月: 2023年2月

What Is an Earth Clamp?

An Earth Clamp is a type of tool used in electrical and welding works, serving as a grounding clamp.

Electrical circuits must be grounded for safety. By using an Earth Clamp, the entire electrical circuit is grounded, preventing electrical leakage and electric shock accidents.

The clamp is also made of metal and is sturdy, so it can be used for a long period of time. However, they are often subjected to bending and other forces, which may cause them to deteriorate and break.

Regular inspection and replacement are necessary because use of a broken wire can cause electrical leakage and electric shock accidents.

Uses of Earth Clamps

Earth Clamp is one of the tools used in work. It is widely used mainly for work related to electricity. The following are some examples of uses for Earth Clamps:

1. Electrical Work

In electrical work involving high-voltage or higher, grounding of the electrical circuit is necessary to discharge residual electric charges and ensure safety. By using an Earth Clamp, grounding work can be performed efficiently and safely. 

2. Welding Work

In welding work, a strong electric current is applied when metals are joined together. The use of an Earth Clamp can prevent electrical leakage and electric shock accidents.

3. Geological Survey

Geological surveys sometimes measure the electrical properties of underground rocks and soil. Earth Clamp can be used to ground the measurement device.

4. Ground Improvement Work

During ground improvement work, electrodes may be installed in the ground. The electrode is embedded in the ground using an Earth Clamp.

5. Electromagnetic Wave Measurement

Electromagnetic wave measurement requires a reference ground potential in order to measure ground-to-ground voltage. By using an Earth Clamp, the measurement device is grounded to the ground and the ground potential is detected.

Principle of Earth Clamp

An Earth Clamp consists of a main unit and wiring.

1. Main Unit

The main body part is a clamp for clamping the target metal part. If the clamp is an alligator type, it has a handle to open and close the clamp by gripping the handle. If the clamp part is a vise, the clamp is opened and closed by turning the handle.

2. Wiring

The wiring section is divided into a wire section and a sheathed section. The material of the wire is generally copper conductor. Copper is often used for electrical wiring because of its high electrical conductivity, corrosion resistance, and heat resistance. In addition, wires for Earth Clamp are often twisted together because of the durability required.

3. Sheathing

Insulating materials such as PVC (polyvinyl chloride) or rubber are generally used, although the sheathing may be omitted. The sheath material prevents direct contact between the clamp body and the wire, thereby preventing electrical leakage and electric shock.

PVC is widely used in general because of its high durability and excellent weather resistance. Rubber is ideal for use as moving wires because of its excellent oil and abrasion resistance. However, it deteriorates due to ultraviolet rays and oxygen, so periodic replacement is necessary.

Types of Earth Clamps

Earth Clamps are available in the following types, depending on the material of the clamp part:

1. Pinch-Type Earth Clamp

Pinch-type clamps are used to clamp a metal part to be worked on. They are characterized by their high versatility, as they can be adjusted to fit the shape of the work object. They are widely used in electrical work and welding operations. 

2. Vise-Type Earth Clamp

This is a vise-type clamp that can firmly hold a metal part to be worked on. It is used for high-precision welding work. 

3. Earth Clamp for Soil

This is an Earth Clamps that can be embedded in the ground. It is shaped like a pile. It is used in ground improvement work and geological surveys. 

4. Magnetic Earth Clamp

This is an Earth Clamp that sticks to metal parts by means of magnets. It is characterized by the fact that it can be easily attached using magnetic force. They are used in electrical work and welding operations.

What Is an Alumina Ball?

An Alumina Ball is a metallic material used for crushing and dispersing various materials and their resistance to polishing.

When solids are crushed or ground mechanically, it results in unevenness and non-uniformity. Alumina balls are mixed with a hard, spherical object called an alumina ball to ensure uniform grinding. By changing the particle size of the alumina ball, the powder can be ground to a fine powder.

Aluminum, the raw material for alumina, is abundant on the earth and is an inexpensive material to produce.

Uses of Alumina Balls

Alumina Balls are used to grind glass, viscosity, and other materials into a fine powder by placing an appropriately sized Alumina Ball in a mill or other specialized equipment and agitating it. Also, when polishing, the metal surface is polished by putting Alumina Balls and the metal or other materials to be polished together with the polishing slurry and agitating them.

The materials to be agitated, ground, mixed, and polished in the mill range from soft materials such as clay to hard materials such as glass and metal. Alumina Balls are used in a wide variety of applications because they can withstand the high strength and abrasion resistance required of balls that are fed into mills for grinding and polishing.

