月: 2022年12月

What Is a Spin Coater?

A spin coater is a device used to apply paint to the surface of a substrate. After a drop of paint is applied to the center of the substrate, the substrate is rotated while controlling the acceleration and rotation speed to create a film with a uniform thickness using centrifugal force.

Although there are some disadvantages, such as the fact that it can only be used on smooth base materials and is not suitable for coating large areas, it can form a variety of thin films with minimal thickness error. This equipment is used for manufacturing semiconductors and displays, coating optical media, etc.

Uses of Spin Coaters

Spin coaters can be used to produce thin films of uniform thickness on smooth substrates.

Spin coaters are used in the field of photolithography. Photolithography is a technology that creates fine patterns on the surface of a substrate, such as a silicon substrate, by applying a photosensitive agent to the substrate and then irradiating it with intense light, such as ultraviolet light. This technology is indispensable for the manufacture of semiconductors and displays.

It is also widely used for coating the surface of optical media such as DVDs and Blu-ray Discs, and for applying light-dimming solutions to lenses.

Principles of Spin Coaters

A spin coater is a coating system that uses centrifugal force generated by rotation to coat the surface of a substrate. It is also known as a spinner. It is a coating method suitable for producing thin films on flat substrates, and is characterized by its uniform evenness in film thickness.

First, the substrate is set in the spin coater, and a drop of coating material is applied near the center of the substrate. Next, the substrate is rotated to apply centrifugal force to the paint and adjust it so that the paint is diffusely applied to the substrate surface. Rotation speed and acceleration can be set by the equipment and should be determined considering the paint’s liquid properties and film thickness. After the rotation is completed, the substrate is removed from the spin coater, and the coating is dried by heating or UV curing. Through these series of operations, a uniform thin film can be produced on the substrate.

The advantages of thin film coating with a spin coater include the ability to form thin films of various thicknesses by precisely setting the liquid nature of the coating, the number of revolutions, and other parameters, and the ability to use a smaller amount of coating material. On the other hand, the disadvantages include the loss of paint during coating and the limitation of coating to a small area.

How to Use Spin Coaters

A spin coater is used to generate a thin film from a compound. Here we explain how to use it.

1. The base in the center of the spin coater is the rotating element. A glass or metal substrate is set on this rotor. The way to fix the substrate to the rotating body is to pull a vacuum to fix the substrate to the pedestal. If a vacuum is not desirable, use double-sided tape or other adhesive tape, but be sure to use highly adhesive tape.
2. Pour the polymer or other compound solution onto the substrate. Pour the solution evenly so that the entire substrate is covered as much as possible.
3. Set the rotation speed and rotation time, and press the start button. When the time is up, the rotation stops, and a uniform thin film is formed on the substrate.

Incidentally, there is a vacuum evaporation system for the same thin film creation. However, polymers and other materials may decompose in a vacuum, making a spin coater suitable in this case.

Other Information on Spin Coaters

1. Eliminating Coating Irregularities with Spin Coaters

Spin coaters produce a uniform thin film, but there are cases where unevenness in the coating occurs, resulting in invisible irregularities. The following are some conditions that can cause coating irregularities.

• Slow rotation speed (fewer revolutions over time)
• High viscosity of the compound solution
• Heaping of the solution is observed at the corners of the substrate

First, the rotational speed is an issue. In basic spin coaters, the slower the rotational speed, the thicker and more non-uniform the film is likely to be. The easiest solution is to increase the rotation speed and extend the rotation time. If you have time, fix the rotation time and measure the film thickness at each rotation speed. The best solution is to find the optimal rotation speed and time.

If the viscosity of the compound solution is high, it will be difficult to spread evenly, resulting in a non-uniform film. One way to deal with this is to dilute the solution concentration to reduce viscosity.

To address the problem of non-uniformity in the corners of the substrate, it is best to use a closed-type spin coater with an automatic drop function. The automatic drop function automatically dispenses the compound solution onto the spinning substrate. The solution spreads quickly to the substrate as soon as it is dispensed, preventing the corners from rising and enabling the formation of a uniform thin film.

What Is a Spiral Pipe?

A spiral pipe, also known as a spiral duct, is manufactured by spirally winding a strip of steel into a duct shape. This method results in a robust and efficient design for various applications.

These pipes can also be made through pressing, deep drawing, or other manufacturing methods, depending on the required specifications.

