月: 2022年12月

What Is a Water Demineralizer?

A water demineralizer is a device that removes impurities from tap water or well water.

Natural water and tap water contain metallic components such as calcium and chlorine ions, which are removed by a water demineralizer. The amount of impurities reduced varies depending on the application. An ultra-pure water demineralizer is a device that produces water with very few impurities.

Water demineralizers range from devices that produce small amounts of pure water in laboratories to large-scale devices that produce large amounts of pure water in factories.

Uses of Water Demineralizers

Water demineralizers are mainly used in research facilities and factories. Specific uses include steam generation in steam boilers for power generation, producing cleaning water used in semiconductor research, manufacturing products in food and beverage factories, steam generation for drying in paper mills, and steam generation for plastic processing in chemical plants.

In research, they are used to remove impurities from water supply, especially in the semiconductor industry, where ultra-pure water demineralizers are used. The food and beverage industries use them to control water quality for food safety, and many other industries use steam from water demineralizers for their steam generation boilers.

Principles of Water Demineralizers

Water demineralizers can be classified into two types: ion-exchange membrane type and semipermeable membrane type. The ion-exchange resin type removes water impurities by exchanging hydrogen ions and hydroxide ions with impurity ions in the ion exchange resin, while the semipermeable membrane type uses a semipermeable membrane to filter out impurities. The semipermeable membrane type is also used for desalination by circulating seawater through it.

Other Information on Water Demineralizers

1. Household Water Demineralizers

Household water demineralizers, typically using reverse osmosis membranes, are known for removing impurities and microorganisms. They are installed under kitchen sinks and supply pure water through a dedicated faucet, with a switchable water supply between tap and deionized water. The principle involves applying pressure to tap water, allowing it to permeate through a reverse osmosis membrane, and circulating water parallel to the membrane to prevent clogging.

2. Electric Regeneration Type Water Demineralizers

Electric regeneration-type water demineralizers, consisting of alternating demineralization and concentration chambers with ion exchange membranes and resin, use DC voltage for regeneration. This process attracts impurity ions to the electrodes, regenerating the ion exchange resin without the need for strong acid or alkali, making it environmentally friendly and easy to manage.

What Is a Controller Board?

A controller board, commonly referred to as an operation panel, is a device primarily used for controlling and operating mechanical systems and devices. Found in settings such as factories and power plants, these panels provide an interface for controlling and monitoring machinery and systems, allowing operators to adjust operations and access vital information in real time.

With capabilities for remote operation through wiring connections, a well-designed controller board ensures safe operation with features like emergency stop switches and alarms for abnormalities, highlighting the importance of proper usage training, maintenance, and record-keeping.

Uses of Controller Boards

Controller boards are utilized across various fields for diverse purposes:

1. Factories

In manufacturing, they manage production processes, enabling start, stop, and speed adjustments of machines, and display process statuses for efficient control.

2. Power Plants

They monitor and control generators and power systems, ensuring stable electricity generation and distribution.

3. Commercial Facilities

Used for managing firefighting and security systems, they facilitate quick responses to emergencies and also control environmental systems like lighting and HVAC for energy efficiency and comfort.

Principle of Controller Boards

Controller boards are tailored to the specific machines they control, comprising operation and display sections, electrical wiring, and protective housing.

1. Control Unit

This unit includes buttons, dials, and keypads for direct control over machinery, offering functionalities like start/stop operations, function switching, and settings adjustments.

2. Display Section

It displays machine and process information, often through touch panels or simpler indicators like lamps and needles for status alerts.

3. Electrical Wiring

Wiring within the panel controls the system and distributes power, including control and power supply cables, with options for Ethernet or serial communication.

4. Housing

The exterior case protects the controller board from physical and environmental damage, made from durable materials like metal or hard plastic, featuring accessible doors and covers for maintenance.

Choosing a Controller Board

Selection depends on the specific needs of the application:

1. Process

Identify the processes requiring control and monitoring to determine the necessary functions and features of the board.

2. Operation Parts

Choose suitable operating components based on the process, balancing cost with functionality, such as push buttons versus touch panels for broader control capabilities.

3. Usage Environment

Consider the environmental conditions, especially for outdoor installations requiring dust and water protection, and select a board with the appropriate IP standards.

