投稿者: tama0512

What Is a Fluorine Coating Agent?

Fluorine coating agents are applied to the surface of a protected object to form a film that gives the protected object various effects, such as slipperiness and stain resistance due to fluorine.

Most products are in the form of a solution of dissolved fluoropolymer, and can be easily applied by brushing or dipping, and can dry at room temperature.

Uses of Fluorine Coating Agents

Fluorine coating agents are used in numerous products and fields because of the various fluorine-derived effects they produce. Examples include touch panel display surfaces requiring water and oil repellency and raw materials for waterproof sprays. Typical applications include coatings on substrates that require waterproofing and on automobile bodies and glass that require antifouling functions.

Principle of Fluorine Coating Agents

Fluorine, the main component of fluorine coating agents, has stable C-F bonds and weak intermolecular cohesive energy (the force of attraction between molecules). This makes the surface tension of fluorine coating agents low. On the other hand, water and oil, which should be prevented from adhering to the object to be protected, attract each other’s molecules, and their surface tension is higher than that of the fluorine coating agent.

Therefore, water and oil with high surface tension become droplets on the film of the fluorine coating agent with low surface tension, and water and oil are repelled. Also, organisms, including microorganisms, have a higher surface tension than that of the fluorine coating agent, making it difficult for them to adhere to the fluorine coating agent, thus making it possible to prevent stains from them.

This repellent property is expressed by the contact angle, which indicates wettability, and is a numerical value that expresses the degree of swelling (liquid height) of droplets formed when a liquid is dropped on a solid surface. Specifically, the angle of the liquid on the solid surface is measured by observing the liquid from the side and measuring the angle of the liquid at the end point of the droplet with respect to the solid surface. A contact angle greater than 90 degrees is considered water repellent, and the contact angle of the fluorine coating agent is also greater than 90 degrees.

Types of Fluorine Coating Agents

There are many types of fluorine coating agents. Typical Fluorine coating agents are listed below.

• Nonflammable Solvent Type
  Non-flammable and safe to use.
• Water-Based Type
  No curing required; type can be diluted with water or alcohol.
• Petroleum Solvent Type
  Cost-effective type.

Some fluorine coating agents have extremely high water repellency and are called “super water repellent fluorine coating agents.” The difference between general water repellency and super water repellency is expressed by the difference in contact angle when a liquid touches a solid surface.

Other Information on Fluorine Coating Agents

Application of Fluorine Coating Agents

As mentioned above, fluorine coating agents are used in a wide variety of products and fields. In the following, we will discuss specific examples of applications of the properties of fluorine coating agents.

1. Water and Oil Repellent
Fluorine coating agents are widely used for products and parts that use ink because of their high water and oil repellency. For example, by applying the coating to the inside of the ink case portion of ballpoint pens, etc., it is possible to visualize the remaining amount of ink and use ink without wasting it.

2. Moisture Resistance
Fluorine coating agents are water-repellent and therefore also perform a moisture-proof function. For this reason, they are used as protective agents for substrates, for example, whose properties change depending on humidity. Fluorine coating agents can be applied so that a thin film can be formed without damaging the substrate, thus providing moisture protection in a form that reduces the weight of the substrate.

3. Stain Resistance
Fluorine coating agents, as mentioned earlier, have low surface tension, which prevents the adhesion of not only water and oil but also microorganisms. For this reason, fluorine coatings are also suitable as coatings for automobile bodies and glass. Fluorine coating agents can be applied by a contractor or by yourself using a spray coating agent.

What Is a Piezo Actuator?

A piezo actuator is an actuator that uses a phenomenon known as the piezoelectric (Piezo) effect.

The piezoelectric (piezo) effect refers to a physical phenomenon in which mechanical energy applied to a piezoelectric material solid, such as quartz or ceramics, generates electrical energy. Since this phenomenon is reversible, a linear displacement is obtained in the piezoelectric material when an opposite electrical signal is input, and this reverse piezoelectric effect is used in many cases in Piezo actuators.

Piezo actuators are characterized by low power consumption, small size, high speed, and no magnetic field.

Uses of Piezo Actuators

Piezo actuators are used in internal positioning mechanisms for HDD drives and semiconductor lithography equipment, ink pumps for inkjet printers, switches for smartphones, and energy harvesting (environmental power generation). Especially in recent years, tactile feedback technology unique to Piezo actuators has been used in many cases as switches for smartphones and in-vehicle car navigation systems.

