月: 2023年2月

What Is an Antistatic Agent?

Antistatic Agents are applied or kneaded into equipment, clothing, or other objects to prevent them from becoming charged with static electricity.

When static electricity is generated, the object collects dust and dirt from the air and deposits them, or causes static electricity to discharge, damaging semiconductor components in the equipment. In the worst case scenario, the object may catch fire, resulting in a fire.

Antistatic Agents are used to avoid various problems caused by static electricity.

Uses of Antistatic Agents

Antistatic Agents are used for two purposes: to prevent static electricity generation in finished products and to prevent problems caused by static electricity generation in the production process of industrial products.

1. Prevention of Static Electricity Generation in Products

• Preventing dust from adhering to furniture and clothing and preventing static electricity
• Preventing dust from adhering to home appliances and electronic equipment, and preventing damage and malfunctions caused by static electricity
• Preventing static electricity from adhering to plastic parts of cars, interior linings, engine covers, and intake parts inside air intake boxes.
• Prevention of static electricity on electronic equipment carrying cases and cushioning materials
• Prevention of adhesion of films, etc.
• Prevention of powder adhesion to bags containing powder

2. Prevention of Static Electricity Generation in Production Processes

• Prevention of static electricity generation in spinning, stretching, and spinning processes in the textile manufacturing process
• Prevention of films from sticking to each other in the film manufacturing process

Principle of Antistatic Agent

Antistatic Agents are applied to plastics or kneaded into them to improve their ion conductivity. This is because improved ion conductivity reduces the generation of static electricity.

Although spray-type Antistatic Agents are generally well known, detergents containing surfactants are another type of Antistatic Agent. Surfactants are used in household clothing detergents. Therefore, after washing, the clothes are less likely to generate static electricity.

Antistatic Agents are available in a variety of types to suit the equipment and clothing to be handled.

Other Information on Antistatic Agents

1. Antistatic Agents for Clothing

For clothing worn on a daily basis, detergents and fabric softeners containing surfactants play the role of Antistatic Agents. There are four types of surfactants: nonionic surfactants, anionic surfactants, cationic surfactants, and amphoteric surfactants. Of these, the surfactant most often used in Antistatic Agent applications is the cationic surfactant.

Cationic surfactants are surfactants that ionize into positive ions in solution. It is often used as the main ingredient in fabric softeners. When laundry containing fabric softener is dried, the frictional resistance of the fiber surface decreases, thereby reducing the generation of static electricity.

In addition, surfactants improve the hydrophilicity of the garment surface, making it easier for water molecules to bind strongly to it as well. Even if static electricity is generated, it can flow through water molecules, preventing static buildup.

2. Precautions When Applying Antistatic Agent to Acrylic Sheets

Acrylic sheets are materials that easily generates static electricity. Especially in winter, when static electricity is easily generated, dust and debris often adhere to products made of acrylic sheets and are difficult to remove.

One way to prevent the generation of static electricity is to spray a water solution containing an Antistatic Agent. Remove large dust and debris first, then apply an appropriate amount of spray and wipe off with a soft cloth.

Some sprays containing Antistatic Agents can damage acrylic panels. When purchasing, it is necessary to confirm that the product can be used on acrylic panels.

3. Antistatic Measures at Production Sites

Antistatic Agents are used to prevent the generation of static electricity, but static electricity is a serious problem in factories. Products containing electronic components may be destroyed by static electricity, for example, if some of the components on the internal circuit board are destroyed.

To avoid such a situation, efforts are being made to prevent the generation of static electricity.

Humidity Control
The humidity in a factory can be set to a high level to maintain a constant humidity level in the factory and reduce the electrical resistance of surfaces of equipment.

Static Eliminator Rod
Arcing metal rods are placed at various locations, and workers can touch them to release static electricity charged on them.

Conductive mats
By placing conductive mats, even if workers are charged, static electricity can be dissipated to ground through the conductive mats. If necessary, use antistatic sprays on products, sliding parts, and other areas prone to static electricity to prevent static electricity generation.

What Is an Anti-rust Spray?

Anti-Rust Spray, as the name implies, is a spray that prevents rust.

It is often used on metal parts used in automobiles, motorcycles, bicycles, and other vehicles. Since a nozzle is provided, the spray can be applied with pinpoint accuracy to only the desired part of the component, making it easy for anyone to handle.

Anti-Rust Spray can be used to apply Anti-Rust treatment in places where large-scale painting work is difficult, such as high-temperature or corrosive environments. The price is relatively inexpensive and can be easily obtained by the general public at home centers or through mail order.

Uses of Anti-rust Sprays

Anti-Rust Spray is used to remove or prevent rust during maintenance rather than during industrial production of machine parts. Anti-Rust Spray may be applied during industrial production, but the difference is that the coating formed by Anti-Rust Spray is relatively thin and the treatment area is limited to a specified area only.

