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What Is an Acoustic Microscope?

An acoustic microscope is a microscope that uses ultrasonic waves to observe the state of a sample by detecting the strength and position of the reflected waves from the sample.

Although its resolution is lower than that of an electron microscope, which is often used in industrial fields, its main feature is that it can measure and observe minute areas with higher resolution than an optical microscope.

Uses of Acoustic Microscopes

Acoustic microscopes are often used in the industrial field to inspect products. An acoustic microscope is characterized by its ability to observe not only the surface of a sample but also its interior and bottom surface by changing the depth of incidence.

Specifically, the microscope is used for internal inspections of electronic components and other general materials, checking the adhesiveness of adhesives, and detecting cracks, voids, and delamination on bonded surfaces. It is also useful for internal inspections of electronic components, etc., internal inspections of general materials, and checking the adhesiveness of adhesives. Both are used to detect cracks, voids, delamination, etc., on bonded surfaces.

Ultrasonic waves propagate while attenuating in areas where materials are continuous, but cannot propagate in non-continuous areas such as gaps, and most of the waves are reflected at boundary surfaces. Therefore, reflected waves reflected from delaminated areas and voids can be detected.

Principle of Acoustic Microscopes

An acoustic microscope utilizes the property that when ultrasonic waves are propagated between different materials at adjacent points, some of them are reflected and some are transmitted. When the reflected wave is detected and observed, the microscope is of the reflection type, and when the transmitted wave is detected and observed, the microscope is of the transmission type.

1. Transmission Type

A transmission type acoustic microscope consists of two acoustic lenses placed so that they face each other with the specimen in between. One acoustic lens has a piezoelectric element that receives ultrasonic waves, and the other acoustic lens has a piezoelectric element that receives ultrasonic waves.

During measurement, ultrasonic waves are injected through one acoustic lens, and the ultrasonic waves transmitted through the sample placed at the focal point are received by the piezoelectric element on the other acoustic lens.

2. Reflective Type

In a reflective acoustic microscope, the acoustic lens and piezoelectric element are placed only on one side. The piezoelectric element receives the incident ultrasonic wave and the reflected wave from the material. Both transmission and reflection ultrasonic microscopes can measure and observe the surface and internal conditions of a sample by analyzing the intensity and phase of the received ultrasonic waves.

Reflective acoustic microscopes are more commonly used commercially than transmissive microscopes. The main reason for this is that the reflective type does not require the sample to be sandwiched between acoustic lenses, so there is no limit to the thickness of the sample. Another major advantage of the reflective type acoustic microscope is that it is simpler to operate and easier to handle, since there is no need to place the acoustic lens in confocal, and image formation and measurement of propagation velocity are also possible.

Other Information on Acoustic Microscopes

1. Advantages of Reflective Acoustic Microscopes

The pulse reflection method, a measurement method using a reflective acoustic microscope, is a strong method for detecting exfoliation and voids inside the sample. In this method, a water-immersed sample is irradiated with ultrasonic waves of pulsed waveforms, and information about the interior of the object is obtained from the internally reflected pulses.

The intensity of this pulse reflection depends on the difference in acoustic impedance of the two materials that serve as boundary surfaces. Acoustic impedance is a quantity defined as the product of the density of the material and the speed of sound, and is almost 100% reflective of the air layer. This makes this pulse reflection method a strong method for detecting delamination and voids in the sample.

2. Cell Observation Using an Acoustic Microscope

Acoustic microscopes that can visualize the inside of cells using high frequencies such as 100 MHz to 200 MHz have been developed. The use of high frequencies during measurement has no adverse effect on cells in water, and such acoustic microscopes enable observation of cells in a living state.

Therefore, changes in intracellular structural proteins can be confirmed without dye staining, as in the past. In addition to the established technology for propagating high-frequency ultrasound through a thin fiber, the tip of the fiber is processed on a concave surface to converge the ultrasound waves, thereby increasing the azimuthal resolution to the cellular level.

Acoustic microscope produces images based on the density and viscoelasticity of intracellular substances, making it extremely suitable for observing the cytoskeleton, which controls cell proliferation and other processes. Taking advantage of this property, a technique has been developed to identify cancer cells from a cancer cell population. Using this technology, fluorescent proteins can be expressed so that normal cells can be identified and how anticancer drugs have acted on cancer cells can be confirmed.