One of the advantages of utilizing Piezo actuators is the ability to create seamless designs. Piezo actuators are also beginning to be used for energy harvesting (environmental power generation), where mechanical energy such as vibration from the environment is used to generate electricity. Energy harvesting refers to the conversion of energy from the environment into electricity.

Principle of Piezo Actuators

The principle of operation of a piezo actuator is based on the physical phenomenon of mechanical micro-deformation (vibration) of a piezoelectric crystal solid when an electric field is applied to a piezoelectric element such as ceramics, and this phenomenon is used in the actuator mechanism.

This physical phenomenon is the opposite of the piezoelectric (Piezo) effect and is called the inverse piezoelectric effect because it converts electrical energy into mechanical energy. The structure of a piezo actuator, at its simplest, consists of a piezoelectric material sandwiched between electrodes and wiring, and because of its simplicity, it has excellent durability and high reliability.

Currently, ferroelectric ceramic crystals such as barium titanate are widely used as piezoelectric materials.

Types of Piezo Actuators

Typical types of Piezo actuators include stacked, bimorph, and tube types.

1. Multilayer Piezo Actuator

This actuator consists of alternating layers of piezo sensors and electrodes, and can easily obtain precise micro displacement. It is also used for precision positioning due to its high generated stress and good response.

2. Bimorph Piezo Actuator

Two longitudinally extensible piezoelectric elements are joined together, and when one is extended, the other is deflected. When a deflection force is applied, electrical energy is generated. For this reason, there are many examples of use as acoustic sensors and flexure sensors.

3. Tube-Type Piezo Actuator

This actuator expands and contracts radially and axially when voltage is applied to the inner and outer electrodes.

Other Information on Piezo Actuators

1. Hysteresis Correction

Piezo actuators are simple in structure, highly reliable, and excel in minute, compact, high-speed operation, but their greatest drawback is that they have hysteresis error. Ideally, there should be a perfectly proportional relationship between the applied voltage and the stroke of the actuator, but in reality, there is a hysteresis variation of up to 15% in the stroke value when the voltage increases or decreases. To compensate for this, products with position detection mechanisms and ASIC feedback compensation functions are also used.

2. Load Considerations

Ferroelectric ceramics are very resistant to loads in the expected operating direction, but unexpected loads such as shear stress, unbalanced loads, and rotational moments may cause the laminate crystals to fracture because of the ceramic crystals. It is important to pay close attention to the manufacturer’s precautions for use and take care not to misuse the product.

What Is a Handy Oscilloscope?

A handy oscilloscope is a small oscilloscope designed for outdoor use and can be operated by batteries.

An oscilloscope is a measuring instrument that displays changes in signal voltage in an electronic circuit as time-series waveform data. By reading the changes in this waveform and the magnitude of the amplitude, changes in the signal are measured. Originally designed for use in laboratories and on factory production lines, these devices require high precision, high sensitivity, high-speed data processing, and other high performance features, resulting in a large chassis and high power consumption.

On the other hand, oscilloscopes are also needed for use in the field where electronic equipment is installed for adjustment and repair of the equipment. In this case, even if the performance is somewhat inferior, the oscilloscope must be small, lightweight, and battery-powered, eliminating the need for a commercial power supply. A handy oscilloscope satisfies these requirements.

Uses of Handy Oscilloscopes

As noted in the previous section, the primary use of a handy oscilloscope is for waveform observation at the site where the equipment is installed. The small size and the fact that it does not require a power supply make it easy to maneuver, easy to use, and increases work efficiency.

Also, because it is battery-powered, it is suitable for waveform observation of equipment in a floating state. However, if the ground level of the device to which the oscilloscope is connected is not fixed and the oscilloscope is in a floating state, there is a possibility of a large potential difference between the two, which may damage the device or the oscilloscope. With battery operation, the handy oscilloscope side is also in a floating state, so such problems do not occur.

Furthermore, handy oscilloscopes are also used by individuals for their electronic work because of their relatively simple and inexpensive functions. Similarly, they are easy to use in classes at educational institutions.

Principle of the Handy Oscilloscopes

There are two types of oscilloscopes: an analog type that uses the afterimage effect of a cathode-ray tube, and a digital type that converts the signal waveform to A/D and records it in memory. All handy oscilloscopes are digital types.