1. Industrial Parts

Anti-Rust Spray is most commonly used on machine tools. Machine tools contain frequently operated parts such as molds and jigs.

Rust on these surfaces can cause poor movement and operation problems, so rust prevention treatment is required during maintenance. To give a specific example, Anti-Rust Spray is used for precision machinery, which can be treated with pinpoint accuracy, because the area to be treated is very small.

2. Automobile Parts

Anti-Rust Spray is also used for the rust prevention treatment of automobile parts that we drive on a daily basis. Automobiles are often exposed to rain and humidity in the outdoor environment, so they are at risk of rust formation.

Rust-preventive treatments are applied during routine maintenance. Specific areas of the automobile that require treatment include the hood, inside the bumper, doors, and trunk compartment.

Principle of Anti-Rust Sprays

To understand the principle of Anti-Rust Spray, we must first understand how metals rust. Metals, with the exception of gold, rarely exist in nature by themselves. Iron, for example, is mined in the form of magnetite steel or brown iron steel.

Later, it is refined by human technology to become a single metal, which is then processed into metal parts for automobiles and other vehicles. However, the surfaces of cut and machined metals react easily with oxygen and water, making them susceptible to rust. Rusting not only deteriorates appearance, but also reduces strength and performance.

Anti-Rust Spray has two components: a rust inhibitor, which forms a thin film on the surface of the metal that shields it from oxygen and moisture; and a passive film, which is a thin layer of rust inhibitor, which is applied to the surface of the metal to prevent rust from forming. This passive film is an oxide but only a few nanometers thick, so it is transparent and maintains the luster of the metal surface.

The other is mineral oil, which allows rust-preventive ingredients to penetrate into the fine crevices of the metal. It can also lift fine rust already on the surface, which can be removed by wiping it off with a rag. Anti-Rust Spray can penetrate to the smallest areas and remove rust if it is only a small amount, and the rust-preventing agent also acts to protect the surface firmly to prevent rusting.

Types of Anti-rust Spray

In areas near the sea where there is a risk of salt damage or corrosive gases, general-purpose Anti-Rust Spray may cause rusting. In such places, Anti-Rust Sprays with ingredients formulated for seawater or corrosive gas environments are suitable.

By properly using the appropriate Anti-Rust Spray according to the situation, it will be possible to maintain the rust-preventing ability for a long period of time.

What Is a Chemical Storage?

Chemical Storage is a special type of storage for storing chemicals or reagents.

They are used in testing and research facilities, factories, medical facilities, and educational institutions. The expected functions include properly sorting the chemicals, keeping reagent bottles from tipping over, ensuring that the chemicals do not change (use of constant ventilation or ventilation equipment), and being able to lock the door if necessary.

It is important that the functions of the Chemical Storage comply with the laws and regulations governing the chemicals to be stored.

Uses of Chemical Storage

Chemical Storage is used to store chemicals in controlled conditions in facilities where chemicals are used. They are used for the following purposes:

1. To Ensure Safety

Chemical Storage is expected to properly store chemicals and chemical agents and minimize risk from breakage, fire, and theft. For breakage, it is important that the body is sturdy and reagent bottles can be stored in a way that prevents them from tipping over.

Against fire, the use of flame-retardant storage units and placement away from combustible materials will reduce the risk. Against theft, measures are taken by locking the chemical storage in a sturdy steel chemical storage. 

2. Quality Maintenance

Ensure that chemicals are stored under appropriate temperature, humidity, and light conditions. Many chemical storage rooms are designed to prevent light from entering, well-ventilated to prevent heat and moisture retention, and some are equipped with ventilation systems.

3. Durability

Since some reagents dissolve plastics or corrode metals, high durability is required in case of leakage or exposure to vapors. Many are made of polyvinyl chloride, stainless steel, or steel finished with durable paint.

4. Classification

One of the expected functions is to classify reagents for easy retrieval and management by organizing and storing them.

5. Compliance with Laws and Regulations

Major laws and regulations related to the handling of chemical substances include the following:

• Fire Service Act
• Poisonous and Deleterious Substances Control Law
• Pharmaceuticals and Medical Devices Control Law (former Pharmaceutical Affairs Law)
• Narcotics and Psychotropics Control Law

One of the expectations of Chemical Storage is to be able to store chemicals under conditions that comply with these laws. For example, in the case of reagents designated as poisonous or deleterious substances, the Poisonous and Deleterious Substances Control Law requires that they be “always locked” in a “sturdy, lockable” storage area and that “key management” be performed.

In this case, select a Lockable Chemical Storage and label the storage location with “Non-Pharmaceutical Poisonous Substance” or “Non-Pharmaceutical Deleterious Substance” etc., depending on the reagent.

