What is Shot blasting?
Shot blasting is a surface treatment process used to clean, strengthen (impart new properties e.g. peening), or polish metal and other materials. It involves the high-speed propulsion of abrasive materials, such as steel shots, grits, or other media, onto the surface of a workpiece. The force of the impact removes surface contaminants like rust, paint, and scale, and can also prepare the surface for further processes like coating or painting.
Key Components and Process of Shot Blasting:
Blasting Media: The abrasive materials used in shot blasting, such as steel shots, steel grits, or sand. The choice of media depends on the material being treated and desired surface finish.
Blasting Machine: This is the equipment used to perform the shot blasting. It consists of a blast wheel or nozzle that propels the abrasive media at high speed towards the workpiece.
Workpiece: The material or component being treated. This could be metal parts, concrete surfaces, glass, or other items requiring surface preparation or cleaning.
Containment and Recovery System: A system that contains the blasting process to prevent the spread of dust and debris, and recovers the used abrasive for reuse.
Different types of Shot Blasting
Wheel Blasting: A centrifugal wheel mechanism is used to propel the abrasive media at high speeds. It’s typically used for larger, bulkier items and is common in automated production environments.
Air Blasting: Compressed air is used to fire the abrasive media through a nozzle using either a suction fed or direct pressure fed system. This method is more precise and is often used for smaller, more intricate parts or surfaces. It often utilises abrasive types such as aluminium oxide, glass beads and plastic media.
What are the benefits of shot blasting?
Effective Surface Cleaning
Removal of Contaminants: Shot blasting efficiently removes rust, paint, scale, and other surface contaminants, leaving the material clean and ready for further processing.
Uniform Cleaning: The process ensures a consistent and even cleaning across the entire surface, which is crucial for maintaining the quality of the workpiece.
Surface Preparation
Enhanced Adhesion: By roughening the surface, shot blasting improves the adhesion of coatings, paints, and other surface treatments, ensuring they bond better and last longer.
Preparation for Welding and Coating: The process is commonly used to prepare surfaces for welding or coating, ensuring that the subsequent layers adhere properly and perform as expected.
Improvement of Mechanical Properties
Increased Durability: Shot peening, a type of shot blasting, induces compressive stresses on the surface of metal parts, which enhances their fatigue resistance and extends their lifespan.
Stress Relief: It helps relieve tensile stresses that may have been introduced during manufacturing processes, reducing the risk of cracking or failure under load.
Cost Efficiency
Reduced Labour Costs: Shot blasting is a highly automated process that requires less manual labour compared to traditional methods like sanding or chemical cleaning.
Material Recycling: The abrasive media used in shot blasting can often be recycled and reused multiple times, reducing material costs.
Speed and Efficiency
Fast Process: Shot blasting is much faster than manual cleaning or sanding, which speeds up production and reduces lead times.
Large-Scale Processing: It is particularly effective for handling large quantities of parts or large surfaces, making it ideal for industrial applications.
Enhanced Product Quality
Defect Detection: The process can reveal surface defects that were previously hidden, allowing for timely correction and ensuring higher-quality finished products.
Improved Surface Uniformity: Ensures a consistent texture, which is essential for high-quality coatings and finishes.
Equipment for shot blasting
- Wheel Blasting Machines: These machines use a centrifugal wheel to propel abrasive media at high speed. They’re typically used for larger, bulkier items and continuous production lines.
- Air Blasting Machines: These use compressed air to propel the abrasive media through a nozzle. They are more precise and are used for smaller, more intricate parts or for surfaces that require specific attention.
- Cabinet Blasters: Enclosed units where the blasting occurs in a contained environment, often used for small to medium-sized parts.
- Portable Blasting Machines: Mobile units that can be moved to different locations, ideal for on-site work like cleaning or preparing large structures.
- Automated Systems: Integrated into production lines for continuous, high-volume processing. These systems often include conveyor belts, rotating tables, or robotic arms.
Cabinet Shot Blasting Equipment
Cabinet Shot Blasting Equipment
Rosler Blast Cabinets with turntables and rotating baskets for automation
Cabinet Shot Blasting Equipment
Cabinet Shot Blasting Equipment
Micro Shot Blasting Units
Micro Shot Blasting Units
Cabinet Shot Blasting Equipment
Cabinet Shot Blasting Equipment
Cabinet Shot Blasting Equipment
Blasting Media (Consumables)
- Steel Shots: Spherical in shape, steel shots are commonly used for cleaning, peening, and surface preparation of metals. They are durable and can be reused multiple times.
- Steel Grit: Angular in shape, steel grit is more aggressive than steel shots and is used for removing heavy rust, scale, or paint.
- Aluminium Oxide: A sharp, angular abrasive used for etching, cleaning, and surface preparation. It is suitable for harder surfaces.
- Glass Beads: Used for creating a smooth, polished finish, often in decorative applications or for gentle cleaning.
- Garnet: A natural abrasive with sharp edges, used in blast cleaning and cutting. It’s environmentally friendly and can be recycled.
- Silicon Carbide: A very hard abrasive, used for aggressive blasting on hard surfaces like glass, stone, and ceramics.
- Plastic Media: Used in delicate applications where the surface must not be damaged, such as aerospace components or soft metals.
- Corn Cob and Walnut Shells: Organic, biodegradable media used for gentle cleaning or finishing, often in the restoration of antiques or delicate surfaces.
Shot Blasting Equipment
Shot Blasting Equipment
If you are currently using shot blasting to achieve your surface finish – but have questions or need any guidance then give us a call.
We also have experts out on the road who would be delighted to come and see your applications and advise on shot blasting for you. Let us know if you would like a visit.