投稿者: anninrika

What Is a Copper Wire?

A copper wire is an electrical wire made of copper, which is an excellent electrical conductor.

Copper is a very good electrical conductor and is one of the materials that can transmit electric current efficiently. Therefore, it is used in various applications such as electrical wiring and electronic devices. Taking advantage of this property, copper wires are made of copper.

Copper is a relatively flexible and easily processable material. This allows wires to be manufactured and installed in a variety of shapes. Other materials with high electrical conductivity include gold and silver, which can be manufactured at a lower cost than these materials.

Copper is also highly corrosion resistant and resists oxidation and corrosion. This makes it suitable for use in a variety of indoor and outdoor environments. Copper wires have a long service life and can remain reliable for decades.

Uses of Copper Wire

Copper wire is used as electrical wire in electrical circuits. The list of uses for copper wire is endless. The following are just a few examples of copper wire applications:

1. General Households

Copper Wire is widely used for power supply and electrical wiring in general households. They can be used for a variety of electrical wiring, from wall outlets to lighting fixtures. Copper wire is safe and reliable and supports the efficient operation of electrical systems.

2. Electronic Equipment

Copper wire is often used for internal wiring in electronic equipment. For example, copper wires are used in most electronic devices such as computers and smart phones. Copper’s high electrical conductivity makes it suitable for signal transmission and power supply, ensuring reliable operation.

3. Automotive

In the automotive industry, copper wire is a widely used component in automotive electrical systems and engine components. Copper wires are used in electrical components such as automotive battery cables, starter ignition systems, lighting, and sensors. Copper’s high heat resistance and durability make it highly reliable in automotive electrical systems.

4. Power Generation and Substations

At power plants, copper wires are often used to transmit power from generators to transmission lines. Copper wires are also essential for regulating voltage and distributing power at substations. Copper’s high electrical conductivity and durability make it ideal for efficiently transmitting power from power plants to demand facilities.

Principles of Copper Wire

Copper wire has very high electrical conductivity because copper atoms can move electrons freely. Free electrons exist outside the copper atom, and these free electrons carry electric current.

As current flows through the copper wire, the free electrons move through the crystal lattice of copper atoms, moving in response to the electric field. The electric field is the cause of the electric current, and the electrons move within the copper wire in accordance with the electric field, which is how the current is generated. Copper’s high electrical conductivity allows current to be efficiently transmitted, resulting in minimal energy loss.

One important law related to the copper wire principle is the Ohm’s law. According to Ohm’s law, current (I) is proportional to voltage (V) and inversely proportional to resistance (R). Specifically, it is expressed by the following equation:

V = I x R

In the case of copper wire, resistance is very low, resulting in almost no voltage drop when current flows, thus increasing the efficiency of the electrical system.

How to Select Copper Wire

Many factors are considered when selecting copper wire. The following are factors in selecting copper wire:

1. Shape

The shape of copper wire should be selected based on its application. When used as an overhead wire, single-core or thicker wire should be used to reinforce its strength. When laying inside a wall or in a narrow space, stranded wire with a group of thin wires is often used.

2. Allowable Current

Copper wire generates heat when a large current is applied, and it is important that this heat generation be kept within the allowable value. Therefore, it is necessary to select thicker diameter products for copper wires transmitting large currents. Copper wire with excellent heat resistance is often used when equipment needs to be downsized.

3. Insulation Coating and Protection

Since copper wire is a conductive material, it may cause a ground fault or short circuit if it comes in contact with the metal that makes up the column legs or enclosure. Therefore, many products cover copper wires with a resinous insulating material to insulate them. Products in which this insulation is further covered with a shielding layer or a sturdy insulator are called cables, and these products are selected according to the application.

What Is a Pellet Press?

A pellet press is a machine that presses and forms tablets, resins, and other materials.

Pellet presses are generally designed to press various materials into a mold and press a plunger into the mold to form the material. Manual, manual hydraulic, and automatic hydraulic types are available. Formed pellets are used as samples for various measuring instruments, test pieces, electrodes, recycled samples, etc.

Applications of Pellet Presses

Pellet presses are ideal for preparing sample pieces for X-ray fluorescence analysis, infrared spectroscopic analysis, and electron microscopic analysis. There are also applications for pellet presses in the preparation of cathodes and anodes for all solid-state batteries, sample pieces for research and development of dental materials, sample pieces for research and development of new products, and pellets for solid electrolytes.

Other examples of applications include tablet cleaner molding, metal powder molding, magnesium molding, ceramics molding, functional material molding, and food molding. It is also used for molding crystalline materials, zeolite, waste paper and plastic fuel RPF, resins, and silica/alumina.

Machines called press pelletizers or pellet molding equipment are used to solidify and reduce the volume of fuels, fertilizers, feedstuffs, and industrial wastes. Continuous production of pellets is possible. Conical rollers press the raw material with uniform pressure.

Principles of Pellet Press

The pellet press works as follows: First, the material is filled into the mold. Then, the plunger pushes the material into the mold, and pressurization begins. As the pressure increases, the air inside the material is pushed out, increasing the density and defining the shape of the pellets.