What Is a Rack Gear?

A rack gear, also known as a “gear rack”, is a type of gear with an infinitely large diameter. It features teeth of the same shape arranged at equal intervals along a square or round bar or plate. When used in conjunction with a pinion gear (a small diameter gear), this setup, known as a rack and pinion, can convert rotational motion to linear motion and vice versa.

Uses of Rack Gears

Rack gears are primarily used in conjunction with pinion gears in machines and devices that require rotational and linear motions. An example of their application is in factory production lines, where they play a crucial role in material handling and process transitions. Additionally, rack and pinion steering mechanisms in automobiles convert steering shaft rotation into linear motion of the tie rods. Other common uses include:

• Focusing mechanisms in telescopes and microscopes
• Vertical position adjustments in drill press spindles and tables
• Positioning adjustments in machine tools
• Lifting mechanisms in construction elevators

Principle of Rack Gears

1. Dimensions and Specifications

The basic dimensions and specifications of rack gears depend on the specific standard being used. Various standard defines the dimensional relationships between rack gears and pinion gears, ensuring compatibility and efficiency in their operation.

2. Length

While theoretically rack gears can have an unlimited number of teeth, practical limitations arise due to potential bending and deformation with longer lengths. To address this, racks are often machined at both ends and connected to match tooth pitches, allowing for extended lengths without compromising accuracy or functionality.

Types of Rack Gears

1. Classification by Tooth Trace Shape

Rack gears can be straight-toothed or helical. Straight-tooth rack gears have teeth perpendicular to the gear‘s longitudinal direction, offering simplicity and ease of manufacturing. Helical rack gears feature obliquely angled teeth, providing higher strength, quieter operation, and suitability for high-speed applications, though they require additional considerations for thrust loads.

2. Classification by Cross-Sectional Shape

Rack gears come in rectangular (square bar) and circular (round bar) cross-sectional shapes, each suited to different applications and installation requirements.

3. Classification by Material

Materials for rack gears vary based on application needs, including carbon steels, low-alloyed steels, stainless steel, resin materials, and copper alloys. Selection depends on required strength, wear resistance, and other operational characteristics.

4. Others

Additional configurations include linear motors with pre-installed racks and pinions, providing integrated motion solutions.

Other Information about Rack Gears

Features of Rack and Pinion

Advantages:

• Support for long strokes
• Ability to handle large loads with modular changes
• High-speed conveyance capabilities
• Versatility in applications through material and design modifications

Disadvantages:

• Higher frictional forces under load
• Tendency for increased noise
• Inherent presence of backlash

What Is a Plunger Pin?

A plunger pin is a device used for positioning or securing an object. It is named so because its tip is designed as a pin. Other types of plungers include ball plungers (with a ball-shaped tip) and index plungers (which can be removed). The built-in spring in a plunger pin pushes the tip against the object for fixing and positioning. These pins are incorporated into various machines and are particularly useful in metal processing and semiconductor manufacturing.

Uses of Plunger Pins

Plunger pins are utilized in various applications to position and secure objects. Each plunger has a built-in spring that presses the tip against the object. The tip engages with a hole or groove in the object, allowing for precise positioning and simple fixation. Plunger pins with a pin tip usually have a longer stroke compared to those with a ball tip. Besides positioning and fixing, plunger pins are also used in metal and mold presses for ejecting parts.

Principles of Plunger Pins

Plunger pins are designed for positioning and fixturing tasks. The pin at the tip of the plunger interacts with an object to perform these functions.

The plunger pin has a straightforward structure: a pin attached to a built-in spring. Other types of plungers, like ball plungers, typically have ball-shaped tips. Each plunger operates by pressing against an object. When pressed, the tip of the plunger retracts, but when aligned with a hole or groove in the object, it extends due to the spring’s tension. This mechanism enables precise positioning and fixing. Thanks to its simple yet effective design, the plunger is widely used in various machines.

Plungers can be categorized into three types:

• Ball plungers, with ball-shaped tips, are ideal for sliding motion and used for positioning sliding parts.
• Index plungers, which can be manually pulled at the tip, allowing for easy positioning and releasing.
• Plunger pins, which can be used for ejecting as well as fixing and positioning, are chosen based on the length of the pin at the tip.