What Is a Vortex Flowmeter?

A vortex flowmeter is a flowmeter that utilizes the Karman vortex.

A Kalman vortex is a line of vortices generated downstream of an object (vortex source) placed in a fluid flow. The name “Kalman vortex” comes from the theoretical clarification by the physicist Kalman.

The vortex flowmeter is simple and robust in construction. Its main features are good accuracy, a wide flow range, and compatibility with a wide variety of fluids.

Uses of Vortex Flowmeters

The main applications of the vortex flowmeter are:

• Measurement of flow rate in steam piping
• Measurement of condensate recovery
• Measurement of boiler water supply
• Control of automobile engines
• Control of coolant flow in coolers

Vortex flowmeters can measure gas, liquid, and steam, so it can be used in any flow measurement scenario.

The caution is to select an appropriate bore size for vortex generation, since measurement is not possible without vortex generation. In the low flow range, the Karman vortex will not be generated and the flow rate cannot be measured.

Principle of Vortex Flowmeters

A vortex flowmeter measures the flow rate by counting Kalman vortices.

Since the frequency of the Kalman vortex is proportional to the flow velocity, the flow velocity can be determined by placing a vortex generating obstacle in the pipe and counting the vortices generated.

The following is an explanation using specific mathematical formulas.

Let the vortex frequency be f (Hz), the representative length of the vortex generating body be d (m), and the flow velocity be v (m/s),

f = S・v/d

The equation f = S・v/d, where S is the vortex frequency of the straw hatcher and v is the flow rate. where S is a proportionality constant called the Strouhal number. This number is determined by the shape and dimensions of the vortex generator.

The flow rate Q (m3/s), if the cross-sectional area of the pipe is A (m2),

Q = A・v = A・f・d/S = K・f

and if the constant of proportionality K between flow rate and frequency is determined in advance, the flow rate can be obtained from the frequency.

Actual vortex generators can be triangular, flat, or trapezoidal in shape, with the trapezoidal shape being considered the most accurate. The vortex is detected by converting the force generated by the vortex into an electrical signal using a sensor (piezoelectric element or semiconductor strain gauge), which is then amplified by a transducer and extracted as a pulse signal or an analog signal.

Other Information on Vortex Flowmeters

1. Straight Pipe Length of Vortex Flowmeters

Other meters that measure the flow rate of fluid in a pipe include differential pressure flowmeters and Coriolis flowmeters. The differential pressure flowmeter has a simple structure, but its disadvantage is that its measurement accuracy is somewhat low, while the Coriolis type has the disadvantage of being limited to the fluids that can be used.

A vortex flowmeter, on the other hand, measures the pressure change caused by the Karman vortex generated downstream of the vortex-generating object installed in the sensing section and converts it to the flow rate. A vortex flowmeter can measure liquids, solids, and gases, and is characterized by the simplicity of its instrumentation.

As is true of most flowmeters, the straight pipe section upstream of the instrument must be of a certain length for more accurate flow measurement. In vortex flowmeter, swirling flow or non-uniform velocity distribution in the pipe will affect the measurement. Therefore, the fluid must be laminar.

Therefore, the upstream of the flowmeter must be rectified, and valves, thermometers, pressure gauges, etc. must not protrude into the piping. The required length of the straight pipe section depends on the design of the piping. 

2. Vortex Flowmeter and Steam

Differential pressure flowmeters are often used to measure steam flow. The differential pressure flowmeter has a simple mechanism, but its flow rate accuracy is inferior to that of other flowmeters.

In such cases, a vortex flowmeter can be used to measure the flow rate of steam accurately.

In the case of steam, the density varies with temperature and pressure. A vortex flowmeter not only provides accurate measurement of flow rate, but some meters are equipped with a temperature sensor to enable conversion to mass flow rate.

In addition, a vortex flowmeter is more suitable than the differential pressure type, mainly because in boilers the steam is wet steam. However, the effects of temperature, pressure, and dryness of this wet steam can result in low accuracy even in a vortex flowmeter.

Vortex flowmeters for steam have a built-in dryness sensor in the detection section and are designed to be able to convert the mass flow rate.

What Is an Incubator Apparatus?

