月: 2023年6月

What Is Plasma Processing Equipment?

Plasma processing equipment is used to perform pretreatment, called plasma treatment, for surface treatment of metals, synthetic resins, ceramics, plastics, and all other materials used in industrial fields.

In plasma treatment, gases such as oxygen are plasmaized by electrical power, and atoms and molecules with unpaired electrons called radicals are imparted to the surface of resins and other materials. The purpose of imparting radicals is to activate the surface of the product to be treated and to increase the hydrophilic properties of adhesion and wettability.

Surface treatments for which plasma treatment is used as a pretreatment mainly include modification such as cleaning and activation, adhesion and bonding, and painting and coating. Plasma processing equipment can simplify conventional processes, improve work efficiency, and reduce costs.

Uses of Plasma Processing Equipment

Plasma processing equipment is now widely used not only in electronics technology but also in all areas of manufacturing, from the automotive and aviation industries to packaging and everyday items. An example of their use in the electronic device industry is the anti-scratch coating of electronic components in circuits. Scratch-resistant coatings can improve the durability of substrates and make cleaning processes more efficient.

Examples in the automotive industry include bonding automotive circuit boards to epoxy resin and cleaning surface oil from metal parts for engines. In packaging and everyday products, it is used for foil stamping on plastics, surface printing, and painting. Other uses include cleaning and coating of medical equipment, etc., taking advantage of the sterilizing effect during processing.

Principle of Plasma Processing Equipment

Plasma is a state in which atoms and molecules in a gas are ionized and split into positively charged positive ions and negatively charged electrons. It is called the fourth state following the individual, liquid, and gas states. The purpose of plasma processing equipment is to ionize oxygen molecules in the air by discharging them in the air, causing the oxygen atoms to be excited and generating plasma containing oxygen ions and free electrons.

The electrons, ions, and radicals of the generated plasma come into contact with the product to be treated, such as the substrate of an electronic component, and the ions and electrons in the plasma react with the molecules of the substrate material to produce hydrophilic functional groups. The formation of hydrophilic functional groups on the surface improves adhesion and wettability.

Types of Plasma Processors

There are two main types of plasma processing machines: atmospheric plasma processing machines that process at atmospheric pressure and vacuum plasma processing machines that process in a vacuum. Atmospheric pressure plasma processing equipment generates plasma at atmospheric pressure by flowing a gas, such as nitrogen or rare gas, through a pair of electrodes and applying high frequency and high voltage.

On the other hand, vacuum plasma processors place a base material in a sealed chamber and irradiate plasma evenly onto the surface of the material. They are mainly used in the manufacture of semiconductors and other electronic components, and in medical applications.

Other Information on Plasma Processing Equipment

1. Features of Plasma Processing

Plasma treatment has two main characteristics. The first is that there are multiple gases that can be plasmaized. In addition to oxygen and nitrogen, helium and other gases can be used for plasma treatment. The chemical properties of the plasma can be changed by combining gases, so the properties of the base material and the functionality to be given can be selected.

The second feature is that there is little damage to the base material. Since the plasma is in a gaseous state, it has little effect on the interior of the material and can act only on the extreme surface.

2. Effects of Plasma Treatment

There are three major effects of plasma treatment.

Hydrophilization
Hydrophilization improves wettability. It refers to the state in which the material becomes more compatible with water and less likely to form water beads. In other words, the opposite of hydrophilic is water repellent.

Improved Adhesion
Plasma treatment improves adhesion between resins and between resins and metals. Plasma treatment forms hydrophilic functional groups on the surface, which will result in a high affinity with adhesives.

Cleaning
Plasma treatment can remove organic contaminants from metal and glass surfaces. This is accomplished by plasma-generated oxygen radicals reacting with the carbon atoms of organic contaminants on the surface of the treated item and releasing them as carbon dioxide, resulting in the cleaning of the surface.

What Is Plasma CVD System?

