月: 2022年12月

What Is a Powder Mixer?

Powder mixing plays a crucial role in various industries, including the food and pharmaceutical sectors. Powder mixers are the primary equipment used for this purpose.

Powder mixers are specifically designed to achieve uniform mixing of powders. Unlike liquids, powders lack fluidity, making manual mixing limited. Therefore, dedicated powder mixers are indispensable for thorough powder blending.

There exists a wide range of powder mixers, each differing in shape and operational principles. The choice of a powder mixer should consider factors such as the powder’s type, specific gravity, and weight.

Uses of Powder Mixers

Powder mixers find applications in various industries, including the food and pharmaceutical sectors.

1. Food Industry

Powder mixers are employed in the production of powdered food products.

2. Pharmaceuticals

Given that pharmaceutical products are administered to humans and animals, ensuring the uniformity of key ingredients is of utmost importance. Powder mixers are crucial in pharmaceutical manufacturing to achieve this uniformity.

3. Chemical Industry

Powder mixers are utilized in the production of various powder-based products, such as resin powders, explosives, uranium powders, pesticides, and powder coatings.

Principle of Powder Mixers

Powder mixers can be categorized into two main types based on their shape, each with its underlying principles.

1. Rotating Vessel Type

This type of powder mixer achieves blending by rotating the container, ensuring that the entire powder inside is mixed uniformly. It effectively utilizes the container’s internal space and minimizes powder breakage by not using blades, as in the agitator type.

Container-rotating type mixers include the W-type mixer, known for high-precision blending, the V-shaped mixer, ideal for rapid and uniform mixing, and the drum-type mixer, which utilizes a sealed drum container filled with powder.

2. Agitation Type

In this type of mixer, blades are installed within a container, and powder is mixed as the blades rotate. It offers advantages such as requiring less installation space and ensuring safety, as the blades are enclosed within the container.

Examples of agitation-type mixers include ribbon mixers, which employ ribbon-shaped blades, and conical screw mixers, featuring a screw inside a conical vessel for mixing.

What Is a Tubular Furnace?

A tubular furnace is a long, cylindrical furnace, typically electric, with heating elements and heat-resistant materials around the internal tube. This structure enables uniform heating, precise temperature control, and adaptable temperature distribution. It’s efficient for direct heating and processing of materials within the tube and offers controlled flow and reaction management. However, design and operational mechanisms can vary significantly based on specific use and construction.

Applications of Tubular Furnaces

Tubular furnaces are used in various applications, including heat treatment, pilot production testing, and R&D. Specific uses include:

1. Heat Treatment Process

For heat treatment of metallic materials and ceramics, especially in quenching and tempering of steel materials, to alter microstructures and properties.

2. Research and Development

In R&D, they are used for the heat treatment of semiconductors, fuel cell material development, and catalyst development, especially in petroleum refining and petrochemicals.

3. Glass and Semiconductor Manufacturing

Used in glass manufacturing for melting raw materials and in semiconductor manufacturing for oxide film formation and annealing.

Principle of Tubular Furnace

A tubular furnace consists of a heating element, core tube, and heat-resistant materials:

1. Heating Element

Includes electric resistance heaters like nichrome, kanthal wire, or silicon carbide. Heaters are selected for durability and temperature characteristics, suitable for high operating temperatures.

2. Core Tube

A protective tube around the heating element, usually made from quartz or ceramic, and stainless steel for lower temperatures.

3. Heat-Resistant Materials

Includes materials like ceramic fibers, bricks, and coatings for insulation and heat retention in high-temperature environments.

Types of Tubular Furnaces

There are open and enclosed types of tubular furnaces, each suited for different applications:

1. Open/Closed Type

Open-ended furnaces allow easy material and gas access, suitable for experiments and research. They can be installed vertically or horizontally.

2. Sealed Type

Sealed tubular furnaces maintain controlled interior environments, ideal for high-precision heat treatment and reaction control in applications like semiconductor manufacturing.