Principle of Alumina Balls

Alumina Balls are made of aluminum oxide, and their high degree of sophistication is achieved by compacting alumina powder into a spherical shape and then processing it at high temperatures. Because of this high-temperature treatment, they are also called ceramics.

When the Alumina Balls are placed in the mill together with the material to be ground, such as glass fragments, and stirred, the hard Alumina Balls compress and break the glass. The glass fragments gradually become smaller and smaller, and eventually turn into a powder. In the case of grinding, the Alumina Balls are placed in the mill with water and an abrasive, and when stirred, the Alumina Balls rub the metal surface to polish it. Alumina itself is light because of its small density and is chemically stable.

Not only can it withstand high temperatures, but it is also resistant to acids and alkalis and has high wear resistance. Furthermore, since they have no adverse effects on the human body, they are widely used as Alumina Balls for stirring and grinding.

Other Information on Alumina Balls

1. Composition of Alumina Balls

The main ingredient of Alumina Balls is aluminum oxide (Al2O3). However, general-purpose products are sintered by adding a small percent of silicon dioxide (SiO2) or magnesium oxide (MgO) as a sintering aid, in addition to the raw material, alumina powder. As a result, the purity of the product is generally 90-95%. It is this type of general-purpose product that is used for general pulverizing applications.

On the other hand, in the above manufacturing process, silicon dioxide and other materials added to the sintered body are unevenly distributed at the crystal interface (grain boundary), resulting in low strength at the interface and inferior durability and corrosion resistance. High-purity Alumina Balls are made by processing at a high temperature near the melting point of alumina to reduce the amount of sintering aids.

High-purity Alumina Balls have a purity of 99.5% or higher and are superior in hardness and strength, making them suitable for grinding materials that would cause wear with general-purpose balls and for applications where contamination of components other than Al should be avoided. They also have excellent corrosion resistance, making them suitable for applications where corrosion is a concern, such as under strong acidic or alkaline conditions. 

2. Comparison of Alumina Balls and Other Ceramic Balls

Alumina Balls are the most common type of ceramic balls that are inexpensive and readily available. However, there are many other types of ceramic balls made of various materials.

Zirconia (ZrO2)
Zirconia balls are made of zirconium oxide and are characterized by higher strength and toughness than Alumina Balls. In addition, zirconia has a high specific gravity, and the impact force generated during the pulverization process is greater than that of Alumina Balls of the same size.

Zirconia balls are used in mechanical milling, a technique that utilizes the energy of pulverization for chemical reactions and material modification.

Silicon nitride (Si3N4)
A material with excellent heat resistance and little strength loss at high temperatures, Si3N4 is used in a wide range of applications, offering a good balance of strength, corrosion resistance, and heat resistance.

Tungsten carbide (WC)
An inorganic compound composed of carbon and tungsten, WC has a Mohs hardness of 9, second only to diamond, and has excellent heat and corrosion resistance. Its extremely high specific gravity makes it suitable for mechanical milling applications due to its high impact force. However, because it is expensive, it is mostly used in research and development.

Tungsten carbide has high hardness, but its toughness is not high, making it susceptible to breakage. Therefore, care must be taken to avoid contamination. Tungsten carbide balls have a few percent of cobalt added as a sintering aid.

Alumina Balls are usually the first choice material because of their strength and properties suitable for general grinding and dispersion applications. However, when special requirements exist, it is important to consider other materials.

What Is Aluminum Cutting?

Aluminum cutting is a machining process that employs machine tools such as lathes, milling machines, NC machines, and machining centers to precisely “cut” and “shape” aluminum.

Compared to processes like pressing or molding, aluminum cutting allows for intricate machining in specific areas, enabling the fabrication of complex shapes. Aluminum’s lightweight nature and excellent machinability make it possible to create precise components, making aluminum cutting a common method across various industries.

Uses of Aluminum Cutting

Aluminum cutting is employed as a machining technique for crafting machine parts that require precision and take advantage of the diverse properties of aluminum. It is used in various applications, including:

1. Machining Parts Affected by Magnetic Fields

Aluminum, being non-magnetic, is ideal for components susceptible to magnetic fields, such as electronic medical equipment, mechatronics equipment, and linear motor vehicles, ensuring unaffected operation.