Principles of Chemical Storage

Chemical Storage is designed to meet the functions of not being damaged by chemicals and not allowing reagent bottles to tip over or contact each other. They are constructed of materials that are non-permeable and highly durable.

Partitions are typically provided between reagent bottles, which prevent reagent bottles from touching each other and damaging each other.

How to Select Chemical Storage

Chemical Storage units come in a variety of materials and shapes. Select the appropriate one for your purpose based on the following characteristics.

1. Material

Polyvinyl chloride (PVC)
Excellent in chemical resistance, especially acid resistance. Small size is lightweight and suitable for carrying around.

Stainless steel
Excellent corrosion resistance, alkali resistance, and electrical conductivity.

Made of steel
Some products are alloyed hot-dip galvanized or coated with melamine baking paint to provide corrosion, water, and moisture resistance. They are available at lower cost than stainless steel.

2. Anti-theft Function

Chemical Storage also includes safe-type products used to store narcotics and other drugs. Some are installed by screwing the bottom of the box to the floor to avoid theft, and the material of those that emphasize theft prevention is often steel.

In addition to the locking function, those that can use biometric authentication for unlocking and those that can store unlock history electronically are also available.

3. Storage Conditions

For reagents that require light shielding, it is safer to employ a windowless storage unit, but if room light can be controlled, a windowed unit can be selected for ease of use with visibility inside.

If ventilation is particularly important, consider storage units with exhaust ventilation.

4. Size

The size of the items you wish to store should be considered. Reagent bottles are standardized and should be selected according to what you wish to use.

As for the size of the storage unit itself, some are portable. It is important to select the right size for your application, such as carrying them locked.

What Is a Liquid Nitrogen Container?

A liquid nitrogen container is a container used for storing, preserving, and transporting liquid nitrogen. Liquid nitrogen is nitrogen in liquid form at temperatures below -196°C and is mainly used to cool objects.　

If used incorrectly, it can cause explosions, asphyxiation, frostbite, and other serious accidents, so it must be handled with care. By using liquid nitrogen storage containers, it is possible to safely and efficiently store, preserve, and transport liquid nitrogen.

Uses of Liquid Nitrogen Containers

Liquid nitrogen containers are used for storage and transportation when liquid nitrogen is used in laboratories and medical institutions where samples are stored and experiments are conducted, in food-related flash freezing, and as a coolant for IT-related equipment. Liquid nitrogen is also used in special analysis equipment.

There are two types of liquid nitrogen containers: open containers and sealed containers. The most common open containers are small to medium-sized containers, while the most commonly sealed containers are large containers with a large capacity. An open container is one in which a cap is simply placed over the mouth of the liquid nitrogen containers and is not fixed, while a closed container is one in which the cap is fixed and the container is hermetically sealed.

Liquid nitrogen containers are not suitable for long-term storage, but they are suitable for daily or short-term use. Liquid nitrogen containers can be used for short-distance transportation, short-term storage and preservation, and periodic replenishment.

Principle of Liquid Nitrogen Containers

Nitrogen expands approximately 700 times in volume when it changes from a liquid to a gas, leading to accidents such as explosions and lack of oxygen. Therefore, liquid nitrogen containers are insulated with a double-layered vacuum structure to stabilize the temperature with high thermal insulation.

In addition, the structure is resistant to shock and vibration to withstand breakage. However, even when stored in liquid nitrogen containers, it will vaporize little by little.

Structure of Liquid Nitrogen Containers

Liquid nitrogen containers consist of an outer tank that forms the outside of the container an inner tank that is filled with liquid nitrogen, and a vacuum insulation layer is placed between the outer and inner tanks. Open-type liquid nitrogen containers have a simple structure that is not fixed by simply placing a cap over the open end of the inner tank and is widely used in university laboratories.

In the open type, the outer tank is generally made of aluminum, and the inner tank is generally made of hard glass, metal, or FRP (fiberglass reinforced plastic).

A self-pressurizing (sealed) liquid nitrogen container has a structure in which a pressurizing coil is placed between the outer and inner tanks, and liquid nitrogen is extracted by increasing the pressure of the inner tank to pressurize the liquid nitrogen in the inner tank.

The self-pressurizing type has a liquid takeout valve placed on the liquid nitrogen takeout side, a pressure boosting source valve used to increase the pressure of the inner tank, and a gas release valve to control an excessive increase in the internal pressure in the inner tank, and by adjusting these control valves, the required amount of liquid nitrogen can be taken out.

Other Information on Liquid Nitrogen Containers

1. How to Use Liquid Nitrogen Containers

Since open-type liquid nitrogen containers are small and relatively lightweight, liquid nitrogen can be taken out by lifting and tilting the container. However, for safety reasons, it is recommended that a siphon or similar device be used to remove the liquid nitrogen.