What Is a Terminal Board?

A terminal board is a device used to connect electrical wiring, commonly found in electrical equipment and control systems. They help to efficiently and safely connect multiple wires and cables, reducing wiring clutter and simplifying maintenance. Terminal boards also play a vital role in ensuring the reliable transmission of signals and power, thereby preventing wiring mishaps and ensuring stable electrical circuits.

Applications of Terminal Boards

Terminal boards are used in various industrial and infrastructural settings, including:

• Fixed telephone line systems, where they help distribute telephone lines from a central switchboard to various locations.
• Control wiring for industrial equipment, connecting multiple sensors, and reducing wiring labor.

Principle of Terminal Board

A terminal board consists of an enclosure and a terminal block:

1. Enclosure

The enclosure, often made of aluminum or steel, protects internal wiring from external elements. It may vary between indoor and outdoor applications, with outdoor versions typically including a drainage roof.

2. Terminal Block

The terminal block connects wires, featuring secure attachments like screws or clamps. Each terminal is usually marked for easy identification and control of connections.

Types of Terminal Boards

Terminal boards are classified based on their specific applications:

1. Low Power Terminal Board

These are used in the telecommunications industry for managing communication cables, including telephone systems.

2. Industrial Terminal Board

Industrial terminal boards, found in industrial facilities, connect and control systems, sensors, actuators, and other devices for signal and power transmission.

3. Grounding Terminal Board

Grounding terminal boards, crucial for electrical safety, are connected to grounding rods or wires to discharge abnormal electrical currents.

What Is an Air Release Valve?

An air release valve, often referred to as an air vent, is a valve designed to discharge air that becomes trapped in liquid pipelines, such as those used for water or oil transport.

These valves are equipped to automatically release air from the system when a certain quantity of air becomes entrapped within the fluid. Air release valves operate seamlessly without requiring any manual intervention.

The primary function of air release valves is to eliminate trapped air in liquid pipelines. This not only enhances the efficiency of fluid transport but also prevents issues such as pipeline vibrations, abnormal noise in pipes and joints, and potential pump malfunctions caused by air entrapment.

Uses of Air Release Valves

Air release valves find application in various scenarios where it is necessary to remove air from the flow path of a fluid, such as air or oil. They are typically installed in locations where the mixing of air within the fluid path is expected or where such air mixing would be inconvenient.

Common instances where air entrapment is likely to occur include systems like hot water boilers and solar heating systems, where the air inside can expand when heated. Additionally, air often accumulates at the high points of pipes and storage tanks. Another critical application is at the inlet of pumps, where it’s essential to prevent air interference in the pump’s operation.

Principle of Air Release Valves

Air release valves consist of several components, including a valve disc, a valve seat, and a float connected to the disc. When the amount of air mixed in the fluid is minimal, the float remains in a high position, causing the valve disc to make contact with the valve seat, effectively sealing the outlet. As the volume of air in the fluid increases, the float descends along with the decreasing water level. Eventually, the valve disc disconnects from the valve seat, allowing the outlet to open. This permits the trapped air to be discharged under the pressure of the fluid. After a sufficient amount of air has been released, the float rises again, closing the valve. This automatic process ensures the efficient removal of air without the need for manual operation or external power sources.

Some air release valves are equipped with an intake function in addition to their air release capability, and these are known as intake and exhaust valves. In situations where negative pressure occurs within the fluid path, such as during temporary water cutoffs, intake, and exhaust valves rapidly introduce air to alleviate the negative pressure, preventing backflow within the pipeline.

It’s important to note that air release valves are designed for specific fluid types and minimum specific gravity requirements. They may not function as intended for fluids with specific gravities below the specified minimum. While most air release valves are compatible with water, if they are to be used with oil or other fluids, careful selection is necessary to ensure compatibility.

What Is an Air Compressor?

An air compressor is a machine that compresses air to a high pressure.