2. Machining Parts Requiring High Thermal Conductivity

Aluminum’s exceptional thermal conductivity, approximately three times that of steel, makes it suitable for crafting air conditioning and heating equipment, engine parts, heat dissipation fins, and heat sinks with demanding thermal properties and intricate shapes.

3. Machining Parts for Low-Temperature Environments

Aluminum can withstand low-temperature environments without brittle fracture, making it ideal for applications involving extreme cold, such as handling liquid nitrogen (-385°F) or liquid oxygen (-360°F). This has led to its use in fields like space development and superconductivity, where precision and material characteristics are critical.

Principle of Aluminum Cutting

Aluminum cutting involves the removal of unwanted material from aluminum using specialized machine tools, shaping it to the desired form and size with precision. This process allows for the creation of a wide range of shapes and high-precision components.

However, complex shapes may require multiple cutting tools and methods, which can increase time and cost. Aluminum alloys, commonly used in components, are assigned numbers ranging from 1000 to 7000 based on their composition. The 5000 series is well-suited for aluminum cutting.

Other Information on Aluminum Cutting

1. Addressing Welding in Aluminum Cutting

During aluminum cutting, the material can melt, leading to welding on the cutting edge. This can affect machining accuracy and cause quality issues. Two methods can prevent weld deposition: “blowing away chips with air” and “using cutting fluid during machining.” These approaches help maintain machining precision and prevent welding issues.

2. Additional Challenges in Aluminum Cutting

While aluminum is suitable for cutting and can be machined continuously for extended periods, it poses some challenges due to its characteristics:

Issues with Long Aluminum Chips: Long chips generated during prolonged cutting can be problematic if they get entangled in the cutting machine, potentially causing machine failure or interruptions.

Concerns Related to the Softness of Aluminum Alloys: Aluminum alloys used in cutting are soft materials and can deform during chucking, especially for lightweight, thin-walled, and long components. Chucking with hard steel fixtures may damage the soft aluminum alloy surface, potentially impacting quality.

Challenges Due to the Formation of an Altered Layer: The surface layer of aluminum cuttings may form an altered layer with different properties than the internal layer, resulting in increased hardness and residual stress. This can necessitate adjustments in subsequent processes and reduce work efficiency.

Impact of Large Cutting Oil Usage: Aluminum cutting often requires a significant amount of cutting oil to prevent surface plucking. Using a large amount of cutting oil increases initial costs for anti-scattering equipment and ongoing costs related to oil replacement.

What Is an Alignment Tester?

An alignment tester is a device used to measure and adjust the wheel alignment on vehicles.

Wheel alignment involves the accurate adjustment of the angles of a vehicle’s tires, which is crucial for ensuring even tire wear and optimal handling.

Uses of Alignment Testers

Alignment testers primarily ensure a vehicle’s wheel alignment is accurate, serving several vital purposes:

1. To Ensure Safety by Improving Driving Stability and Handling

Correct alignment enhances vehicle stability and handling, reducing the risk of accidents by making it easier to control and maneuver, especially during sudden directional changes.

2. Even Tire Wear

Improper alignment leads to uneven tire wear, decreasing tire lifespan. Properly aligned wheels ensure even tire wear, extending their service life.

3. Improved Fuel Economy

Incorrect alignment increases tire rolling resistance, which can worsen fuel efficiency. Accurate alignment optimizes tire angles, improving fuel economy.

4. Tire and Suspension Protection

Continued misalignment strains tires and suspension components, potentially causing premature failure and damage. Proper alignment mitigates these risks.

Principle of Alignment Testers

Alignment testers commonly employ sensors or lasers to ascertain the position and angle of tires and wheels. Sensors placed at strategic points measure distances and angles to evaluate vehicle alignment.

When lasers are used, a reflective device mirrors the laser back, allowing the measurement of alignment parameters based on the reflector’s distance and angle.

Key alignment parameters include caster, camber, and toe—caster relates to the wheel’s vertical axis tilt, camber to the tire’s tilt, and toe to the tire angle orientation. Precise measurement of these parameters reveals the vehicle’s alignment state.

Vehicles are positioned on a measurement platform, with sensors and lasers attached to various parts for data collection. This data is then analyzed by specialized software to assess the vehicle’s alignment.

Types of Alignment Testers

Alignment testers are categorized as follows:

1. Optical Alignment Tester

Utilizes laser or optical technology to gauge vehicle wheel alignment. Reflectors attached to each tire enable the measurement of alignment angles and positions at high speeds.