There are two types of siphons: a manual type using a rubber ball and a type that automatically pumps liquid using a controller. In particular, since it is difficult to see the liquid level inside a dewar for cooling the EDX detector of an electron microscope, a siphon with a level sensor can prevent liquid nitrogen from overflowing and cover precision instruments with liquid nitrogen.

When storing containers, special lids must be used to prevent water from freezing inside and blocking extraction. In the unlikely event that the lid is lost or otherwise inaccessible, the container should be covered with a dry rag to prevent it from opening to the atmosphere while avoiding hermetic sealing.

The inner tank has only the minimum necessary structure and is fixed in place. For this reason, it is vulnerable to lateral forces and requires careful storage. Self-pressurized (sealed) liquid nitrogen containers have a structure in which gas is extracted by adjusting multiple valves, and care must be taken in handling each adjusting valve.

To remove liquid from the container, start by closing the gas release valve and opening the pressurization valve and then confirm the internal pressure of the container is rising. Then, open the liquid takeout valve and take out the liquid nitrogen containers while making sure that the pressure inside the container does not rise excessively.

After the liquid nitrogen has been taken out, close the liquid nitrogen withdrawal valve and the pressurizing valve in turn, and then open the gas release valve to lower the internal pressure of the container.

Precautions When Using Liquid Nitrogen Containers

When handling liquid nitrogen, care must be taken to avoid asphyxiation, frostbite, and explosions. To prevent frostbite, use gloves and face guards during use, and wear footwear that is impervious to liquid nitrogen, since slippers and the like may come into direct contact with liquid nitrogen when it is spilled.

Similarly, it is recommended to use dry, specialized gloves, as military gloves and the like may be penetrated. If liquid nitrogen is to be moved in and out indoors, the room must be well ventilated. Also, when using an elevator, do not share the elevator with liquid nitrogen because the interior is a closed room.

If liquid nitrogen is placed in an elevator, put up a sign or other warning so that others will not get on the elevator. For rooms where liquid nitrogen is frequently used, we recommend installing oxygen monitors.

If it is an open type, of course, it is not designed to be sealed, so sealing is strictly prohibited. It is also strictly prohibited to leave the equipment without a lid, as explained in the instructions for use. This is not only because liquid nitrogen vaporizes faster, but also because water and oxygen may liquefy and mix inside the storage container.

Liquid oxygen, in particular, can react rapidly when it comes into contact with organic matter (liquid oxygen has a bluish tint). Ensure to cover the container with a dry cloth or other covering if the lid is misplaced. The open type is structurally vulnerable to shaking and shock and should be used with care, as the vacuum insulation layer may break.

In the self-pressurizing type, a safety valve maintains the internal pressure in a safe condition, so it should be checked regularly to ensure that the safety valve is functioning properly. It is also dangerous to look into the outlet as it may not be taken out correctly or may blow out suddenly if freezing occurs in the piping.

What Is an Extreme Pressure Grease?

An extreme pressure grease is a grease that has excellent high-load lubricating, metal surface protection, and friction resistance performance. It also has a sealing performance, such as water resistance and adhesion. It is intended to lubricate and protect parts such as high-rotation bearings, metal sliding parts under high loads and high speeds, and gears under high loads.

Although it is necessary to further reduce viscosity to reduce clay resistance, viscosity is a general value in order to maintain the adhesion and sealing properties originally required for grease. Clay resistance can be freely adjusted by additives.

Uses of Extreme Pressure Greases

Extreme Pressure Grease is used to withstand conditions that exceed the normal lubricating capacity of the base oil. Examples of such extreme pressure conditions include gear galling, impacts that exceed the lubrication capacity of the base oil, and the presence of foreign matter such as sand. For this reason, they are used in the following applications:

1. Automobile Wheel Bearings

Automobile wheels are subjected to strong rotating forces. Extreme Pressure Grease plays a key role in reducing friction in this area and helping smooth rotation. 

2. Machine Tool Gears

Machine tool gears are subject to high forces and cannot be adequately lubricated with ordinary grease. Extreme Pressure Grease is used to extend the life of gears and ensure efficient operation.

3. Agricultural Machinery

Agricultural machinery is used in an environment where dirt, sand, and other foreign matter can easily enter, so normal grease tends to degrade lubrication effectiveness. Extreme Pressure Grease maintains lubricating performance even under such severe conditions.

Principle of Extreme Pressure Greases

Unlike ordinary grease, Extreme Pressure Grease contains special ingredients called Extreme Pressure Additives. The lubrication range under normal conditions depends on the performance of the base oil and thickener. However, when extreme pressure occurs, there must be an intervening lubricant.

