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What Are Integrated Circuits?

Integrated Circuits are electronic components that are loaded with a concentration of circuits.

Often abbreviated as IC, it is an electronic circuit in which a number of electronic elements with various functions are assembled on a single semiconductor substrate and connected to each other by internal wiring to perform a specific function.

A circuit consists of multiple circuit elements and the wiring that connects them. These circuit elements are mainly resistors, capacitors, and transistors. By combining all of these elements and wiring into a single substrate (chip), the level of integration is increased.

ICs are used in all kinds of electrical products in the world, and the miniaturization of ICs has enabled us to use compact and convenient products such as smartphones.

Among ICs, large scale ICs with 100,000 to 10 million elements are called LSI (Large Scale Integrated).

Before the development of Integrated Circuits, each electronic element (resistor, diode, capacitor, transistor, etc.) had to be mounted individually on a printed circuit board and connected by external wiring.

In contrast, in popular semiconductor circuits, capacitors and resistors (passive elements) and diodes and transistors (active elements) are placed on a single-crystal silicon semiconductor substrate and connected to each other by internal wiring. Compared to the age of the ore radio, the size has been miniaturized to less than 1/30,000th of its original size and less than 1/1 billionth of its area.

How Integrated Circuits Work

Integrated Circuits are made of semiconductors. A semiconductor is a substance that is between a conductor and an insulator and has the property of conducting a small amount of electricity. There are various types of semiconductors, but in general ICs are made of silicon.

By combining pure silicon crystals with a mixture of impurity atoms, transistors can be made in which the flow of electricity (electrons) can be controlled. Large-scale combinations of these transistors can be used to assemble logic circuits that perform calculations and processing. Resistors, capacitors, and wiring can also be manufactured by processing silicon in the same way.

In the manufacturing process, hundreds to thousands of Integrated Circuits are baked at a time on silicon crystal disks called wafers using optical equipment in a clean facility called a clean room. Then, they are separated into individual pieces, wires are attached to connect them to the outside world, and packaging is completed.

Types of Integrated Circuits

1. Typical IC Types

• CPU
  The CPU is the brain of a computer and is responsible for control and arithmetic operations. The control section manages the order of processing and the data to be handled, and the arithmetic section processes the data.
• GPU
  A GPU is a processor used to draw on a display. Integrated Circuits for color display, etc., are often used in AI because these circuits are similar to those used in neural networks.
• FPGA
  FPGAs are ICs that allow users to freely build their own original circuits through programming. Integrated Circuits include many logic circuits, switches, and memory.
• SRAM
  SRAM is used as a cache due to its high speed operation. A cache is a memory built into the CPU that stores only frequently accessed data.
• DRAM
  DRAM is used as main memory. It stores running program code, data being worked on, etc.
• Flash memory
  Flash memory is used as memory for storage, including USB memory and SSD.

2. Basic Structure Type

• Semiconductor Integrated Circuits
  A large number of various passive and active elements are incorporated on the same semiconductor substrate and connected by internal wiring.
• Membrane Integrated Circuits
  Passive elements such as resistors and capacitors in the form of a film are embedded on an insulating substrate and connected by internal wiring. Integrated Circuits are classified into Thin-Film Integrated Circuits and Thick-Film Integrated Circuits based on the thickness of the element film.
• Mixed Integrated Circuits
  Also called hybrid ICs, these circuits incorporate additional active elements such as diodes and transistors in the film Integrated Circuits and connect them with external wiring. Integrated Circuits can also be divided into Silicon ICs and Compound ICs based on the substrate material.

Types of Roles

• Memory IC
  A semiconductor that can store a variety of information and retrieve it when needed. (DRAM, SRAM, etc.)
• Microcomputer IC
  As the central processing unit (CPU) of a computer, it controls peripheral devices such as input/output devices.
• ASIC
  A dedicated IC for a specific application. There are cases in which they are designed from scratch for each individual application or only the wiring circuits are modified, which has the disadvantage of high cost and long delivery time.
• System LSI
  An IC that contains CPU, memory, logic, peripheral circuits, etc., on a single chip.

What Is a Transformer?

A transformer is a static induction device that uses electromagnetic induction to convert an alternating voltage or current to a desired value.

Generally, a transformer that steps down voltage is known simply as a transformer, while a transformer that steps up a voltage is called a step-up transformer.