2. 3D Alignment Tester

Employs 3D cameras and sensors for precise position and angle measurements of each tire. This method uses 3D modeling for real-time data analysis and simultaneous measurement of multiple alignment parameters, boasting high accuracy and speed.

3. Sensor Type Alignment Tester

This tester uses sensors fixed to the tires and wheels to measure alignment. The direct attachment to the vehicle ensures high measurement accuracy.

4. Head Type Alignment Tester

Features a measuring unit, or “head,” attached to the wheel to assess alignment parameters, providing high accuracy due to the direct contact with each tire.

5. Incremental Alignment Tester

Utilizes incremental sensors or gyroscopes to measure vehicle inclination or angles, ideal for assessing camber and caster parameters.

With various alignment testers available, selecting the appropriate one is crucial for precise alignment measurements.

What Is an Appliance Server?

Appliance Servers are servers optimized for a specific application running on a network, with integrated hardware and software.

They are designed to simplify operation and management, enhance security, and achieve high performance. They also play an important role in ensuring that companies and organizations can provide a stable supply of applications running on their networks.

Uses of Appliance Servers

Appliance servers are primarily used for the following applications:

1. Network Security

Appliance servers provide functions related to network security. They provide firewall, VPN, threat detection, intrusion prevention, and other functions that companies can use to protect their information.

2. Data Storage

Appliance servers can be used for data storage. This type of server incorporates a fast storage system to store large amounts of data and is ideal when a business needs to process large amounts of data.

3. Collaboration

Appliance servers can be used by a business to collaborate with employees or partners in different locations. This type of server provides all the tools team members need to be productive, including file sharing, email, and calendaring.

Appliance Server Principle

An appliance server consists of dedicated hardware and optimized software.

1. Hardware

CPU, memory, storage, etc. are optimized to meet application requirements, ensuring fast and stable processing. In many cases, redundancy and scalability expansion are also taken into account.

2. Software

Software is optimized to provide application- and function-specific functionality. For example, firewall appliance servers provide functions to detect and block external attacks. Web server appliances also provide load balancing and caching functions to provide a fast and stable website.

How to Choose an Appliance Server

When choosing an appliance server, it is important to confirm the following points:

1. Application Requirements

Before selecting an appliance server, check the requirements of the application you will be using. It is important to understand the functionality and performance requirements of the application and to select an appliance server that meets those requirements. 

2. Hardware Specifications

The hardware specifications of the appliance server directly affect the performance required for operation, so compare CPU, memory, storage, and other specifications to select the optimal specification for your application requirements.

3. Support System

Appliance servers are integrated with hardware and software, so you will need expert knowledge in the event of a problem. Check to see if the appliance server you have selected has a good support system and check the details of the maintenance contract.

4. Cost

Appliance servers may be more expensive than regular servers because they integrate dedicated hardware and software. Compare multiple appliance servers for appropriate cost performance.

Other Information on Appliance Servers

Appliance Server Operation

Appliance servers have a dedicated management interface that makes it easy to install, configure, and maintain applications. They also have security measures such as minimally restricted OS functionality and automated software updates to protect systems from misconfiguration and malicious attacks.

Appliance servers are designed to provide fast and stable service with hardware and software optimized for specific applications and functions. Therefore, it is essential to select and configure the appropriate appliance server.

What Is an Abbe Refractometer?

An Abbe refractometer is a device used to measure the refractive index of a material using the critical angle method. It resembles a microscope in appearance, and measurements are made visually through the eyepiece. This instrument is essential for manufacturers of optical equipment as it allows them to evaluate optical materials such as optical film and optical glass.

Uses of Abbe Refractometers

The Abbe refractometer is employed to determine the refractive index of various samples, including liquids, solids, and films. This measurement is crucial for assessing the optical performance of materials such as films, glass, lenses, and more. It finds extensive use in manufacturing and analysis companies.

Additionally, the refractometer principle is also applied in hand-held sugar meters, allowing the measurement of sucrose concentration in samples to evaluate the sweetness of vegetables and fruits.

Principle of Abbe Refractometers

The Abbe refractometer, resembling a microscope, is used by placing a sample on a prism. By looking through the eyepiece, one can observe the light emitted from the prism and its brightness or darkness. Since the refractive index is influenced by temperature, some prisms have a thermostatic water circulation system to control temperature.