Once the maximum load is reached, the pressure is held for a certain amount of time so that the particles of the material adhere to each other, resulting in a stable pellet. Higher pressure ensures reliable molding and pellets with a smooth surface. With the automatic pressurization system, pressure can be controlled in steps, making it possible to create high-quality pellets even from materials that are difficult to mold.

The type that incorporates a heating device in the pellet press can press by increasing the temperature. High-temperature pressing is possible for compression molding tests and sample preparation of resins and powders.

Types of Pellet Presses

1. Classification by Driving Method

• Manual-type

This method uses the principle of leverage to move a plunger by a lever or screw to produce pellets hydraulically. Since hydraulic pressure is increased by hydraulic pressure, the press can be operated with light force. Since it is manual, it does not require electricity and is easy to use. Subtle adjustment of pressure increase and speed is possible. It is used for trial products in laboratories and for making a small number of pellets.

• Manual-automatic type

The built-in electric hydraulic pump allows easy adjustment of pressure. The speed of pressure increase, upper limit of pressure, holding time, etc. can be automatically controlled.

• Automatic type

Programmable, automatic, homogeneous pellets can be produced. For mass production.

2. Classification by Press Method

There are two types of powder press methods using dies: uniaxial and biaxial. Uniaxial pressing is a method in which the lower die is fixed and pressed by the pressurizing force of the upper punch. Friction between the walls of the powder-filled mold can cause a density difference between the upper and lower pellets, resulting in deformation and cracking.

Biaxial molding is a method in which the mold is not fixed, and the pellets are pressed in a floating state. The mold moves up and down in accordance with the movement of the powder during molding, thereby reducing the density difference between the top and bottom.

3. Classification by Added Functions

• Heating device

The specimen can be pressed at high temperatures. There are also high-temperature types capable of temperatures up to 400°C. Some are equipped with a water-cooling device. Some models are equipped with a water-cooling system, which enables fine adjustment of the mold temperature.

• Pressurization equipment

Combined with the pressure-resistant cleaning device CIP, this method applies pressure to the sample and presses it. Pellets are formed by applying uniform pressure from all directions using water pressure. Pressing is possible up to a surface pressure of about 2 tons.

Other Information on Pellet Press

KBr tablet method

The KBr tablet method is a basic method for infrared spectroscopic analysis of solids. It is suitable for measurements when the sample is rare. Potassium bromide KBr to which a small amount of sample is added is pressed into tablets to be used as a sample for the infrared spectrometer.

What Is a Hydrogen Compressor?

A hydrogen compressor is a device that compresses hydrogen gas.

Hydrogen compressors are used to compress hydrogen gas under high pressure or to liquefy hydrogen by cooling it. Compared to gas, liquefied hydrogen is much smaller in volume, which is advantageous for storage and transportation.
Hydrogen compressors come in a variety of forms, including mechanical types such as positive displacement and centrifugal types, and methods that use electrochemical reactions.

A familiar example of a hydrogen gas application is fuel cells. They are gradually becoming popular for use in automobiles, household power generation, and water heating. Hydrogen energy does not produce carbon dioxide gas and emits only water, making it an excellent energy source in this environmentally conscious age. A great leap forward is expected in the future.

Applications of Hydrogen Compressors

1. Storage and transportation of hydrogen

Hydrogen gas is an excellent method of storage and transportation because its volume is reduced to 1/800 when liquefied. Hydrogen can be liquefied by a hydrogen compressor at a hydrogen production plant and stored in a storage tank. It can also be loaded into transportation tanks on ships and tanks of trailer trucks for transportation to the destination.

2.  For fuel cells

Hydrogen is supplied to automotive fuel cells by installing a hydrogen compressor at a hydrogen gas station, increasing the pressure to the required level, and filling the vehicle’s hydrogen tank. In Japan, 70 MPa is used. Fuel cells for home use are cogeneration systems and are used to generate electricity as well as to heat water. In addition, generators using fuel cells are also in practical use.

3. Other Applications

Liquefied hydrogen is used as a raw material in chemical plants, pharmaceutical plants, fertilizer production, etc., as fuel for power plants, engine compressors, etc.

Principles of Hydrogen Compressor

Hydrogen gas is the element with the lowest density, and various methods must be used to increase pressure. Mechanical compressors, such as volumetric and centrifugal types, as well as electrochemical and thermal types, are used.

Mechanical compressors have a high-pressure ratio, so most are multi-stage compressors. They also require high temperatures, so cooling is also important. The maximum discharge pressure is about 100 MPa. Electrochemical reaction type and thermal type have the features of no moving parts, no vibration, no noise, and oil-free.

Types of Hydrogen Compressors

The types of hydrogen compressors used include positive displacement type, centrifugal type, electrochemical reaction type, and thermal type.

1. Positive Displacement Compressors

The positive displacement compressor changes the volume to inhale, compress, and discharge gas. The types of hydrogen compressors in practical use include reciprocating compressors, screw compressors, and diaphragm compressors.