Transformers consist of an iron core and windings. They have two windings wound around a ring-shaped iron core. The winding connected to the power supply is called the primary winding, and the winding connected to the load side is called the secondary winding. The characteristic of a transformer is that it generates heat when in use due to iron loss and winding resistance, so energy is consumed by heat and output is reduced.

Transformers with a capacity of 50 kVA or less are defined as small capacity, those with a capacity of 500 kVA or less are defined as medium capacity, and those with a capacity of over 500 kVA are defined as large capacity, but the range is vague and undefined. They can also be referred to as low voltage, high voltage, ultra high voltage, extra high voltage, etc., depending on the voltage used.

Types of Transformers

There are various types of transformers, classified by structure, refrigerant, and cooling method.

Classification by Structure

• Internal Iron Type Transformer: This type has the iron core inside the windings and is widely used because it is easy to manufacture and maintain and is resistant to mechanical stress.
• Outer Iron Transformers: These transformers have the iron core on the outside of the windings and are difficult to manufacture and maintain. The outer iron type is mainly used for low-voltage and high-current applications.

2. Classification by Cooling Medium

• Oil-Filled Transformers: Insulation is achieved by enclosing mineral oil or synthetic insulating oil in a tank, which cools and insulates at the same time.
• Dry-Type Transformers: These transformers use air or gas (SF6: sulfur hexafluoride gas) as a refrigerant and are often used in small transformers.

3. Classification by Cooling Method

There are three types of refrigerant cooling methods for both oil-filled and dry-type transformers.

• Self-Cooling Type: Cooling is done by natural convection of the refrigerant.
• Water-Cooled: Cooling water is circulated to dissipate heat.
• Wind-Cooling Method: This method cools by forcibly blowing air through a fan.

In addition to the above, the classification can be made in detail according to the number of phases, insulation method, heat resistance class, etc., but the three main types are listed above. Although transformers are sometimes classified according to their intended use, the structure of transformers is the same only that the designation changes depending on the place of use and how the transformer is used.

Principle of Transformers

When an AC voltage is applied to the primary winding of a transformer, a magnetic flux is generated in the iron core, and when the generated flux passes through the iron core and crosses the secondary winding, an induced electromotive force is generated.

When the primary voltage (V1), secondary voltage (V2), number of primary windings (n1), and number of secondary windings (n2) are used, the relationship V1/V2 = n1/n2 is established. The output voltage is proportional to the turn ratio, and any desired voltage can be obtained by changing the primary voltage or the number of windings (e.g., tap switching).

What Are Circuit Boards?

A board is a component that serves as the foundation for creating a circuit by connecting multiple electronic components with wires.

There is also a universal board, which can be connected simply by inserting jumper wires or components and can be used to create your own circuits in a simplified manner.

A printed circuit board (PCB) is an insulator with copper wiring patterns and pads for connecting electronic components on its surface, and electronic circuits are completed by connecting electronic components with solder. Similar to ICs, printed circuit boards can be designed using CAD and mass-produced by manufacturing equipment in the image of literally printing.

They are used in a wide variety of devices ranging from small electronic devices such as smartphones to servers, industrial equipment, and automobiles, making them indispensable components for modern society.

Circuit Board Materials

To accommodate a wide variety of products, printed circuit boards are available in a variety of materials.

1. FR-1,2 (Paper Phenol Substrate)

Used as single-sided boards for white goods, remote controls, etc.

2. FR-3 (Paper Epoxy Substrate)

Similar to paper phenolic substrates, FR-3 is used as a single-sided substrate, and is used for high-voltage circuits and circuits that require moisture resistance.

3. FR-4,5 (Glass Epoxy Substrate)

Most multilayer boards are made using this material. FR-5 has high heat resistance and is used for automotive applications.

4. CEM-3 (Glass Composite Substrate)

Although CEM-3 has inferior mechanical properties and stability to glass epoxy substrates, it can be manufactured at a lower cost and is used as a double-sided substrate for products that cannot be handled with a single-sided substrate. They are used in home appliances and audio/visual equipment.

5. Glass Polyimide Substrate

With its excellent flexibility and heat resistance, a glass polyimide substrate is used as a flexible substrate.

Circuit Board Classification

First, printed circuit boards are broadly classified into two categories according to material: rigid rigid substrates and soft flexible substrates. When simply referring to a board, rigid boards are generally referred to. Flexible substrates are thin and bendable, so they are widely used in thin products and moving parts such as robots. In addition, there are other classifications based on the number of layers and structure as shown below.