When light travels from a medium with a higher refractive index to one with a lower refractive index, total internal reflection occurs if the angle of incidence exceeds a critical angle. This critical angle is the minimum angle of incidence at which total internal reflection happens. When a sample is placed on a prism with a higher refractive index than the sample and light is directed at the boundary between the prism and the sample, light incident parallel to the boundary surface will refract at the critical angle.

Observing the light emitted from the prism, one can identify a contrast in light intensity between the region above and below the critical angle, allowing the determination of the refractive index of the sample. Precisely, the refractive index can be calculated based on factors such as the critical angle, the angle of light emission from the prism, the prism’s apex angle, and the refractive index of the prism.

Additional Information on Abbe Refractometers

1. How to Measure Solids

While some Abbe refractometer models can measure the refractive indices of solids, accurate measurement of solids requires attention to detail. Irregular contact surfaces with the prism can lead to measurement errors. Therefore, when measuring solids, proper sample preparation and the use of an intermediate liquid may be necessary.

The process for measuring solid samples involves:

1. Flattening the surface of the solid sample, typically through filing, ensuring it will be in contact with the prism surface of the Abbe refractometer. If the solid is in powder form, uniform grinding is necessary.
2. Applying an intermediate fluid to the polished surface of the solid sample. Intermediate liquids fill the gap between the prism surface and the sample. Options include monobromonaphthalene, anise oil, and methyl salicylate.
3. Placing the solid sample so that the polished surface makes contact with the prism surface. The stability of the temperature should be ensured, and measurements should be repeated to verify consistency due to the increased potential for errors in solid sample measurements.

2. Wavelength of Abbe Refractometers

Abbe refractometers typically measure refractive indices using the D line of the sodium spectrum, with a median wavelength of 589.3 nm. However, certain models allow for wavelength adjustment within the visible or infrared spectrum, expanding the range of measurements. This feature can provide more comprehensive information than using the sodium spectrum alone.

Changing the light source wavelength can be achieved through methods such as employing an optical filter to transmit specific wavelengths or using an excitation element other than sodium (such as mercury or cadmium). The refractive index measurements at different wavelengths yield valuable data, as the curve representing refractive index against wavelength shape varies depending on the substance, allowing substance identification and impurity detection.

Moreover, measuring the refractive index at multiple wavelengths is highly effective in materials development and quality control, especially for materials where the refractive index is a critical parameter.

What Are Asphalt Emulsions?

Asphalt Emulsions are materials that can be applied at room temperature. It can be applied at room temperature, whereas asphalt is usually applied in liquid form after heating.

Uses of Asphalt Emulsion

1. Road Paving

Asphalt emulsion is used as a prime coat or tack coat for asphalt pavement. Asphalt pavement generally consists of a roadbed formed by crushed stones on the ground, a base layer and a surface layer formed by placing a heated asphalt mixture on top of the roadbed.

Asphalt emulsion is spread on the surface of the roadbed after the roadbed is formed to form a prime coat that improves the fit between the roadbed and the base layer that is formed on top of it. It is sometimes referred to simply as an emulsion. When used as a prime coat, it also has the effect of penetrating into the roadbed surface and stabilizing it.

It is also effective in preventing scouring of the roadbed due to rainfall, preventing surface water penetration, and blocking the capillary rise of moisture from the roadbed. Asphalt emulsion may also be sprayed on the surface of the base layer after the base layer is formed to form a tack coat that improves the fit between the surface layer and the base layer that is formed on top of it.

In other cases, they are spread after the formation of the surface layer to treat the surface of the pavement. Asphalt emulsions are also suitable for waterproofing structures other than pavements.

2. Promotion of Greening

Asphalt emulsions are also used to promote greening. For example, when seeds are sown on the surface, they will be washed away by rain.

However, if a mixture of seeds, soil, fertilizer, and water is sprayed on the surface and then covered with the emulsion, the seeds can be protected from erosion by rain. Asphalt emulsion is therefore also suitable for promoting revegetation.

Principle of Asphalt Emulsion

Asphalt emulsion is made by dispersing fine particles of asphalt in water using an emulsifier. They can be sprayed at room temperature. After spraying, the water and asphalt particles separate, causing the asphalt particles to aggregate and form an adhesive film.

The main components are straight asphalt, water, and emulsifiers, with the main component, straight asphalt, accounting for 50% to 70% of the total. After straight asphalt, water is the next most abundant component, followed by emulsifiers.

Types of Asphalt Emulsions

Asphalt emulsions are classified into three categories based on the type of emulsifier, which is a surfactant: cationic emulsion, anionic emulsion, and nonionic emulsion.

