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What Is a Painting Robot?

Painting robots are industrial robots used for painting.

Most painting robots are equipped with a painting gun attached to an articulated arm to handle delicate painting tasks. Painting robots can reduce the risk of health hazards caused by organic solvents contained in paints when painted by humans.

Painting Robots can also improve productivity and reduce human error and variation. In fact, in a roof Painting Robot case study, productivity was increased by a factor of 35, and the use of robots in industry is rapidly increasing.

Applications of Painting Robots

Painting Robots have been introduced in the automotive industry and many other manufacturing sites where painting is required. A wide range of sizes, from large ones for automobiles to small ones for electronic components, are now available on the market, and their introduction is further expanding.

Since production is more stable than when done by humans and human health hazards can be reduced, it has also begun to be introduced in the fields of roofing, wall construction, daily necessities, and various parts. In some cases, Painting Robots are being used in the traditional craft of lacquerware.

Principle of Painting Robot

Painting Robot consists of an industrial robot with a painting gun attached. Since the paint sprayed during painting also splashes on the robot itself, explosion-proofing was an issue.

Many robots are articulated with 5 to 6 axes, and the following three types of robots are mainly used:

1. Vertically Articulated Robots

Vertically articulated robots have 5 to 6 axes of vertically rotating joints and can move in a manner similar to a human arm in appearance. By changing the direction of the axes, the robot can rotate not only vertically but also diagonally. It can also be used for painting complex shapes.

2. Horizontal Articulated Robot

Joints and links are connected horizontally, and rotation is possible in the horizontal direction. Since the robot moves almost exclusively in the horizontal direction, it is suitable for coating flat objects.

3. Rectangular Coordinate Robot

This robot has a structure in which three axes slide and move, and is also called a Cartesian Coordinate Robot. Since they cannot perform complex movements, they are suited for objects with simple shapes.

Other Information on Painting Robots

1. Examples of Painting Robot Applications

Introduction of Wall Spray Painting Robot
The distance between the wall and the Painting Robot is measured by a distance sensor, and the robot’s position is controlled to maintain the distance at a constant level. This technology ensures uniform distribution of the coating volume and quality equivalent to that of skilled workers.

It is also possible to use “human-robot collaboration,” in which the robot is semi-automated and a person works in the corners of the wall and other areas that are difficult for the robot to work in.

Introduction of Painting Robot in Lacquer Ware
Painting of lacquerware, which used to be done by hand because of the need for skilled techniques, is now performed by a vertically articulated Painting Robot. The work, which previously required two people, can now be done by a single assistant, greatly increasing labor productivity by about threefold.

In addition, the new system contributes to solving the problem of technical succession due to the declining birthrate and aging population.

Introduction of Painting Robot for Roof Painting
In the case of the introduction of Painting Robot to the roof painting operation, labor productivity increased 35 times before and after the introduction of Painting Robot.

2. Painting Robot Painting Method

Painting Robots use an electrostatic coating method with a beautiful finish. Electrostatic coating is a coating method that utilizes the mechanism of static electricity. The workpiece is the positive electrode and the Painting Robot is the negative electrode. High voltage is applied to the atomized paint to charge the negative electrode, and the paint is applied to the positive electrode workpiece along the electrostatic lines. The advantages of this method are that less paint is wasted, the number of coating man-hours is greatly reduced. It is also environmentally friendly.

The most commonly used coating guns are the rotary atomization method and the electrostatic atomization method. The rotary atomization method spreads the paint in an application pattern while atomizing the paint. An air motor is rotated at high speed, compressed air is used to create an air film between the shaft and bearings. This mechanism rotates at high speed without contact. These rotations cause the paint to form a fine atomization, which is then pneumatically ejected in the direction of the workpiece.

The electrostatic atomization method uses electrostatic force to atomize the paint. The electrostatic coating method is widely used for mass-produced industrial products such as automobile bodies, railroad cars, electrical products, steel office equipment, and housing-related parts.

What Is a Pillow Packaging Machine?

Pillow packaging machines are used to package food, pharmaceuticals, machine parts, and other products.

It is called “pillow packaging” because the packaging form is shaped like a “pillow,” and it is suitable for high-speed mass packaging.

It can be filled with gas when packaging products, which slows down the speed of product deterioration.

Pillow packaging is not vacuumed sealable or aseptic and is unsuitable for heat-sensitive products because heat is applied during sealing.

Other types of packaging machines, such as shrink seal (heat shrink) packaging machines, small box packaging machines, and vacuum packaging machines, can also be used, depending on the product to be packaged.

Applications of Pillow Packaging Machines

Pillow wrapping machines are mainly used in the food industry and for bulk packaging of pharmaceuticals.

There are also packaging machines suitable for packaging pharmaceuticals, and each zone of machine is divided into separate zones.

Vertical pillow wrapping machines are not suitable for products that may be damaged if the product is dropped into the film from the top.