The reciprocating type compresses gas through the reciprocating motion of a piston. Various types are available depending on the arrangement of the cylinders. The swash plate type, in which the piston reciprocates in the axial direction, is also of this type. The screw type compresses gas by rotating a two-axis or single-axis screw to reduce the volume. Diaphragm type compressors compress by reciprocating diaphragms.

2. Centrifugal Compressor

Centrifugal compressors convert the velocity energy of the gas into pressure by rotating an impeller at high speed. Hydrogen gas is the gas with the smallest density, and increasing the pressure requires increasing the impeller speed. Centrifugal hydrogen compressors are in practical use in the U.S., and in Japan, ultra high-speed single-shaft multi-stage and multi-shaft multi-stage compressors are under development.

3. Electrochemical Reaction Type Compressor

The electrochemical reaction type is not a mechanical compressor, but a method of obtaining compressed hydrogen through a chemical reaction. When voltage is applied to the electrodes, hydrogen ions are reduced to hydrogen and hydrogen is extracted from the cathode. This method is now in practical use in Germany and the U.S., and Japan is likely to expand it in the future.

4. Thermal Compressor

This method boosts pressure by applying heat to hydrogen gas. When hydrogen gas is stored in a hydrogen storage alloy, heat is generated, and metal hydride is formed. Then, when heat energy is applied to the metal hydride, hydrogen is separated, and high-pressure gas is obtained. The output pressure is about 25 MPa. Metal hydride is a stable substance and very safe. Heating is an environmentally friendly method since waste heat can be used. In Scandinavia, it is deployed in hydrogen stations.

Other Information on Hydrogen Compressors

1. Lubrication system of Hydrogen Compressors

Three types of lubrication systems are used.

• Lubrication type

This method injects oil into the sliding and sealing parts of the cylinder and screw to lubricate, seal, and cool. There are methods such as splashing, oil pumping, and pressure lubrication. Oil mist is contained in the discharged gas.

• Oil-free type

This method does not use any oil or water in the gas passage. No oil or water is contained in the discharged gas.

• Water circulation type

Water is injected into the screw to lubricate, cool, and seal. The oil rate of the discharged gas is zero.

2. Advantages of oil-free type

Oil-free hydrogen gas has many advantages. Many industries require pure hydrogen. These include the mobility sector, power generation/storage, chemical/petrochemical, fertilizer, and refining. The advantage of oil-free is that it does not affect the chemical reactions used in its production. It is also important that it does not affect the process or equipment.

What Is a Construction Bulldozer?

A construction bulldozer is a piece of construction equipment used mainly in construction work to remove, transport, and level the ground.

A bulldozer is a heavy machine with an earth removal plate called a blade attached to the front of its body. Its main role is to push earth and sand in the direction of travel to level the ground. By changing attachments, the bulldozer can perform various types of work. There are two types of drive systems: crawler (infinite track) type and wheel type.

Uses of Construction Bulldozers

Bulldozers are used for earth removal, pushing, and leveling in construction work. These include civil engineering, dam construction, building construction, and site development. They are also used for snow removal and wetland work. By changing attachments, bulldozers are used for digging up and moving large rocks, root cutting, etc.

Bulldozers are available for special work. At disaster sites, they are operated by radio control. Amphibious bulldozers work by radio control and are used in places where dredgers cannot enter or leave. Underwater bulldozers can travel on the seabed and are remotely controlled by divers.

Principle of Construction Bulldozer

Pushing earth and sand out of the ground requires a great deal of force and driving power. Crawler type bulldozers are often used because of their high driving force. The gears are reduced along with the engine speed to produce powerful propulsive torque.

To dig up and crush large rocks, a jaw called a ripper is used. The ripper helps break up rocks and separate rocks from sediment. Bucket-type blades can efficiently transport sediment.

Operations using blades require the blade to be tilted from the vertical or oriented to the left or right relative to the direction of travel. Hydraulic pressure is used to change the angle of inclination.

Features of Construction Bulldozers

1. A wide variety of attachments

By changing attachments, various types of work can be performed. There are various types of attachments such as blade shape, jaw type ripper, bucket type, radio remote control, snow removal type, winch type, etc.

2. Various types of crawler shoes

There are various types of crawler shoes for wetland work, including standard types, which can be selected according to the application. The cross section of the shoe is triangular and wide. Shoes for snow and rock are also available.

Types of Construction Bulldozers

There are many types of bulldozer blades and rippers.

1. Classification by Blade

• Straight-type

This is a standard type of blade. It can be tilted to the vertical direction when viewed from the side by a hydraulic cylinder, and has a large capacity to push out a large amount of material at one time.

• U-type

This type of bulldozer has a U-shaped blade with both ends bent forward to push out a large amount of earth and sand. This type is used for super-large bulldozers.

• Angle-type

The blade is angled to the left or right in the direction of travel. It is used for one-sided cutting work and heaping and spilling work. In power angle dozers, the blade angle can be changed hydraulically from the operator’s seat.

2. Classification by Ripper

• Multi-shank type

This is a standard 3-jaw ripper. It crushes large rocks. The number of shanks can be changed according to the hardness of the rock.