Plasma CVD equipment is a type of equipment that performs a type of chemical vapor deposition method.

Plasma CVD stands for plasma-enhanced chemical vapor deposition. The raw material gas is turned into a low-temperature plasma state (glow discharge ionized into cations and electrons) to generate active ions and radicals that cause chemical reactions on the substrate to deposit and form a thin film.

Uses of Plasma CVD Systems

Plasma CVD technology is used for reinforcing films for cutting tools (titanium nitride, carbon nitride, DLC (diamond-like carbon)), semiconductor insulating and protective films, wiring and electrode materials (silicon nitride, silicon oxide, copper, aluminum, tungsten, polycrystalline silicon, compound semiconductors, etc.). These materials are used as insulators, protective films, wiring and electrode materials (silicon nitride, copper, aluminum, tungsten, polycrystalline silicon, compound semiconductors, etc.). Its use in high-performance power devices to control and supply energy, which is key to economic and industrial development, is also expanding rapidly.

The supply gas for plasma CVD systems is usually a carrier gas such as hydrogen, nitrogen, argon, or ammonia mixed with a raw material gas such as SiH4 (silane) or WF6 (tungsten hexafluoride).

1. Oxides

Silicon dioxide (SiO2) is an oxide of silicon. It has excellent electrical insulation and thermal stability and is used in semiconductor device interlayer insulating films.

As semiconductors become thinner, they are more prone to leakage currents, where current leaks out from unplanned locations; the presence of SiO2 helps prevent leakage currents.

2. Nitride

Silicon nitride (Si3N4) is a nitride of silicon. It has excellent strength and thermal conductivity and is used as a substrate material for power devices that generate a lot of heat.

Nitrogen and ammonia are used together with SiH4 to form nitrides, so they also play the role in raw material gases. Semiconductors in general perform functions related to arithmetic and memory, such as memory. Power devices, on the other hand, are for things like diodes.

3. Carbide

Silicon carbide (SiC) is a carbide of silicon, a member of the compound semiconductor family along with GaN (gallium nitride, or GaN), AlGaN, etc. Like Si3N4, it is used in power devices in place of Si IGBTs because of its superior strength and thermal conductivity.

Compared to silicon compounds, power loss is lower, leading to smaller devices.

4. Metals and Metal Compounds

The gate of a transistor is formed from a gate oxide film (formed by thermal oxidation) and a gate electrode (mostly polycrystalline silicon). Tungsten plugs used for the gate electrode and source-drain contacts are formed by plasma CVD. (See Figure 3)

Principle of a Plasma CVD System

Figure 1. Basic configuration of a plasma CVD system

The raw material gas is selected from a pressure reduction range of 10-4 to 100 Pa, depending on the desired conditions. The power supply frequency most commonly used for plasma excitation is 13.56 MHz (RF: Radio Frequency), and the discharge type is a capacitively coupled type using parallel plate electrodes. 

One of the parallel plates may be used as a shower head to supply process gas, or a heater may be inserted in one of the plates to control the temperature. There are many controllable parameters, such as power supply frequency, electrode structure other than the parallel plate type, raw gas composition, discharge volume, and temperature. Therefore, it is possible to deposit various types of thin films with various functionalities, ranging from inorganic to organic materials.

Other Information on Plasma CVD Systems

1. Semiconductor Device Structure and Manufacturing Process

Figure 2. Basic structure of semiconductor devices (memory)

Plasma CDV systems are widely used in the manufacture of semiconductor devices. For example, in the case of memory devices, complex multilayer wiring is formed on top of the MOSFET (metal oxide semiconductor field-effect transistor) formed on the substrate (wafer). layers are formed on top of the MOSFET (metal oxide semiconductor field-effect transistor) formed on the substrate (wafer) and separated by an interlayer insulating film.