Also called a compressor, it sucks in air, pressurizes it with pistons, rotors, and other parts, and stores it in a tank or sends it out through a hose or pipe. Air compressors are used in a variety of fields, including industry, construction, and medicine.

The pressure and volume of air used vary with each application, and various types of air compressors produce compressed air depending on the conditions. Generally, the type and size (equipment size and output) of the appropriate air compressor is determined by the air volume and discharge pressure (air pressure).

Uses of Air Compressors

Air compressors are used to pressurize air and can be used for a variety of applications.

1. Civil Engineering and Construction

Air compressors are used to power air tools such as drills, hammers, and wrenches. They are lighter, smaller, more powerful, and safer than electric tools because they do not generate sparks or heat.

2. Painting Field

Compressed air is also used in airbrushes and spray guns to apply paint evenly to surfaces such as automobiles and furniture. Air compressors are used as a source of this compressed air.

3. Industrial Fields

Compressed air is also used in automatic control valves. In this case, a digital regulation electrical signal from a control device such as a DCS or PLC is converted into an air pressure signal according to its output, and the air pressure is often used as the regulation volume.

4. Other

This is used for cleaning by blowing dust and debris away using high-pressure air delivered from an air compressor. It can remove dirt from electronic components, machinery, and other small parts.

It is also useful when using high-pressure air delivered from an air compressor to lower the temperature. The rapid expansion of air causes a decrease in temperature. This principle is used to cool food, medicine, and other products. A typical example is an air chiller for cooling.

Principle of Air Compressors

Air compressors operate based on the Boyle-Charles law. Boyle-Charles’ law is the law that volume and pressure are inversely proportional if the temperature of a certain amount of gas is constant.

In other words, the smaller the volume, the greater the pressure. Air compressors use this law to create high-pressure air and supply it where it is needed in the following sequence

1. Suction

Air compressor sucks ambient air. As the air is sucked, it is filtered to remove foreign matter and dirt. 

2. Compression

The aspirated air is compressed inside the compressor, which rotates at high speed. This causes the air molecules to pack tightly together, increasing air pressure. Common types of air compressors include piston and rotary screw types.

3. Storage

Compressed air is stored in a tank. The tank acts as a buffer to ensure a stable supply of high-pressure air.

4. Supply

Stored compressed air is supplied to where it is needed through valves and regulators. Used in air tools, automotive tires, manufacturing processes, or other applications, compressed air is efficiently utilized as an energy source.

Types of Air Compressors

Air compressors are classified into four categories based on the method of compression

1. Reciprocating Compressors

This type of air compressor consists of a piston and a cylinder. The piston moves back and forth to compress the air in the cylinder. Reciprocating compressors can achieve high pressure but are prone to vibration, noise, and heat generation.

2. Rotary Compressor

This type of air compressor consists of a rotor and housing. The rotor rotates to compress the air in the housing. They generate less vibration and noise and generate less heat. 

3. Centrifugal Compressor

The centrifugal force of the impeller (impeller) gives velocity energy to the gas, which is converted into pressure to compress the gas. While they are suitable for larger sizes, they are not suitable for high compression.

4. Axial-Flow Compressor

This compressor compresses gas by rotating blades with an airfoil cross-section, causing the gas to flow in an axial direction. Since it compresses in stages, it can handle high compression and is suitable for larger sizes.

There are other ways to classify air compressors besides the compression method. Typical examples include the number of compression stages (1-stage, 2-stage, multi-stage), lubrication/sealing method (oil-injected, dry oil-free, water-lubricated oil-free), cooling method (air-cooled, water-cooled), control method (inverter, unload control, safety valve control), and shape (tank mounted, package type).

What Is Mobile Shelving?

Mobile shelving, also known as mobile racks, are specialized storage shelves designed with a movable structure. They move on floor rails, offering space-saving benefits by potentially increasing storage capacity by 150% to 200% compared to fixed shelves. Mobile shelving can adjust shelf density to store items of varying sizes and heights effectively.