• Giant-type

Long shanks for deep drilling.

• Parallel link

Equipped with a parallel link mechanism to maintain a constant penetration angle even if the penetration depth is changed.

3. Classification of bulldozers

The standard classification of bulldozers by weight is as follows: small size: 3 to 12 tons, medium size: 13 to 24 tons, large size: 28 to 42 tons, and super large size: 44 tons or more. Another classification by the location where they are used is dry-land bulldozers and wet-land bulldozers. Wetland bulldozers are designed to work in soft ground.

Other Information on Construction Bulldozers

1. Characteristics of Bulldozers in Japan

In Japan, many bulldozers for wetlands can be used at construction sites on soft ground. The ground contact area of the crawler is widened to reduce ground pressure, and a specially shaped shoe is used. It has better lateral sliding characteristics and excellent rolling pressure effect.

2. Qualifications Required

To handle a bulldozer, a qualification is required: to drive and operate a vehicle of 3 tons or more, it is necessary to obtain a national qualification in vehicle-based construction machinery operation skills. The course consists of a classroom lecture and practical skills training at a designated training institute. The content of the course includes the structure and handling of traveling equipment, structure, handling, and working methods of work equipment, driving knowledge, and laws and regulations. Practical skills include driving operation, operation of work equipment, and signaling.

3. Manufacturers of Construction Bulldozers

There are very few manufacturers of bulldozers, with Caterpillar of the U.S. and Komatsu of Japan almost monopolizing the world market. Komatsu has developed radio-controlled bulldozers for use at disaster sites or to improve work efficiency. And in recent years, Komatsu has introduced bulldozers that use GPS satellite positioning systems and 3D CAD design data to assist operators and automatically control blades.

Caterpillar also developed a bulldozer in 2009 that is powered by an engine and driven by an electric motor. This product can be said to be environmentally friendly.

What Is a Plastic Adhesive?

A plastic adhesive is an adhesive that is particularly suitable for bonding plastics.

Some plastics can be bonded with general adhesives, but there are some materials that are difficult to bond with general adhesives. In such cases, a special adhesive or primer is necessary.

In some cases, even plastics made of easily bondable materials can be bonded more firmly using plastic adhesives. There are various types of plastic adhesives, so it is important to choose the right one depending on the application and situation.

Uses of Plastic Adhesives

Plastic is a resin material that is widely used in everyday items around us.
Plastic adhesives have the following applications:

• Repair of kitchenware, bath components, and other water-related items
• Interior repairs
• Repair of toys
• Various daily necessities and small articles
• Electronic devices
• Home appliances
• DIY and crafts

In DIY and crafts, adhesives are used to make plastic models and figures. Some types of adhesives can also be used for works that are expected to be exposed to water (e.g. snow globes).

Adhesives for professional-use are used for joining gaskets, bonding various plastic components, fixing parts, and laminating large areas and flat plates.

Principles of Plastic Adhesives

One method of bonding difficult-to-bond plastics is to use a primer. Primer is used to improve the adhesion of material surfaces.

It is a low-viscosity liquid with low non-volatile content. In addition to improving adhesion, it also stabilizes the surface, prevents corrosion of metal surfaces, improves adhesion, and prevents deterioration of the adhesive. Primer must be allowed to sufficiently dry before applying the adhesive, and must not be mixed with the adhesive. The type of primer required depends on the type of adherend and adhesive.

Some acrylic adhesives using methacrylate, etc., can adhere to difficult-to-bond plastics without a primer by using a mechanism that fills gaps with microbeads or other contained particles.

Types of Plastic Adhesives

Plastic adhesives are available for household and commercial use. Different types of products are used depending on the material and application.

1. Household Plastic Adhesives

There are various types of household-use plastic adhesives, such as those that come with a primer set and can easily bond PE and PP, and those that can be used with only one adhesive. There are also adhesives with different characteristics, such as heat-resistant, water-resistant, and impact-resistant adhesives, as well as adhesives that can be used for metals and woods other than plastics.

Heat- and water-resistant products are particularly effective for repairing parts exposed to heat and water in kitchens, baths, and other areas, and for crafting works that are exposed to water. Regular instant adhesives can also be used for ABS and PVC.

2. Professional-Use Plastic Adhesives

Plastic adhesives for professional-use include synthetic rubber-based adhesives and acrylic adhesives using methacrylate, etc. In particular, adhesives for hard-to-bond plastics can be used. Some adhesive products, especially those for hard-to-bond plastics, contain microbeads or other fine particles to improve adhesive performance.

Cyanoacrylate adhesives, epoxy adhesives, polyurethane adhesives, and silicone adhesives are also used for plastics that are easy to bond, such as ABS, acrylics, and nylon. The appropriate one should be selected according to the application.

Other Information on Plastic Adhesives

Types of Plastics

There are various types of plastics made of different materials, and the ease of joining them with adhesives depends on the type. Polyesters such as polyethylene (PE), polypropylene (PP), and polyethylene terephthalate (PET) are thermoplastic and used in a variety of applications, but all are difficult plastics to bond.