What Is Industrial Ventilation?

Industrial ventilation are designed to exchange indoor air with outdoor air.

They are installed in houses and buildings for the purpose of hygiene control and the prevention of condensation. They take the form of ventilation fans, ducts, and other equipment.

Uses of Industrial Ventilation

Industrial ventilation are employed in various settings in modern society. In some cases, industrial ventilation is required by law. Examples of use include detached houses, public facilities like schools and hospitals, commercial facilities like department stores and theaters, and special buildings such as apartment buildings.

Ventilation helps maintain a constant oxygen concentration in rooms and is effective against sick building syndrome and deodorization.

Principles of Industrial Ventilation

Industrial ventilation is broadly categorized into two types: mechanical ventilation and natural ventilation.

1. Mechanical Ventilation

Mechanical ventilation utilizes a blower, such as a propeller fan or sirocco fan, to introduce outdoor air into a room and discharge indoor air. All-fresh type air conditioners also provide ventilation by air-conditioning outside air and sending it indoors. They are commonly used in high-rise buildings and large commercial facilities.

2. Natural Ventilation

Natural ventilation is achieved through the use of windows and sliding doors. It relies on natural airflow without mechanical equipment. This method is sometimes employed in gymnasiums.

Types of Industrial Ventilation

1. Type 1 Industrial Ventilation

Type 1 systems simultaneously exhaust and supply air. They maintain indoor air pressure relative to the outside by adjusting exhaust and intake volumes. However, they may have higher initial and maintenance costs and can potentially contribute to sick building syndrome due to microorganism growth in ducts.

2. Type 2 Industrial Ventilation

Type 2 systems supply outside air with a blower and exhaust through a separate port. They create positive pressure in rooms, preventing outside air pollution. This method is suitable for clean rooms, but may cause condensation within walls.

3. Type 3 Industrial Ventilation

Type 3 systems use natural air intake and mechanical exhaust, creating negative indoor pressure. They are often used in kitchens and restrooms to prevent odor spread and moisture accumulation.

What Is a V-Belt Pulley?

A V-belt pulley is a disk-shaped component used to transmit power using a V-belt.

The V-belt pulley is a belt with a V-shaped cross section and is used in combination with the V-belt pulley, which has a V-shaped groove and a larger contact area than the flat belt and pulley, resulting in higher transmission efficiency.

V-belt pulleys are used in many rotating machines, and V-belt pulleys are one of the most frequently used pulleys in Japan.

Uses of V-Belt Pulleys

V-belt pulleys are used in a wide variety of equipment, from home appliances to industrial equipment. The following are examples of V-belt pulley applications:

• Belt conveyors and compressors
• Automobiles and bicycles
• Industrial pumps
• Portable generators

Due to the strong engagement between the belt and pulley, V-belt pulleys are used in machines that rotate at high speeds. On the other hand, V-belt pulleys are not suitable for use when the distance to the power transmission object is short.

When the distance is short, flat belts tend to be used, which are subject to less wear.

Principle of V-Belt Pulley

The V-belt has a V-shaped cross section, and the V-belt pulley has V-shaped grooves dug into it; the V-belt fits into the grooves of the V-belt pulley and rotates the pulley by friction.

The key points of power transmission are belt tension and belt surface roughness.

1. Belt Tension

The stronger the belt tension, the stronger the engagement with the pulley, which creates higher transmission efficiency. However, too much tension may cause the belt to break, so proper adjustment is necessary.

The strength of the belt tension can be quantitatively controlled by using a belt tension gauge. 

2. Surface Roughness

V-Belt pulleys have a wide range of contact surfaces with the belt, so the roughness of each contact surface is an important factor in determining transmission efficiency. The rougher the surface creates a higher frictional force and the higher the transmission efficiency.

On the other hand, it also has the disadvantage of increasing wear and shortening the life of the machine. After prolonged use, the grooves on the V-belt pulley gradually become worn and the surface becomes smooth. In this condition, the belt and pulley tend to slip and transmission efficiency is reduced, so replacement is necessary.