It is suitable for packaging flour, drinking water, mayonnaise, snacks, bean sprouts, machine parts, etc.

It can also be used for confectioneries individually packaged in a continuous vertical line and with gussets on the sides and bottom.

Horizontal pillow wrapping machines can pack tray containers, ice cream, chocolate, dried noodles, vegetables, toys, stationery, and pharmaceuticals in bulk but are not suitable for powders, granules, or liquids.

Horizontal pillow wrapping machines can be further classified into two types: “forward pillow wrapping machines,” in which the back seal is below the product, and “reverse pillow wrapping machines,” in which the seal is above the product.

Principle of Pillow Wrapping Machine

1. Vertical Pillow Wrapping Machine

The film is made into a tube, the overlapping parts are sealed, the product is filled from the top, and the top is sealed horizontally and separated.

Various functions can be added to the pillow wrapping machine, such as gas filling, gusset creation, film misalignment correction, product bite prevention, and sensor to prevent empty wrapping.

2. Horizontal Pillow Wrapping Machine: Positive Pillow Wrapping Machine

The film is fed from the top of the product and wrapped from the top to form a cylinder, and the overlapped portions are sealed. This machine is suitable for wrapping products on trays, products of a certain shape, and lightweight products. 3.

3. Horizontal Pillow Wrapping Machine: Reverse Pillow Wrapping Machine

The film is fed from the bottom of the machine, and the product is wrapped from the bottom to form a cylinder, and the overlapped portions are sealed.

Since the seal is on top of the product, it is easy to check for roll-in and is better suited for wrapping heavy products than regular pillow wrapping. Since the product is placed on top of the film, it is possible to wrap moist or long vegetables, and the conveyor is less contaminated.

Other Pillow Packaging Machine Information

The trouble with Pillow Packaging Machines

One trouble that can occur when working with a pillow-wrapping machine is film snaking. The cause may be a problem with the film or with the wrapping machine, and countermeasures must be taken according to the cause each time.

Typical causes and countermeasures for film snaking are as follows:

• If the Film is Too Thick or Too Thin: Installing a guide on the roller part of the wrapping machine or strengthening the brake on the take-up may improve the problem. Replacing the take-up is another solution.
• If the Film is Too Slippery: Installing guides on the packaging machine or wrapping the rollers with non-slip tape may be a solution.
• If the Film is Too Slippery: Powder dusting can be effective.
• Uneven Printing: Adjusting the roll stiffness may help.
• If the Installation or Rotation of the Wrapping Machine Rollers is Distorted: The rollers of the wrapping machine need to be adjusted.

Pillow wrapping machine film

In a pillow-wrapping machine, a sheet of film is sealed back-to-back and wrapped into a tube. To avoid seal failure, the appropriate sealing temperature must be selected based on the characteristics of each film material. There are various types of films used for packaging.

Typical film materials and characteristics are as follows:

1. Low-density Polyethylene (LDPE)

LDPE has excellent water resistance, acid/alkali resistance, heat sealability, and impact resistance. On the other hand, it tends to be inferior in organic solvent resistance and heat resistance. 

2. Non-oriented Polypropylene (CPP)

Compared to LDPE, CPP has superior moisture resistance and transparency. On the other hand, it tends to be inferior to LDPE in flexibility and impact resistance. 

3. Biaxially Oriented Polypropylene (OPP)

This is a film processed by stretching CPP film; it is less stretchable than CPP and has superior tensile strength, moisture resistance, and transparency. On the other hand, OPP-based films have a narrower temperature range and tend to shrink more easily. 

4. Polyvinylidene Chloride-coated OPP (KOP)

This film is an OPP film coated with polyvinylidene chloride. It has excellent moisture-proofing, gas-blocking, and aroma-retaining properties. 

5. Polyester (PET)

This film is made by biaxially stretching PET resin to provide strength and heat resistance. It is inferior in gas barrier properties, moisture retention, and impact resistance but is strong, has excellent heat/cold resistance, and has aroma retention properties.

What Is Used Wastewater Treatment Equipment

Used wastewater treatment equipment purifies effluent discharged from industry, agriculture, and other industries, as well as from sewage and other human waste.

Water treatment is an indispensable process in our daily lives in terms of efficient use of water, prevention of environmental pollution, and prevention of odors and other pollution. For this reason, many companies are striving for technological innovation to improve the efficiency of wastewater treatment.

Depending on the type of wastewater, removal of various types of substances is required, including heavy metal removal, organic matter removal, denitrification, and phosphorus removal.

Uses of Used Wastewater Treatment Equipment

Wastewater treatment equipment is used in all industries, including industry, agriculture, livestock, and water treatment plants.

In the industrial field, there is a strong demand for industrial wastewater recycling in Singapore, where water is scarce. Emerging countries such as China, the Middle East, and Southeast Asia require not only wastewater recycling but also sewage purification from the standpoint of environmental pollution prevention.

