This process is adopted for surface preparation prior to any coating or painting, or metal spray application. The best technical word is abrasive blasting. In fact, there are so many types of abrasive, and every abrasive has its own quality and performance characteristics. Sand is the most commonly used abrasive and is cheaper also, but its recycling is very less. This is an expandable media and breaks into very fine particles after striking the metallic surface under compressed air pressure, which is normally 6 bar. It is generally banned due to silicosis disease. Sand/shot/grit/copper slag all are a type of abrasive. There are three basic principles of abrasive blasting with the help of compressed air. In this process, any type of abrasive can be used.
In this process, abrasive is stored in a pressure vessel/tank. Compressed air pushes the abrasive stored in a tank, and another compressed air line is fed at the bottom of the tank to give kinetic energy to abrasive particles. Abrasive and air mixture is passed thru the blasting hose under high air pressure, say a maximum of 6 to 6.5 bar air pressure and finally ejects thru a venturi nozzle made of tungsten carbide and other hard material and gives acceleration to abrasive air mixture. Generally, this process is carried out inside an abrasive blasting cabinet or in an open place suitably covered. Operators place the nozzle over the material to remove any rust/scale/deposits to clean the surface. This is called surface preparation. Job is free of any foreign substance, and virgin metal is exposed, suitable for further application for painting/coating/metallizing.
This is almost the same process as that of pressure blasting, but in suction blasting, there is no compressed air pressure on the abrasive. Generally, this process is carried out inside an abrasive blasting cabinet. Abrasive is conveyed to the blasting gun by a partial vacuum created inside the blasting gun. Abrasive gets mixed with air inside the gun chamber and ejects thru the blasting gun. The kinetic energy of abrasive particles is generally lower in this process, and hence most commonly used for light removal of scale and cleaning other sophisticated products like automobile pistons, turbo parts, engine valves, surgical equipment, stainless steel parts and much other similar application.
This process is used for very fine scale and smooth finish on the job. Water is used as liquid media. Generally, this process is carried out inside an abrasive blasting cabinet .common abrasive is aluminium oxide, glass bead, urea, and melamine. A suitable ratio of water and abrasive is stored in the abrasive storage tank, and for continuous agitation; compressed air is injected into the mixture. Else abrasive will get sedimented at the bottom. This mixture is called abrasive slurry. With a special polymer pump, it is pumped into the blasting gun, and there is a separate connection in the blasting gun for compressed air. This air accelerates the slurry mixture and around 6 bar of air.
Pressure the mixture, eject thru the blasting gun and throw it on the job to be cleaned. All scales and deposits are removed and give a very clean and smooth surface finish.
In this process, abrasive is propelled on an object by centrifugal force and not by the help of compressed air. Thru the feed funnel, the abrasive, mainly steel shots and cut wire shots only, are fed at the centre of the blast wheel, and it rotates at a very high speed, says 2880 rpm or less, by variable ac drive, and shots get discharged radially. The velocity of shots striking the job surface is in the tune of 70 to 80 meters per second. At this high impact, the surface of the job gets totally cleaned and free of any previous coating/paint etc. A nearly white metal finish is achieved with suitable roughness on the job surface. It is desired for further application and process on the job. The main application is for castings, forgings, the automobile sector, the aviation industry, electrical transmission lines fittings etc. and similar applications.
It is similar to shot blasting, except air pressure is kept high at around 8 to 9 bar, and so is the blast wheel speed at 2800 rpm. Constant distance of nozzle/wheel is maintained, and even shots are classified at every recycling so that equal sizes of shots are used for this purpose. Fine and broken shots are removed by the classifier, and only used shots are fed into the blast wheel.
This process induces compressive strength into the job and increases its flexibility of the job, mainly used for helical, coil springs, helicopter blades, gears, and automobile and aviation parts. Shot peening intensity is measured by an Almen gauge in the a, b and c range. It creates a bow effect on the job, and in common language, it is a bombardment of round steel shots on the job at constant velocity and constant distance during the process.
This is a type of abrasive used for blasting purposes and is mainly used in compressed air-operated blasting only.
This is a type of abrasive used for blasting purposes and is mainly used in compressed air-operated blasting only. Mainly used for aluminium, stainless steel, and brass components. Automobile and aviation application is the most common for this abrasive.
Strict quality control right from the raw material stage to the finish stage is fully controlled and subject to check at each stage of manufacturing. Unlike others, we maintain the quality and thickness of steel sheets, abrasion-resistant rubber and its thickness, and blasting hose quality in terms of antistatic property, flexibility, rubber hardness, purity of rubber, and shore hardness.
Blasting nozzles are long-century types made of tungsten carbide, boron carbide, silicon carbide, and proper hardness in the Mohs scale.
In an airless shot blasting machine, there are so many points to be checked while comparing price and quality aspects. Since shot blasting machines are self-destructive machines hence great importance is given to raw material, hardness, thickness, etc.
Alloy steel, manganese steel, ni hard, and hi-carbon hi chromium parts are used in airless shot blast machines. Unlike others, we do not compromise on the chemical properties of these castings, weight and thickness of the parts to reduce the cost. It ultimately depletes the quality and longevity of the machines. The longevity of parts is almost double in our machine than our nearest competitor. This saves time and maintenance costs drastically, which is evident only after use for several months. Although parts like control cage, impellers, blade sets, and blast wheel liners are common wear and tear items, however, if the right metallurgy and hardness and; proper thickness is used in manufacturing, these parts last longer. We in pcs made a policy not to compromise on price and dilute technical specification. It is evident that almost all our client place repeat orders on us due to the trust and the quality of the machine being manufactured by us.
Every week blast hose, blasting nozzle, wheel blade, impeller, and control cage should be checked. If any vibration and sound are observed in the airless shot blasting machine, immediately blade set should be inspected. Change the total blade set to maintain the dynamic balancing of blast wheels. Generally, users do not replace a total set of the blade, and this develops vibration and damages the dynamic balancing. Finally, the bearings and motor gets damaged.