The process is carried out to prevent metal fatigue, cracking, cleaning and surface hardening.

In shot blasting, the role of shot is to remove impurities, rust, scattered pieces of rubbish or remains that may affect metal strength. It is environment friendly and a rapid, cost-effective surface finishing method which is used for cleaning, polishing metal and other surface by applying high-speed stream of shots. It is used in almost every industry that uses metal like aerospace, automotive, construction, foundry, ship building, rail, etc. At macro level there are two types of shot blasting such as grit blasting and abrasive blasting. In grit blasting, there is particle size sand process called sand blasting processing. Sand is basically used to eliminate foreign deposits, so the polish surface sand blasting surface treatment is to remove the paint or add texture. Meanwhile silica particles are also guided to the surface using air gun. Abrasive blasting is used to implement the height of the wear and tear. Usually abrasive blasting is used in a hard metal surface to clean and reach very high pressure. Meanwhile, it is used quite like small steel ball, broken glass, etc.

Broadly, there are two technologies used in shot blasting – wheel blasting and air blasting. Wheel blasting is the airless blast operation that uses a wheel with centrifugal force to propel the abrasive against the parts. It is a high-velocity, high-efficiency blasting operation with typically quick time cycles for the operation. The purpose is to remove contaminants like mill scale, sand on foundry pieces, old coatings, etc., strengthening the material or creating an anchor profile. One of the most important aspects of the wheel blasting operation is maintaining a balanced working mix, in order to create the right quality of finish and to work as effectively and efficiently as possible. Wheel blasting directly converts electric motor energy into kinetic abrasive energy by rotating a turbine wheel. The capacity of each wheel goes from approximately 60 kg per minute up to 1200 kg per minute. Air blasting is also called as air cannon which is used to clean, peen or polish metal. It is a de-clogging device composed of two main elements such as pressure vessel and triggering mechanism. Air blast machines can take the form of a blast cabinet; the blast media is pneumatically accelerated by compressed air and projected by nozzles onto the component. For special applications a media-water mix can be used, this is called wet blasting. In both air and wet blasting, blast nozzles can be installed in fixed positions or can be operated manually or by automatic nozzle manipulators or robots. The blasting task determines the choice of the abrasive medium in most cases any type of dry or free running abrasive medium can be used.

Shot blasting machines
Shot blasting machine is a kind of casting equipment which cleans or strengthens the surface of the work piece by high-speed running shots. It is a mechanical method of propelling abrasive using a centrifugal wheel to remove surface and other impurities from the surface of steel applications. General, blasting prior to finishing serves three primary purposes such as it cleans and de-scales surfaces, adds texture to enhance paint adhesion and properly reduces maintenance costs by increasing coating life.

Technology upgradation and challenges
In the latest technology development and upgradation, the machines are made in such a way that it becomes more and more user-friendly. The durability of machine is of utmost important in shot blasting technology as the machine is self-destructive and self-eating type. The focus is made to increase the durability of machine by using better metal alloys. “The heart of the machine is blast wheel. It is an upgraded technology to improve life and is easy to maintain. The dust collector is the lung of the machine. The efficiency of the same has been increased to obtain clean air discharge in atmosphere. The media quality is also improved by use of improved alloy and better heat treatment process,” says Chirag Modi, Technical Director, Surface Finishing Equipment Co.

“The current challenge of shot blasting machine lies in development of better and durable machine which gives more life to all the parts. The machine is to be automated by using electronics so that the requirement of skill operator is reduced. Use of robot can be explored to reduce dependents on manual operators,” he adds.

Reducing maintenance
The shots of shot blast machine run in high speed, hence the maintenance of equipment and operation is of high importance. Much attention should be paid during maintenance of shot blasting machine. “Worn out impeller blade, turbine wheel and control cage are the items to be replaced frequently because this machine gets damaged by itself if the high-manganese steel plate, rubber sheet and other protective devices in the shot blast cleaning chamber are worn so replace them immediately. Otherwise, the shots might hit through the wall of the chamber, fly out and hurt the personnel around,” says Vipin Chawla, Proprietor, Vands Engineering Solutions.

“We are specialised in reducing maintenance of machine by providing high-quality spares. New inventions have been made in the material of spare. We provide spares with new materials like high-abrasion resistant castings, tool steel and spares with tungsten carbide coating,” he adds.

Surfex – clean and reliable shot blasting
Surfex offers technically advanced shot blasting machine. The blast wheel has been revamped to improve life and is easy to maintain. The area coming in fire of shot blasting has been made of alloy steels which give life up to 8-10 years. “The liberal use of PLC programme makes operation of the machine extremely users friendly. The dust collector technology is upgraded to meet the latest emission and environment standard. Surfex offers sturdy and robust machine. All the parts of blast wheel are made of high-end alloy, augmenting the life of these parts manyfold,” said Modi.

Surfex offers sturdy and robust machine. All the parts of blast wheel are made of high-end alloy, augmenting the life of these parts manyfold.
Chirag Modi, Technical Director,Surface Finishing Equipment Co.

We provide spares with new materials like high-abrasion resistant castings, tool steel and spares with tungsten carbide coating.
Vipin Chawla, Proprietor, Vands Engineering Solutions