Therefore, the principle of capturing signal waveforms is exactly the same as that of digital oscilloscopes. However, because they are small and battery-powered, there are many limitations in terms of functionality. The main limitations are as follows:

• Small waveform memory capacity
• Waveform sampling frequency cannot be increased to high speed
• Limited accessories such as probes
• Limited number of channels (most models have a 2-channel configuration, few have more)
• Complex trigger conditions cannot be set

On the other hand, because it is battery-powered, the ground level can be set independently of the ground as described in the previous section, so an ordinary probe can be used even in situations where a differential probe is required with an ordinary oscilloscope.

Types of Handy Oscilloscopes

Miniaturized handy oscilloscopes are available in the following types:

1. Type That Converts a PC Into an Oscilloscope

This type is a digitizer that converts signals to A/D and stores them in memory, and is connected to a PC via USB. This type is generally simple and inexpensive, but it is not strictly speaking a handy device, since a PC is indispensable for waveform observation.

2. All-In-One Type

This type is equipped with a display device and is capable of capturing signal waveforms and displaying waveforms independently. The captured signal waveforms can be output to an external device via USB or a memory card, and the data can be analyzed using a PC. In addition, the built-in rechargeable battery allows measurement without connecting to a commercial power source, as long as the battery is charged with an AC adapter. Some models can use commercially available alkaline batteries.

3. Type With Digital Multimeter Function

In addition to the functions of an oscilloscope, it integrates the functions of a digital multimeter and a frequency counter. Although the individual functions are not as good as those of dedicated measuring instruments, the single unit provides a complete set of measurement functions, making it extremely convenient, especially when brought to the site where the equipment is installed for measurement.

What Is a Rust-Proof Sheet?

Figure 1. Image of anti-corrosion sheet

A rust-proof sheet is a sheet used to prevent rust on objects such as metals. It is also called rust-proof paper.

Rust-proof sheets are manufactured by impregnating or applying a chemical that has rust-proofing properties to a material such as paper. By simply wrapping a metal or other product that you want to prevent from rusting with a rust-proof sheet, you can easily protect the object from rusting. Since it is in sheet form, it can be freely transformed according to the size and shape of the object, and can easily be used for everything from simple packaging to sealed packing.

Uses of Rust-Proof Sheets

Rust-proof sheets are used to protect and preserve objects from rust for a long period, such as in rust-prone materials or in environments where rust is likely to occur. They are used in industries that handle metals such as steel and automobiles, where rust can cause quality problems.

To prevent rusting of products of various sizes, there is a wide range of products that can be used for small parts to large steel products. Although there are variations from product to product, the rust-preventing effect can be expected to last approximately six months to one year. However, it is recommended to use the product as soon as possible after purchase, as the rust-preventive ingredients vaporize and lose their effectiveness even if the product is not used.

Principle of Rust-Proof Sheets

Figure 2. Anti-rust sheet principle

Rust-proof sheets are manufactured by coating or impregnating the base paper with rust-proof paint. Products requiring special moisture resistance are laminated with polyethylene using a laminator.

The principle of how rust-proof sheets prevent metal from rusting is as follows.

The rust-proof sheet contains a rust-proof agent that gradually vaporizes (sublimates) at room temperature, and the vapor quickly fills the sealed space between the sheet and the metal.
The vaporized rust inhibitor dissolves in the moisture on the metal surface. The dissolved rust inhibitor is physically and chemically adsorbed as molecules or ions to form a “rust inhibiting film.”
The rust-preventive film shields the steel from the outside air, which causes rust, and prevents it from changing into rust.
This rust-preventive film made of vaporizable rust-preventive agent is extremely thin and has weak adsorption power, so it does not cause any change in the external appearance of the metal surface. After rust-preventive packaging, metal products can be used immediately without cleaning the surface. In addition, because it is a rust inhibitor that utilizes vaporization, it is expected to have an immediate effect.

Figure 3. Adsorption mechanism of rust inhibitors on metal surfaces

An important condition for rust-proof sheets is that they do not contain active substances or other substances that can cause rust to form. Therefore, the sheets must also be made of materials that do not contain chlorine ions or acids that can cause rusting.