Plasma CVD systems are mainly used to form MOSFET gate electrodes, wiring layers, and interlayer insulators, which require fine patterning after deposition. Basically, printing technology is used for patterning, and the following steps are repeated. 

Figure 3. Basic deposition process for semiconductor devices

1. On top of the base pattern, a new pattern material (polycrystalline silicon, Al, C, W, SiO2, Si3N4, etc.) is uniformly deposited by CVD.
2. A photoresist film (positive or negative) is formed on top of the first film.Positive films are less soluble in solvents due to excitation light, while negative films are more soluble.
3. The resist is dissolved, forming a pattern of the remaining resist on top of the deposited film.
4. Etching (stripping process) is applied from the top of the pattern to remove the film.
5. Remove the resist.
6. A pattern is formed on the film.

By repeating the above process, semiconductor devices can be formed.

2. Thermal CVD and Optical CVD

Depending on the energy given, it can be classified into plasma CVD, thermal CVD, and optical CVD.

• Thermal CVD
  This is a method of film deposition in which the components are thermally decomposed and chemically reacted by treating the feed gas at high temperatures. (This method cannot be used for substrates that are sensitive to heat, such as plastics.
• Optical CVD
  Methods that use laser light or ultraviolet light energy to activate family decomposition and chemical reactions.

What Is a Blast Cabinet?

Blast cabinets are equipment used to polish and clean and remove metal surfaces.

There are two types of blasting: air blasting with compressed air and sandblasting, which enhance workability by adding sand to compressed air and blowing it vigorously. Blasting also requires regulators, filters, and dust collectors, so there are some that are equipped with these features.

Blast cabinets are widely used in areas such as surface preparation of metal products, surface preparation prior to painting, removal of dirt and rust, and dental laboratory work. Blast cabinets are efficient and safe because the operator can do the work inside the equipment. In addition, performing polishing operations inside the cabinet prevents environmental contamination and workplace pollution.

Blast cabinets are made of steel, aluminum, plastic, and other materials and come in a variety of sizes and shapes. The appropriate blast cabinet should be selected according to the intended use and workspace.

Uses of Blast Cabinets

Blast cabinets are often used for pretreatment and finishing operations that require precision in bonding and painting, whether metallic or non-metallic. In metal processing, blasting can improve the accuracy of painting and press work by making the surface uneven.

Blasting can also remove dirt and rust from metal surfaces. Furthermore, since blast processing is not affected by the size or shape of the object to be processed, it is suitable for processing fine areas and complex shapes that are difficult to process with machines.

Therefore, they are used in a wide range of fields, including aircraft and automobile parts, plastic products, and electronic components. However, care must be taken in blast processing because the type and particle size of the abrasive material used in the process and the processing pressure may scratch or deform the surface of the object. Safety measures are also taken because the dust and dirt generated by processing may contain harmful substances.

Principle of Blast Cabinets

Processing using a blast cabinet consists of mixing an abrasive with compressed air and spraying it at high speed onto an object to polish its surface. In a blast cabinet, the air is compressed by an air compressor, mixed with an abrasive, and sprayed through a nozzle directly onto the object to be processed.

The abrasive is sprayed evenly onto the object and the surface can be processed more efficiently. The process is not affected by the shape of the object to be processed, making it possible to process even complex shapes.

Furthermore, dust, sand, and other particles generated during processing are vacuumed by a dust collector, so the processing site can be kept clean.

Types of Blast Cabinets

There are two main types of blast cabinets: pressure blast cabinets and suction blast cabinets.

1. Pressure Type Blast Cabinet

Pressure blast cabinets perform processing by mixing the processing material in compressed air and spraying it at high pressure. It has high abrasive power and is effective for large objects and thick parts.

Surface finishing and cleaning can also be performed depending on the type of abrasive. However, due to the high pressure, the noise and vibration are loud and may affect the surrounding environment. Careful attention should be paid to the location and environment where it is used.