These shelves enhance access control and security, with some models allowing restricted access to sensitive documents through keys or other means. They may also meet specific requirements like fire and dust protection, making them ideal for long-term storage of low-liquidity products, documents, books, and other items.

Uses for Mobile Shelving

Mobile shelving finds application in various industries, with flexible design and customization to meet specific needs:

1. Office

In offices, they store documents and files, maximizing space and providing an organized environment.

2. Warehouse

Warehouses use mobile shelving for efficient inventory management, accommodating diverse products, and facilitating easy item retrieval.

3. Library and Archive Facilities

Libraries and archives use them for book and material storage, enabling efficient space usage and restricted access to certain sections.

Principle of Mobile Shelving

Components of mobile shelving include:

1. Rail Unit

The rail unit guides the path of mobile shelving, allowing horizontal movement of shelf units.

2. Moving Mechanism

The mechanism, which can be manual or motorized, enables shelf movement via wheels or similar devices.

3. Shelf Unit

A structure supporting stored items, typically in the form of shelves or drawers.

Types of Mobile Shelving

Mobile shelving comes in motorized, manual, or handle-operated types:

1. Motorized Type

Driven by electric motors, these shelves are controlled using buttons, remote controls, or other devices, suitable for storing heavy loads with options for additional features.

2. Manual Type

Operated by human power, suitable for small-scale storage and personal use, offering low-cost installation and quiet operation.

3. Handle Type

Operated using a handle, ideal for small-scale storage, similar to the manual type.

Other Information on Mobile Shelving

How to Install Mobile Shelving

Installation methods include mounting, anchoring, or embedding:

• Foundation Type: Laying plywood panels on the floor and fixing the rails, offering flat or stain-resistant specifications.
• Anchor Type: Securing the rails directly into the floor with anchors, providing excellent earthquake resistance.
• Embedded Type: Embedding the rails in a floor groove, suitable for pallet racks and allowing carts to pass through.

What Is a Magnetic Seal?

A magnetic seal is a seal unit for rotary motion that uses a magnetic fluid attracted by a magnet to seal.

They are sometimes referred to as Magnetic Fluid Seals or Vacuum Seals. A rotary seal seals and seals the hydraulic fluid that allows equipment to function over the long term.

Magnetic seals are primarily used in atmospheres, dust, oil mist, gases, and vacuums.

Uses for Magnetic Seals

The primary use for magnetic fluidic seals is in the bearings of HDDs in personal computers and other hardware. Magnetic fluidic seals improve durability and reduce noise from rotation.

Other applications include semiconductor manufacturing equipment, analytical equipment, and other equipment where a vacuum field must be maintained. However, a single vacuum seal is not sufficient to seal the vacuum field. Therefore, a vacuum is maintained by configuring multiple vacuum seals in a multi-stage configuration.

In addition, magnetic seals using rare earth magnets can strongly hold magnetic fluid due to the strong magnetic field. Vacuum seals that can maintain a difference of 1 atmospheric pressure are used for CVD equipment, RVD equipment, ion implantation equipment, etc.

Principle of Magnetic Seals

The mechanism of the magnetic seal is based on the property that magnetic fluid is attracted to a magnet. A permanent magnet and magnetic fluid are placed around the axis of rotation to be sealed, and the magnetic fluid is held in place around the axis of rotation to create a seal.

The stronger the magnetic force, the greater the pressure resistance of the magnetic fluid, and it is common to design a single magnetic seal with a multi-stage structure of 10 to 20 stages. By forming multiple stages, a magnetic seal with a large pressure resistance is completed.

There are three types of magnetic fluid: water-based, hydrocarbon oil-based, and fluorocarbon oil-based. The hydrocarbon-based type is commonly used. Water-based magnetic fluids can evaporate, and hydrocarbon-based magnetic fluids are more suitable from the standpoint of type and price. Fluorocarbon oil-based magnetic fluids are used when chemical stability, low vapor pressure, and heat resistance are required.