How to Select Rust-Proof Sheets

Rust-proof sheets are available in a variety of types, including those for ferrous and non-ferrous metals, zinc and iron, and copper and copper alloys, as well as those for iron and steel, which are labeled “for iron and steel.” They also vary in thickness, width, length, and other dimensions, depending on the product. Select a product that matches the type and size of the metal product you want to use.

The coated type has been used in many products for many years, but because it is manufactured by coating the surface of paper with an anti-corrosion agent, the rust inhibitor may adhere to the product when unpacking. The impregnated type, on the other hand, has the rust inhibitor soaked into the paper, eliminating such concerns. Currently, the impregnation type is often used unless there is a special reason.

If higher corrosion protection is required, polyethylene laminate products are effective. They are effective in preventing the inflow of water and moisture from the outside and the outflow of vaporized rust-preventive components to the outside.

Some manufacturers may also disclose the results of discoloration tests on plastic and rubber. If the product you want to prevent rusting has plastic parts, it is safe to check before purchasing. Some manufacturers provide samples for testing, so if you are concerned, you may want to take advantage of this.

What Is a Pressure Increasing Valve?

A booster regulator is a pneumatic device used to increase the pressure of compressed air.

Generally, the pressure of compressed air used in facilities is about 1.0 MPa at the highest, but the pressure normally used is around 0.5 MPa.

When increasing the pressure used, it is necessary to change the pressure setting of the compressor when increasing the pressure of compressed air lines throughout a factory or business facility. However, if the pressure is to be increased for only a limited number of production lines or circuits, installing a pressure increasing valve at the inlet of the required location will serve that purpose.

In addition to this, a dedicated air compressor may be installed, or pneumatic drive may be used to select water, hydraulic oil, light oil, kerosene, or heavy oil for pressure intensification.

Uses of Pressure Increasing Valves

If the need arises to increase the pressure at a single point in the compressed air equipment used in a factory, increasing the pressure setting of the compressor will result in a significant increase in electricity costs. This is especially true for pressure resistance tests and air leakage inspections.

Some data indicate that lowering the set pressure of a compressor by 0.1 Mpa can lower electricity rates by about 7-8%. In such cases, installing a pressure increasing valve in front of the mechanical equipment that is under pressure is an effective means of reducing the pressure. By installing a pressure increasing valve, the pressure can be increased only where necessary.

Note that the flow rate of the increased pressure will decrease as the set pressure increases. Also, pressure increasing valves consume compressed air.

Principle of Pressure Increasing Valves

1. Pressure Increase Mechanism

The pressure increasing valve is operated by compressed air drive and requires no electricity. The pressure can be increased beyond the set pressure of the compressor. The difference between 2x and 4x pressure increasing valves is the internal structure.

In the case of 2x intensification, the structure consists of two cylinders of the same diameter, two intensification chambers, and two drive chambers. The cylinders of the drive chambers have pistons of the same diameter. The input pressure received by the two pistons then acts on the piston in one intensification chamber to increase the pressure.

The two pistons are connected by rods and synchronized. When the piston moves to the end of the cylinder, a sensor is activated, switching the pneumatic circuit so that the drive and intensification chambers are reversed and the intensification continues.

The construction of the quadruple intensifier is the same as that of the double intensifier, having two cylinders of different diameters, two intensification chambers, and a drive chamber. By making the total pressure-receiving area of the two pistons in the drive chamber four times larger than the pressure-receiving area of the one piston in the intensification chamber, 4-fold intensification is possible. Other operations are the same as in the case of 2-fold intensification.

2. Installation of Air Tank

For both 2X and 4X pressure boosting types, an air tank is generally installed to store pressure and prevent pulsation. The air tank is refilled to prevent pressure drop when pressure drops temporarily due to increased flow.

In addition, since the pressure increase is intermittent, it is effective in reducing pulsation. An additional benefit is a reduction in the intermittent operating noise of the pressure increasing valve. Compressed air contains oil and water, which must be discharged as they are separated when cooled in the air tank.

If the tank is not installed, insufficient flow will probably shorten the life of the pressure increasing valve, as it will be continuously driven.

Features of Pressure Increasing Valve

Advantage

• It requires no power source and is powered by compressed air.
• Compressed air pressure can be increased up to 2 to 4 times. The pressure can also be adjusted.
• Overall energy savings can be achieved by lowering the compressed air pressure for the entire plant and increasing pressure only where it is partially needed.