Although emulsifiers are less abundant than other components, their properties greatly affect the properties of asphalt emulsions.

1. Cationic Emulsions

Cationic emulsions are emulsifiers for cationic emulsions. After spraying, the water and asphalt particles easily separate and a film is formed without waiting for the water to evaporate.

Cationic emulsions account for most of the asphalt emulsions used in asphalt paving because they can quickly form a film on the surface of crushed stone.

2. Anionic Emulsion

Anionic emulsions are emulsions that use an anionic emulsifier. They have the disadvantage that it is difficult for water and asphalt particles to separate and it takes time to form a film.

However, they are highly stable as emulsions and can be stored for long periods of time. They are used as slurry seals, asphalt emulsions for waterproofing, etc.

3. Nonionic Emulsions

Nonionic emulsions are emulsifiers. They are characterized by their lack of electrical charge and high chemical stability. They can be easily mixed with alkaline materials such as cement, and are used as emulsions for roadbed reclamation methods and cement emulsion mortars.

Other Information on Asphalt Emulsion

Advantages of Asphalt Emulsion

Ordinary asphalt has low fluidity at room temperature. Therefore, when it is used for road paving, it must be heated to several hundred degrees celsius or mixed with organic solvents. This causes problems such as the generation of foul odors when heated.

Asphalt emulsion, on the other hand, does not require heating and can be applied at room temperature. Therefore, the use of asphalt emulsions is expanding as they are easy to handle, do not generate foul odors, and contribute to the environment by reducing carbon dioxide emissions.

What Is Acrylic Resin Paint?

Acrylic resin paint is a type of paint primarily composed of acrylic resin. It was first developed around 1950. Acrylic resin is created through the copolymerization of components like acrylic acid, methacrylic acid, esters, styrene, and other monomers. Due to its versatility in molecular design, acrylic resin is used not only in paints but also in applications such as adhesives and organic glass.

Figure 1. Typical monomers that make up acrylic resins

While acrylic resin paint initially gained popularity due to its excellent color and gloss, it has been largely replaced by higher-performance urethane and acrylic silicone resin paints today. Additionally, concerns about volatile organic compounds (VOCs) have led to a shift from solvent-based paints to water-based paints.

Uses of Acrylic Resin Paints

Acrylic resin paints are still widely used for applications such as exterior wall painting and DIY projects, although their use has decreased with the advent of urethane resin paints. They find application as topcoats on surfaces like concrete, mortar, roof tiles, and PC concrete, both indoors and outdoors.

These paints are also popular in furniture and DIY projects due to the wide range of available colors. Acrylic resins can be tailored to specific applications, resulting in coating films with varying levels of flexibility and hardness by adjusting the type of monomer and degree of polymerization.

Types of Acrylic Resin Paints

Figure 2. Different mechanisms of acrylic resin paint film formation

There are two main types of acrylic resin paints: solvent-based acrylic paints and water-based acrylic emulsion paints.

1. Solvent-Type Acrylic Paints

Solvent-type acrylic paints are formulated by dissolving the acrylic resin in a thinner, solvent. These paints offer excellent resistance to weather, water, alkali, and oil due to paint film formation at the molecular level. However, they are associated with the odor of the solvent and contain toxic substances.

Given their primary use in construction, consideration must be given to the environment and safety of workers who handle these paints.

2. Acrylic Emulsion Paints

Acrylic emulsion paints, also known as waterborne acrylic resin paints, are produced by emulsifying and dispersing acrylic resin in water. Similar to solvent-based acrylic paints, they can be tailored to enhance functionality. Recent developments have introduced additives such as antiseptic, antifoaming, antifungal, and antifouling agents to improve paint performance.

Acrylic emulsion paints are odor-free and free from damage caused by toxic substances, making them suitable for various architectural applications. Their functionality has expanded with the inclusion of additives, making them increasingly popular.

Additional Information on Acrylic Resin Paints

1. Advantages and Disadvantages of Acrylic Resin Paints

Figure 3. Comparison of characteristics of various paints

The advantages of acrylic resin paints include their affordability, excellent color and gloss, wide color variety, ease of use for amateurs, and suitability for layering. However, they are vulnerable to ultraviolet (UV) rays and degrade relatively quickly due to weathering factors.

UV rays and other environmental factors can cause plasticizers in acrylic resins to gradually decrease, leading to hardening and cracking of the coating film. As a result, the service life of acrylic resin paints is relatively short, typically ranging from 5 to 8 years. Acrylic silicone resin paints, which offer longer service life, have become more common.