Their design, featuring overlapping steel strips in a spiral pattern, enhances the strength of the pipe, making it suitable for demanding applications.

Spiral pipes are commonly used as air conditioning ducts in building equipment construction due to their efficient airflow characteristics.

They are preferred for their smooth inner surfaces that minimize pressure loss, and their ease of installation and connection.

Available in various materials like hot-dip galvanized steel, stainless steel, galvalume steel sheets, and PVC, they cater to diverse needs.

Uses of Spiral Pipes

Spiral pipes are versatile and used extensively as air conditioning ducts across various settings:

• In industrial environments like petrochemical and pulp manufacturing plants, semiconductor factories, and chemical and gas processing facilities.
• For specialized applications in hospitals, retail buildings, and sewage treatment plants.
• In residential settings for chimneys, water heater boilers, and ventilation systems.

Characteristics of Spiral Pipes

Spiral pipes are known for their high strength, low friction loss, and leak resistance:

• The spiral construction reinforces the duct, making it ideal for high-speed air, dust collection, and smoke exhaust systems.
• Their roundness and smooth inner surface reduce air resistance and friction loss, leading to more efficient airflow.
• Compared to square ducts, spiral pipes have lower leakage rates, thanks to their spiral fittings.
• Ease of installation and material versatility make them suitable for a wide range of applications.

What Is a Straight Grinder?

Straight grinders are hand-held grinders and are also known as portable or hand grinders. They are distinct from disk grinders, and operate by rotating a spindle with a cylindrical grinding wheel at high speeds, making them suitable for grinding, polishing, and deburring tasks.

Commonly used in both manufacturing and DIY projects, straight grinders excel in finishing small parts and working on surfaces unsuitable for disk grinders.

Uses of Straight Grinders

As a versatile type of grinder, straight grinders are employed for cutting, polishing, and deburring various materials, particularly metals. They are adept in finishing intricate tasks such as deburring castings, welding finishes, and heavy-duty grinding. Their suitability for grinding on inclined surfaces and removing weld beads makes them preferable in certain scenarios over disk grinders.

Principles of Straight Grinders

While structurally different from disk grinders, straight grinders serve similar functions. They feature a small, replaceable cylindrical grinding wheel on a rotating spindle, in contrast to the larger disk-shaped wheel of disk grinders. The choice between the two types often depends on the material and size of the workpiece.

Due to the risks associated with their high-speed operation, safety laws require users to complete special training. This training is essential for new employees and transferees before they begin working with grinders. Additionally, it is recommended to have detailed procedures and manuals for grinder use, and to initially work under the supervision of experienced workers.

What Is a Stripper?

A stripper is a tool used to cut off the end of the vinyl or other covering partially from a wire coated with vinyl or another material. This tool is generally referred to as a wire stripper.

The wire stripper is similar in shape to a pair of needle-nose pliers. The wire is placed between the jaws of the wire stripper, and then it is gripped tightly or pulled to remove the insulation or covering.

Some types of wire strippers also function as nippers.

Uses of Strippers

There are two types of wire strippers: manual and automatic, depending on the application and cost.

On the other hand, various methods can be used to remove the insulation from a wire, such as using a utility knife or a combination of nippers and needle-nose pliers, especially for wires that are not typically coated.

Nippers and pliers are basic tools required for electrical work and circuit design verification, so you will almost always have them on hand.

Therefore, using these tools is an effective method when, for example, work must be done on the go and the number of tools you can carry is limited, or when you do not have a dedicated wire stripper available.

Principles of Strippers

Using these tools as wire strippers requires a certain amount of skill.

Whether using nippers and needle-nose pliers or a utility knife, applying the right amount of force is crucial to prevent damaging the wire.

Improper handling may result in the wire becoming thin or, in the worst case, breaking during use.

Therefore, sufficient practice is required before using the methods mentioned above.

Finally, let’s explain how manual and automatic strippers work.

As mentioned earlier, a manual stripper involves inserting the wire into the jaws of the tool at the position where the insulation needs to be removed. The wire is secured in place by closing the jaws. To remove the insulation, the user firmly grips the stripper and moves it in the direction of the wire’s end that needs to be stripped.

Automatic strippers operate in a similar way to manual strippers: the wire is clamped in the jaws of the tool at the position where the insulation needs to be removed. The jaws are selected according to the wire’s thickness. When the user firmly grips the body of the stripper, the spring mechanism automatically separates the insulation from the wire.

What Is Stainless Steel Wire?