Other Information on Magnetic Seals

1. Advantages of Magnetic Seals

High sealing and non-dusting properties
Since magnetic seals are sealed with a liquid, gaps are difficult to form. Also, since it is not a contact between individuals, it does not generate any wear dust due to friction.

Low Friction Torque
Since the contact is not between individuals with contact pressure like an oil seal, the loss resistance can be kept extremely low.

Low Heat Generation and Low Noise
The friction generated by the contact between the individual and the liquid generates almost no heat or noise.

Sealed in Both Rotating and Stationary Conditions
The sealing performance of an individual oil seal is due to the pumping effect caused by the rotation of the shaft. The seal is maintained as the shaft rotates. Magnetic seals seal regardless of whether the shaft is rotating or stationary, as long as the magnetism is maintained.

Relatively Easy to Design
Individual oil seals require a detailed design of the lip shape in contact with the rotating shaft. In contrast, magnetic seals are relatively easy to design. 

2. Disadvantages of Magnetic Seals

Limited Heat Resistance
Magnetic fluid has the property of becoming less magnetic as temperature increases, and once it reaches the Curie point, it loses its magnetism completely. The pressure at which it can be sealed decreases at higher temperatures.

Not Suitable for Sealing Liquids
Since magnetic fluid is a liquid that seals, there is a risk that the magnetic fluid may dissolve depending on the liquid to be sealed.

Not Suitable for Reciprocating Seals
While individual O-rings can be used for reciprocating sealing, magnetic seals are not suitable for reciprocating sealing because the magnetic fluid may be taken out.

Not Suitable for High-Pressure Seals
Magnetic fluid increases sealing pressure by reducing the gap between the rotating shaft and the magnetic pole pieces that provide magnetic force to the magnetic fluid. However, it cannot seal as high pressure as an individual oil seal.

Since the pressure that can be sealed decreases with temperature and rotational speed, it is important to design for the operating environment.

What Is a Magnetometer?

A magnetometer is a device designed to measure the strength and direction of magnetic fields. Various types are available, including those utilizing the Hall effect and electromagnetic induction. These devices have diverse applications, from ore vein detection to product manufacturing inspection and medical equipment integration.

Applications of Magnetometers

Magnetometers are used in various contexts for magnetic field measurement:

1. Detecting Magnetism Buried Underground

Used for locating ore veins or removing underground mines. Near-surface detection often employs electromagnetic induction methods, while deeper objects are detected via geomagnetic field analysis, identifying ferromagnetic object-induced distortions.

2. Medical Equipment for Testing

Applied in magnetocardiogram and magnetoencephalography examinations by measuring the body’s magnetic field.

3. Nondestructive Testing Equipment

Used in inspecting ferromagnetic materials to identify damages or defects, and in security gates at airports for detecting metallic items through induced eddy currents.

Principle of Magnetometer

Magnetometers operate using various methods:

1. Vibrating Sample Magnetometer

Measures magnetic fields by vibrating the sample in a uniform magnetic field, enabling high-speed measurements at diverse temperatures and magnetic field strengths.

2. Magnetic Field Gradient Magnetometer

Measures the sample’s magnetic field by inducing magnetization through an alternating magnetic field, extracting this force as an electrical signal.

3. Fluxgate Magnetometer

Operates on electromagnetic induction, using two coils wound around a highly permeable iron core to measure the magnetic field through the induced electric current.

Other Information on Magnetometers

Hall Element

Hall elements in some magnetometers detect magnetic fields by outputting a voltage, representing the magnetic field strength through the Hall effect-induced voltage.

What Is a Shredder?

Shredders are machines that crush objects by rotating rollers with blades. There are various types of shredders, ranging from small ones for shredding small amounts of rocks, wood, fruit, etc., for experiments to industrial ones for disposing of concrete and waste materials.

A similar type of machine is a crusher, but one that uses a reduction gear (gear) and is applied to objects larger than 20 mm is generally called a shredder. Reduction gears increase torque and enable shredders to crush large or hard objects. For this reason, shredders are sometimes used as a pretreatment for shredder.