Disadvantage

• About half of the supplied air is exhausted, resulting in energy loss.
• It is common to install an air tank on the secondary side.
• Because of its intermittent operation, it has the disadvantage of being noisy.

Other Information on Pressure Increasing Valve

How to Use Pressure Increasing Valve

First, connect the supply air pipe to the IN side port and the air tank piping to the OUT side port.

After piping, supply air to the facility and adjust the pressure to the required level by turning the adjustment knob while checking the pressure gauge reading on the OUT side.

What Is Disposable Protective Clothing?

Disposable protective clothing is protective clothing intended for onetime use only.

It is worn over regular clothing, and the most appropriate type of clothing is used for each of the various uses of protective clothing. Conventional applications include training and exercises for the Self-Defense Forces, operational use, and treatment of infectious diseases in hospitals (e.g., H1N1 influenza, SARS, etc.). Infectious disease treatment in hospitals (e.g., H1N1 influenza, SARS), and so on. Recently, however, the need for use in the medical field in coronary disasters has been increasing, and availability has been decreasing.

Figure 1. Overview of protective clothing

Uses of Disposable Protective Clothing

Disposable protective clothing is used to protect workers from a variety of hazards in any workplace.

Hazards include acids, alkalis, chemicals, radioactive materials, and viruses. They also include sharp objects such as knives, high-speed flying objects, high temperatures, flames, and electrical sparks.

ISO/JIS standards provide detailed specifications depending on the characteristics of the clothing and the type of hazardous factor. Protective clothing for use in handling acids, alkalis, organic chemicals, other gases and liquids, and particulate chemicals. There are different types of protective clothing depending on the target hazardous substance and the structure of the chemical protective clothing, and the performance requirements are specified for each type.

Specific examples of disposable protective clothing include the following:

• Sites where skin may be exposed to or come in contact with acids, alkalis, organic chemicals, dust, or other hazardous chemicals, such as chemical plant construction
• Prevention of freezing when working in cold weather
• When working with asbestos
• Dioxin and PCB treatment
• Secondary infection control during treatment of new coronary infections
• Radioactive material handling and decontamination work
• Sites that need to cope with mechanical shocks such as chain saws

Types of Disposable Protective Clothing

Disposable protective clothing is classified into various types based on the uses of and materials used.

1. Classification by Use

Figure 2. Example of special protective clothing

Chemical Protective Clothing
Protective clothing is designed to prevent the penetration of toxic gases and chemicals. 

Protective Clothing for Biohazard Control
Protective clothing to protect against the risk of exposure to or contact with biohazardous materials (pathogens and biologically derived substances that may harm humans).

Protective Clothing Against Heat and Flame
Protective clothing is used to protect the body from heat and flames. Examples include smelters in the steel industry, where workers are exposed to high radiant heat and high-temperature molten metal splatter.

Protective Clothing to Cope With Mechanical Shocks
Protective clothing is used to prevent cuts and puncture wounds caused by sharp objects such as knives. As a specific example, at a site where chainsaws are used, the lower half of the body, below the thighs and knees, should be protected.

Protective Clothing Against Radioactive Contamination
Protective clothing is used for the purpose of protection against contamination by radioactive materials.

Protective Clothing Against Electricity
Clothing used to protect the body from electrical hazards, and protective clothing used to prevent electrostatic charging.

Protective Clothing Against Cold
Protective clothing is used to protect the body from the cold in areas or special locations where the outside temperature drops to negative temperatures.

High Visibility Safety Clothing
Protective clothing is used to increase visual recognition of the wearer’s presence in order to prevent contact and collision accidents caused by vehicles, construction equipment, and other moving objects.

2. Classification by Material

Figure 3. Various protective clothing materials

Non-woven Fabric One Layer Type
This product is made of spun bond polypropylene. The spun-bonded single-layer structure has many voids between fibers. Although the barrier property is somewhat inferior, it is inexpensive and suitable when cost is important. This fabric is sufficient for light soiling.

SMS
This product is made of SMS polypropylene. It has a three-layer structure of spun bond, melt blown, and spun bond. It features strong abrasion resistance and a cloth-like feel to the touch. Although relatively inexpensive, it is resistant to abrasion and light soiling, and has a high barrier effect against dust and splashes.

