Fundamentals of Blast Processing

Blast processing is a surface treatment and finishing method in which abrasive particles—referred to as blasting media—are propelled onto the surface of a workpiece. Through this impact, operations such as cutting, cleaning, polishing, and surface modification can be performed.

Blast processing includes several types of technologies, such as:

  • Air Blast (Sand Blast)

  • Shot Blast

  • Wet Blast

  • Dry Ice Blast

Blast processing is widely used in industries such as automotive manufacturing, shipbuilding, aerospace, and electronics. Its applications are diverse and include surface preparation, matte finishing, deburring, shot peening, and mold polishing.

◆ Characteristics and Advantages of Blast Processing

What kind of processing method is it?

  • Blast processing is a physical processing method that changes the surface structure of a product by propelling abrasive media at high speed onto the surface.
  • Unlike chemical treatments such as etching, electropolishing, or acid pickling, blast processing does not rely on chemical reactions and therefore does not impose excessive hazards on operators.

◆ What kind of surface does it produce?

Uniform Non-Directional Surface.

During blasting, countless abrasive particles are propelled by air and randomly collide with the surface, forming a uniform surface texture without directional patterns.
This type of surface can provide various functional benefits, including improved durability, enhanced adhesion, and better sliding or friction characteristics.

◆ What materials can it be applied to?

Applicable to Various Materials

By selecting appropriate blasting media—considering material type, shape, and particle size—blast processing can be applied to a wide variety of materials such as metals, ceramics, glass, and plastics.


Among various surface processing technologies, blast processing has fewer limitations regarding the material, shape, or size of workpieces compared with other methods such as machining, etching, chemical conversion treatment, or coating. This flexibility allows it to be applied to a wide range of products.
Replacing conventional processes with blast processing can improve productivity and product quality, helping many manufacturers resolve challenges in their production processes.

For surface coating processes such as plating, painting, or coating, blast processing can create an optimal base surface that significantly improves adhesion. Therefore, it is often used not only as a standalone process but also as a pre-treatment or base preparation step to achieve better overall results.


The industrial origin of blast processing dates back to 1870 in Philadelphia, USA. Benjamin Chew Tilghman was inspired by the phenomenon of desert sand being blown against window glass and causing abrasion. He patented this concept and named the process the “Sandblast Method.”.

With the development of synthetic abrasives, modern sandblasting has evolved beyond the use of natural sand. Today, various blasting media are used, including metal, resin, and ceramic abrasives.

As a result, this technology is also referred to as Air Blast or Abrasive Blasting. Depending on the shape of the blasting media used, it may also be called Bead Blasting or Grit Blasting.


◆ Quality Improvement through Pre-Treatment for Adhesion, Coating, and Thermal Spraying

Blast processing is widely used as a surface preparation step before bonding, coating, or thermal spraying. Some applications are also defined by standards such as JIS.

In this process, abrasives with strong cutting ability are used, such as:

  • Alumina (Product name: Fujirandom A / Fujirandom WA)

  • Steel grit

By blasting these abrasives at high speed, rust and contaminants on the surface are removed while simultaneously forming a uniform surface roughness without directionality.

Such clean surfaces with increased surface area provide several benefits:

  • Improved adhesion

  • Prevention of uneven coating

  • Reduction of internal corrosion

Examples:

  • Pre-treatment before coating bridge components

  • Surface preparation for heavy anti-corrosion coatings on steel structures

  • Plating pre-treatment of high-strength bolt joints

  • Adhesion preparation for electronic components

  • Teflon coating preparation for home appliances

◆ Improved Appearance through Matte (Nashiji) Finishing

Nashiji finishing is a surface treatment technique that creates fine uneven textures on metal surfaces, producing a unique tactile feel and soft luster.

This process is also referred to as:

  • Nashiji finishing

  • Matte surface treatment

By adjusting the type and particle size of abrasives, a variety of soft luster textures can be produced.

Examples:

  • Matte finishing of large stainless steel panels used in construction

  • Anti-glare treatment for medical equipment and measuring instruments

  • Scratch removal on stainless steel products

◆ Efficient Cleaning and Surface Cleaning for Reuse

Blast cleaning is a method in which abrasive media are blasted at high speed to remove contaminants from surfaces quickly and easily.

Compared with manual cleaning, it is more efficient. Compared with chemical cleaning processes, it presents fewer hazards to operators, making it a safe and efficient cleaning method widely used in many industries.

Examples:

  • Removal of residual resin from injection molding machine screws

  • Cleaning residual resin from molds

  • Dry ice cleaning of food production lines

  • Cleaning jigs used in vacuum deposition equipment

◆ Deburring and Post-Processing such as Removal of Casting Sand

Post-processing by blasting refers to the removal of burrs, unwanted projections, and casting sand generated during machining or forming processes.

