What is Shot Blasting?

After a factory produces a part, it undergoes a final process before finishing, known as pre-finishing. During pre-finishing, the part’s surface is cleaned and primed for painting or drilling. The primary means of cleaning the surface is through shot blasting.

Despite its name resembling sand blasting, shot blasting is vastly different in terms of surface treatment and cleaning. Shot blasting is a highly aggressive method for surface treatment that is typically used on larger and tougher surfaces.

In essence, shot blasting involves propelling “shots” onto a surface that needs to be cleaned using an industrial machine powered by centrifugal or mechanical force. Unlike traditional methods that use pressurized air, shot blasting uses a spinning wheel to hasten the delivery of the selected abrasive.

Technologies of Shot Blasting

While the surface treatment industry has a variety of available technologies, shot blasting mainly employs two abrasive delivery methods.

Wheel blasting

Wheel blasting was first carried out using air for abrasive delivery. However, spinning wheels were later employed to maximize efficiency and output power. These wheels were designed with centrifugal force in mind and could disperse a greater amount of abrasive over an exposed surface.

The typical speed of a Shot Blasting machine ranges from 65 to 110 meters/second. Moreover, the dispersal area was spacious enough to ensure uniform cleaning or treatment of a surface. From 60 kg/min to nearly 1200 kg/min, the amount of abrasive delivered quickly not only cleaned the surface but also did it efficiently. Therefore, wheel blasting is a preferred method for large-scale work.

Air Blasting

While wheel blasting requires minimal power, air blasting is a power guzzler. Air blasting is still utilized in certain sectors as it was the initial form of the shot blasting process.

This method of abrasive delivery is akin to sand blasting, where compressed air propels shots onto targeted surfaces. However, the limitations of this process become apparent when larger forces are required. For the same amount of abrasive delivery, air blasting requires 16 times more horsepower than wheel blasting.

Additionally, the number of workers required to operate a high-powered air blasting machine is exponentially larger compared to the two workers needed to safely operate a wheel blasting machine.

Process of Cleaning in an Industrial Shot Blasting Machine

When manufacturing a metal or non-metal part in a factory, it does not emerge as the shiny, polished product seen in showrooms or retail shops. Prior to achieving that final appearance, it is vital to remove all oxides, uneven surfaces, and other impurities from the surface of the part.

Performing this process by hand is neither efficient nor safe. This is where shot blasting machines are used in many manufacturing plants. These machines are large, highly efficient, safe, and user-friendly. Here are the steps involved in pre-finishing a part using a shot blasting machine.

Handling and feeding. The first step in most industrial production processes is the delivery of parts to the machine. The parts to be cleaned are brought to the conveyer belt, rolling table or tumbler depending on the size of the part.
If smaller parts in large quantities are to be cleaned then they are fed to a tumbler where the central part moves in a circular motion, while inlets are used for abrasive delivery. For gears and spare components, special tables are used while the pipes are fed into the machine with the help of a continuous process.
Blast cabinets. The blast cabinet is where the magic happens. There are openings and closings that allow parts to enter and exit smoothly. Blast cabinets are where the parts to be cleaned meet with the abrasive delivery system and the cleaning process begins.
Since there are abrasives flying all over the place, the blast cabinets are sealed and the inner linings of the cabinets are made of abrasive resistant materials. The cabinets are also connected with the dust collector system to keep the cabinet and the environment clean.

Inside the cabinet shots are propelled at high speed against the work surfaces to be cleaned as the parts enter from one sealed opening and comes out of another sealed exit.
Abrasive delivery. As mentioned earlier, either of the two technologies are used for the purposes of abrasive delivery. Whether it is air blasting or wheel blasting, they are both connected to the blast cabinet.
With specific nozzles or openings in the blast cabinets, high speed abrasives are delivered. They bounce off against the surface of the part produced, cleaning it in the process, and the dust created is collected separately.
Dust collection. One of the main reasons why manual cleaning of the parts produced is largely discarded is because of the cost and also the environmental impact of the dust production. Oxides, metal and non-metal small particles are released into the air, all of them are harmful for the workers as well as the environment.
Wearing protective gear does the trick but still the environment and workspace are made dirty due to the dust flying everywhere. This is where shot blasting has an advantage as it is a controlled process where the release of dust can also be controlled.

Inside the blast cabinets dust is created after the abrasives come in contact with the work surface. Those dust and abrasives are collected separately so that the abrasive material can be refed into the cabinet, while dust can be discarded.

The dust collected is then disposed of properly so that the impact on the environment is less, the workers can be protected and the environment can be kept clean.

So, Sandblasting or Shot Blasting, What Should You Use?

Well, the answer to that question depends on your specific needs. If you have small parts, sandblasting can be a cost-effective approach, as can shot blasting for large quantities.

However, industrial operations often find shot blasting more economical as it processes components of varying sizes. Sandblasting, meanwhile, is a technology worth considering for its portability and relative ease of use.

Eurobalt® for Your Shot Blasting Needs?

You have the option of choosing between sandblasting and shot blasting, depending on your needs. Eurobalt Engineering provides both possibilities to meet your production requirements. You can select either option for machined, cast, or sintered parts, and our team of skilled workers will complete the job.

Our factories are equipped with both sand and shot blasting machines, so simply inform us of what you require for the production of your goods and we will handle the rest, including surface cleaning. We offer pre-finishing services and also provide powder coating to give your parts the desired look and protection.

So, whether you prefer to call us, shoot us an email, or fill out the form on our website, let us know your manufacturing requirements.

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