In the livestock industry, wastewater containing large amounts of livestock feces and urine is discharged in large quantities, so Used Wastewater Treatment Equipment is used to prevent environmental pollution and foul odors.

Principle of Used Wastewater Treatment Equipment

Used wastewater treatment equipment generally performs pretreatment, coagulation/precipitation separation, and filtration of the received sewage, and after adjusting the pH, etc., it is discharged or reused. The wastewater treatment process is divided into two major processes: pretreatment and biological treatment.

1. Pretreatment Process

In the pretreatment process, substances that inhibit biological treatment are removed. Heavy metals (copper, nickel, zinc, etc.) and suspended solids are treated by coagulation and sedimentation.

2. Biological Treatment Process

In the biological treatment process, organic matter is removed from the pretreated water using the decomposition ability of microorganisms. The amount of organic matter in the water is expressed in terms of BOD (biochemical oxygen demand) and COD (chemical oxygen demand), and the water is purified until these values fall below standards.

The activated sludge method is most commonly used in wastewater treatment and water purification plants. The activated sludge method refers to a method in which wastewater is treated by aerobic microorganisms using the dissolved oxygen in the water to break down organic matter through aeration and sedimentation and separation.

Another method is the biological membrane method. In the biological membrane method, microorganisms are attached to carriers to create a membrane-like structure that absorbs and decomposes pollutants in wastewater.

Other Information on Used Wastewater Treatment Equipment

1. Small Used Wastewater Treatment Equipment

Small wastewater treatment equipment is used at construction sites and small factories. This is because the amount of wastewater discharged is small and can be handled on an in-house scale.

Applications include wastewater from detergents, wastewater from grinding, and wastewater from food processing. Because of their small size, they can be transported by 2- to 4-ton trucks and can be easily installed. In addition, the system can perform the series of treatment operations described above, is simple to operate, and requires a low investment cost.

On the other hand, a large amount of domestic and industrial wastewater is discharged every day. Therefore, used wastewater treatment equipment itself is not suitable for use with small wastewater treatment equipment because of its large scale.

2. Used Wastewater Treatment Equipment in Factories

Factory wastewater contains many contaminants. Therefore, treatment equipment should be considered according to the type of pollutant and the wastewater characteristics of each factory.

Types of pollutants
Treatment facilities are considered for each substance, such as oil, organic matter, ammonia, and toxic metals in the treated wastewater. For example, activated sludge facilities are needed to reduce BOD (biochemical oxygen demand) and COD (chemical oxygen demand), while coagulation sedimentation facilities are needed to treat SS (suspended solids).

Wastewater Characteristics of Each Plant
The specifications of equipment differ for each plant because the concentration of hazardous substances in treated water, pH, and other wastewater characteristics are different for each plant, such as food, electronic parts, and petroleum/petrochemical plants. For food factories, these include anaerobic treatment using methane fermentation and filtration using bio-filters.

In the case of electronic component factories, inorganic wastewater and organic wastewater are treated separately because inorganic substances such as fluorine and arsenic are used in large quantities. In addition, the concentration of each toxic substance in the treated water at the plant is determined by the relevant laws and regulations. In order to achieve the required treatment concentration, the specifications of the equipment are determined after the preconditions for the amount of treated water and raw water concentration are established.

What Is an Ultrapure Water System?

An ultrapure water system is a device that produces ultrapure water. Natural water and tap water contain various salts and organic matter and are not ultrapure. In research and development, these impurities are likely to affect the results of experiments. In the manufacturing industry, impurities in water can affect product quality. Therefore, in these fields, ultrapure water from which impurities have been removed is used.

Among pure water, ultrapure water is the one with the highest degree of purity. Water purity is measured based on electrical resistivity. Theoretical purity of water is 18.24 MΩ-cm. In common parlance, ultrapure water is water that has achieved 18 MΩ-cm.

Uses of Ultrapure Water Systems

Ultrapure water is used in the research and development field and in semiconductor manufacturing. In the research and development field, it is often used in biotechnology experiments and clinical trials of pharmaceuticals. In the semiconductor manufacturing industry, it is used for cleaning semiconductor parts and precision equipment.

However, ultrapure water cannot be stored in glass containers or polyethylene tanks. This is because its dissolving capacity is much higher than that of tap water and dissolves containers in minute quantities. Therefore, ultrapure water is produced by an Ultrapure Water System and used only when necessary and in necessary quantities.

Principle of Ultrapure Water Systems

Ultrapure water systems purify tap water to produce ultrapure water. In this section, the principle is explained using a reverse osmosis membrane + ion exchange pure water device as an example. This system uses the three steps of filtration, reverse osmosis, and ion exchange to produce an ultrapure water system.

1. Filtration

Powdered activated carbon filters filter out impurities such as residual chlorine and large debris in the tap water.