FS
This is a product in which film laminate is used. It has a structure in which a thin film material is attached to the surface of polypropylene, spun-bonded nonwoven fabric, or the like. It has high barrier properties against dirt and dust, and excellent waterproofing properties, making it suitable for work in watery areas.

Tyvek® (Japanese Brand of Polyester Foil)
Tyvek is a special material unique to DuPont, consisting of continuous microfibers of high-density polyethylene (0.5~10 microns) bonded together by heat and pressure, which provides excellent barrier properties against particles of 1 micron or less. Two-layer protective clothing with polymer coating is also available.

How to Choose Disposable Protective Clothing

As mentioned above, there are various types of protective clothing available, depending on the type of hazard. Work supervisors and personnel in charge of operations must acquire the correct knowledge of these hazards and protective clothing, and select protective clothing that matches the hazard. If used incorrectly, the possibility of health hazards increases.

In addition, if the knowledge is not sufficient, contaminated protective clothing may be taken outside the work area as it is, and there is a high risk of a secondary hazard if personnel other than those involved are exposed to the hazard. It is necessary to investigate the hazards in the surrounding environment, select appropriate protective clothing, and thoroughly educate workers on the correct way to use and put on and take off the clothing.

What Is a Disposable White Coat?

A disposable white coat (disposable lab coat, single-use lab coat) is a lab coat intended for onetime use only. It is worn over plain clothes, student uniforms, work clothes, suits, etc.

There are resin (polypropylene, vinyl, nylon, etc.) and cloth coats for various uses, and the most appropriate one is used depending on the intended use. Disposable white coats are used in high school and university chemistry experiments, hospitals (surgery, treatment of infectious diseases), and food processing sites.

Uses of Disposable White Coats

Uses of disposable white coats include:

• Experiments for students in high school and college chemistry experiments
• Treatment in the infectious disease ward of the hospital
• Dental treatments
• Father’s presence at birth
• Food processing plant
• Electronic component manufacturing site
• House mold removal work
• Spray painting work

Since there are different types of disposable white coats, it is important to choose the type that best suits the installation environment and the intended use.

Types of Disposable White Coats

There are two types of disposable white coats: plastic and cloth.

1. Disposable White Coat Made of Plastic

The greatest feature of this product is that it can be mass-produced in factories, although there is a possibility of allergic reactions when it comes into contact with the skin because it is made from chemicals. Since they can be mass-produced in factories, their cost is lower than that of fabrics, which is another attractive point. Although disposable lab coats cannot be reused, they can be recycled again as resin material through material recycling.

Currently, disposable white coats made of resin are the mainstream. From the perspective of the circular economy, it is desirable to use mainly disposable white coats made of resin, which can be turned in a closed loop.

2. Disposable White Coats Made of Cloth

It is ideal for people with sensitive skin, as it does not irritate the skin when worn. Also, because it is made of cloth, it can be washed and reused instead of being thrown away.

Other Information on Disposable White Coats

Advantages of Disposable White Coats

Prevent the Spread of Pathogens
In laboratories where microorganisms and bacteria are studied and in hospitals where infectious diseases are treated, discarding lab coats after each operation prevents pathogens from remaining in the laboratory or work area. When white coats are used for a variety of purposes, they must be carefully cleaned to keep them clean at all times, but inadequate cleaning may result in the presence of pathogens.
In addition, several people, including those involved in the cleaning process, may come into contact with contaminated lab coats. Using disposable white coats eliminates the risk of spreading pathogens from contaminated white coats and protects worker safety.

Prevent Worker Exposure to Chemicals
In places where chemicals are handled, wearing a lab coat can prevent workers’ clothes from being soiled by chemicals and prevent them from being exposed to chemicals on their skin, causing chemical wounds. However, the use of a disposable lab coat can cause the chemicals on the lab coat to permeate and harm the worker.
The use of disposable white coats eliminates the risk of wearing a chemically contaminated white coat, thereby reducing chemical injury to as close to zero as possible.

Prevent Cross-Contamination
Cross-contamination refers to the spread of contamination when an object that has become highly contaminated due to the attachment of pathogens or bacteria comes into contact with a less contaminated object. Cross-contamination is a serious problem in pharmaceutical manufacturing and food processing.
Using the same lab coat over and over not only increases the risk of cross-contamination by pathogens and bacteria, but also the detergent used to clean the lab coat and the lab coat fiber itself can cause cross-contamination. Disposable white coats are an effective means of eliminating these risks.