Stainless steel wire is a wire-like material made of stainless steel.

It has the characteristic of being more resistant to rust than other metals and alloys. Stainless steel, the main material used in stainless steel wire, has, in addition to corrosion resistance, additional properties such as high strength and heat resistance, as well as excellent workability. For this reason, it is used in a wide variety of fields and applications.

Depending on the type of stainless steel, it can be modified to meet the specifications of the application by adding treatments such as heat treatment and annealing.

Uses of Stainless Steel Wire

Stainless steel wire is used in a very wide range of applications, taking advantage of its various features, such as corrosion resistance, heat resistance, strength, and hygiene. In terms of industry fields, stainless steel wire is used in the automotive industry, food industry, construction industry, energy industry, electronic components, and medical industry.

Specifically, it is used for parts in automobiles and smartphones, taking advantage of its corrosion and heat resistance. It is also used for parts of medical equipment and surgical tools due to its hygienic and high-strength characteristics. Stainless steel wire netting is also used for barbecued meat due to its hygienic and high heat resistance characteristics.

Principle of Stainless Steel Wire

Stainless steel wire is a steel wire with high corrosion resistance and strength, because the properties of stainless steel are not compromised and its characteristics are utilized in the processing of the wire. Stainless steel is an alloy made by adding at least 10.5% chromium, nickel, molybdenum, titanium, etc. to iron, which is the main component.

Chromium combines with oxygen to form a thin protective film on the surface of the steel, and this coating makes stainless steel corrosion resistant. This film, called a passive film, is very thin (about 3 parts per million), but it is very tough, and even if it breaks off once, it can regenerate automatically if there is oxygen around it. It also protects the interior from corrosion.

After surface treatments such as rust removal and coating addition, stainless steel is drawn into wire under computer control to produce steel wire to the specified specifications.

Other Information on Stainless Steel Wire

1. Stainless Steel Wire Standards

The 35 types of steel wire are classified into 35 categories based on composition, manufacturing method, and characteristics, and are indicated by adopting a symbol combining an alphabetic part and a numeric part, such as SUS201. The austenitic type is about 18wt% and the ferritic type is about 18wt%.

Austenitic steel wire contains about 18 wt% chrome and about 8 wt% nickel. Ferritic and martensitic steel wires contain about 17 wt% and 13 wt% of chrome, respectively. These composition ratios vary slightly depending on the type of steel wire.

There are also distinctions such as soft No. 1 and soft No. 2 depending on whether the steel wire is tempered or not. Tempering refers to heat treatment or wire drawing treatment of steel wire. Soft No. 1 is steel wire that has been drawn and heat-treated for solution treatment. For soft No. 2, austenitic steel wire is drawn after heat treatment for solution treatment, and ferritic and martensitic steel wire is drawn after annealing.

2. Difference Between Stainless Steel Wire, Hard Steel Wire, and Piano Wire

Hard steel wire and piano wire are similar to stainless steel wire. The major difference between hard steel wire and piano wire is the difference in quality: both are made from steel, but piano wire is specified to contain fewer impurities such as phosphorus, sulfur, and copper than hard steel wire.

In addition, piano wire is specified with respect to flaw depth in corrosion tests and total coal layer depth in decarburization detection tests. Piano wire is also very strict regarding physical properties such as tensile strength and wire diameter. Since piano wire requires a higher level of quality than hard steel wire, the price is correspondingly higher.

On the other hand, unlike piano wire and steel wire, stainless steel wire has regulations regarding the composition ratio of chromium and nickel. Piano wire and steel wire rust, while stainless steel wire has superior corrosion resistance and heat resistance.

What Is a Step Attenuator?

An attenuator is a circuit or device that can attenuate a signal by a specified amount without distorting it.

There are two types of attenuators: fixed and continuously variable attenuators, in addition to step attenuators.

A fixed attenuator attenuates the signal by a fixed amount, while a variable attenuator can vary the attenuation linearly, and a step attenuator can vary the attenuation in steps.

Although there are several types of attenuators, the purpose of attenuating signals remains the same. Therefore, in the following explanations, unless otherwise specified, all explanations will be common to all attenuators. Expressions such as step attenuator will only be used when necessary.

Uses of Step Attenuators

Typical applications of attenuators are signal level adjustment and impedance matching.

Suppose the signal level is too high for the input signal when connecting to a subsequent circuit or device. In that case, it is used as a signal level adjustment function to adjust the signal level to an appropriate level and send it to the subsequent stage.