The inclusion of Extreme Pressure Additives provides high lubricating performance when extreme pressure occurs. Extreme Pressure Additives reduce friction by creating a thin protective film on the metal surface. When high pressure is applied, this protective film chemically reacts with the metal surface to form an even stronger film. This is the reason why Extreme Pressure Grease can maintain its lubricating effect even in areas subjected to high pressure.

Extreme pressure is the frictional resistance applied to a point or line of contact. Normal lubricant film becomes thinner as the load increases, causing metal-to-metal contact and increased wear and friction, resulting in seizure. The use of extreme pressure additives avoids seizure and makes it possible to maintain the thickness of the oil film.

Types of Extreme Pressure Grease

Extreme Pressure Grease is mainly classified into the following types. The characteristics differ depending on the thickener, which is the main component of the grease.

1. Lithium-Based

Lithium Extreme Pressure Grease is the most commonly used type of Extreme Pressure Grease. It has excellent performance at high and low temperatures and water resistance.

2. Calcium-Based

Calcium Extreme Pressure Grease has excellent water resistance and is often used in wet environments. However, it is weak against high temperatures. 

3. Aluminum-Based

Aluminum-based Extreme Pressure Grease is more resistant to high temperatures than lithium-based grease. However, its water resistance is inferior to that of lithium-based grease.

4. Polyurea Type

Polyurea Extreme Pressure Grease is extremely resistant to high temperatures and has a long service life. It is used in applications that require continuous use at high temperatures and for long periods of time, such as electrical equipment and high-speed rotating equipment. However, its high price is a drawback.

Other Information on Extreme Pressure Grease

Extreme Pressure Additive
Contact surfaces under high loads are always accompanied by high temperatures, and these high temperatures trigger the reaction of Extreme Pressure Additives. Extreme Pressure Additives are stable at room temperature and relatively low temperatures and become active and react with metals at slightly lower temperatures before reaching higher temperatures where fusion can occur.

Extreme Pressure Additives are substances that generally contain sulfur, chlorine, or phosphorus. They include sulfide oils and fats, sulfide esters, sulfides, and chlorinated hydrocarbons, as well as lead naphthenate and compounds containing two or more of the elements in the same molecule.

What Is a Heat Resistant Double-Sided Tape?

Heat Resistant Double-sided Tape is a tape used for repair and maintenance of hot items such as electrical wiring.

It has viscous areas on both sides. Made of materials such as aluminum and polyimide, it provides electrical insulation, masking, and other functions. There are various types of tapes depending on their thickness and hardness. Harder and thinner tapes are more resistant to displacement. Also, softer and thicker tapes are more resistant to unevenness.

Some tapes can withstand high heat up to 1,000°C, while others are thin Heat Resistant Double-sided Tape with a thickness of less than 50 µ. It is important to choose the right one for your purpose, taking adhesiveness and flame resistance into consideration.

Uses of Heat Resistant Double-Sided Tapes

1. Automotive Industry

In the automotive manufacturing process, adhesion is required in high temperature environments. Heat Resistant Double-sided Tape is used to fix engine compartment and exhaust system components and interior parts. The heat resistance ensures adhesion under high temperatures.

2. Electronic Device Manufacturing

Heat Resistant Double-sided Tape is used for wiring and fixing parts inside electronic devices and on circuit boards. This is especially important in situations where high temperatures are generated and durability is required.

3. Construction Industry

Heat resistance is also required for bonding and attaching building materials. Suitable for outdoor installation and use in high-temperature environments, and effective fixing is possible. 

4. Industrial Machinery

May be used for assembly of machine parts and equipment in factories. Adhesion is maintained even in high-temperature working environments, supporting efficient production processes.

5. Heat Treatment

Used for masking to protect specific areas during the heat treatment process of metals. It is required to have properties withstand high temperatures.

6. Food Industry

Used to repair conveyor belts in food processing lines and to produce food packaging materials that require heat resistance.

7. Aerospace Industry

In the manufacture of aircraft and spacecraft, it may be used in areas where durability in high-temperature environments is required.

Heat Resistant Double-Sided Tape Features

1. Heat Resistance

Heat Resistant Double-sided Tape maintains stable adhesive performance even in high temperature environments. This characteristic is achieved by a combination of special heat-resistant material and adhesive. Applicable for use in high-temperature operations and areas where high temperatures are generated. 

2. Durability

Heat-resistant tape is durable enough to withstand long-term use. It maintains stable adhesive strength against environmental changes and vibration under high temperatures, providing reliable bonding.

3. Bonding Strength

Heat Resistant Double-sided Tape demonstrates strong adhesive strength to a variety of materials. Even in high-temperature environments, the tape can be firmly bonded without peeling or deterioration.