An incubator apparatus is designed to culture a wide range of organisms including animal and insect cells, Escherichia coli, other bacteria, and plants by controlling their environment (temperature, humidity, etc.) for optimal growth. Bioshakers enhance bacterial cultures through agitation, while CO2 incubators introduce carbon dioxide to maintain the pH level for mammalian cell cultures.

Uses of Incubator Apparatuses

Incubator apparatuses are pivotal in growing animal cells and microorganisms by precisely controlling environmental conditions. They are widely utilized in life sciences and biology for protein expression in E. coli, among other applications. Typical operating temperatures range from +4°C to +70°C, catering to various research needs.

Principle of Incubator Apparatuses

While specific controls vary, maintaining appropriate temperature conditions is crucial. Temperature can be regulated in gas or liquid phases, with the former offering ease of adjustment but sensitivity to ambient changes, and the latter providing superior thermal retention but more challenging temperature management.

Types of Incubator Apparatuses

1. Bioshaker

Bioshakers perform essential mixing of liquid medium and air, with right-to-left and rotary shaking options for different culture vessels. Baffled triangular flasks, often used for their efficient medium and air mixing, are suited for rotary shaking.

2. CO2 Incubator

CO2 incubators control CO2 levels and humidity, using around 5% CO2 for pH stability and trays of sterile water to maintain 90-95% humidity. They accommodate both adherent and floating mammalian cells, with specific considerations for each cell type’s incubation.

Other Information on Incubator Apparatuses

1. Bacteria Incubator Apparatus

This type of incubator, set to maintain temperatures around 38℃, is used primarily in food processing for the growth inspection of microorganisms like E. coli and Salmonella. Its design facilitates microorganism color identification post-reagent application.

2. Cell Incubator Apparatus

Used for culturing human-origin mammalian cells, these incubators support cell observation and protein use from cells. Regular tasks include medium exchange and passaging culture to ensure optimal cell conditions, with recent advancements in automatic incubators simplifying these processes.

3. Terminology

The term “incubator” traditionally refers to egg incubation devices. However, in the context of scientific apparatus, different terminologies apply:

• Incubator apparatus: culture apparatus
• Microorganism incubator apparatus: bacterial culture apparatus
• Anaerobic culture apparatus: anaerobic culture apparatus

What Is a Vibration Isolator?

A vibration isolator is a device used to reduce vibrations transmitted from the ground, foundation, floor, or other surrounding areas so that they are not transmitted to the equipment.

Vibration isolation, also known as vibration insulation, is the practice of preventing vibrations generated by the surrounding environment from being transmitted to the equipment being tested. Likewise, “vibration isolation” can refer to stopping vibrations generated by a source from spreading to the surrounding area. The term “vibration control” encompasses both preventing the transmission of existing vibrations and stopping the source of vibrations from transmitting them.

Vibration control is also known as “vibration damping.” Vibration control is the damping of vibrations by direct action on the object to be controlled. There are two types of vibration isolators: passive isolators, which suppress and prevent vibrations from the surrounding environment, and active isolators, which use sensors and actuators to perform vibration-damping movements.

Applications of Vibration Isolation Benches

Vibration isolators are used in precision processing equipment and as the base of electron microscopes. Minimizing the effects of vibration is essential for micron-order processing and measurement in precision measuring instruments, semiconductor and liquid crystal manufacturing inspection equipment, as well as ultra-precision processing machines.

Vibration suppression is also important for observation under high magnification with electron microscopes.

Principle of Vibration Isolation Table

There are two types of vibration isolators: passive and active. It is important to select the most appropriate method depending on the purpose of use, ambient environment, and natural frequency of vibration.

1. Passive Type

Passive vibration isolators combine elasticity, such as springs, and viscosity, which acts as a damper. Elasticity, of which springs are a typical example, temporarily stores vibration energy by deforming itself and reduces vibration through temporary energy accumulation.

Viscous uses the viscosity of air or fluid to absorb vibration energy by converting it into heat. Vibration is absorbed by the damper converting the vibration energy stored by the spring into heat.

Another key to the principle of vibration isolation is how fast the spring and damper move. If the pendulum is moved slowly and widely, it will swing widely, but if it is moved quickly and finely, it will hardly move at all.

