What is Shot Blasting?

After a part is manufactured in a factory, it goes through one final process before finishing, it is called pre-finishing. In pre-finishing the surface of the part is cleaned and prepared for painting or drilling. A primary method of cleaning the surface of the part is shot blasting.

While the name “Shot blasting” may sound similar to sand blasting, the processes are drastically different when it comes to cleaning or surface treating. Shot blasting is a highly aggressive way of surface treatment which is used for tougher and larger surfaces.

To put it simply, shot blasting is a process where the “shots” are propelled by an industrial machine at the surface to be cleaned with the help of centrifugal or mechanical force. Instead of pressurized air, shot blasting utilizes a spinning wheel to accelerate the delivery of the selected abrasive.

Technologies of Shot Blasting

While the surface treatment sector has different technologies, shot blasting primarily utilizes two methods of abrasive delivery

Wheel blasting

Wheel blasting: While initial air was used for the purposes of abrasive delivery, later spinning wheels were used to increase efficiency and output power. The wheel was used with centrifugal force in mind and also the ability to disperse a higher amount of abrasive on an exposed surface.

The speed of a normal Shot Blasting machine ranges from 65 to 110 m/s. Also, the dispersal area was large which meant a surface was cleaned or treated uniformly. From 60 kg/min to almost 1200 kg/min the quantity of abrasive delivered in a short period of time not only made the surface cleaner but also did it in a short amount of time. This is the reason why wheel blasting method is popular in large scale work.

Air Blasting

Air blasting. Air blasting is still utilized in certain sectors, it was the first iteration of the shot blasting process. This method of abrasive delivery is similar to that of sand blasting where compressed air was used to propel shots on targeted surfaces.

The limitation for this process is exposed when larger forces are required. While wheel blasting works with little power, air blasting is a power guzzler. For the same quantity of abrasive delivery, air blasting method requires 16 times more horse power than wheel blasting.

The numbers of workers needed to operate such a high-powered air blasting machine was also exponentially large while two people could operate a wheel blasting machine safely.

Process of Cleaning in an Industrial Shot Blasting Machine

When a metal or non-metal part is manufactured in a factory, it does not come out as the shiny product seen in the showrooms or retails shops. Before all the shine and colour, oxides, uneven surfaces and other impurities from the surface of the part are removed.

While it can be done by hand, the process is neither safe, nor efficient. This is where most manufacturing plants use shot blasting machines. They are large, extremely efficient, safe, and easy to use. Here are the steps that go into 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 purely depends on the need you have. If the parts are small in size and volume, then sandblasting is an economical approach, while the same can be said about large quantities and shot blasting.

It is quite economical for an industrial operation to use shot blasting as components of different sizes need to be processed. While the portability and relative ease of use makes sandblasting a technology to have.

Eurobalt® for Your Shot Blasting Needs?

You can choose sandblasting and shot blasting depending upon your need. Eurobalt Engineering offers you both possibilities for your production needs. When working with us, you can choose either of the choices for the machined, casted or sintered parts we manufacture and it will all be done by experienced workers.

We operate both sand and shot blasting machines in our factories, so tell us what you are manufacturing and we will make it and clean the surface for you. We can do the pre-finishing and, if you want, we can do the finishing as well, with powder coating, to give your parts the look and protection you desire.

So, pick up the phone, write us an email, or head on over to our forms page and tell us your manufacturing needs. We are fast, we are thorough, we are experienced, and we are looking forward to hearing from you.

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