If the impedances of the sender and receiver do not match when an input signal connects to a circuit in a subsequent stage, noise or signal reflection may occur, which may result in inconvenience to the expected operation. The step attenuator is used as an impedance-matching function to prevent such inconveniences.

Principle of Step Attenuators

An attenuator has a structure called a T-type circuit or N-type circuit that combines resistors.

In addition, to obtain a specified amount of attenuation, a T-type or N-type circuit may be configured by connecting multiple stages of each of these circuits in a dependent manner.

If the purpose is to attenuate the signal, the objective can be fulfilled by inserting an appropriate resistor.

For example, consider the case of a TV receiver used to measure the reception performance of TV broadcasts.

The reception conditions may be made worse by attenuating the strength of the incoming radio signal in steps using a step attenuator. The receiver evaluates the level of input signal attenuation to see if it can be received without problems and if the amount of attenuation meets the design target value.

In this case, digital terrestrial broadcasting sends broadcast signals in the 470 to 710 MHz range, and these frequencies are input to the TV set. Therefore, since it is necessary to attenuate the signal flatly at all frequencies, resistors cannot be used for this type of test, and a step attenuator is required.

Thus, attenuators in high-frequency circuits must attenuate while maintaining impedance.

Overview of Stud Welding Equipment

Stud welding equipment efficiently welds studs—like nuts and bolts—to various metal surfaces. This welding technique is valued for its quick operation and strong welds, offering consistent quality regardless of operator skill.

Applications

These machines are indispensable across multiple sectors, including automotive, construction, and manufacturing. They play a crucial role in attaching components to metal sheets in electronics, vehicles, and building foundations, where durability is paramount.

Operating Principles

Stud welding involves placing a stud between the equipment’s electrodes and applying current, creating a robust weld in moments. It encompasses several methods:

• Power Arc: Ideal for thick materials, providing high-strength welds using direct current.
• Short Cycle: A quicker variant of the power arc, often used in the automotive sector for galvanized metals.
• Capacitor Discharge: Utilizes stored energy for rapid welds, suitable for thin or non-steel materials.

Benefits

Stud welding equipment offers high-speed welding, minimal distortion, and consistent quality, enhancing productivity across various applications. Its ability to produce clean welds with minimal markings makes it a preferred choice for many industries.

What Is a Cylindrical Lens?

A cylinder lens is a lens in the shape of a cylinder (cylindrical). It has a mantle shape with a portion of the side surface of the cylinder cut out.

The incident plane of the lens is divided into two components, the x-axis, and the y-axis. Only one axis has a curvature that acts as a lens, while the other has no curvature and acts merely as a window. Therefore, only one direction of the image is enlarged or reduced.

This is used to change the magnification of the image in only one direction.

Uses of Cylindrical Lenses

Cylinder lenses convert a laser beam into a line (laser line generator) to focus light on a slit aperture or line sensor. They can also collimate an elliptical beam of a semiconductor laser with different spread angles in two orthogonal directions into a circular beam to obtain a parallel beam (collimating).

For image processing applications, it is used to correct astigmatism and to enlarge or reduce the height of an image in only one axis direction.

Specifically, they have significant roles in laser printers, photocopiers, barcode scanning, laser projectors, holography equipment, laser markers, etc.

Principles of Cylindrical Lenses

Cylindrical lenses can have a variety of shapes, including rectangular, square, circular, and elliptical. Plano-convex shapes diverge light, while plano-convex shapes focus light. Extending the total length of a cylindrical lens along a non-curvature axis does not affect the optical power of the lens.

For example, when a narrow laser beam is injected into a cylindrical lens, a flat laser beam is emitted because the beam is diffused in the direction with curvature (direction perpendicular to the matrix). In contrast, in the direction without curvature (along the matrix), the beam is the thickness of the original laser beam.

When looking at the laser surface spread like a sheet with a camera, objects crossing the sheet will shine through, and the position, size, and speed of these objects can be examined. A typical example is the Particle Image Velocimetry (PIV) method.

Also, when a sheet of light is shone on a wall, a straight line is drawn, which can be combined with a level to project a highly accurate horizontal line. This is called a laser marker and is utilized on construction sites.

What Is a Syringe Filling Machine?