2. Reverse Osmosis

Filtered tap water is purified by reverse osmosis. Normally, when aqueous solutions of different concentrations are separated by a semipermeable membrane, water molecules move from the solution of lower concentration to the solution of higher concentration. This is called osmosis.

As water molecules move, a force called osmotic pressure is generated, which eventually reaches equilibrium with the gravitational force on the volume of water moved. In contrast, when a pressure higher than the osmotic pressure is applied, water molecules can be moved from an aqueous solution of higher concentration to aqueous solution of lower concentration. This phenomenon is called reverse osmosis.

In an ultrapure water system, high pressure is applied to tap water to transfer water molecules that do not contain impurities to produce pure water. An osmosis membrane that can purify water molecules by this reverse osmosis phenomenon is called a reverse osmosis membrane. The water purified here is already pure enough to be called pure water.

3. Ion Exchange

The aforementioned inorganic ions contained in trace amounts in pure water are removed by ion exchange. Ion exchange is a method of improving purity through the use of ion exchange resins. Pure water produced by reverse osmosis contains trace amounts of calcium and chlorine ions. By filtering this pure water through an ion exchange resin, the impurity ions are adsorbed by the resin and become ultrapure water.

This is the main principle of the ultrapure water system. Ultrapure water systems are also available that include a UV sterilization system after the ion exchange is completed. There are also various types of products that reuse ion exchange membranes or distill tap water.

Other Information on Ultrapure Water Systems

1. Industrial Applications of Ultrapure Water Systems

An ultrapure water system is used in the cleaning process of semiconductor devices, as mentioned above. If the cleaning water contains microscopic impurities, there is a risk of short-circuiting the circuit. Therefore, the ultrapure water system is an essential part of semiconductor manufacturing technology.

Other uses include water for steam generators in steam turbine generators and water for humidification in factories.

2. Precautions When Using Ultrapure Water Systems

The ultrapure water system is a delicate device, and there are several precautions that must be taken in order to obtain high-purity ultrapure water. As a general rule, water should be collected on an as-needed basis, and the initial flow of water should be drained. This is because there is a risk of contamination of the area around the water sampling port by outside air. To prevent contamination from the environment, it is also necessary to keep the water sampling port clean and to avoid bubbling when sampling.

Ultrapure water is also known as hungry water. The name is derived from its ability to take in substances. Because of this property, its electrical resistivity decreases over time. Therefore, ultrapure water should be used as soon as possible after collection.

What Is a Gun Drill?

A gun drill is a specialized tool designed for deep hole drilling, originally developed for manufacturing gun barrels. It operates by ejecting high-pressure cutting oil through its tip, removing chips during the drilling process, and allowing for the drilling of deep or narrow holes in a single operation. With its excellent linearity, a gun drill is capable of creating precise holes in hard-to-machine materials such as stainless steel and heat-resistant alloys.

Uses of Gun Drills

Gun drills are ideal for drilling holes with depths over five times their diameter, particularly for diameters ranging from 3 to 30 mm. Their ability to eject chips during drilling makes them highly efficient and accurate for deep-hole drilling. Common applications include:

• Food Machinery: Parts for liquid filling machines, coolers, dairy milking machines, and other food processing equipment.
• Transportation Equipment: Components for automobiles, railroad cars, and aircraft.
• Industrial Machinery: Spindles, shafts, cylinders, injectors, hydraulic systems, and gear reducers.
• Electricity: Parts for electrical and electronic devices, semiconductor heat plates, and LCD manufacturing equipment.

Principle of Gun Drills

Gun drills utilize a high-pressure pump to inject cutting oil into the cutting area. The drill’s hollow design facilitates the circulation of cutting fluid, which carries chips out through a V-shaped groove in the drill’s shank. Different drill tip designs, such as kidney or two-hole types, offer variations in oil delivery and head rigidity. The long shanks of gun drills often require a drill bush at the machining point to enhance bending rigidity, ensuring minimal misalignment and high precision in drilling.

Other Information on Gun Drills

1. Gun Drilling Machines

Gun drilling is performed on dedicated machines, which are specialized lathes designed for this process. Unlike traditional lathes, the material is stationary while the gun drill rotates. Continuous injection of cutting oil from the drill’s tip prevents hole blockage and damage to the drill. Gun drills have a driver at their base, allowing them to be held by the machine’s chuck, with cutting fluid supplied through the drill’s shank.

2. Gun Drilling on Machining Centers

While dedicated gun drilling machines are ideal, gun drilling can also be performed on general-purpose machining centers, NC milling machines, and NC lathes for hole depths up to approximately 40 times the hole diameter. These machines must have a center-through coolant function. Due to the gun drill’s cutting-edge design, a pilot hole is typically required to initiate the drilling process to precise specifications.

What Is a Robotic Screwdriver?

A Robotic Screwdriver is a robot that automatically performs screw fastening tasks that were previously performed by a worker.