2. Active Type

In an active vibration isolator, a sensor fixed to the floor or other surface constantly senses external vibrations, and through an actuator generates vibrations that have a frequency opposite to that of the sensor. This allows the device to remain stationary as the external vibration and the vibration generated by the table cancel each other out.

Active vibration isolators can be divided into two control methods: feedback control, in which the vibration of the equipment or vibration isolator is sensed by a sensor, and feedforward control, in which the vibration of the floor or ground is sensed.

Other Information on Vibration Isolation Table

What Are Vibration Transmission Characteristics That Indicate Vibration-Isolation Performance?

A graph of vibration transmission characteristics shows the performance of a vibration isolator. The vertical axis is the vibration transmission coefficient (db) and the horizontal axis is the vibration frequency (Hz). Generally, the vibration transmission characteristics rise to a peak at a certain frequency, touching the vertical axis at 0, and then decrease with increasing frequency in a gentle arc like the ridgeline of Mt. Fuji. Zero on the vertical axis indicates that the vibration transmission coefficient is 0db, or synchronous. The object moves as if it were one with the vibration source. In other words, the vibration is transmitted as it is.

The peak part of the vibration transmission characteristics is a condition called “resonance”. It means that the object vibrates very loudly in response to the generated vibration, and in some cases, the machine may be destroyed. Resonance is a point to be avoided in machinery. The area where the frequency increases from resonance and the vibration transmission coefficient becomes negative, which is less than zero, is the vibration-isolation area.

When selecting a vibration isolator, the frequency of vibration in the installation environment can be used to determine the degree to which vibration can be suppressed based on the magnitude of the vibration transmission coefficient.

What Is an Infrared Microscope?

An infrared microscope, utilizing infrared microspectroscopy, analyzes microscopic samples by employing infrared light, which, despite its limited spatial resolution due to the diffraction limit, enables detailed spectral analysis. Modern infrared microscopes often integrate Fourier transform infrared spectroscopy (FTIR) and total internal reflection capabilities, enhancing their analytical potential.

Uses of Infrared Microscopes

Primarily used in failure analysis and materials science, infrared microscopes excel in examining microscopic samples, identifying foreign matter and defects through differential infrared absorption rates, and measuring semiconductor thickness with less impact from surface irregularities. Interferometry methods measure semiconductor thickness by analyzing the optical path difference of reflected light.

Principle of Infrared Microscopes

Infrared microscopes combine microscopic imaging and spectroscopic analysis. Samples are initially observed under visible light to locate the target area and then analyzed under infrared light for detailed spectral data.

Types of Infrared Microscopes

1. Infrared Spectrometer

This type uses infrared light to illuminate a sample, capturing the spectrum of transmitted or reflected light. Utilizing a Cassegrain optical system instead of refractive lenses, it achieves spatial resolutions limited to a few to several micrometers, with the infrared band between 2.5 and 25 micrometers revealing material-specific spectra.

2. Fourier Transform Type (FT-IR)

The FT-IR microscope characterizes samples using a continuous light beam, analyzing all wavelengths simultaneously through an interferometer. Its advantages include simultaneous multiple wavelength detection, high signal-to-noise ratios, improved wavelength resolution, and an extended measurement range. DTGS and MCT are two common detector types, with MCT requiring liquid nitrogen cooling for optimal performance.

Other Information on Infrared Microscopes

Measurement With a Two-Dimensional Array Detector

Advanced infrared microscopes using two-dimensional array detectors necessitate liquid nitrogen cooling to prevent damage from heat. While some models can operate without liquid nitrogen, cooling significantly affects measurement capabilities and accuracy.

What Is a Beamsplitter?

A beamsplitter is an optical element used to separate a single beam (the speed of light) into two beams.

Beamsplitters are sometimes abbreviated as BS or B/S in optical path diagrams. When light passes through a beamsplitter, it is divided into transmitted and reflected beams at a ratio designed into the Beamsplitter. The ratio can vary from 1:1 to 2:8.

In particular, a 1:1 ratio is sometimes referred to as a half-mirror. Usually, the ratio is fixed, but it is possible to make a device that can arbitrarily divide light by combining it with a wavelength plate. Also, separated beams can be recombined by passing them through a beamsplitter again.

