In several industries, abrasive blasting is used to prepare, finish, and clean the surfaces of various materials, such as glass, wood, polymers, and metals. Compared to chemical cleaning, surfaces can be cleaned much more quickly and efficiently to facilitate the effectiveness of additional treatments or for aesthetic reasons.
To maintain their structural integrity and increase their lifespans, metals like steel require corrosion protection, which is why they find widespread application in the building and manufacturing industries.
It is necessary to thoroughly clean and prepare the surfaces of these materials before applying protective coatings. Most applications now use abrasive blasting as their method of choice for surface preparation and cleaning.
In this reading, we’ll explore what abrasive blasting is, its applications, history, types, diagram, components, and how it works. We’ll also learn some benefits of abrasive blasting.
Let’s get started!
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What Is Abrasive Blasting?
Abrasive blasting is the process of removing paint, corrosion, or other particles from a surface using a high-pressure blast of water or air. It is frequently used to get surfaces ready for painting or other finishing techniques, and it can be used on both metal and non-metal surfaces. Sometimes, graffiti on buildings or other structures is removed using this method.
With the right safety precautions in place, abrasive blasting is simple and effective. But if not done correctly, abrasive blasting can also be dangerous. Small particles can cause illnesses like silicosis when they get into an operator’s lungs. Some people may experience an allergic reaction to some natural blast media, including corn cobs or walnut shells, which could lead to anaphylactic shock.
Application Of Abrasive Blasting
Abrasive blasting is used in several industries, including:
- Construction and contracting.
- Metal casting and foundry work.
- Shipbuilding and hull cleaning.
- Metal finishing.
- Concrete.
- Automotive repair and restoration.
- Painting.
- Surface coating or powder coating.
- Surface preparation.
- Monument engraving.
- Welding.
- Glass work, such as etching, decorating and engraving.
History Of Abrasive Blasting
Benjamin Chew Tilghman patented abrasive blasting in 1870. Observing water and wind-blown sand erosion presumably inspired the idea. Sand was the first abrasive, but inhaling silica particles caused silicosis, a deadly respiratory condition.
The air processor enabled industrial sandblasting in 1893. Thomas Pangborn used compressed air to Tilghman’s blast system in 1904 to make a metal-cleaning sandblaster. After that, in 1918, the first sandblasting enclosure was built. This was a forerunner of today’s abrasive blast cabinets.
This early enclosure had a window to view the blasted object and a barrier to prevent workers from inhaling dust. At this time, exhaust fans were introduced. New abrasive media were introduced in 1939, many of which are still used today.
Types Of Abrasive Blasting
Sandblasting
Sandblasting equipment blasts dry silica abrasive particles at a part. It blasts silica or quartz abrasives onto surfaces. The sharpness and size consistency of the abrasive made it ideal for uniform finishing.
These particles will easily remove any impurities from the part’s surface because of their lightning-fast speed. Sandblasting is used for metal corrosion removal. The mechanism fires dry abrasives with air pressure.
A handheld nozzle ejects air and abrasive sand. Environmental regulations limit sandblasting’s use in open spaces. Health risks include silicosis from the silica used. Due to the risk of inhalation or pollution, this method is no longer recommended for abrasive blasting.
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Wet blasting
Wet blasting was created to solve air blasting’s biggest problem—controlling airborne dust. This device injects water into the nozzle near the high-air-pressure abrasive’s exit. Some models mix water and abrasive before ejecting it via the nozzle.
In either instance, air, water, and abrasive particles leave the nozzle and hit the surface at high pressure to clean it. The cleaning byproduct must be contained and disposed of according to environmental standards.
Vacuum Blasting
Vacuum blasting is dustless. This uses a blasting machine with vacuum suction to remove pushed abrasives and surface impurities. The control device immediately sucks these materials back in. Vacuum blasting recycles used abrasives more efficiently and cheaply. It also reduces cleaning debris. But the recycling feature makes vacuum blasting slower than other approaches.
Centrifugal Blasting
Wheel blasting is another name for centrifugal blasting. In this method, a motor-operated blade wheel shoots abrasives at the surface at high speeds. The lack of pressurized air pressure makes this procedure more beneficial. It cleans better and generates more consistent surfaces.
Centrifugal blasting is larger and less portable. It cannot work on inconsistent services. Centrifugal blasting debris is collected by a collector and recycled. This makes it a good option.
Soda Blasting
Recently developed soda blasting employs air pressure to blast sodium bicarbonate onto the surface. Sodium bicarbonate removes impurities from materials’ surfaces well. The abrasive shatters on impact, clearing impurities. This type of abrasive blasting is less aggressive and demands less force. They work on chrome, plastic, and glass.