Other Information on V-Belt Pulleys

1. Centering of V-Belt Pulley

If the V-belt pulley is used with the motor side misaligned with the machine side, the V-belt pulley and pulley will wear faster, and an unexpected load will be applied to the equipment. This condition is expressed as “off-centering.”

To prevent the above, centering of V-belt pulleys is a very important operation. Centering using water thread is a widely used method. Yarn is applied to the upper and lower surfaces of the pulley on the motor side and the machine side, and the lifting of the yarn is compared.

With the yarn pressed against one side, the other side is floated, and the timing when the yarn leaves the pulley surface is checked. This method allows visual confirmation of the parallelism and misalignment of the surfaces, and is repeated several times while making fine adjustments.

In recent years, laser centering devices have become widely available because they are easy to use and highly accurate.

2. Wear of V-Belt Pulley

V-belts and V-belt pulleys gradually wear over time. Since V-belts wear out faster, V-belts need to be replaced more frequently. However, V-belt pulleys also wear gradually and need to be replaced as they age.

The wear rate of a V-belt pulley can be measured with a measuring instrument called a groove gauge; the groove gauge is pressed against the groove of the V-belt pulley and the gap between the groove and the groove gauge is measured with a gap gauge. The groove gauge must be used according to the standard of the V-belt pulley, such as the ISO standard, or wedge belt.

Different groove gauges should be used depending on the diameter of the V-belt pulley. It is necessary to confirm the standard and size of the V-belt pulley to be measured in advance.

As for the wear limit, in most cases, the manufacturer’s allowable value is 0.8 mm gap. However, since it varies depending on the model, the allowable value of the V-belt pulley used should be checked before measurement.

What Is a Plastic Screw?

A plastic screw is a screw made from resin (plastic) instead of metal.

Compared to metal screws, plastic screws are lighter in weight and have superior insulation, corrosion resistance, and thermal insulation properties. Polycarbonate (PC) is the most common material used for plastic screws, while PEEK and RENY are also used. The characteristics of the screw also vary depending on the material used.

Plastic screws are manufactured in a variety of shapes and sizes, such as small screws, hexagonal bolts, potato screws, and knurled screws, to suit various locations and applications. Dimensions are made according to JIS and ISO standards, as with metal screws. However, due to the difference in manufacturing methods from metal screws, some dimensions may not conform to JIS or ISO standards.

Uses of Plastic Screws

Plastic screws are used in a variety of industries, with applications varying depending on the type of resin used. For example, PC is used in electrical and electronics to medical fields for its high impact resistance and balanced mechanical and electrical properties. PEEK is suitable for office automation equipment, automobiles, IC wafer carriers, and LCD manufacturing jigs due to its excellent chemical, heat resistance, and abrasion resistance. RENY is used as a substitute for metals in automobiles, general machinery, and other applications because of its extremely high strength and modulus of elasticity, as well as excellent oil and heat resistance. PPS is used in automotive and mechanical parts for its high heat resistance, and PP is widely used for plastic screws in everyday items due to its low specific gravity and versatility.

Principles of Plastic Screws

Even though they are made of plastic, the fastening principle of a plastic screw is the same as that of a regular screw. By using the spiral slope of a screw, a large axial force (fastening force) can be generated even with a relatively small tightening torque. However, compared to metal, the elasticity of resin is much smaller, resulting in a lower fastening force. Therefore, plastic screws are best utilized in applications where their unique characteristics, rather than strength, are needed.

Manufacturing Method of Plastic Screws

Plastic screws are typically manufactured by injection molding. This process involves melting resin and pouring it into a mold, which is then cooled to form the screw. In some cases, screws are manufactured by cutting or press working. Press working involves softening plastic sheets by heating and pressing them between sheets in a mold attached to a press machine.

Characteristics of Plastic Screws

Plastic screws have many excellent features, such as lower specific gravity compared to metal screws, high electrical resistance, excellent insulation properties, corrosion resistance, low thermal conductivity, no magnetism, unique plastic appearance, and recyclability.

What Is Nylon Casting?

Nylon casting refers to the production of nylon through a casting method.

The casting method involves the reaction of monomers, the raw materials, within a mold to create the material. As the resin cools, internal strain can develop within the material, potentially leading to deformation and, in some cases, breakage.