Uses of Beamsplitters

Beamsplitters are mainly used in optical instruments, such as cameras and microscopes. Beamsplitters are available in two types: cube-type beamsplitters, which consist of two right-angle prisms laminated together, and plate-type beamsplitters, which consist of thin glass with a special coating.

Beamsplitters of the plate type are often used in fluorescence optical microscopes. The cube type is used when the optical system needs to be compact or when the amount of transmitted and reflected light paths needs to be aligned. In general, cube-type beamsplitters tend to be more expensive, while plate-type beamsplitters tend to be less expensive.

Principle of Beamsplitters

Beamsplitters can separate two beams by reflecting some of the light through a dielectric multilayer film. Beamsplitters come in cube and plate shapes, and the principle differs depending on the shape.

1. Cube Type

Cube-type beamsplitters consist of two right-angled prisms bonded together with an optical film called a dielectric multilayer. By adjusting the thickness of the dielectric multilayer film, the ratio of reflected light to transmitted light can be changed. The characteristic feature of the cube type is that the angle of incidence of light into the Beamsplitter is 0 degrees. Therefore, reflection may occur on the same axis of the incident light and return as stray light in the direction of the light source.

2. Plate Type

In the plate type, a dielectric multilayer film is deposited on a flat glass plate. Since light enters the plate at a 45-degree angle, stray light is less likely to occur as in the cube type, but since transmitted light is refracted out, there is an optical path difference with reflected light. Therefore, alignment in the optical system is important, and care must be taken because frequent removal and insertion can quickly cause axis misalignment, etc.

Types of Beamsplitters

There are two types of beamsplitters, depending on the polarization characteristics of the reflected beam

1. Non-polarizing Beamsplitter (NPBS)

Non-polarizing beamsplitters simply split the beam and have no polarity. They are used in a variety of optical applications and are indispensable in microscopes and interference optics.

Usually, the reflective side has a chromium-based coding and the transmissive side has none. Therefore, it is important to note that, if the incident path is wrong, the intensity of the two split beams will differ greatly. As mentioned above, when the ratio of transmitted light to reflected light is 1:1, it is called a half mirror and is also utilized in coaxial epi-illumination, one of the inspection lighting applications. By using coaxial epi-illumination, the positive reflected light from the object can be efficiently picked up and a clean image can be acquired.

2. Polarizing Beamsplitter (PBS)

Beamsplitters are used to separate beams into S and P polarization. They are used in semiconductor and liquid crystal lithography equipment, interference optics, and various measuring instruments, and are utilized as elements to create a polarization state from an unpolarized state by utilizing the characteristics that P-polarized light is transmitted and S-polarized light is reflected. Their extinction ratio is high, often around 1,000:1, depending on the product.

By combining a polarizing beamsplitter and a waveplate, it is possible to split light at any desired ratio; linearly polarized light passing through a quarter-waveplate can have its polarization angle changed according to the angle of the waveplate. If a polarizing beamsplitter is placed behind the optical path of the waveplate, it is possible to create a device in which the beamsplitter can split the beam at an arbitrary intensity ratio by adjusting the angle of the waveplate.

Other Information on Beamsplitters

Difference Between a Beamsplitter and a Prism

The difference between a beamsplitter and a prism is the application. A cube-type beamsplitter consists of two right-angle prisms. On the other hand, a cube-shaped prism is created by forming an optical thin film on the slope of one prism to function as a beamsplitter and joining it with the other prism. Since two prisms are utilized, the optical thin film is not in direct contact with the air, and no degradation of the thin film occurs.

Prisms are used in applications that actively use refraction to change the optical path or spectroscopy, but when utilized as beamsplitters, there is no refraction of transmitted light, and the optical element utilizes reflection and transmission.

What Is Sludge Disposal Equipment?

Sludge Disposal Equipment is equipment that treats the sludge generated in wastewater treatment and other processes.

In factories and sewage treatment plants, sludge remains during product manufacturing and after wastewater treatment, and must be treated to meet standards. Generally, Sludge Disposal Equipment is used.

There are various types of Sludge Disposal Equipment due to differences in treatment methods, depending on whether the sludge is organic or inorganic. The main principles include the use of microorganisms and dehydration. The equipment is selected according to the type of sludge.