High-speed abrasive blasting effectively removes:

  • Burrs from plastic or metal parts

  • Residual casting sand and core sand

Because countless abrasive particles impact the workpiece simultaneously, even narrow grooves and inner diameters that are difficult to process manually can be cleaned reliably.

Examples:

  • Removal of resin burrs from molded lead frames in electronic components

  • Deburring aluminum die-casting parts

  • Removal of internal casting sand from industrial equipment components

  • Sand removal in lost-wax casting processes

◆ Durability Improvement through Shot Peening

Shot peening is a cold working process in which spherical particles called shots collide with the surface of a workpiece at high speed.

This process induces plastic deformation and compressive residual stress on the surface, resulting in:

  • Suppression of crack propagation

  • Increased surface hardness

  • Improved wear resistance

Examples:

  • Automotive gears and shafts

  • Micro-particle peening for mold components and tools

◆ Productivity Improvement by Creating Surface Texture (Gemini Treatment®)

By creating a uniform textured surface with micro-irregularities, the actual contact area of sliding surfaces can be reduced, thereby improving sliding performance.

Because frictional resistance is reduced, applying this treatment to components used in production equipment can improve overall productivity.

Since the surface texture is directly formed on the material itself, there is no risk of peeling as seen in coating processes.

Examples:

  • Prevention of powder adhesion in food factory hoppers

  • Prevention of powder adhesion on plastic mesh and metal sieves

◆ Defect Reduction in Plastic Molding (Improved Resin Flow and Mold Release)

The uniform surface texture created by blast processing, ranging from nanometer to several micrometer levels, reduces the contact area between molten resin and the mold surface.

This allows the resin to maintain better flow and move smoothly during molding.

Directional polishing marks can create resistance when resin shrinks. However, the non-directional uniform surface structure created after MKS treatment improves multidirectional sliding performance and reduces resin adhesion during shrinkage, thereby improving mold release performance.

Examples:

Improvement of mold-related molding defects such as:

  • Sink marks

  • Short shots

  • Voids

  • Bridge defects

◆ Quality Improvement through Mirror Finishing and Polishing (SIRIUS-Z®)

SIRIUS-Z is our proprietary technology that further evolves blast processing to facilitate precision polishing and finishing.

Using SIRIUS-Z, even non-skilled operators can perform polishing easily and uniformly, and automation can also be implemented easily.

This technology is particularly effective for polishing complex shapes, narrow grooves, and internal diameters, and it is suitable for mass production processing.

Examples:

  • Polishing molds used in musical instrument manufacturing

  • Removal of coating droplets from drill tools and cutting tool

Manufacturing environments continue to evolve with time, and industries face various challenges such as:

  • Improving production efficiency

  • Enhancing product quality

  • Reducing environmental impact

In this context, blast processing plays an important role and continues to contribute to solving these challenges through technological advancements.


Automation and Labor Reduction in Blast Processing

Automation in blast processing equipment is rapidly advancing.

Because air blasting uses nozzle systems, robots can hold blasting guns and perform automated processing.

Automation provides several advantages:

  • Reduced processing time

  • Mitigation of labor shortages

  • Easier quality control and consistency

Additionally, the use of robots enables precise blasting of complex shapes and large components, expanding the range of industrial applications.

Ultra-Fine Particle Peening: Alpha Treatment®

As products become lighter and more compact, components are becoming smaller and thinner, creating durability challenges.

Alpha Treatment is a life-extension technology applicable to precision components.

Based on our proprietary high-precision blasting technology, this peening process forms a strengthened surface layer through nanocrystalline strengthening, without significantly changing the dimensions or shape of the component.

At the same time, the formation of micro-textures improves sliding performance.

This technology is widely used in:

  • Cutting tools and blades

  • Precision press molds (punches and dies)

  • Gear reducers and other industrial components.

Finishing of 3D Printed Parts

The 3D printing market is rapidly expanding, particularly in aerospace and automotive industries where additive manufacturing is widely used for production and prototyping.

However, because 3D printing is a layered manufacturing process, surfaces often contain visible step marks called layer lines, which require significant time and labor to remove.

Using Pollux technology, both metal and resin 3D printed parts can be efficiently processed for:

  • Removal of layer lines

  • Surface visualization (transparency improvement)

  • Precision polishing

This significantly improves finishing efficiency.


Power Micro International Company offers comprehensive surface-engineering and anti-adhesion solutions to eliminate soldering/erosion defects and enhance productivity.


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