Steel Grit Blasting
Steel grit blasting uses spherical steels. This technique is frequently applied while trying to clean metal surfaces. It effectively removes paint and rust from steel surfaces. Steel grit also smooths surfaces and hardens metal via peening.
In this process, steel can also be substituted with other materials like silicon carbide, aluminum, and walnut shells. Cleaning depends on the surface.
Bristle Blasting
Bristle blasting is the only cleaning method that does not use an abrasive. This approach removes impurities by directly rotating steel wire bristles against the substance. The surface is smooth and consistent. This approach is popular for cleaning corroded metal surfaces.
Dry-ice Blasting
Dry-ice blasting is an unusual abrasive blasting method. High-pressure air and carbon dioxide pellets clean the surface. The carbon dioxide is non-toxic and does not react with the pollutant on the part surface, making it excellent for cleaning food processing equipment.
Cold-freezing liquid carbon dioxide creates dry ice pellets. These pellets look like snow and cause a thermal shock when they hit the surface at fast speed. This shock breaks surface-contaminant bonds, dislodging it. The pellets vaporize at higher temperatures.
This method is fast and clean. No abrasive needs recycling or cleanup. Non-reactive carbon dioxide pellets are eco-friendly. No abrasion occurs. Cleaning pellets remove impurities without damaging surfaces. Also ideal for cleaning sensitive electrical components.
Pencil Blasting
Micro-blasting, or pencil blasting, uses high-pressure air and fine powder to provide an abrasive. This abrasive exits a small nozzle in a precise stream to clean specific surfaces. The fine-sized nozzle allows these devices to regulate pressure for more than surface cleaning.
It can drill, deburr, and cut surfaces. Some even scratch glass and change diamond surfaces. In precise situations, pencil blasting is most useful.
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Bead Blasting
These glass beads polish, deburr, and peen metal. Spherical glass beads form micro-dimples as they hit. It produces a more consistent aggregate finish. The glass beads are 100% recyclable, making it cost-effective.
The finish is cleaner and brighter with glass beads. Glass beads make the abrasive non-toxic and eco-friendly. On aluminum, delicate glass beads look drab or slick. However, coarser beads finish uniformly but roughly.
Diagram Of Abrasive Blasting
Component Of Abrasive Blasting
Abrasive blasting involves the use of a number of pieces of equipment, from the blast pot and the operator blasting cover to the blasting hand glove. The major components of abrasive blasting include:
Abrasive Blast Pot
When abrasion is needed, this is the primary part of a blasting system that manages and retains the grit or sand. It helps with surface preparation for coating and painting applications in sand and grit blasting procedures. Additionally, it is the perfect tool for removing rust and paint off substrates.
Blasting Coverall
Blasting coveralls protect blasters from the dangers of abrasive blasting materials. The blasting coverall is almost the most crucial piece of personal protection equipment used in abrasive blasting. During any hazardous process, blasters are kept safe, secure, and comfortable by wearing blasting coveralls.
Blasting Helmet
When blasting, blast operators can protect their breathing and stay protected from dust, sand, and shot by using a blasting helmet. The blasting helmet is very effective equipment that includes an air-feed hose, a view window with a replaceable lens or lens protection, and a head suspension mechanism that allows the device to move with the operator’s head.
Breathing Hose
A breathing hose, also called an air line, is a tube or hose that brings compressed air from the air compressor or air tank to the blaster’s mask.
CPF (Air filter unit)
Before pressurized air enters your respirator, a device called a CPF, or air filtration unit, filters out moisture, oil, and dirt particles. This device lets you breathe in air that is quickly dangerous to your health or life.
Blasting Hose
Abrasive blasting systems cannot work without blasting hose. The purpose of blasting hoses is to supply abrasive materials for use in jet engines and blast cleaning facilities.
Blasting Nozzle
A blasting nozzle is a tool used to quickly apply air and an abrasive blasting mixture to a material’s surface that has pitting and requires repair, followed by corrosion protection. A blasting nozzle is attached to the end of the hose, which is used to discharge the mixture of air and abrasive.
Tungsten carbide, aluminum, boron carbide, and silicon nitride are some of the materials that make up an air blasting nozzle. These can handle the force and pressure at the exit tips of the nozzle while spraying abrasive and pressurized air at high speed and pressure on a surface that has flaws or corrosion.
Dead-man Hose
The tube that transports and holds compressed air supply from the air compressor or air tank to the sand pots dead-man unit and switch is known as a dead-man hose or twin air-line.