Applications of Sludge Disposal Equipment

A wide range of plants use Sludge Disposal Equipment directly or indirectly, including food processing plants, steel products, chemical products, electronic products, pharmaceuticals, automobiles, paper manufacturing, wastewater from the manufacture of used paper, sewage treatment plants, machine shops, and rolling mills.

Sludge is broadly divided into organic and inorganic. Note that sludge from domestic wastewater and food factory wastewater containing organic matter is organic sludge.

Principle of Sludge Disposal Equipment

Inorganic sludge is generated when wastewater contaminated with inorganic substances is treated. There are many types. For example, in a plating factory, various metal oxides are discharged.

Organic sludge, on the other hand, is generated when wastewater contaminated with organic materials is treated, and is typically generated when biological treatment is performed at sewage treatment plants.

1. Inorganic Sludge

There are several types of inorganic sludge. Sludge such as lime, gypsum, and coal is found in wastewater from ore washing, dust collection, etc. Sludge such as metal oxide powder is found in steel wastewater and collected dust wastewater; sludges of heavy metal hydroxides such as Fe, Al, Cr, Cu, and Ni are found in plating and acid wastewater.

Oil-containing coagulation sludge is also found in wastewater from machinery plants and rolling mills. Flocculated sludge such as sulfate bands and iron salts can be found in wastewater from suspended water treatment at water purification plants.

2. Organic Sludge

There are various types of organic sludge. Activated sludge in food factories occurs in factory wastewater. Organic chemical activated sludge is included in wastewater from organic chemical plants and petrochemical plants.

3. Sludge Treatment

Sludge treatment is easy to transport and is first dewatered to remove water to form a cake. The water content of sludge can be in one of the following states: bound water, internal water, surface-attached water, or free water.

The appropriate dehydrator is selected based on the state of water in the sludge. Free water and surface-added water can be separated relatively easily. Cake-like sludge is dried for metal recovery and reuse, incineration, landfill, or decomposition.

Types of Sludge Disposal Equipment

There are various types of Sludge Disposal Equipment, which may be a combination of equipment. The following are examples of Sludge Disposal Equipment:

1. Various Types of Dehydrators

Sludge is first treated by using a dehydrator to remove water. The sludge that has been dehydrated and concentrated is called cake. There are many types of dehydrators.

Vacuum Dehydrator
The entire drum is immersed in sludge and sewage while the center of the rotating drum is depressurized. The sludge adheres to the cloth on the outside of the drum to be concentrated and made into a cake.

Multi-disc Type Dehydrator
Thin discs and spacers are combined to form a cylindrical filter body, which is rotated and dewatered by combining several of them. The sludge is flocculated with a coagulant and dewatered.

Belt Press Type Dehydrator
This device dehydrates sludge by sandwiching it between two filter cloths. Suitable for dewatering organic sludge.

Filter Press Dehydrator
Sludge is packed into a filter chamber and pressurized for dewatering.

Centrifugal Dehydrator
This device separates solid components in a liquid by centrifugal force. It is capable of separating not only solids and liquids mixed together, but also liquids with different specific gravity.

2. Pressurized Floatation Device

This device is used to separate substances that have a lower specific gravity than water from water. It generates fine bubbles in the water, adsorbs flocculated flocs in the bubbles, and floats to separate sludge.

3. Activated Sludge Disposal Equipment

Microorganisms are grown on the contact material, and the bacteria are directly attached to the sludge. The bacteria capture and settle on the sludge, making it a compact device with high purification capacity.

Running costs can be reduced because there is little excess sludge. Air is fed into the sludge for the microorganisms, and oxygenated Sludge Disposal Equipment is also available to further activate the sludge by feeding oxygen into the sludge.

4. Membrane Separation Activated Sludge Disposal Equipment

In the membrane separation activated sludge process, a membrane with microscopic holes is immersed in an aeration tank to directly filter sewage and separate sludge. The sedimentation tank required for normal activated sludge treatment is not necessary, saving space and reducing treatment costs.

In addition, the treated water is of good quality and microorganisms can be removed, eliminating the need for disinfection.

What Is Grinding Machinery?

Grinding machinery (grinder) is a machine tool for precision finishing by grinding the surface of a workpiece by bringing the workpiece into contact with a grinding wheel rotating at high speed. There are many types of grinders, depending on the combination of the motion of the grinding wheel and the workpiece. There are many types of grinders, such as for inner and outer diameters of cylinders, for flat surfaces, and for gears.