4. Diverse Applications

Heat Resistant Double-sided Tape is used in a wide range of applications due to its heat resistance. It plays an important role in various fields such as the automotive industry, electronics manufacturing, construction industry, industrial machinery, and food industry.

5. Freedom of Design

Heat Resistant Double-sided Tape, a flexible material, can be applied to complex shapes and curved surfaces. This allows for special shapes and designs.

6. Easy Installation

Heat Resistant Double-sided Tape can be installed more easily than conventional fixing methods such as bolts and nails. It improves work efficiency and facilitates the product assembly process.

7. Environmental Friendliness

Some Heat Resistant Double-sided Tape is made of environmentally friendly materials. This minimizes environmental impact during product disposal.

Types of Heat Resistant Double-Sided Tape

Types of Heat Resistant Double-Sided Tapes can be classified according to the material used.

1. Silicone

Heat resistant tapes based on silicone material are suitable for use in high temperature environments. Silicon is resistant to high temperatures and has excellent weather resistance and is widely used in the manufacture of electronic devices and automotive parts.

This tape is characterized by heat resistance and durability, and has excellent characteristics of maintaining high adhesive strength while leaving no residue.

2. Acrylic

Heat resistant tapes based on acrylic materials are used not only in high temperature environments, but also outdoors and in situations where resistance to chemicals is required. Acrylic tape provides strong adhesion to a variety of materials and is highly durable, making it useful in construction and industrial machinery assembly.

3. Glass Cloth

Heat-resistant tapes based on glass cloth have the ability to withstand high temperatures while also providing excellent abrasion resistance and chemical resistance. It is often used in the aerospace and military industries, among others, and plays an important role in environments that require high reliability.

4. Metal Foil

Heat-resistant tapes based on metal foil have high thermal conductivity and are sometimes used as heat insulators or conductive materials. They play an important role in industrial applications, especially for thermal management under high temperature conditions and electromagnetic shielding.

5. Special Synthetic Polymers

Heat resistant tapes based on specific thermoplastic polymers are designed to provide heat resistance suitable for specific applications. These tapes are suited for use under special conditions and are customized for specific industries and applications.

What Is a Rod End?

A rod end is a type of spherical plain bearing.

A spherical plain bearing has a spherical outer ring in a bearing housing (or the inner surface of the housing is spherically machined) and a ball-shaped inner ring with a drilled hole in it. In general, spherical plain bearings and rod-end bearings may also be treated as synonyms.

Link balls and link ball joints are also functionally treated as a type of rod end, but are not covered here.

Uses of Rod Ends

Figure 1. Example of rod end use

Rod Ends are mechanical elements that are used to fasten the housing end of a spherical plain bearing with a male or female thread to the end of a rod (shaft), such as a connecting rod, to fix or connect two parts, and allow the relative displacement of the two parts by means of their spherical plain structure.

It is mainly used to connect parts using links or to transmit linear motion to other parts. They are used in a wide range of fields, including construction machinery, industrial machinery, automobiles, and aircraft.

Rod Ends are used to connect parts by threading male threads, which are threaded at one or both ends of a shaft called a connecting rod, into the female threads of the rod end housing. A pin, shaft, bolt, or other component is inserted into the hole drilled in the center of the rod end’s ball-shaped inner ring, and the inner ring and pin or other component are fastened with a nut or other means. The distance between parts and the length of the connecting rod can be adjusted by the screwing depth of the rod end and the connecting rod.

Principle of Rod End

Figure 2. Configuration of rod endchol

Rod Ends consist of a bush that is the inner ring into which bolts and nuts are inserted vertically, and a “holder” that is threaded and connected to other parts such as a connecting rod.

A spherical plain bearing is incorporated. The spherical inner ring ball, which is drilled to insert a bolt or nut vertically, and the outer ring incorporated in the housing make spherical contact to enable smooth and flexible rotational motion.

It acts like a human joint, making it suitable for applications with complex movements. They can also withstand high loads, making them suitable for handling high weights.

Types of Rod Ends

Figure 3. Types of rod ends (Steel)

The holder part of rod end has a male thread and a female thread, and is selected according to the structure of the connecting rod or other parts to be connected.

There are two types of bushings: lubricated and non-lubricated.

1. Lubricated Type

The oil-feeding type has a grease nipple attached to the housing. In the lubricated type, grease is injected through the nipple using a grease gun or the like. In the oilless type, self-lubricating synthetic resin is incorporated in the outer ring of the holder. 

2. Oilless Type

Lubrication-free type does not require lubrication, and is used in confined spaces where lubrication is not possible or in maintenance-free applications.

Figure 4. Types of rod ends (Plastic)

Some rod ends are made of resin. Resin contains solid lubricant and can be used without lubrication or oil supply. Compared to metal rod ends, resin rod ends are lightweight and require no oil or grease, making them suitable for use in dusty environments.