Acetal resins such as POM (polyoxymethylene) and PTFE (polytetrafluoroethylene) are also known as difficult plastics to bond.

ABS resin, polyvinyl chloride (PVC), acrylic resin, and nylon are other known materials that are relatively easy to bond and can be used with ordinary adhesives. All of these materials have high plasticity and are commonly used for building materials, household goods, and equipment components.

However, in the case of acrylic materials, since many products utilize the transparency of the material, high transparency and non-yellowing characteristics are basically required for the adhesive as well. In the case of PVC, the ease of adhesion differs depending on the formulation of the same polyvinyl chloride. In particular, recyclable polyvinyl chloride manufactured using relatively new formulations is a relatively difficult material to bond.

What Is a Metallic Adhesive?

Metallic adhesives are adhesives that can bond on metal surfaces.

Adhesives for metals include those that can bond between metals such as stainless steel, iron, and aluminum, as well as those that can bond between metals and non-metallic materials (e.g., plastic, wood, ceramics, and carbon fiber). Many products have excellent heat resistance, water resistance, and impact resistance.

Uses of Metallic Adhesives

Metallic Adhesives are used in a wide range of applications, whether for household, industrial, or architectural use. Metals that can be bonded include stainless steel, titanium, aluminum, iron, galvanized steel, copper, brass, and many others. Other non-metallic materials that can be bonded to metals include plastics, wood, glass, ceramics, carbon fiber, and many others.

1. Household Use

Household metal adhesives are used in applications such as DIY furniture, repair of kitchen, bathroom, and other water-related items, cord repair for digital equipment, car body and muffler repair, water pipe repair, and fence repair. It is also possible to repair eyeglass frames and accessories such as necklaces. Other applications include handmade accessories, gluing and repairing model trains, and repairing fishing tackle such as lures.

2. Industrial Applications

In industrial applications, metal adhesives are used as an alternative welding method to mechanical fastening and welding. Typical applications include bonding metal parts such as electronic components, heaters such as wire thermocouples, sensors, and other building materials and structures.

Principle of Metallic Adhesives

Metallic Adhesives, like general adhesives, bond by adhesive force and cohesion. Adhesion is the force that binds different molecules together, while cohesion is the force that holds the same type of molecules together. Adhesives are effective when they adhere to the surface of an object in liquid form as a liquid substance and cure. Curing is caused by polymerization, chemical reactions with curing agents, and evaporation of solvents.

There are several types of adhesives that can be used for metals, and each type has a different adhesion mechanism. The adhesion strength of adhesives is usually due to physical (mechanical) bonding, chemical bonding, or dispersion bonding.

1. Epoxy Resin-Based Adhesives

Epoxy resin-based adhesives are one type of adhesives that can be used on metals, and are available in one- and two-component types. Generally, the two-component type is the most common, in which adhesion proceeds through a chemical reaction caused by mixing two liquids. Compared to ordinary adhesives, this type of adhesive has the characteristic that its volume does not decrease easily when it cures. Other than metals, it can be widely used for bonding to wood, ceramics, glass, etc., and can also be used for bonding to non-metals. These adhesives have particularly excellent properties in terms of durability, heat resistance, and water resistance.

2. Elastic Adhesives

Elastic adhesives are adhesives that remain soft even after curing and have rubber-like elasticity. They are particularly suitable for bonding materials that are made of different materials. However, it cannot be used for bonding metals.

When bonding different materials, cracking, warping, or peeling may occur over time due to differences in the coefficient of thermal expansion. The coefficient of thermal expansion is a value that indicates the rate at which the length and volume of an object expands as the temperature rises. Elastic adhesives are less likely to crack, warp, or peel because the adhesive becomes elastic and rubber-like after curing. Also, since the adhesive layer absorbs shock, it is often relatively resistant to impact and vibration.

Types of Metallic Adhesives

Metallic Adhesives can be broadly divided into those for household and commercial use. Different products have different characteristics such as thermal conductivity, electrical conductivity, heat resistance, and UV resistance, and should be used according to the intended use. In addition, some types of metal adhesives can bond metals and non-metals, but not metals to metals, so care must be taken.

1. Household Use

For household use, instant adhesives for metals, epoxy resin-based adhesives, and elastic adhesives are used. Instant adhesives for metals are instant adhesives with high adhesive strength to metal surfaces. Instant adhesives cure by chemical reaction, so they can bond instantly without waiting for time to dry. The main reaction proceeds with moisture in the air or on the surface of the substance to be bonded.

Among various metal adhesives, the time to dry, capacity, impact resistance, water resistance, heat resistance, and UV resistance vary depending on the product. It is necessary to select the appropriate one for the application. For example, a quick-drying adhesive that cures in a short time is suitable when the range of use is narrow, such as for bonding metal fittings of accessories or repairing various small parts. On the other hand, if the area of use is large, such as repairing houses, cars, motorcycles, etc., a long curing time will be easier to work with. The longer the time to cure, the easier it is to make corrections after application.