Rotors made of stainless steel are rotated to crush objects as they are chewed to pieces, so the rotation speed of the rotor and the fineness of the blades are important. Initially, a trial operation should be made with coarse blades rotating at low speed, and the blades should be replaced with finer blades step by step while crushing a small amount of material and observing how the shredder performs.

Uses of Shredders

Shredders are mainly used to crush hard objects coarsely. If the material is to be ground down to powder form, it must be processed in a shredder after crushing.

Shredding materials used for extraction or reaction increases the surface area per volume, which increases extraction efficiency and reaction speed. Shredding is also effective for reducing storage space because of the reduced bulk. However, there are some disadvantages to shredding samples that are easily oxidized in air, such as the fact that shredding makes them more susceptible to oxidation. Judgment must be made according to the sample.

Principle of Shredders

The basic structure of the shredder and its crushing mechanism are as follows:

1. The material to be shredded is put in through the feed port. To facilitate feeding, a hopper, which acts as a funnel, is attached to the feed port.

2. The inputted materials fall into the crushing chamber. In the shredding chamber, a rotor with blades like gears rotates and crushes the material as it is fed in. The rotation speed of the rotor and the fineness of the blades determine the crushing capacity. If the rotation speed is too fast, the fed material will be bounced off the rotor and will not be entrained. If the blades are too fine, they will clog and stop rotating. It is recommended to start with a trial run with coarse blades rotating at a low speed and optimize the rotation speed and blades by crushing a small amount of material at a time and observing how it goes.

3. The bottom of the shredding chamber is equipped with a screen, which acts as a “sieve.” The screen has holes of a certain size, and only pieces that are crushed finer than these holes pass through the screen and fall into the discharge outlet.

4. The shredded pieces coming out of the discharge outlet are collected in bags or batts.

Difference Between Single-Shaft and Twin-Shaft Shredders

Shredders are classified into “single-shaft” and “twin-shaft” types according to their shredding style. Each has its advantages and disadvantages, so knowing this classification will help you select the right model.

Single-shaft shredders have fixed blades lined up on both walls of the shredding chamber, and rotors drive between them. The material is pushed into the shredding chamber by an instrument called a pusher and is then caught by the rotor. The material is cut into small pieces by repeatedly passing between the rotor and fixed blades, and only those pieces that are smaller than the fineness of the screen are discharged. The advantage is that the shredder has high cutting power and can produce fine pieces, while the disadvantage is that the processing speed is slow.

The twin-shaft shredder has no fixed blades and two rotors installed in parallel. The material is fed into the shredder and is shredded by being caught between the two rotors. The advantage is the high processing speed, while the disadvantage is that fragments tend to be coarse and unevenly sized.

The single-axis type is recommended when the fineness of shredding is required, and the twin-shaft type is recommended when processing speed is required.

Wood Shredders

Some shredders are specialized for shredding wood. They are used to dispose of scrap wood and produce wood pellets, and a variety of models are available, ranging from small models for home use to large models for wood processing plants.

Small models for home use are primarily used to shred selected branches and small wooden furniture. They are sold under such names as “garden shredders” and “wood chippers,” and some models can be purchased inexpensively.

Some of the larger models for professional use are equipped with an engine and can run on caterpillars. When wood is piled up in multiple locations in a large workshop, efficiency can be improved by having the shredder move and work instead of carrying the wood.

One point to keep in mind when using shredders for wood is that the rotors are not strong enough. Because they are not designed for shredding rocks or concrete, accidentally feeding in rocks or other hard objects may cause the blades to spill, leading to malfunction.

What Is a Grinder?

A grinder is a processing machine used primarily for surface finishing and other polishing processes.

Various polishing methods exist, requiring appropriate grinding wheels and abrasives. Depending on the grinder, the workpiece may be placed close to a high-speed rotating grinding wheel. Care must be taken to avoid burns from sparks or being caught in the machine during operation.