It has corrosion resistance, chemical resistance, etc. Resin can absorb vibration, so it can be applied to applications involving vibration.

How to Select Rod End

Rod End should be selected so that the following two points meet the design conditions. 

1. Static Load Capacity (Radial Direction)

Figure 5. Allowable load calculation formula

Static load capacity is a measure of the mechanical strength of a rod end. Refer to the manufacturer’s catalog or instruction manual for details. The allowable load is calculated from the static load capacity using the above formula, and the rod end should be selected so that the load is less than the allowable load. 

2. Allowable Inclination Angle

Figure6. Allowable tilt angle

The angle between the centerline of the long axis of the rod end holder and the centerline of the bushing hole is called the tilt angle, which is used within the allowable range when positioning the parts to be connected using the rod end. The allowable inclination angle is also provided by each manufacturer, so please refer to their catalogs or instruction manuals.

What Is a Volumetric Flask?

A volumetric flask is a type of laboratory glassware used to measure and maintain a precise volume of liquid, offering greater accuracy compared to a graduated cylinder. Unlike graduated cylinders, volumetric flasks are designed for high precision in volume measurement.

Typically made of glass, some volumetric flasks are also constructed from plastic or resin. The flask features a flat, spherical bottom extending into an elongated cylindrical neck, which can be sealed with a stopper. Volumetric flasks are available in transparent colorless types or a brownish tint known as a tea flask.

Uses of Volumetric Flasks

Volumetric flasks are primarily used for maintaining a specific volume of a solution. They are essential in ensuring consistent concentrations in various solutions.

While clear, colorless volumetric flasks are commonly used, brown volumetric flasks, referred to as “brown flasks,” are utilized for light-sensitive materials. An example is the use of brown flasks for silver nitrate solutions, which are prone to light-induced discoloration. Volumetric flasks come in various shapes, including designs with wider cylinders for convenient handling of liquids.

Principle of Volumetric Flasks

Volumetric flasks are designed for precise volume control, particularly when maintaining constant concentrations. They are more accurate than graduated cylinders due to their specialized design.

One key feature is the placement of the measurement scale, or the “mark line,” in the narrow neck of the flask. This design reduces the diameter at the measurement point, enhancing scale accuracy and minimizing errors. The term “TC” on the flask stands for “to contain,” indicating that the volume of liquid up to the mark line corresponds to the volume specified on the display. Each flask has a defined volume tolerance, ensuring the accuracy of measurements.

Difference Between Volumetric Flasks and Graduated Cylinders

While both volumetric flasks and graduated cylinders are glass laboratory instruments used for measuring liquid volumes, they have distinct purposes and characteristics.

A volumetric flask is designed for diluting a liquid to a specific volume with high precision, as exemplified by a 100 ml flask used for creating specific volume solutions. On the other hand, a graduated cylinder has a scaled cylindrical body for reading the volume of liquid it contains, making it more suited for general volume measurements rather than precise dilutions.

What Is a Mechanical Valve?

A mechanical valve is a control valve that changes the flow of air operated by human power or by contact with an object.

To make an actuator such as a pneumatic cylinder work, it is necessary to switch the flow of compressed air freely. In the case of a single-acting cylinder, compressed air is supplied in the forward direction when moving forward, and in the reverse direction when moving backward, the compressed air is released into the atmosphere.

The valve that controls the direction of air flow is called a directional valve. Directional valves can be controlled in three ways: electrically, pneumatically, or by human or mechanical contact. A solenoid valve is operated by an electrical signal to open and close the valve, while a pneumatically operated valve is called a (air) pilot operated valve.

A mechanical control valve is operated by hand or foot, or by mechanical contact with an object, such as a limit switch. Such a control valve operated by human power or mechanical contact is called a mechanical valve because it is operated by mechanical action.

Uses of Mechanical Valves

Figure 1. Classification of mechanical valves by method of operation

Mechanical valves are useful in places where fire is strictly prohibited and explosion-proof specifications are required. Since actuators such as pneumatic cylinders can be operated only with pneumatic devices without using electrical signals, there is no need to worry about leakage of electricity or electric shock.

Push buttons, levers, and pedal types are available for those operated by human hands and feet. Besides being used as supply shutoff valves installed at the entrance of equipment, they are mainly used in semi-automated equipment. They may also be used as start-up switches for air sequence control.

Those with mechanical operation include plunger and roller types. Used as a switch for cylinder operation or workpiece position confirmation, it generates a signal for air sequence control.

For example, it is possible to control the cylinder to stop moving automatically when the door is opened or to operate only when the door is opened.