Robotic Screwdrivers automate screw fastening operations and increase manufacturing efficiency. In addition, the robot’s error detection function detects missing products caused by dropped screws or floating screws due to faulty screw work, enabling stable production.

There are many different types of screw fastening robot systems, including multi-axis robots, SCARA robots, parallel link robots, Cartesian coordinate-type screw fastening robots, dual-arm screw fastening robots, and small table-top types.

Applications of Robotic Screwdrivers

Robotic Screwdrivers are often used in production lines for mass-produced products. Robotic Screwdrivers are used for fastening screws in areas where human labor is inefficient. For example, the robot is useful for fastening machine cases, where many screws are used, or where the screw size is too small to be fastened by hand.

The robot can handle many types of screws, such as pot screws, countersunk screws, truss screws, Semmes screws, and Y recesses. It can also be adapted to hex bolts and hex nuts. A wide range of screw materials are available, including steel materials, aluminum alloys, and resin.

However, there are some areas where it is difficult to utilize Robotic Screwdriver. For example, when there is an obstacle nearby, on an inside surface, or when used in a deep hole. Therefore, it is important to select a model according to the application.

Principle of Robotic Screwdriver

A Robotic Screwdriver mainly consists of a robot, an electric screwdriver, a controller, and a screw feeder.

1. Robot

The robot is a device used to precisely position the electric screwdriver to the part to be fastened. There are various types of robots used for Robotic Screwdriver. SCARA Robots with multi-joints for easy movement and Cartesian Robots are often used.

2. Electric Screwdriver

This is attached to the end of the arm of the robot.

3. Controller

The robot’s position information and the electric screwdriver’s torque, rotation angle, and other information are controlled by the controller. The screw feeder stores screws and supplies them to the Robotic Screwdriver for efficient fastening work.

Other Information on the Robotic Screwdriver

1. Functions of the Robotic Screwdriver

The Robotic Screwdriver has a variety of additional functions to perform the screw fastening operation automatically. First, the controller connected to the electric screwdriver has functions such as torque and rotation angle management, torque and rotation angle control, screw fastening patterns, and good/fail judgment.

The tightening torque and rotation angle are very important information for automating screw fastening operations. Some models are also equipped with sensors to detect abnormalities or defects in the screw parts themselves, such as a screw hole being crushed or jammed. 

2. Coefficient of Friction Important for Screw Fastening

The key to proper screw fastening is to obtain the required axial force. Axial force is the force that holds the screw in place and is generated by the elastic force of the screw as it is pulled back. In normal screw fastening operations, it is not possible to directly check how much axial force was generated for each screw. Therefore, as substitute characteristics, the tightening torque and rotation angle are monitored.

The most common and widely used parameter is the tightening torque. Tightening torque is sometimes specified in assembly drawings of DIY products for the general public. However, proper axial force can only be obtained by tightening a screw with the specified tightening torque if the frictional force generated when fastening the screw is within the expected range.

Specifically, it is the coefficient of friction between the contact surfaces of the screw’s peaks and troughs, and between the head of the screw and the surface on which the screw is seated. If the coefficients of friction in the two areas related to the screw are higher than the expected range, sufficient axial force cannot be obtained even when working with the appropriate tightening torque.

Conversely, if the coefficient of friction is lower than expected, the axial force generated is too high and the screw may break or spin out. It is important to recognize that the tightening torque and rotation angle are only surrogate values for screw fastening, whether done manually or robotically, and that the correct axial force cannot be obtained if the coefficient of friction is not within the assumed range.

What Is Oil Mist Eliminator?

An Oil Mist Eliminator is a device designed to extract the lubricating oil used in metal processing by machine tools. This oil often becomes particulate due to high-speed operation. The device then condenses and discharges the graded oil into an oil outlet, subsequently releasing clean air into the external environment. In the field, it is commonly referred to as a “mist collector.”

Oil mist is harmful to the human body if it gets in the eyes or enters the respiratory tract. It can also create “haze” in the factory, causing poor visibility.

Uses of Oil Mist Eliminator

Oil Mist Eliminators are usually compact and mounted overhead on machine tools, while larger collectors are mounted horizontally on the machine.

The typical use of oil mist removers is to suck up the mist generated by the machine, remove the oil with a filter, and send clean air into the factory.

The filter naturally becomes dirty with oil, so periodic filter cleaning is required. In some cases, the filter itself is not needed, as some types of equipment use a filterless structure.

Principle of Oil Mist Eliminator

There are three main types of Oil Mist Eliminators: the filter method, which removes oil by sucking the aspirated mist through a filter, the electric method, which removes oil by using electrodes attached to the oil by electrostatic force, and the “centrifugal separation type,” in which a disc inside the collector is rotated at high speed and oil is separated by centrifugal force.