Impact-resistant types are appropriate for areas subject to loads and impacts such as joints, while heat resistance is required for electronic equipment and areas around car engines. Water-resistant adhesives are required for use in kitchens, bathrooms, and other watery areas. For crafts and handicrafts such as accessory making, adhesives with a transparent finish can be used to keep the adhesive from being visible and to maintain its aesthetic appeal. In addition, since adhesives may stick to the container if stored for a long period of time, it is appropriate to select a small volume product if the amount or frequency of use is small.

2. Commercial Use

Metallic adhesives for professional use are alternatives to welding, screws, etc. Specific types include epoxy resin adhesives, acrylic resin adhesives, hot-melt adhesives, and light-curing adhesives. Curing time, dischargeability, workability, impact resistance, water resistance, heat resistance, and electrical conductivity vary depending on the product, so it is necessary to select the right one for the application.

What Is a Thin-Film Evaporator?

A thin-film evaporator is a device for separating and refining mixtures by forming a thin film to concentrate and evaporate low-boiling-point components (solvents).

Low-boiling point solvents can be evaporated in a short time. Since the heating time can be shortened, it is especially effective for separation and purification of heat-sensitive compounds. It can also be used to process high-boiling point liquids by creating a high vacuum.

Applications of Thin-Film Evaporators

Thin-film evaporators are used to concentrate, dry, and powder solutes (samples) by removing solvents, and to recover reusable solvents and water from spent solvents, waste liquids, and process liquids.

1. Chemistry

In the chemical industry, it is used to separate and purify organic compounds in general, such as amines, esters and other aromatic substances, latex, and monomers. It is also used to recover acetic acid, and to purify monoglycerides, fatty acid amides, various fatty acids and fatty acid derivatives, methacrylic acid derivatives, acetylene derivatives, and compounds with high boiling points.

2. Pharmaceuticals

Major applications in the pharmaceutical industry include the distillation and processing of vitamins, fats and oils such as DHA, EPA, and squalene, as well as the concentration and purification of common organic compounds.

3. Food

Thin-film evaporators are also commonly used in the food industry. Specific applications include the concentration and purification of proteins and sugars, as well as the concentration treatment of various juices, milk, etc.

4. Machinery & Electronics

Thin-film evaporators are also used in the refining of vacuum pump oil, refrigerator oil, and transformer oil, as well as in the vacuum heating treatment of sealing and molding materials used in electronic and semiconductor components.

5. Waste Liquid Treatment

Thin-film evaporators are used for concentration, water recovery, solvent recovery, and volume reduction of process liquids and waste liquids in general industrial production. They are used in various fields such as cutting oil waste in the metal industry, metal surface treatment industry, chemical industry, textile industry, leather industry, and dye industry.

Principles of Thin Film Evaporators

Thin-film evaporators concentrate and dry solutes based on the principle of evaporating solvents by forming a thin film in an evaporation tube equipped with a heating mechanism. Wipers and other devices are built into the evaporation tube to efficiently form a uniform thin film. Since the inside of the evaporation tube is usually designed to be depressurized, the solvent can be removed at low temperatures and in a short time by lowering the boiling point of the solvent through depressurization.

The solute precipitated as a solid is scraped off with a wiper or similar device and sent to a collection vessel. The evaporated solvent is passed through a tube as a gas, trapped in a cooling tube, and re-cooled to be recovered as a liquid. Usually, the evaporation tubes and liquid and gas channels of lab-scale equipment are made of transparent materials such as borosilicate glass, which are resistant to corrosion and chemicals and allow for internal observation.

Types of Thin-Film Evaporation Devices

Thin-film evaporators come in a variety of sizes, ranging from laboratory-size to large, industrial-use ones. Laboratory-size ones are usually made of glass, while industrial-scale ones are made of stainless steel or other materials.

In a normal thin-film evaporator, the evaporation tube is vertical so that the distillate flows down, enabling efficient separation and purification. For this reason, most equipment feeds the mixture to be separated from the top, but there are also rising thin-film evaporators that introduce the mixture from the bottom and heat it to rise. Other shapes include horizontal thin-film evaporators used for industrial applications.

4. Centrifugal Thin-Film Evaporators

Centrifugal thin-film evaporators are a type of thin-film evaporators for industrial use. Centrifugal thin-film evaporators are equipped with rotating blades and use centrifugal force to thin-film the processing liquid on the inner surface of the body. Solvent is evaporated by heat transfer from the jacket and vacuum decompression. Generally, these are large devices for industrial use and are available in a variety of types, including horizontal, vertical, scraping, and sanitary types. They have high separation efficiency and are especially suitable for distillation of high-boiling point solvents.

5. Short-Path Evaporators

Short-path evaporators are similar to thin-film evaporators. Short-path evaporators are capable of creating a higher vacuum in glassware than thin-film evaporators. The short-path evaporator is more suitable when operation in a high vacuum is required, such as for distillation and separation of high-boiling-point components. It is also more suitable for thermally sensitive separations because it can lower the operating temperature and shorten the time required.