2. Suction Type Blast Cabinet

Suction-type blast cabinets perform processing by spraying the material to be processed toward the object to be processed. Because of its lower pressure and less abrasive power than pressure-type blast cabinets, it is suitable for processing delicate parts and thin plates.

Depending on the type of abrasive, it is also possible to remove surface contamination and perform light abrasive processing. In many cases, the machine is equipped with a dust collector to collect the processed materials, which also improves the work environment. However, since it is a suction type, it may be difficult to collect the processing material depending on the work object.

What Is a Floor Hinge?

A floor hinge is a device that can support the load of a swinging door embedded in the floor.

It is installed on the shaft side of the door and is used for heavy doors such as large glass doors at the entrances of commercial facilities and condominiums. There are several types, including those for general doors, tempered glass doors, and fire doors.

It is installed on the floor below the door, and although it is not often noticed, it is an important part of the door opening and closing.

Uses of Floor Hinges

Floor hinges are used to adjust the angle and speed at which doors open and close, and serve the same function as door closers. Floor hinges have a built-in hydraulic damper, and by adjusting the damper, the speed at which the door opens and closes can be adjusted. This ensures safe passage and eliminates slamming and loud closing.

The door can be selected to match the floor finish material and door size, and some are compatible with a variety of materials to attach stone, carpet, tile floors, and other floor finishes used in the surrounding area. There is also the ability to adjust the door opening angle, which can be set to 90°, 120°, 180°, etc., depending on the installation location and application. However, the installation of a door hinge is mandatory.

Floor hinges are durable and can be used for a long period, but there is no possibility of removing dust from the interior or corrosion causing failure. Frequent maintenance is necessary, such as checking for water accumulation. The manufacturer’s recommended period of use is approximately 10 years.

Principle of Floor Hinges

The door is mounted on an axis on one side of the wall, and the open/close operation is performed from the opposite side of the axis, causing the door to open and close. The floor hinge body is attached to the axis of the door, and at the top of the floor hinge there is a component called the pivot, which is supported by the pivot and the top and bottom of the floor hinge, thereby mounting the door and controlling its movement and angle.

There are three major components of a floor hinge: the main body part, the cement case that is embedded in the floor side to house the main body, and the floor plate that covers the top part. In order to attach the main unit directly to the shaft of the door, the cement case that houses the main unit is embedded in the floor part.

If this cement case is unstable, the door will not open and close smoothly if it is not properly set up, so it is important to fix it firmly by mortar or welding. The arm portion of the main body to be placed on the main axis of the door is attached to the bottom axis of the door, and a metal plate is placed over the top to prevent the main body from being exposed.

Other Information on Floor Hinges

1. Precautions for Using Floor Hinges

The characteristics differ depending on the material of the floor surface. For stone, a plate called a floor plate is designed to fit neatly even when stone is applied, such as 20 mm or 30 mm, to create a sense of unity, while for carpeted floors, a thickness of 5 mm or 10 mm is secured.

By choosing floor hinges that match the finish, the metal floor plate can be hidden and will not spoil the atmosphere of the place. Conversely, it is important to note that this product is not compatible with thin materials, such as P-tiles and floor tiles. In such cases, the metal part of the floor plate will stand out.

2. Waterproof Floor Hinge

Some locations where floor hinges are installed are subject to water or moisture. Sealing material is used at various locations inside floor hinges to prevent water, moisture, and dust from entering. However, it is not completely waterproof, so overconfidence is not advised.

3. In Case of a Malfunction

Floor hinges are intended to be used for long periods of time, but because they are used frequently and support heavy loads, they can naturally fail. Failures are often caused by dampers, which prevent doors from closing fully, open and close too fast and too slowly, or prevent doors from closing.

If not repaired or replaced as soon as possible, the door or door frame will likely be affected, resulting in deformation or damage to the door or frame.

What Is a Flexible Container Bag?