Principle of Mechanical Valves

In mechanical valves, a button is pressed by a human, or a plunger is pressed by a door or workpiece, which releases a flow path or is blocked by a valve. This is the principle of changing the pressure of airflow.

There are three types of valve structures: poppet type, spool type, and sliding valve type. The poppet type has a simple structure but requires a large amount of force to operate. This makes the valve more sealed, making it suitable for high-purity gas lines.

The spool and sliding valve types can be operated with relatively small force, but require a longer stroke.

How to Select Mechanical Valves

Figure 2. Difference in flow direction by port of 2-position mechanical valve (JIS symbol)

As with solenoid valves, the number of ports must be selected for mechanical valves as well.

2-Port Valve
A 2-port valve simply stops or diverts airflow. If you look at the 2-port, you will see a square on the left side, which means that air flows when the pushbutton is pressed. On the right side, the A and P ports are not connected, so no air flows.

3-Port Valve
A 3-port valve has an exhaust port and functions to supply and exhaust air. They are often used to operate single-acting cylinders or to signal air pilot lines. When the button is pressed, air flows from P to A. When the button is released, the air in A is exhausted out through the R port.

4- and 5-Port Valves
The 4- and 5-port valves have a function to intake air from the P port and supply and exhaust air alternately from the A and B output ports. One or two exhaust ports are available.

When connected to a double acting air cylinder, it can slide in both directions.

2. Position of Mechanical Valves

Depending on the number of switching positions the directional valve has, it can have two or three positions. For example, if the valve is designed to switch between state 1 and state 2 by “pushing” or “not pushing” a switch, it has 2 positions, and if it is a lever-type manual switching valve, it has a third state 3. In the case of a lever-type manual switching valve, a valve that has a third state (state 3) is in the 3-position. In the case of mechanical valves, state 3 is a 3-position closed center, which means that both ports A and B are sealed.

3. Method of Operation After the Button Is Pressed

A switch that returns to its original state by spring force when the button is released after being pressed is called a spring return type. A switch that retains the pressed state is called a retention type. It is also important to consider the operation after the switch is pressed when making a selection.

4. Other

Figure 3. Classification of mechanical valves by method of operation

There are various other selection points, such as the size of the port piping opening and the operating pressure. Because of these various types, it is important to design the pneumatic circuit in advance and determine which components will be needed before purchasing.

Other Information on Mechanical Valves

Precautions for Using Mechanical Valves

Because the valve must be moved under pressure by compressed air, a large amount of force is required, especially for valves with poppet-type valves. For example, an object that is intended to push the plunger may be pushed back the other way. Be sure to check the catalog value, as it states how much load should be applied.

It is important to always use a filter in the compressed air supply circuit to all directional control valves to ensure that debris and condensate are removed. Select a filter with a filtering fineness of 5 µm or less.

Air pressure containing large amounts of condensate can cause malfunctions to other pneumatic equipment, so countermeasures should be taken by installing after coolers, air dryers, etc.

What Is a Machine Reamer?

A machine reamer is a type of reamer used for hole finishing on a machine tool. Unlike a hand reamer, which is used for hand finishing, a machine reamer has a straight or tapered handle (shank). It can be attached to a tool (chuck) that holds the blade on the machine.

The shape of the blade is straight, and the machine reamer consists of a blade section that cuts a hole at the cutting edge and a “burnishing section” behind the blade that crushes and smoothes out surface irregularities.

Uses of Machine Reamers

The basic use of a reamer, not limited to machine reamers, is as a finishing hole tool to improve hole accuracy after drilling.

They can produce high roundness and surface roughness that cannot be achieved with drills or end mills, as well as inside diameter dimensions that have strict standards. They are used for holes to insert positioning pins in molds, for machining sliding parts such as shafts of engine parts, and for machining injection ports such as nozzles.

Since reamers process according to the pre-drilled hole, it is important to select an appropriate pre-drilled hole diameter.

Principle of Machine Reamers

The mechanism of a machine reamer is to prepare the hole with the burnishing section while machining the hole with the cutting edge, which allows for high hole accuracy. However, a reamer by itself cannot drill a hole, and if the downhole is small, chips will clog the blade, making it impossible to process the hole.

On the other hand, if a hole is drilled at the very edge of the reamer finish to reduce the load, the surface roughness will not be good because the burrs and scratches created during the drilling process will not disappear.

Furthermore, it will not be possible to correct a slightly oval-shaped hole, so the pre-drilled hole is often drilled 0.2 to 1.0 mm smaller than the finished dimension.

Broach reamers are also used in the same manner and for the same purpose, but instead of a straight edge, the broach reamer has a twisted blade. The broach reamer is used for finishing through holes because chips are discharged forward. The twisted shape also prevents chips from clogging, enabling machining with good surface roughness, but its disadvantage is that it is a little expensive.