Syringe filling machines are devices designed to accurately dispense materials into syringes for various applications, ensuring high efficiency and purity during the filling process. These machines are capable of handling different types of materials, including medium to high viscosity fluids and materials sensitive to contamination or air bubble infiltration.

Applications of Syringe Filling Machines

These machines find extensive use across several industries, notably in:

• Dental industry for filling materials like resin cements and silicone impression materials.
• Electronics manufacturing for dispensing conductive materials, silver paste, and other electronic component materials.

How Syringe Filling Machines Work

Syringe filling machines are available in manual and automatic models, primarily utilizing a downward filling approach. This method involves setting the syringe tip downwards and filling it by applying pressure from the bottom. The machines are designed to prevent air bubble entrapment and material contamination, ensuring accurate and clean filling.

Key Features

Key benefits of using syringe filling machines include:

• Prevention of bubbles and impurities.
• High reproducibility of filling volumes to eliminate wastage.
• Capacity to fill syringes ranging from 3 ml to 180 ml.
• Simple design for easy cleaning and maintenance.

Types of Syringe Filling Machines

The choice of syringe filling machine depends on the specific application and material characteristics. Options include:

• Machines capable of simultaneously filling multiple syringes.
• Vacuum-equipped machines for handling high-sealing plungers.
• Fully automated systems with integrated filling and vacuum pressure control.
• Models designed for two-component materials, filling twin syringes separately.
• Machines with material heating options to reduce viscosity and speed up the filling process.

Selecting the right syringe filling machine involves considering the material’s properties, the required filling volume, and the specific industry application to ensure optimal performance and efficiency.

What Is a Syringe?

Figure 1. Image of a syringe

A syringe is the cylindrical part of a syringe, excluding the needle and plunger, used to fill the syringe with liquid. It is also called a syringe tube or outer tube. Currently, disposable plastic (polypropylene) syringes are the most common, but glass (borosilicate glass) syringes are also used as needed.

Uses of Syringes

Uses of syringes can be divided into two main categories: medical and laboratory. Plastic syringes, which are currently mainstream, are sterilized and packaged individually and are disposable. This prevents infection in the medical field and contamination in chemical experiments. Since plastic syringes cannot be heat sterilized, ethylene oxide gas sterilization or radiation (gamma ray) sterilization is used. On the other hand, glass syringes are used in the following cases. In this case, medical glass syringes are sterilized and used repeatedly for each specification.

• In the medical field, when there are concerns about drug adsorption or leakage of resin additives in plastic syringes
• When there is a risk of resin dissolving in organic solvents, such as in organic chemistry experiments.

1. Uses of Medical Syringes

In medical applications, syringes are mainly used for blood sampling, drug injection, and enemas. Pre-filled syringes may be used to inject drugs such as immunizations to prevent infection and improve work efficiency.

2. Uses of Laboratory Syringes

In addition to medical use, syringes are also used as experimental instruments in physics, chemistry, and life sciences. Their main uses include the injection of liquids and gases, volume measurement, pressurization and depressurization, dripping, and dispensing.

Principles of Syringes

Figure 2. Image of a syringe in use

Syringes are usually used with a movable plunger (pusher) with a needle attached to the tip. Syringes come in various capacities, but the size and shape of the connection to the needle are standardized regardless of the capacity. Therefore, needles of any size and length can be attached.

Types of Syringes

Syringes can be classified according to the shape of the tip and the position of the needle connection.

1. Classification by Tip Shape

• Luer-Lock Type: The part where the needle is attached is threaded and can be secured to prevent the needle from falling out.
• Luer-Tip Type: The needle is secured in place using the taper of the needle attachment portion. The advantage is that the needle is easy to attach and detach.
• Luer Metal Type: The tip is made of metal and has high strength.
• Enema Type: This shape is found in devices such as enemas used for enema and bladder cleansing. The tip is slightly rounded for insertion into the body.
• Catheter Tip Type: The tip of a catheter syringe for connection to a catheter is thicker than the tip of a regular syringe for injection. The shapes of the catheter syringes and syringe tips are different to prevent fluid administration errors due to the mistaken use of catheter syringes and syringes for injectable syringes.

2. Classification According to the Position of the Needle Connection

• Middle-Mouth Type: The connection part is located in the center of the tube. The middle-mouth type is commonly used for small syringes with a 10 ml or less capacity.
• Side Mouth Type: The connection part is located off-center of the cylinder. Even syringes with large capacities can become punctured at a shallow angle. Also, the tip is located at the end, which makes it easier to release air.