1. Filter-Type Oil Mist Eliminator

The filter type Oil Mist Eliminator is characterized by its simple structure, which makes it inexpensive to install. Due to its simple structure, it can be installed on top of the machine, thus taking up less space.

2. Electric Oil Mist Eliminator

Electric Oil Mist Eliminator, on the other hand, is complicated and expensive, but it is filterless and does not require filter replacement. Therefore, it does not generate industrial waste and is easy to maintain. However, because it uses high voltage, it must be handled with care.

3. Centrifugal Oil Mist Eliminator

Centrifugal Oil Mist Eliminator is inexpensive and easy to maintain because its structure is simple and filter-less, just like the filter type. The disadvantage is that it cannot capture particles smaller than 1 µm.

What Is a Shaking Machine?

Figure1. Typical Shaking Machine

A shaking machine is a machine that shakes and agitates a sample in a container, such as a test tube, flask, or aliquot funnel.

It is also called a shaker. Shakers are often used for time-consuming sample separation, elution, dissolution, and cultivation of aerobic microorganisms.

There are various types of shakers, such as reciprocating, swiveling, and figure-8 shakers, as well as horizontal and vertical shaking directions, depending on the model. Some models are equipped with heating and cooling functions, and can also be used for shaking culture.

There are also sieve shakers that can be used to sieve powders as well as liquids.

Uses of Shakers

Shakers are generally used in the life sciences and chemistry for experiments that require long periods of constant shaking. The main applications in the testing field include various dissolution tests, dissolution of samples, and cultivation of aerobic microorganisms.　

In particular, elution tests for soil environmental require the elution of heavy metals in soil by a shaker under specific conditions. In the culture of aerobic microorganisms, the conditions vary depending on the microorganism. It is necessary to calculate the shaking width and shaking speed of the Shaker and to adjust the appropriate oxygen transfer rate.

Other applications include the elution of dioxin and residual pesticides in vegetables with hexane, for example, to test for residual pesticides in food products and to analyze eluted components of industrial waste.

Principle of Shakers

Figure 2. Temperature-controlled shaker

The shaker has a power unit built into the base of the shaking table. The power unit transmits power from the motor to the pulleys via a belt, which converts the rotation of the motor into a reciprocating motion of the shaking table.

Models with a temperature control function have a heater or cooling system under the base. In some cases, the thermostatic bath and shaker are integrated.

Depending on the model, the size of the base can be changed according to the use of the shaker. Some models can be optionally reshaped by placing a special plate for each vessel on top of the base to make it easier to use according to the respective vessel.

Powder sieve shakers use electromagnetic magnets to generate vertical vibrations in the oscillator. A spring adjusts the amplitude of the oscillation, and the sieve is shaken vertically.

Types of Shakers

Figure 3. Various shaking machines

Shakers come in a variety of sizes: small, medium, and large. The choice should be made according to the application and the size and shape of the container. For example, a large shaker should be used for elution tests in soil analysis.

For an in vitro test with a small amount of sample, a small shaker should be selected. In particular, a small shaker should be used when the sample is placed in an incubator for microorganism or cell culture applications. This type of shaker is designed to handle ambient temperatures from about 0 to 50°C and ambient humidity up to about 95% RH.

Most small tabletop shakers fit in the size range of approximately 200 to 300 mm (width) x 180 to 250 mm (depth) x 100 to 170 mm (height). The upper limit of allowable load weight is about 2 kg for most models. Swing types include reciprocating, swiveling, seesaw, horizontal eccentric, figure-8, and other types, with horizontal and vertical directions. Some models incorporate multiple shaking methods that can be switched manually.

Shaking speed can be changed within a range of approximately 20 to 200 rpm. The step- or non-step type depends on the product, and many models have a built-in timer.

What is a Thermal Analyzer?

A thermal analyzer is a generic term for a device that measures changes in a sample when heat is continuously applied to it. It consists of a mechanism for continuously changing the temperature of a sample and a mechanism for detecting and recording the physical properties to be measured. Different analysis names are given to each of these devices depending on the physical property to be measured.

The analyses performed using thermal analyzers include Differential Thermal Analysis (DTA), which analyzes the temperature difference between a measurement sample and a standard sample, Differential Scanning Calorimetry (DSC), which analyzes the difference in calorific values, and DSC Calorimetry (DSC) to analyze differences in heat content, Thermogravimetry (TG) to measure weight changes, and Thermomechanical Analysis (TMA) to measure changes in length.

Uses of Thermal Analyzers

Thermal analysis using a thermal analyzer is used to measure the thermophysical properties of any material. The structure and state of materials change with temperature changes, and the properties and functions of materials change accordingly. Understanding the behavior of materials in response to changes in temperature is very important for controlling properties and quality, and for understanding exothermic/endothermic behavior during reactions.