Compared to other molding methods, less strain is generated during the casting process, resulting in superior dimensional stability. Additionally, reduced deformation due to strain results in a material that is stronger than standard nylon.

Uses of Nylon Casting

Nylon casting finds applications in the automotive industry, particularly in the production of bearings. Bearings are components designed to support rotating shafts, reducing friction during rotation and thereby lowering energy consumption and the risk of component failure.

Traditionally, bearings were predominantly made of metal due to their need for durability. However, as automobiles have become lighter to improve fuel efficiency, there is a growing consideration for plastic bearings. Nylon casting, known for its lightweight and strength, is utilized as a material in this context.

Principle of Nylon Casting

Various types of nylon resins exist, with Nylon 6 being the most commonly used type in nylon casting. Nylon 6 is produced through the ring-opening polymerization of a substance known as ε-caprolactam.

Nylon 6 is the most prevalent form of nylon. While Nylon 6,6 is another common variant, it exhibits slightly different physical properties. While Nylon 6,6 has a higher melting point, Nylon 6 offers superior processability.

Nylon 6 has several advantages:

• Oil resistance, suitable for use around engines.
• Higher melting point than other resins, enabling use at elevated temperatures.
• Lightweight and durable.

Despite its numerous advantages, Nylon 6 also has disadvantages. Its significant drawback is its high water absorbency. Nylon molecules contain amide groups, which are hydrophilic and prone to reacting with water, leading to hydrolysis. Hydrolysis can result in dimensional deformation and loss of strength.

Types of Nylon Casting

1. Cast Nylon Casting 6 (Polyamide 6)

Cast nylon casting 6 is a linear polymer produced from ε-caprolactam, known for its excellent abrasion and impact resistance. It also exhibits chemical resistance and weather resistance, making it suitable for outdoor and harsh environment applications.

However, due to its moisture-absorbing tendencies, dimensional changes may occur in humid environments. Major applications include gears, bearings, gears, packing, and textiles.

2. Cast Nylon Casting 66 (Polyamide 66)

Cast nylon casting 66 is a high-strength linear polymer produced from adipic acid and hexamethylenediamine. Consequently, it offers better heat resistance and abrasion resistance compared to cast nylon casting 6.

It is suitable for use in high-temperature environments, such as insulation in automotive parts, electrical equipment, mechanical parts, and industrial components. It also exhibits favorable friction properties, making it widely employed in sleeves, bearings, gears, and other components.

3. Cast Nylon Casting 12 (Polyamide 12)

Cast nylon casting 12 is a linear polymer produced from amine lauroyl chloride, known for its excellent flexibility and low-temperature resistance. Its softness allows for easy bending and twisting, and it also exhibits chemical resistance.

Common applications include automotive and aerospace components like fuel tanks, brake tubes, and cable sheaths. Additionally, it finds extensive use in medical equipment and sports gear.

4. Cast Nylon Castings (Oil-Resistant)

Some variants of cast nylons offer enhanced oil resistance, making them highly suitable for applications involving oil, gasoline, and other fuels.

They are employed in engine components, fuel system parts, and various machinery and vehicle parts exposed to oil and grease.

What Is a Laboratory Container?

A laboratory container encompasses all types of containers used in scientific experiments and research.

Laboratory containers include a wide range of items, such as containers for holding substances and reagents, measuring instruments used to measure the amount of substances and reagents, cleaning instruments used to clean laboratory equipment, and storage containers used to store substances and reagents.

Laboratory containers include beakers, flasks, vials, screw-neck bottles, and other such items used for conducting experiments or storage. They can be made of glass, resin (synthetic resin), or metal, and are used for different purposes.

Uses of Laboratory Containers

Laboratory containers are essential for a variety of scientific experiments and research in fields such as chemistry, biology, and medicine. They are also used in a wide range of fields, including medical and pharmaceutical research and development, agricultural and livestock research, and in science experiments in educational programs from elementary school to university.

Glass and plastic containers are used for measuring liquids, such as beakers. Resin containers are mainly used for storing samples, while metal containers are used for storing, weighing, and transporting liquids and solids. Special resin containers are used for special purposes such as washing bottles and come in a variety of shapes depending on the application.