Dead-man Control Switch
Sandblasting machines often have a dead-man control switch or handle that allows the operator to remotely turn on and off the machine. If the operator drops the handle or loses control of it, these fail-to-safe handles will stop blasting.
Blasting Hand gloves
It is necessary to wear hand gloves during abrasive blasting procedures because of the hazardous nature of the process and to protect blasters from abrasive materials that could injure or damage their hands.
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How Does An Abrasive Blasting Work?
An abrasive blast system usually consists of the following three components, which include a blasting pot, a propelling device, and a blasting nozzle. The media is typically propelled to the blasted surface by compressed air or a wheel driven by centrifugation.
You can reuse and recycle the media in a blast room, shot blaster, or blast cabinet until it is all gone. It is possible to recycle or dispose of the discarded media in outdoor blasting.
The first blast cabinets were wet blast cabinets, which employed a slurry blasting technique in which abrasive media is blasted via a nozzle after being mixed with water. They would then reuse this slurry mixture.
The development of dry blasting chambers allowed for the use of a greater variety of abrasives. Direct pressure systems and siphon systems are the two types of dry blast cabinets. The media in a siphon system blast cabinet is drawn from a hopper within the cabinet and then forced through the blasting gun by compressed air.
A siphon blast system can run for extended periods of time without interruption. A pressure pot accelerates media through a blast hose and nozzle in a direct pressure blast cabinet. Direct pressure blasting systems provide a few benefits.
First, compared to a typical siphon system, the blasting process is more effective and can be completed faster. Second, unlike conventional sandblasting cabinets, direct pressure systems can handle heavier media.
Wet blasting employs the propulsion of water to clean the surface, whereas dry blasting uses the impact of the propelled media to influence the blasting surface. This is one of the primary differences between the two methods.
If you want a more precise surface profile, wet blasting, also known as dustless blasting, is usually the better option.
Benefits Of Abrasive Blasting
There are many benefits to abrasive blasting in a variety of sectors and applications:
Efficient Surface Preparation
Abrasive blasting works incredibly well for getting surfaces ready for bonding, painting, or coatings. It effectively gets rid of scale, rust, old paint, and other impurities, leaving the surface clear and ready for further treatments.
Precision and Control
By modifying variables like pressure, nozzle type, and abrasive substance, operators can precisely regulate the blasting process. With this level of control, treatment can be focused, making sure that only the material that needs to be removed is removed.
Conservation & Restoration
Abrasive blasting is a crucial technique in historical preservation and restoration projects because it can gently remove old coatings, filth, and grime from delicate surfaces, restoring them to their original splendor.
Better Adhesion
Abrasive blasting improves the adhesion of paints, coatings, and adhesives by producing a clean, roughened surface. This results in better performance and finishes that last longer.
Environmental Benefits
Abrasive blasting may be environmentally beneficial, depending on the type of abrasive material the process uses. Some non-toxic and recyclable alternatives include baking soda and broken glass.
It can be a very quick process, which enables quick surface treatment and preparation. This is especially crucial in industries where productivity and efficiency are essential.
Effective Cleaning
This technique works well for cleaning big surfaces or intricate constructions like tanks, bridges, and industrial machinery. Abrasive blasting can get to places that other cleaning techniques might find difficult to reach.
Versatility
It works with many different materials, such as concrete, metal, glass, wood, and more. Because of its adaptability, abrasive blasting finds use in a wide range of industries, including construction, automotive, aerospace, and art restoration.
Customizable Finish
There are many different surface finishes available, ranging from a smooth, even surface to a textured, roughened one, depending on the abrasive substance, pressure settings, and blasting technique used.
Cost-Effective
When working with large or complex structures, abrasive blasting is frequently more economical than other surface preparation or cleaning techniques.
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FAQs
What is the abrasive blasting process?
Abrasive blasting, also known as sandblasting, uses high-pressure abrasive material to smooth, roughen, shape, or remove surface impurities.
The right phrase is Abrasive Blasting, not Sandblasting. Modern industry uses sandblasting and abrasive blasting. Airborne abrasives remove the top layer of a substrate, coating, contaminant, or corrosion.
What material is used for abrasive blasting?
Plastic and metal blasting materials include plastic grit, steel shot, aluminum oxide, cut wire, and copper slag. These strong, adaptable materials are ideal for heavy-duty industrial applications, granite and marble surfaces, and deep etching.
How many types of abrasive blasting are there?
Blasting can be dry or wet, depending on the particle environment. Wet blasting comprises wet shot blasting and wet blasting, while dry blasting covers sand, blower, and shot blasting.
How loud is abrasive blasting?
Abrasive blasting typically produce 112 to 119 dBA when air is discharged from the nozzle.