:
o Cleaning and preparation of parts after heat treatments.
· Electric transformers:
o Cleaning and preparation of surfaces of electric transformer before painting.
o Grind glass.
o Artistic blasting.