Grinding machinery is characterized by its ability to machine even hard materials such as hardened steel and special alloy steel, which are difficult to machine by ordinary cutting methods. Those that perform machining by precisely adjusting the machining volume through machine operation are called mechanical grinding machinery, and are distinguished from free grinding machinery, the so-called grinders.

Uses of Grinding Machinery

Grinding machinery is mainly used for finishing the surface of workpieces. After primary and secondary machining to shape and precision by cutting, grinding is performed to finish the dimensions and surface properties of the workpiece with even higher precision.

Examples include crankshafts, camshafts, gears, screws, splines, tools, jig grinding, and rollers. They are also used for processing glass, jewelry, and ceramics.

Principle of Grinding Machinery

Grinding machinery uses a grinding wheel to remove the surface of the workpiece for high-precision machining. The grinding wheel used is made of abrasive grains solidified with a bonding agent, and has numerous pores inside. The abrasive grains act as cutting edges during machining, and they peel off from the bonding agent during machining and are discharged together with chips.

Grinding machinery can produce very clean work surfaces because the stripping and ejection process is constantly repeated and new abrasive grains are always used. Grinding machinery performs high-precision machining with a very small depth of cut. Since grinding is done repeatedly with a high peripheral speed grinding wheel, a large amount of heat is generated.

For this reason, the grinding wheel is continually cooled by pouring a processing fluid or other means. Grinding Machinery requires only a small depth of cut, so it has the disadvantage of taking longer machining time than other machining methods.

Types of Grinding Machinery

There are several types of grinding machinery depending on the purpose of grinding and the shape of the workpiece.

1. Surface Grinding Machinery

The workpiece is fixed to a table that moves in the front-back and left-right directions. The flat surface of the workpiece is then ground with a rotating grinding wheel. 

2. Cylindrical Grinding Machinery

The periphery of a cylindrical workpiece is ground. The workpiece is moved left to right and the grinding wheel is moved up and down. Both the grinding wheel and the workpiece are rotated at high speed while grinding the outer circumference. 

3. Internal Grinding Machinery

The internal surface of a cylindrical workpiece is ground. The fixed workpiece is rotated at high speed and grinding is performed with a grinding wheel inserted into a hole in the workpiece.

4. Centerless Grinding Machinery

Centerless grinders grind cylindrical or cylinder-shaped workpieces and are also called a centerless grinding machinery. The workpiece is ground by placing it between two grinding wheels with different rotation speeds. Since the workpiece can be moved in the axial direction for continuous operation without being fixed, it has the advantage of higher productivity.

Other Information on Grinding Machinery

1. Grinding Machinery Grinding Wheels

A tool called a grinding wheel is required for the grinding process using a grinding machinery. The grinding wheel has three elements: abrasive grains, bonding agent, and pores. The abrasive grains are used to scrape away the abrasive grains and worn abrasive grains naturally drop off and new abrasive grains appear on the surface.

The abrasive grains work to scrape the object. The bonding agent binds the abrasive grains and adjusts the performance of the grinding wheel. Pores help to discharge chips to prevent clogging and to reduce the heat generated by the grinding wheel.

Abrasive grains are particles of hard materials used to cut metals and difficult-to-cut materials. Alumina (aluminum oxide) and silicon carbide are generally used. Alumina is used for grinding steel and nonferrous metals, while silicon carbide is used for nonferrous metals. Diamond or CBN (cubic boron nitride) abrasive grains are used for hard-to-cut materials.

The bonding agent is an adhesive used to harden abrasive grains. There are three types of bonding agents: ceramic-based, resin-based, and metal-based. Select a grinding wheel made of the material that best suits the processing purpose, such as “vitrified” (ceramic-based) for precision grinding, “resinoid” (resin-based) for a wide range of grinding and finishing operations, and “metal” (metal-based) for rough grinding and cutting. 

2. Chuck of Grinding Machinery

The chuck used to attach the workpiece to the grinding machinery depends on the type of grinding machinery. Surface grinding machinery is used to cut rectangular materials, so the chuck is a table type. The workpiece is fixed by sucking it with a magnetic chuck, such as a magnet or a vacuum chuck.