A flexible container bag is a large-capacity, sturdy bag used to transport a single batch of powder, waste, or agricultural products.

The official name is flexible container bag, but it is sometimes called “flexible container” or “ton bag” for short.

Flexible container bags come in a variety of dimensions, with the most commonly used being 1,100 mm (diameter) x 1,100 mm (height) / 1,000 L capacity / 1,000 kg load capacity. Some are as small as 500 mm (diameter) x 500 mm (height) / 100 L (capacity) / 100 kg (load capacity), making them useful for putting away small equipment and parts.

Uses of Flexible Container Bags

The primary uses of flexible container bags are transportation and storage. They are used in various industries, such as agriculture, forestry, fisheries, waste disposal, construction and civil engineering projects, and manufacturing. Specifically, flexible container bags are used when it is difficult to transport the following items individually.

• Agriculture, Forestry and Fisheries
  Rice, soybeans, potatoes, flour, feed, compost, rice husks, pruning scraps, etc.
• Waste Disposal and Treatment Industry
  Sludge, waste, etc.
• Construction and Civil Engineering Business
  Soil, cement, sandbags, construction waste, etc.
• Manufacturing Industry
  Products, intermediate products, raw materials for chemical resins, sake lees, etc.

As mentioned above, they are used as carrying bags for all kinds of items, as well as for refilling carrying containers. They are also used as storage bags, but mold may occur if food items are stored for long periods of time.

Features of Flexible Container Bags

Advantages

Flexible container bags are not only easy to transport with forklifts, etc., but can also be stacked on pallets or in tiers. Compared to manually carrying paper bags, jute bags, etc., the time and workload required for transport and storage can be greatly reduced, leading to increased efficiency.

Another advantage of flexible container bags is that they are lightweight and easy to handle because they are made of woven synthetic fiber material. They can be folded when not in use, which has the advantage of taking up less space in a warehouse.

Disadvantages

Polypropylene, the material used for flexible container bags, has low weather resistance, and leaving it outdoors for a month or so will cause UV degradation and damage. For use in places exposed to ultraviolet rays, such as rivers and construction sites, or for long-term use, products with a weather resistance of approximately 1 to 5 years that contain UV weathering agents are suitable.

In addition, since flexible container bags cannot be carried by hand, lifting equipment such as a forklift truck is essential.

Types of Flexible Container Bag

Flexible container bags are mostly made of soft polypropylene or polyethylene and weigh only about 2 kg. They have a very simple structure, and the bags are available in round or square shapes.

The following is a list of typical types of discharge ports and their main applications.

• No Outlet
  Soil, compost, waste, etc.
• Exhaust Outlet Small Mouth
  Rice husks, root vegetables, feed, fertilizer, chemical resin materials, etc.
• Exhaust Outlet Fully Open
  Feed, fertilizer, chemical resin raw materials, etc.
• With an Inside Bag
  Sludge, powder, hazardous materials such as asbestos, watery materials, and moisture-sensitive materials

How to Select Flexible Container Bags

Flexible container bags are sold in a variety of capacities, from small types with a capacity of approximately 500 L to large types with a capacity of over 2,000 L. It is easier to work with flexible container bags if you choose the right product for the contents. If food-related materials are to be placed in flexible container bags, it is important to choose products that are food compatible.

In addition, regardless of the contents, if degassing or moisture proofing is required, it is important to choose flexible container bags with functional features such as aluminum inner bags or laminated inner bags.

How to Use Flexible Container Bags

Flexible container bags are constructed with a suspension belt or rope on the outside, which allows them to be easily lifted and transported with a forklift, crane hook, or bar. The method of discharging the contents differs depending on the shape and type.

There are types that discharge from the bottom by untying the string at the outlet, fully open types with an inverted belt, and others. If the flexible container bag is filled with powder or granular materials, it is convenient to use a “suction-extraction type device” together with the bag, which allows removal from the top.