In a typical thermal analysis, phenomena such as glass transition, crystallization, melting, and decomposition caused by heating are traced graphically with temperature on the horizontal axis and each parameter (weight change, dimensional change, etc.) on the vertical axis. For example, in TG-DTA analysis, by simultaneously measuring the sample weight change when the sample temperature is changed and the temperature difference between the sample and reference material, it is possible to analyze what kind of change occurs at what temperature in the material.

Studies are also conducted to observe changes in morphology by combining thermal analysis with measurements with an optical camera or optical microscope or to analyze gases using gas chromatography simultaneously.

Principle of Thermal Analyzers

A thermal analysis instrument consists of a detection section, a temperature control section, and a data processing section. The detection section is equipped with a “heater,” “sample mounting section,” and “detector,” and it heats and cools the sample and detects its temperature and physical properties.

The configuration of the detector varies depending on the thermal analysis to be performed. DTA and DSC, which measure temperature, measure the temperature difference between a standard and measured substance. The temperature control section controls the heater temperature according to the program set before the measurement. In the data processing section, signals from the detector are input and recorded, and the obtained measurement data is analyzed.

Analysis Methods of Thermal Analyzers

Various methods are used in thermal analysis depending on the characteristics of the object to be analyzed. There are five analysis methods commonly used in thermal analysis: differential thermal analysis (DTA), differential scanning calorimetry (DSC), thermogravimetry (TG), thermomechanical analysis (TMA), and dynamic viscoelasticity measurement (DMA).

The details of each method are as follows:

1. Differential Thermal Analysis (DTA)

When a sample itself undergoes a transition or undergoes some kind of reaction due to a temperature change, a change in the temperature difference from a reference material occurs, and this change is detected. This allows us to detect reaction phenomena such as melting, glass transition, crystallization, vaporization, and sublimation.

The glass transition is sometimes difficult to detect with DTA because the temperature change is more gradual than other state changes. In the case of unknown samples, it is difficult to understand the reaction phenomena by DTA curves alone fully, so data interpretation methods are often used in combination with thermogravimetry (TG).

2. Differential Scanning Calorimetry (DSC)

A reference material and a sample are similarly subjected to temperature changes, and thermocouples detect their respective temperatures. If there is a temperature difference, the temperatures are heated by a heater so that the temperatures are the same. DSC measures the energy required for this heating. This is why it is called differential scanning calorimetry. In general, it can be measured with higher precision than DTA. It can measure transitions, such as melting, glass transition, and crystallization, as well as specific heat capacity. 

3. Thermogravimetric Measurement (TG)

A reference material and a sample are similarly subjected to temperature change, and the weight difference between the reference material and the sample is tracked (a reference material that does not change in weight in the measurement temperature range is used). The sample to be measured undergoes reactions that change its mass, such as sublimation, evaporation, pyrolysis, dehydration, etc., as a result of temperature change. Since not only the weight change but also the sample temperature change can be measured at the same time to detect changes in the state of the sample, analyzers that can simultaneously perform DTA analysis are in widespread use. 

4. Thermo-mechanical Analysis (TMA)

A probe is applied to the sample to detect displacement due to temperature change. Measuring the displacement while changing the load applied to the sample is also possible. The main measurement targets are thermal expansion, thermal contraction, glass transition, curing reaction, and examination of thermal history, which are phenomena in which the shape changes due to temperature change. Melting and crystallization can also be detected because shape changes accompany these reactions. Still, care must be taken to maintain constant contact between the probe and the sample to ensure proper detection.

5. Dynamic Viscoelasticity Measurement (DMA)

A cyclic load is applied to the sample, and the strain generated in the sample is detected and output as a function of temperature or time. This instrument is used to examine glass transition, crystallization, and thermal history, which are reactions involving intramolecular motion and structural changes. The initial state of melting can also be measured, but as with TMA, measurement becomes impossible as melting progresses and the shape changes.

Other information on Thermal Analyzers

Applications of Thermal Analyzers

As mentioned above, the combination of an optical microscope and other devices is applied to various research. In the method of real-time observation of changes in morphology and coloration in combination with optical microscopes, it is possible to observe the white cloudiness of samples associated with crystallization and liquid crystal transition, as well as changes in samples near the temperature of state change.

Other analyzers have been developed to analyze gases produced during heat treatment by combining thermal analyzers with devices such as FT-IR (Fourier Transform Infrared Spectrometry) and MS (Mass Spectrometry). By combining information on thermophysical properties obtained by thermal analysis with information on gases, a deeper understanding of the thermal response of materials can be obtained. In combination with other temperature-generating devices, thermal expansion and contraction can be observed in various situations.

What Is a Glove Box?

A glove box is a device that enables work in a sealed environment by integrating a glove and a sealed container. They are mainly used when performing work where contact with the outside air or humans is undesirable. For example, cell culture work or work involving the handling of gases harmful to the human body.

Glove Box Applications

Glove boxes are used in many laboratories, mainly in the biological field, such as cell culture and in materials research, where contact with the outside air can cause some kind of reaction.