In the case of cylindrical grinding machinery, both centers of the material are fixed in place in order to process a cylindrical workpiece to reduce its diameter. In the case of an internal grinding machinery, the end of the material is attached to a three- or four-jaw chuck, as on a lathe, for machining.

What Is an Ultrasonic Cutting Machine?

An ultrasonic cutting machine is a device that uses ultrasonic waves to perform cutting and polishing operations. Cutting oil or abrasive slurry is applied between the ultrasonically vibrating tool and the workpiece, causing the surface of the workpiece to undergo brittle fracture and material removal gradually. Ultrasonic processing machines consist of a transducer that vibrates ultrasonically, an oscillator that drives the transducer, and a cutting tool.

Ultrasonic machining is one of the few machining methods that can process three-dimensional shapes of brittle materials, even if the materials are not conductive.

Applications of Ultrasonic Machining Tools

Ultrasonic machines are used to process brittle materials and materials that are difficult to process by general machining. Examples include cutting hard ceramic and metal materials, cutting hard-to-cut carbon fiber, processing quartz glass, and polishing molds.

In addition to hard materials, ultrasonic processing machines are also used for cutting cakes and pie crusts that easily lose their shape, slicing bread, and cutting pizza into pieces, which are commercialized as ultrasonic food cutters. The microscopic ultrasonic vibration reduces frictional resistance between the blade and the food, resulting in a clean-cut surface.

Principle of Ultrasonic Processing Machines

Ultrasonic processing machines apply ultrasonic vibrations to blades to reduce cutting resistance and achieve high processing speed and high precision cutting. There are several ultrasonic machining methods, including cutter and grinding, but the principles of typical methods are explained here.

In spindle machining, ultrasonic vibration is applied to the machining jig, and the jig is rotated for machining. In abrasive grain processing, abrasive grains are poured into the ultrasonically vibrating processing jig, and then ground and processed in small quantities.

The following is a brief description of the oscillator and transducer that make up the ultrasonic processing machine. The oscillator converts electric power into ultrasonic vibration. Since the operating frequency of the transducer varies with the blade and grinding wheel, it is equipped with an electronic circuit to adjust it to the optimum frequency.

The transducer consists of a bolted Langevin-type transducer (commonly called BL transducer) that generates ultrasonic vibration, a fixed horn that increases the amplitude, and a blade that transmits the vibration. There are several types of blades depending on the application, and they are used according to the situation.

What Is a Machine Vise?

A machine vise is a jig that is attached to a table or machine to hold the object in place so that it does not move when processing metal plates and other materials. They are mainly used for processing, such as milling, grinding, and drilling. By using a machine vice to precisely and strongly fix an object, the X, Y, and Z axes can be made accurate and the accuracy of machining can be improved.

However, a powerful load is applied during machining, so care must be taken to avoid lifting even when using a machine vise.

It is important to select a machine vise that is compatible with the machine to be processed, such as a milling machine or machining center.

Usage of Machine Vises

Machine vises are used to fix objects in machining centers and milling machines. In most cases, machine vises are clamped to a table, etc. Some models are fixed to an electromagnetic chuck for precision machining, while some models are equipped with a function to prevent lifting during machining.

There are machine vises made of cast iron to withstand powerful work, and other materials to suit the application. Machine Vises are also available in sizes ranging from small to large, depending on the object to be processed.

Principle of Machine Vises

Screws or shafts are used to clamp and secure the object to the table or equipment. There are two types of fixing methods: handle-type and wrench-type.

In the handle-type, once the object is clamped in the machine vise, simply turn the handle to secure it in place.

In the wrench-tightening type, the object is clamped in the machine vise, and the shaft is fixed in the groove hole on the side by turning the wrench and moving the movable mouthpiece.

Take care that the object is clamped in a slightly loose position and that the shaft is properly seated in the groove hole. As you tighten the rod bolt, the shaft acts as a fulcrum to pinch and secure the object. Tightening the rod bolt when the shaft is just caught in the groove hole may cause failure.

Normally, a machine vise is clamped to a table, but there are cases where a machine vise is fixed on a milling machine using an electromagnetic chuck.

The machining direction is usually one direction, but with models such as a sign vise with an inclination, a two-dimensional vise in which the vise itself rotates, and a three-dimensional vise, you can set the machining direction by yourself.