Characteristics of Laboratory Containers

Beakers, commonly used for measuring liquids, are made from materials such as glass, polypropylene, or stainless steel and generally have a spout. Heat-resistant ones are also used for heating liquids.

Glass containers used to store powders and liquids are sturdy, resistant to chemical reactions, and easy to check their contents. Borosilicate glass containers, in particular, are characterized by high heat and chemical resistance. Screw-top bottles with screw-on caps are available in light-shielding tan or shatterproof coated versions. Vial bottles with rubber stoppers can store drug solutions under aseptic conditions.

Polyethylene and polypropylene are used for plastic containers. Polyethylene is resistant to strong acids and alkalis and has excellent cold and water resistance. Polypropylene is the lightest, has physical strength, is not easily deformed, is heat resistant, and is used for food storage.

Metal containers are made of stainless steel, steel, enamel, or aluminum, and are more durable and easier to clean than glass or resin. They are available in cups, lidless vats and trays, and tanks and bottles with lids.

What Is a Square Head Bolt?

Square head bolts and square head screws, are bolts with a square head (square or rectangular).

A square head bolt has a square head, whereas a hexagonal bolt has a hexagonal head.

“Diamond head bolts” and “T-Head Bolts” with a rectangular shape are also available as Square Head Bolts, but they are not classified as square head bolts.

Figure 1. Shapes of square, Rhombic, and T-type head bolt

The following are the standards for square head bolts:

• ASME B 18.2.1 square head bolts

Uses of Square Head Bolts

Square head bolts are mainly used for construction reinforcement hardware. The square shape of the bolt head prevents the corners of the bolt head from wearing down and rounding off, even when tightened with a high torque, and thus allows for firm tightening with little possibility of damage.

Construction reinforcement hardware is hardware that is attached to the corners of timbers, such as beams and columns, to prevent warping and distortion and to reinforce the building structure. Square Head Bolts are used to fasten the hardware to the wood.

Compared to hexagonal bolts, square bolts have a larger contact area between the tool and the screw, so there is less slippage between the socket or wrench and the bolt head. Since the corners of the bolt head are less prone to wear, rounding, and damage, square bolts are used for screws that require high torque. It is used for screws that are strongly fixed or not to be removed, and can be turned without slipping the tool.

Principle of Square Head Bolts

Figure 2. Shape of square bolt

Square head bolts are the same as the hexagonal bolt and are fastened to the object to be fastened by means of a screw (in this case, “screw” refers only to the screw shape). Like hex head bolts, square head bolts are tightened by inserting a tool such as a wrench or socket into the head of the bolt.

Square head bolts are threaded with metric coarse threads or inch threads. The length of square head bolts is indicated by the length of the shaft, including the threaded part, excluding the height of the bolt head, in the same way as the length of ordinary bolts such as hexagonal bolts.

Types of Square Head Bolts

There are two types of square head bolts. The bolts with a width other than the standard size are called “large square bolts.”

In addition, three types of surface roughness are specified as the degree of bolt finish.

• Top: Rz25 for the surface roughness of the seat (the surface of the lower part of the bolt head in contact with the part to be fastened), the cylindrical part and the top surface of the head, and Rz50 for the side surface of the head.
• Middle: Rz25 for the surface roughness of the seat, Rz50 for the cylindrical part, and no special requirements for the top and side surfaces of the head.
• Normal: No particular surface roughness is specified.

Other Information on Square Head Bolts

1. Main Materials and Surface Finish of Square Head Bolts

Square head bolts are made of materials with relatively low strength classifications are used for steel bolts. It is necessary to select the appropriate strength classification for the location and application.

However, commercially available square head Bolts are also available in stainless steel, such as SUS304, for use in locations where corrosion resistance is required.

Strength classifications and materials of bolts are as follows:

• Strength class 6: Ordinary steel, carbon steel, SS400, S20C, etc.
• Strength class 8: Ordinary steel, carbon steel, SS400, SWRCH, etc.

However, many commercially available square head bolts are uni-chrome plated to prevent rusting during storage. 

2. Tightening Tools

Figure 3. Square bolt tightening tool

Common types of tightening tools include single-sided wrenches, T wrenches, and sockets (square holes). Sockets can be square (4-point) or octagonal (8-point), and octagonal sockets are called double 4-point sockets.