What Are Ultraviolet Protective Glasses?

Ultraviolet protective glasses are glasses that protect the eyes from ultraviolet (UV) radiation.

Ultraviolet rays, part of the electromagnetic waves emitted by the sun, are in the ultraviolet region and have wavelengths shorter than visible light. Prolonged exposure to UV radiation can cause a variety of health problems to the skin and eyes, so appropriate UV protection should be taken. UV protective eyewear can be used to prevent UV exposure to the eyes.

Exposure to sunlight and glare can cause eye fatigue and stress. UV protective eyewear can be used to reduce glare and ensure comfortable vision.

Uses for UV Protective Glasses

UV protective eyewear is used for a variety of purposes. The following are just a few examples of uses for UV protective glasses:

1. Construction Industry

Because construction workers typically work outdoors and are exposed to increased UV radiation from the sun, it is recommended that they wear UV protective eyewear. This protects workers’ eyes and prevents eye health problems.

2. Agriculture

Agricultural workers require working outdoors for extended periods of time. Due to prolonged exposure to sunlight, UV protective eyewear may be required during agricultural work. They also help protect the eyes from pesticides and chemicals.

3. Medical Care

Dentists often use UV curing materials in dental procedures. These materials harden when exposed to ultraviolet light and serve to reinforce the teeth. When working with UV-curing materials, dentists need to protect their own eyes from UV light when treating patients’ teeth.

Dermatologists may also perform phototherapy when diagnosing and treating skin diseases. In these cases, UV irradiation is necessary, and medical personnel use UV protective eyewear to protect their eyes while treating patients.

4. Food Industry

In the food manufacturing industry, UV germicidal lamps are used to sterilize surfaces such as package containers. This prevents microbial growth and contamination and maintains product quality. It is recommended that workers working around this equipment wear UV protective eyewear to protect their eyes.

Principles of UV Protective eyewear

The lenses of UV protective eyewear have the ability to filter out specific UV wavelengths. This is achieved by applying a special coating to the lens or by using a special material; UV filtering prevents UV rays from passing through the glasses, thus preventing direct exposure of the eyes to UV rays.

UV protective eyewear is designed to block UV rays while allowing visible light to pass through. They protect the eyes from UV rays without affecting everyday vision or visual quality. This enables the function of providing vision as a pair of spectacles.

Other UV glasses that absorb UV rays are also available. Absorbing ultraviolet protective eyewear works by drawing ultraviolet rays into the lens and absorbing them, thereby protecting the eyes.

How to Select UV-Protective Glasses

When choosing UV protective eyewear, several important factors should be considered. The following are key factors in selecting UV protective eyewear:

1. Size

The frame size of the glasses is an important factor in selecting the right product for the shape of the face. If the frames do not fit, comfort and protection may be compromised. It is important to select the appropriate size by checking the width of the frames and it is recommended to try on the frames to check the fit.

2. Ultraviolet Ray Cutoff Rate

One of the most important features of UV protective eyewear is the UV cut-off rate. The UV cutoff rate is indicated on the label or description of the glasses, so choose a product with a high cutoff rate (usually 99% or higher).

3. Material

Frame material is an indicator that affects durability and comfort. Common materials include plastic and titanium. Choosing a lightweight, durable material will ensure comfort during prolonged use.

Lens material is also important in protecting the eyes. Polycarbonate and other materials that are lightweight and strong are generally used.

What Is a Transformer Bushing?

A transformer bushing is a component that provides electricity while supporting electric wires using transformer insulation.

Electric wires need to be supported because they are affected by gravity, but if they are supported by metal parts, they will cause ground faults and short circuits. Therefore, they must be robustly supported by insulators, resin, or other insulating materials. Transformer bushings play a crucial role in supporting and insulating the wires, as well as transmitting electrical energy.

It has high insulation performance and can insulate both the high-voltage side and the low-voltage side in a transformer. Generally, bushings with larger isolation distances are used on the high-voltage side.

With proper maintenance and inspection, transformer bushings are long-lasting and highly reliable components. They contribute to the stability and supply reliability of the power infrastructure.

Applications of Transformer Bushings

Transformer bushings are used in transformers and peripheral equipment. Peripheral equipment includes bus ducts and anti-collision plates. Applications include power distribution plants and substations.

1. Electric power distribution plants

Power distribution plants are facilities that branch power lines and distribute power. They often have transformers, which convert high-voltage lines to low-voltage lines for easier handling. Transformer bushings are used at the junction points of high-voltage transmission lines and low-voltage distribution lines to provide isolation in the transmission and distribution of power.

2. Receiving substations

Transformer substations are facilities that receive high-voltage power from transmission lines, convert it to low-voltage power, and supply it to general consumers. Transformer bushings ensure the insulation performance of transformers and prevent ground faults and short circuits in transformers. This improves the safety and reliability of the receiving substation.

Principles of Transformer Bushing

Transformer bushings are components that efficiently and safely transmit electric power while insulating electric wires. Its structure is based on a combination of insulators and conductors.