Hassle-Free
In places where contamination can lead to serious problems, the work environment must be kept at a high level of cleanliness at all times. As mentioned above, the risk of cross-contamination exists when white coats are used, so thorough cleaning and cleanliness control is required to prevent problems, which require time and effort to manage. By using disposable white coats, the cleanliness of white coats can be maintained at a high level at all times, eliminating the need for management.

What Is a Rotary Bar?

A rotary bar is the tip tool used when using a micro grinder.

It is used for cutting steel and other materials, chamfering, deburring, and shaping the cutting surface. It is highly versatile, capable of processing such as gentle curves. Because of its small size and fine machining capability, this tool is widely used in fields that require precise machining down to the smallest detail, such as in the manufacture of precision instruments and electronic components. It is also used as an easy-to-use tool among DIY and craft enthusiasts.

Uses of Rotary Bars

Rotary bars are used to cut general workpieces, nonferrous metals such as aluminum, brass, magnesium, and plastics, resins, and difficult-to-cut materials such as stainless steel, nickel, chromium, and titanium.

In particular, with the use of specialized blades, rotary bars can cut difficult-to-cut materials such as carbon fiber reinforced plastics (CFRP). They are also used for cutting with hand tools and robots.

Specific examples include cutting in the manufacturing process of automotive and aircraft parts. They are also used by DIY and craft enthusiasts when cutting or machining of small parts is required, and by selecting the blade shape to suit the uses of the application, a wide variety of machining is possible.

Rotary bars are indispensable tools in situations where precision cutting is required. By selecting a blade that is appropriate for the material and shape of the workpiece, an accurate and beautiful finish can be achieved.

Principle of Rotary Bars

A rotary bar removes material by applying cutting force to the workpiece through contact of a blade attached to a rotating bar.

There are several types of rotary bars, including cross cut, spiral cut, aluminum cut, and MC cut, and the blade type must be selected according to the uses of the bar.

The cross cut has low cutting resistance and minimizes mechanical vibration, enabling cutting of hard materials such as carbon steel and stainless steel. Spiral cuts help shorten cutting time because of their high cutting volume, and they eject needle chips. The aluminum cut has a blade shape that prevents welding of work pieces and is suitable for cutting aluminum and magnesium alloys. The MC-CUT has a small number of blades and is capable of rough machining.

Rotary bars also have specialized diamond-cut and other blade types, which are used for cutting difficult-to-cut materials such as carbon fiber-reinforced plastics. They are also used for cutting by hand tools and robots, and are widely used in various fields. By selecting the appropriate type for the cutting shape and material, more efficient and accurate cutting can be achieved.

Types of Rotary Bars

Two types of rotary bars should be used depending on the cutting shape and material: high-speed steel rotary bars and cabled rotary bars.

1. High Speed Steel Rotary Bar

Rotary bars made of high-speed steel (HSS) are commonly used to process metals and plastics, etc. Because of its relatively high hardness and resistance to temperature changes, HSS can be used for long periods of time without wearing out the cutting edges of high-speed rotating rotary bars. HSS rotary bars are also suitable for carving and other detailed work.

2. Carbide Rotary Bar

Rotary bars made of carbide (a hard alloy) are used to process hard materials such as metal and wood. Carbide is an alloy composed mainly of metals such as tungsten and tantalum, and has very high hardness. As a result, carbide rotary bars have a sharp cutting edge and can cut smoothly even through hard materials. However, they are relatively expensive and are not suitable for long-term use.

What Is a Hematocrit Capillary Tube?

A hematocrit capillary tube is an instrument used in blood testing.

Blood is composed of cellular components: blood cells (red blood cells involved in oxygen transport and white blood cells involved in the body’s immune defense) and platelets, and plasma, the liquid component that suspends these cellular components. In healthy human blood, the majority of cellular components are red blood cells. Red blood cells contain hemoglobin (Hb), which gives blood its red color and oxygen-binding capacity.

Plasma is composed primarily of water (about 93%), with other components including salts, various proteins, lipids, and sugars (e.g., glucose). The hematocrit, or the percentage of red blood cell volume in the blood, is sometimes determined during a blood test. For example, it can be used as an indicator of anemia. Anemia is a thinning of the blood, and hematocrit is used as an indicator of this condition.