Acrylic silicone resin paints incorporate a silicone component into acrylic resin molecules, mitigating the drawbacks of pure acrylic resins. These paints are often used for residential exteriors.

2. Acrylic Resin Paint Manufacturing Process

In general, paints undergo a five-step manufacturing process. Acrylic emulsion paints require additional dispersants and additives compared to solvent-based acrylic paints due to the dispersion of more particles in water-based formulations. Reactive cross-linking agents are sometimes added to increase the strength of the coating film.

• Pre-kneading: Resins, pigments, surfactants, and solvents are mixed to create a particle dispersion (mill base).
• Dispersion: The mill base is dispersed in a dispersing machine until uniform.
• Mixing: Additives and other ingredients are introduced to improve paint performance.
• Filtration: The paint is filtered to remove foreign substances.
• Coloring: Colored paints are mixed with the finished paint to add color. After coloring, each container is filled and shipped.

3. Characteristics of Acrylic Resin Baking Coating

Acrylic resin baking coating involves applying acrylic resin paints to an object and then subjecting the object to heat to thermoset the acrylic resin. This process significantly enhances the strength of the coating film. For acrylic resin, a high temperature of 140°C to 180°C is required for 20 to 30 minutes. Baking coating increases the hardness, scratch resistance, and adhesion of the coating film.

Baked coating improves weather resistance, reducing degradation, fading, and chalking caused by UV rays, which are common weaknesses of acrylic resins. However, baked-on acrylic resin coating may be less flexible and prone to cracking. Therefore, it is suitable for outdoor products.

Other applications include indoor and outdoor furniture, wall coatings, and painting small parts due to its unique characteristics. Examples include vending machines that require weather resistance and accessories that demand colored paints. However, the use of baking coating is limited by the heat resistance temperature of the object to be coated and its size.

 

 

What Is an Accent Wall?

An accent wall is a wall that significantly alters the ambiance of a room with other walls in basic colors.

For a room, even a simple change in the pattern or color of the wall can have a large impact on the impression and atmosphere of the space, making it one of the most effective remodeling methods, especially when the room layout is unique to the resident.

The construction of an accent wall itself is relatively inexpensive and simple, such as repainting walls or replacing wallpaper, making it an easy challenge.

Uses for Accent Walls

Generally, walls in most rooms tend to be a single basic color, such as beige or white.

While this may make the room look cohesive and calm, it often lacks interest and does not make the room that much more attractive.

By adding “accent walls” to monochromatic walls, we can create a “focal point,” a point that immediately catches the attention of anyone who enters the room.

To easily create a stylish and glamorous space in a room, lighting, furniture, and accessories can be placed around this focal point, the accent walls.

Principle of Accent Walls

The greatest effect that can be obtained is the ability of accent walls to transform a space in a room and make it stylish all at once.

A room space with only expansive colors such as beige and white certainly has the advantage of feeling expansive.

On the other hand, however, it tends to lack a sense of tension and crispness, creating a sloppy atmosphere.

Adding accent walls to such a room can create a sense of tension and liveliness in the room space by making the walls of the room different from their surroundings.

If the presence of the wall can be increased, items such as furniture and accessories around the wall will stand out as if they are brought to the foreground, creating a three-dimensional effect in the visual field with the accent walls as the centerpiece.

Accent walls also have the effect of serving as a “focal point” that draws the eyes of people entering a room.

Therefore, it is also easy to compose a stylish and easy layout of lighting, furniture, accessories, etc., centered on the wall.

Popular materials for accent walls include stone, tile, brick, and wood.

Stone, tile, and brick can give a space a European look, and they work very well with modern lighting, furniture, and accessories to add accents to a space while maintaining an open atmosphere.

On the other hand, wood accent walls have the advantage of creating a warm and inviting space in a room, bringing a relaxed atmosphere to the occupants.

Some materials not only look good, but also absorb moisture and sound, so when introduced with such materials, accent walls can be effective not only in terms of good-looking design but also in terms of bringing excellent functionality to the room.

In addition to changing the material, changing the color of an existing wall is also a feature of accent walls, and the impression that a room gives to people can be quite different depending on the color.

When choosing a color, the balance of colors is of paramount importance.

First choose the base color, such as beige or white, which occupies most of the walls and ceiling of the room. Next, select the sub-color, which determines the impression of the room by the color of the accent walls. Last is the accent color, which is used for a single point of interest.