The most important function of a transformer bushing is to completely insulate the charging section. This prevents electrical ground faults and short circuits. Insulation is provided by insulating materials, which typically include ceramic, glass, and polymers (plastics). Transformer bushings have conductors inside to transmit electrical energy from the high-voltage side to the low-voltage side.

These conductors are made of highly conductive materials such as copper or aluminum to ensure reliable current transmission. Transformer bushings are attached to the transformer itself or to equipment at the receiving substation to establish a power transmission path. The high voltage side is often connected to transmission lines or transformers, while the low voltage side is connected to the power distribution system.

How to Select a Transformer Bushing

When selecting a transformer bushing, several important factors should be considered. The following are transformer bushing selection factors:

1. Operating Voltage

The voltage level of the transformer bushing should be selected to match the voltage level of the wires to which it will be connected. It is important to comply with the voltage range designed for safe operation within the specification voltage range. Bushings for high voltage and special high voltage are sold, with special high voltage bushings available for 66kV, 154kV, 275lV, and other types.

2. Insulator Material

The insulating material of the bushing is important to insulate the charging section. Common insulating materials include ceramic and polymer (plastic). Ceramic insulators are robust and less susceptible to contamination, while polymer insulators are easier to mass produce and process.

3. Allowable Current

The allowable current of a bushing indicates its performance with respect to current loading. It is necessary to select a bushing that matches the design current of the transformer and has the allowable current capacity to handle the load.

4. Dimensions

The dimensions of the bushing must match the design of the transformer and peripheral equipment. It is important to select bushing dimensions for the high voltage side and the low voltage side and plan to fit into the installation space.

5. Contamination Resistance

When used outdoors, the bushing’s resistance to contaminants is important. Especially in salt-affected areas, it is necessary to minimize the adhesion of contaminants by surface treatment of the bushing. Transformer bushings for protection against salt damage are also available.

What Is UV Curable Adhesive?

UV curable adhesives are adhesives that cure by irradiating with ultraviolet (UV) light. They cure through a chemical reaction initiated by the application of activation energy using ultraviolet light, and are characterized by their ability to bond quickly.

They can also bond a wide range of materials, including electronic components, metals, glass, and plastics. However, UV irradiation lamps are required and cannot be used on parts that cannot be irradiated.

Uses of UV Curable Adhesives

UV curable adhesives can bond a wide variety of materials, including glass, plastics, metals, and ceramics, and can shorten working hours through high-speed bonding. They are used in many industrial fields, including automobiles, electronic components, assembly of smartphones, digital cameras, and liquid crystal displays, and optical components. Approved ones are also used in medical applications, and the adhesives are used in dental fillers and cements, as well as in the assembly and repair of medical equipment.

Principles of UV Curable Adhesives

1. Bourdon Tube Gauge

UV curable adhesives are activated by irradiation of ultraviolet light as an energy source, causing a photopolymerization reaction to proceed. The main components are a photoinitiator, a polymer or monomer as the main ingredient, and additives (stabilizers, etc.). The initiation and progression of the polymerization reaction are as follows:

1. The photoinitiator absorbs UV light and generates the active species: radicals, cations, or anions.

2. The active species generated by the initiator cause the polymerization reaction of the adhesive’s main component to proceed. Monomers are converted into polymers with larger molecular weights, and components that were originally polymers are converted into larger polymers.

3. The melting point rises as the molecular weight increases due to the polymer formation, and the adhesive goes from a liquid to a gel-like state, then quickly becomes solid and cures.

Characteristics of UV Curable Adhesives

One of the characteristics of UV curable adhesives is that the curing reaction proceeds quickly, from a few seconds to a few minutes, and the working time can be shortened compared to other adhesives. However, it should be noted that UV irradiation lamps are always required and that they cannot be used on parts that cannot be irradiated with UV light. The chemical bonds created by UV irradiation are strong bonds such as covalent bonds, and they also have excellent chemical resistance, heat resistance, and moisture resistance.

In the past, mercury lamps were used for UV irradiation, but UV LED products with high output and long life are now commercially available, and are now regarded as an environmentally friendly method.

Types of UV Curable Adhesives

The types of UV curable adhesives are mainly divided into acrylic resin-based adhesives using a radical polymerization reaction and epoxy resin-based adhesives using a cationic polymerization reaction.

In acrylic resin-based adhesives, radicals are generated from the polymerization initiator by UV irradiation. This radical reacts with the acrylic resin, causing a radical polymerization reaction to proceed, resulting in the formation of a polymer and curing. In epoxy resin-based adhesives, UV irradiation generates acid from the polymerization initiator, which reacts with the acrylic resin. As a result, a cationic polymerization reaction proceeds, resulting in polymerization and curing.

In general, acrylic resins are less expensive and have the advantage of faster curing speed. On the other hand, cationic polymerization type resins are not inhibited by oxygen and are less prone to shrinkage during curing. Therefore, epoxy resin-based adhesives may be more suitable for applications such as lenses, where positional accuracy is required. Curability, hardness, and viscosity also vary depending on the product, and some can be adjusted. Appropriate selection should be made according to the application.