The hematocrit capillary tube is the instrument used to measure this hematocrit.

Uses of Hematocrit Capillary Tubes

Hematocrit capillary tubes are primarily used to measure hematocrit in blood tests. It is also sometimes used to obtain small amounts of plasma in animal experiments.

1. Measurement of Hematocrits

Hematocrit measurements may be performed when anemia, dehydration, bleeding, or other medical or surgical conditions are suspected. A low hematocrit reflects a low number of circulating red blood cells and is an indicator of reduced oxygen-carrying capacity or overhydration.

Examples of conditions that can cause low hematocrit (anemia) include.

• Internal or external bleeding – hemorrhage
• Complications of Chronic Renal Failure – kidney disease
• Pernicious anemia – vitamin B12 deficiency
• Hemolysis – associated with transfusion reaction
• Autoimmune diseases and bone marrow failure

A high hematocrit may reflect an absolute increase in red blood cell count or a decrease in plasma volume.

• Severe dehydration – e.g., in cases of burns, diarrhea, or excessive diuretic use
• Erythrocyte Excess – erythrocyte Excess
• Viral polycythemia vera – abnormal increase in blood cells
• Hemochromatosis – inherited disorder of iron metabolism
• Indicators of overdose of exogenous erythropoietin (EPO), which stimulates red blood cell production

2. Animal Experiments

Because of its ability to collect very small amounts of blood and to obtain plasma by centrifugation, it is sometimes used to obtain minute amounts of plasma, mainly from animals (micro sampling).

Principle of Hematocrit Capillary Tubes

The most commonly used hematocrit capillary tube is a capillary tube (capillary tube) with a heparinized inner surface. Untreated (plain) capillaries are also available.

When one end of the capillary tube comes in contact with the collected blood, the blood is sucked into the capillary tube by capillary action. At the same time as the blood is sucked up, the heparinized blood is anticoagulated with heparin.

The capillary is then centrifuged to separate the blood cells from the plasma. The hematocrit is determined from the length of the blood cell portion (erythrocyte column), which appears red, and the plasma portion, which appears colorless to pale yellow (in humans).

Other Information on Hematocrit Capillary Tubes

1. Definition of Hematocrit

Hematocrit is defined as the ratio of red blood cell volume to total blood volume, also known as packed cell volume (PCV). When heparinized blood (heparin is an anticoagulant) is centrifuged, the red blood cells become packed at the bottom of the tube and the plasma remains as a clear liquid at the top. The ratio of this volume of packed red blood cells to the total blood volume is the hematocrit.

Hematocrit is reported as a percentage or ratio. In healthy adults it is about 40-48%, but in newborns it can reach 60%.

The following is a summary of the abbreviations associated with discussing hematocrit.

• Hct: Hematocrit
• ctHb: total hemoglobin concentration
• Red Blood Cell (RBC)
• MCV: Mean cell volume
• MCHC: mean corpuscular hemoglobin concentration

2. How to Use It When Measuring Hematocrit

Seal
One end of the capillary must be sealed before centrifugation. If not sealed, centrifugal force will cause the blood to flow out. To seal the capillary, a special putty is used.

After the blood is sucked up, one end of the capillary is sealed by sticking one end into the special putty and allowing the putty to bite into the inside of the capillary. The sealed side should face outward, i.e., toward which centrifugal force is applied.

Scale Plate
To obtain a hematocrit value from the centrifuged blood sample in the capillary tube, refer to the scale plate. Move the scale down the sample until the bottom of the packed red blood cell column first lines up with the “0” line on the scale plate, then the top of the plasma column lines up with the “100%” line.

At this point, read the values at the border between the red blood cell column and the plasma column. The white layer, the layer between the red blood cell and plasma columns, makes up about 1% of the sample, but this layer is not included on the red blood cell side.

3. How to Use It as a Micro-Blood Sampler

A glass capillary tube is used, and the blood is collected and the sealed capillary tube is centrifuged as in normal use. The glass capillaries are used because they are folded in the process of centrifugation. After centrifugation, a scratch is made on the border between the blood cell column and the plasma, slightly closer to the plasma, with a glass cutter, and the capillary is folded.

The broken capillary is placed in a collection vessel (e.g., microtubes) and centrifuged to collect the plasma in the vessel. Since this method is difficult to perform, recently, a special device for micro-sampling has been developed.