Uses of Grinders

Grinders are mainly used to finish the surface of parts, but they can also be used for rough polishing to remove burrs. In addition to surface finishing, polishing is also used to finish the inside of cylindrical parts. This is because the smoothness of the polished surface improves the sliding properties of the parts.

Polishing is also used for cylinders, rail sliders, and many other parts that perform sliding movements. Recently, there are many desktop size grinders available, which are increasingly being used for polishing silver jewelry and removing burrs from plastic models at home, as well as in factories.

Principle of Grinders

Abrasive grains contained in grinding wheels and abrasives used for polishing exert an effect similar to that of small blades, gradually shaving off the workpiece. The most typical type of polishing is “grinding wheel polishing,” in which the workpiece is polished by placing it against a grinding wheel rotating at high speed.

Although this is a very simple polishing method, it requires a great deal of skill. The finish varies depending on the small differences in the force and angle at which the workpiece is pressed against the grinding wheel. As processing proceeds, the grinding wheel itself also wears out and becomes worn out, so it must be replaced with a new grinding wheel at the appropriate time while monitoring the amount of wear and tear on the grinding wheel. In principle, filing with sandpaper is similar, but more efficient.

A similar procedure exists for buffing, in which a “buff” made of soft material such as cotton or felt is used instead of a whetstone for polishing. It is more effective in smoothing surfaces than whetstone polishing and is used for mirror finishing. On the other hand, polishing takes time, so it is not suitable for applications that involve reducing the thickness of the workpiece.

Since grinders work by moving the workpiece close to an object rotating at high speed, care must be taken to avoid injury during operation. In particular, when polishing with gloves, there is a possibility that frayed threads could get caught in the high-speed rotating parts. Even with a small grinder, the force of entrapment is so great that it is dangerous and can lead to serious injury. Also, depending on the material of the workpiece, sparks may be generated upon contact with the grinding wheel, so care must be taken to avoid burns.

Other Information on Grinders

1. Stainless Steel Surface Treatment Using an Electrolytic Grinder

Stainless steel is a metallic material with rust and corrosion resistance and heat resistance due to the several-nanometer-thick passivation film formed on its surface by bonding with oxygen in the atmosphere. However, if the proper surface condition is not maintained due to machining, surface finishing, transportation, or storage, the passive film will not form evenly, resulting in defective products.

Electropolishing is a process that aims to remove impurities and roughness from the surface of stainless steel cleanly and form a passivation film with high properties. In a stainless steel electropolisher, the surface is electrochemically dissolved and cleaned in microns by passing a direct current through the stainless steel, the object to be polished, as an anode in an electropolishing solution.

Rough surface convexities are preferentially dissolved to reduce surface roughness, and defects that are difficult to remove by normal polishing, such as burr coverings and voids underneath, caused by polishing or machining, can be smoothed out. It is also highly productive because the processing method is simple, and depending on the size of the electrolytic solution tank, large amounts of polishing can be performed.

Passive film has excellent corrosion resistance and heat resistance, but its thickness is thin and weak at only a few nanometers, so the smoother the stainless steel surface, the more uniform and highly adherent the film will be. Electropolishing is an important process to maximize the characteristics of stainless steel.

2. Electrolytic Combined Grinder

Electrolytic combined polishing, which combines physical polishing with abrasives, is effective when an even smoother surface than electropolishing is required. A rotating polishing disc is used as a cathode, and the surface of the workpiece is subjected to electrolytic solution and electric current while it is being moved and polished.

The passive film on the convex surface is mechanically removed, and the metal is eluted from it, resulting in smoother polishing than when electrolytic and mechanical polishing are performed independently. The feature of this process is that it can achieve a roughness on the order of nanometers.

Because it can polish not only flat surfaces but also curved surfaces such as pipes, it is widely used for semiconductor manufacturing-related parts, piping, valves, and medical equipment that require precision and durability.