What Is a Fluoropolymer Paint?

Fluoropolymer paints are paints with fluoropolymer as the main ingredient.

Fluoropolymers have extremely high weatherability, chemical resistance, and abrasion resistance, and exhibit very good characteristics as a coating material. For this reason, they are widely used for surface protection of buildings and automobiles, which require high quality.

Applied to metal and concrete surfaces, it protects the surfaces and prevents deterioration caused by chemical substances and climatic changes, as well as stains caused by pollutants. Another feature of this product is its low adhesiveness, which makes it stain-resistant and easy to clean.

Although expensive, once painted, it maintains its beauty for 15 to 20 years. Although the initial investment is larger, the number of maintenance cycles can be reduced. As a result, it may be economically advantageous with lower running costs.

Uses of Fluoropolymer Paints

Fluoropolymer paints are used in a variety of applications due to their high durability and chemical resistance. Typical uses of fluoropolymer coatings are in high-value buildings such as skyscrapers.

The exterior walls and roofs of buildings are constantly affected by the natural environment, such as sunlight and wind and rain, so weather resistance is required. High-rise buildings, for example, are difficult to maintain and require weather resistance, so fluoropolymer coatings are used.

Fluoropolymer coatings may also be used on automobiles and ships. Exterior parts of automobiles and ships deteriorate due to salt damage and ultraviolet rays, so weather resistance is necessary. In addition, it is stain-resistant and chemical-resistant, making it easy to clean.

In addition, its adhesive properties are also used in food processing lines. Food does not adhere to the equipment, and clean and safe conditions can be maintained.

Principle of Fluoropolymer Paints

Fluoropolymer paints are paints with fluoropolymer as the main ingredient, and their properties are due to the extremely strong bonding power of fluoropolymer resins. Fluoropolymers have carbon-to-carbon bonds as the main chain, and fluorine atoms are bonded to the carbon. This bond between carbon and fluorine atoms is extremely strong and stable, making it less susceptible to ultraviolet rays and temperature changes.

Fluoropolymers have extremely high heat resistance and chemical stability, and are used in a wide variety of applications. Fluoropolymer paints can be used to impart these properties to surfaces. Fluoropolymer paints will adhere to surfaces in two main ways.

One is to apply a solution containing very fine particles of fluoropolymer to the surface. When the solution dries, the fluoropolymer particles will adhere to the surface and form a fluoropolymer coating film.

The other method is to charge the fluoropolymer electrically and apply it to the surface. In this case, the particles are adsorbed to the surface by the force of static electricity and form a fluoropolymer coating film.

Types of Fluoropolymer Paints

Fluoropolymer paints come in many types depending on their structure. The following is an example of one type of fluoropolymer paints.

1. PTFE-Based Paint

Polytetrafluoroethylene (PTFE) is used in this coating. It is characterized by its extremely low viscosity. Because of its excellent lubricity, it is used as a coating for frying pans and other cooking utensils.

It is also often used for lining the inside of pipes, taking advantage of its extremely low adhesiveness.

2. ETFE-Based Paint

Ethylene tetrafluoroethylene (ETFE) is the main component of this paint. It has extremely high heat resistance and weather resistance. It is also characterized by its high light transmittance.

It is mainly used for building exteriors, roofs, and green house sheets.

3. PVDF-Based Paint

This coating is based on polyvinyl difluoride (PVDF). It has high chemical resistance and abrasion resistance, and is excellent for surface protection of concrete and metal. In addition, it can prevent the adhesion of dirt and mold, thus maintaining the aesthetic appearance of surfaces for a long period.

4. FEP-Based Paint

This paint is mainly composed of fluorinated ethylene propylene (FEP). It is characterized by its extremely low viscosity.

It is mainly used for the inner surface coating of pipes and valves, etc. By applying FEP coating to the inner surface, fluid flow can be smoothed, and corrosion and dirt adhesion can be prevented.

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.