Furthermore, it is important to consider the compatibility with lighting, furniture, accessories, etc., and decide on colors while thinking about the total image of the room.

What Is a Screw Plug?

Screw plugs are used as oil drain hole plugs in automobiles.

Screw plugs are also commonly called “drain plugs” or “drain bolts”. Although it is called a plug, it is not a spark plug for gasoline engine ignition.

The name of the screw plug itself is “Automotive Parts – Screw Plug” as defined in the JIS standard. A plug for a threaded pipe fitting is sometimes called a “Screw Plug” for short. Here, however, we will use the one specified in the aforementioned JIS standard.

Uses of Screw Plugs

Figure 1. Example of screw plug use

As shown in Figure 1, screw plugs are automotive parts used as plugs for oil (lubricating oil) drainage holes in engines and gearboxes, as well as other liquid drainage holes. For example, the sides and bottoms of engines and gearbox housings are threaded with oil drainage holes, and Screw Plugs are screwed into these holes to seal them.

Principle of the Screw Plug

The role of the Screw Plug is the same as that of a plug in a threaded pipe fitting, i.e., to screw and seal a threaded plug into a threaded outlet or the like. However, it is necessary to prevent leakage from the gap between the male and female threads. The method of preventing leakage depends on the type of screw and is explained in the section on Types of Screw Plugs.

The following three types of screws are used in Screw Plugs:

Type of screw	Applicable standard
Tapered pipe threads	JIS B0203
Metric coarse thread	JIS B0205
Fine metric threads	JIS B0207

Types of Screw Plugs

Figure 2. Types and shapes of screw plugs

1.Classification by Screw Type and Head Shape

Screw Plugs are classified by screw type and head shape as follows:

Type		Type of screw	Type by head shape
Type 1	Type A	Tapered pipe threads	Square head
	B1 type		Hexagon socket
	B2 type		With square hole
	C type		Hexagonal head
2 types	Type A	Metric coarse thread, metric fine thread	Hexagon head
	Type B		Hexagon head with flange
	Type C		Hexagon socket head with flange

Type 1, B1 and B2, do not have a hexagonal head, but have a hexagonal or square hole drilled in the screw shaft to allow mounting without the head protruding from the surface of the mounting area. They can be used in tight spaces with a hexagonal or square L-shaped wrench, etc.

Other types have a square or hexagonal head protruding from the surface of the mounting area.

2. Classification by Screw Tip Shape

Figure 3. Tip shape of screw plug

Screw Plugs are classified into two types: those with a flat screw tip and those with a slightly tapered pilot tip, and those with a straight or tapered tip (only in the case of tapered pipe screws).

3. Classification by Leakage Prevention Method

Figure 4. Types of screw plugs and leakage prevention methods

In the case of Type 1 Tapered Screw Plugs for pipes, sealing tape is wrapped around the male threads of the Screw Plug and screwed into the female threads of the housing, etc., so that the gap between the screws is tightly sealed.

In the case of two types of metric coarse and fine threads, a gasket is inserted between the seat surface of the Screw Plug and the housing surface. The Screw Plug is then screwed into the eye thread side of the housing, etc., so that the seat surfaces are sealed in close contact. 

4. Classification by Material

The table below lists the materials of common Screw Plugs:

Material		Applicable standards
SWCH10A-12A, SWCH10K-12K, SWCH43K-48K	Cold headed carbon steel	JIS G3539
S10C～S20C, S43C～S48C	Carbon steel for machine structural use	JIS G4051
C3604	Copper and copper alloy bars	JIS H3250

If made of steel, Ep-Fe/Zn5c surface treatment is applied for rust prevention, as specified in JIS D0201 Automotive Parts – General Rules for Electroplating.

5. Other

There are other types of Screw Plugs available on the market that are not specified in the JIS standard. For example, some have a magnet attached to the tip of the screw to absorb sludge and iron powder deposited in the oil tank or oil pan and prevent impurities from flowing into the engine and other parts.

Sludge is a sediment of oil and engine fuel, such as burnt scum and rust.

Other Information on Screw Plugs

Screw Plug Sizes

The sizes of Screw Plugs specified in the above JIS standards are as follows

Type		Screw size
Type 1	Type A	R1/8 to R1
	B1 type, B2 type	R1/16 to R1
	Type C	R1/8 to R1/2
2 types	Type A, Type B, Type C	M6 to M36