In the field of materials development, in particular, the outside air contains not only oxygen, which causes oxidation but also moisture, which causes corrosion. Therefore, experiments in the open air often cause unexpected reactions, making it an inadequate experimental environment.

In such cases, gloveboxes were invented to allow manual experiments to be conducted while keeping experimental specimens in a space isolated from moisture and oxygen.

Types of Glove Boxes

Glove boxes can be broadly classified into two types based on differences in their internal cleanliness control mechanisms.

1. Vacuum-type Glove Box

One is a glove box in which the internal space is evacuated once and then filled with an inert gas such as nitrogen or argon.

2. Displacement-type Glove Box

The other type of glove box is a displacement glove box, in which the interior is replaced by an inert gas without drawing a vacuum.

The vacuum-type glove box, in which a vacuum is pulled once, can create a space with a high level of cleanliness because impurities such as moisture and oxygen inside the glove box can be wiped out.

In addition, if the sample to be placed in the glove box is very reactive, it is likely to react with the container body and the glove as well. Therefore, to accommodate highly reactive samples, it is necessary to appropriately select a wide range of materials for the body and glove, from plastic to stainless steel.

How to select a Glove Box

In general, a vacuum-type glove box provides a cleaner space but requires a vacuum pump as accessory equipment. These are often expensive and a bit large for simple experiments in which the environment is not severe. For this reason, it is a good idea to start with a displacement-type glove box when using it for experiments that are relatively less dependent on the surrounding environment or when introducing it.

In either case, however, it is important to select materials for the body and glove that are not reactive to the sample you plan to experiment with.

Additional Glove Box information

1. Glove Boxes and Inert Gases

Nitrogen is frequently used as an inert gas, not only in glove boxes. For example, it is used as a purging gas for food packages due to its inert properties, and it is also frequently used in electronics-related factories, such as those in the semiconductor field.

Nitrogen is readily available in the atmosphere at a volume ratio of approximately 78.1%, making it cost-effective. Its specific gravity is 0.97, which is slightly lighter than air = 1.

Argon, on the other hand, is also present in the air, but at only 0.93% by volume. However, it is still the third most abundant gas in the atmosphere. As a noble gas, argon is even less reactive than nitrogen. Its specific gravity of 1.38 makes it heavier than nitrogen or air, so it accumulates in the glove box and pushes air out from above.

Argon gas is required when a more inert environment is required. In addition, maintaining the pressure inside the glove box higher than atmospheric pressure prevents atmospheric air from entering through the slightest gap in the glove box, thus maintaining a cleaner environment.

2. Moisture removal inside the Glove Box

After the inside of the glove box is replaced with inert gas, moisture may be generated when the desired reaction proceeds. Moisture in the glove box is removed by a moisture adsorbent. The adsorbent may be activated carbon or a special material called a molecular sieve.

Molecular Sieve Description
A molecular sieve is a crystalline zeolite. It is a porous crystal, and impurities in the glove box are removed by the adsorption of molecules into these pores. Naturally, the adsorption characteristics can be controlled by changing the crystal structure, so if you want to absorb only specific organic gases, it is important to select a molecular sieve that matches your application.

In recent years, a wide variety of molecular sieves have become available. As mentioned earlier, it is possible to select the adsorption target by controlling its crystallinity. In most cases, adsorption is possible under conditions where the effective diameter of the molecule is <0.3 nm, <0.4 nm, or <0.5 nm.

If all you want to do is to remove moisture, you only need to select those with <0.3nm and it is possible to create an ultra-low humidity atmosphere with a dew point temperature of -76°C or lower (moisture content: 1ppm or lower). A molecular sieve that has absorbed moisture can be regenerated and reused by flowing inert gas or by vacuum heating.

3. Oxygen removal in Glove Boxes

Removing oxygen is also important when an anaerobic environment is required or when handling materials that are highly reactive to oxygen.

Two types of catalysts can be used to remove oxygen: oxygen adsorbents such as nickel and copper and precious metal catalysts such as palladium and platinum.

When oxygen adsorbents are used, an inert gas containing several percent hydrogens must be passed through the catalyst to regenerate it, whereas precious metal catalysts do not require a regeneration gas during regeneration. Although the introduction cost of precious metal-based catalysts is higher, they are safer and have lower running costs because they do not use hydrogen-mixed gas.

4. Points to note when using a Glove Box

Due to the sealed nature of the glove box, dirt tends to accumulate inside the glove box due to reagents, etc. Therefore, it is necessary to clean the inside of the glove box to prevent contamination.

In addition, although the glove box can create an atmosphere of less than the ppm order in terms of moisture and oxygen, the environment deteriorates rapidly if only a small amount of air is introduced. To maintain a strict environment inside the glove box, it is important to remove moisture and oxygen properly when reagents are placed inside the glove box and to perform regular maintenance to prevent holes in the gloves.