1. Single-Sided Substrate

Wiring and electronic components are mounted on one side of the board. Although complex circuits cannot be mounted, they can be manufactured at low cost.

2. Double-Sided Substrate

This is a board on which wiring and electronic components are mounted on both sides of the board. Compared to single-sided boards, more complex circuits can be mounted.

3. Multilayer Board

This is a board in which wiring is formed not only on both sides of the board but also inside the board. The boards are stacked using an adhesive sheet called prepreg to form a single board.

4. Build-Up Substrate

This is fabricated by repeating via processing and wiring formation for each layer. This is a multilayer substrate consisting of 4 to 10 layers, with 1 to 3 wiring layers formed on each of the front and back surfaces of 2 to 4 layers of a substrate called a core substrate.

5. Thick Copper Substrate

This type of substrate is used in equipment that handles large currents. To cope with high current, the thickness of copper used for the wiring pattern is increased. They are used in industrial machinery, machine tools, trains, automobiles, etc.

What Are Machining Tools?

Machining Tools refers to equipment that processes materials using cutting tools. etc. In this article, machining is defined as the act of cutting, polishing, etc., of a material, and the term machining tool refers to the equipment used to perform the machining process.

There are various types of machining tools, depending on differences in processing methods and cutting tools. Familiar examples include electric drills for drilling holes in wood and steel plates, and electric screwdrivers for tightening and loosening screws at high speed. Large-scale machine tools include drilling machines, which are larger versions of electric drills used in the manufacturing industry; machining centers, which are used for drilling and plane grinding; and grinders, which polish the surface of materials.

Types of Processing Methods

Machining methods can be broadly divided into two types: cutting and grinding.

1. Cutting

Cutting is a processing method in which a cutting tool is used to shave a material. There are two types of grinding methods: one is to rotate the cutting tool side and the other is to rotate the material side. The method that rotates the cutting tool side is often used for grinding flat surfaces or making holes, while the method that rotates the material is suitable for making cylindrical objects.

2. Grinding

Grinding refers to a processing method in which a grinding wheel is used to shave or polish the surface of a material. It is used to remove corners and make surfaces smooth and shiny.

Types of Machine Tools

The following are typical types of machine tools. In this article, the table on which the material is fixed is referred to as a table.

1. Drilling Machine

A drilling machine is a machine tool that combines an electric drill and a table. A material is fixed to the table and the drill is rotated and applied to the material for the purpose of making holes. A tool called a tapper can also be used to cut screws.

2. Milling Machine

Milling machines are used to cut materials by fixing materials to a table and rotating cutting tools such as drills, end mills, and milling cutters. By changing the cutting tools, a wide range of machining is possible. 

3. Machining Center

A machining center is a machine tool that is equipped with an automatic tool changer (ATC device) on a milling machine, which enables automatic operation by moving the tool and table under program control. 

4. Lathe

A lathe is a machine tool that rotates a table on which a material is fixed and applies a fixed cutting tool called a bite to cut the material. It is suitable for making cylindrical objects. 

5. NC Lathe

An NC Lathe is a machine tool that is equipped with an ATC device on the lathe, and the cutting tools are moved by a program to enable automatic operation.

6. Grinder

A grinder can shave the surface of materials by rotating a grinding wheel. Grinders are used to remove corners and thin the thickness of materials. There are two types of grinders: a small type that is hand-held and applies the grinding wheel to the material, and a type that applies the material to the grinding wheel installed on the machine.

7. Grinding

Grinding machines are used to sharpen or polish a material by fixing the material on a table and repeatedly moving a rotating grinding wheel back and forth over the material. It has high accuracy and is mainly used for surface finishing.

What Is FA Equipment?

FA (Factory Automation) Equipment is a general term for devices and systems that automate production lines and inspections in factories, etc.

FA Equipment can be used to increase productivity per hour because it can operate much faster than human processing speed. In addition, it also leads to cost reductions through labor savings, which is why demand for this equipment is increasing worldwide. Also, the equipment can efficiently detect defects that cannot be detected by the human eye during product inspections, thereby reducing the percentage of defective products and improving the product yield rate.

Types of FA Equipment

There are various types of FA Equipment, ranging from large-scale equipment that completely automates a production line to controller-type equipment that can be connected to existing equipment to perform programmed operations.

Currently, full automation of production lines is not very realistic due to the high cost involved. In fact, it is common to introduce the system at key points in the process, such as parts supply by parts feeder or automatic quality inspection. Furthermore, in order to reduce the cost of FA Equipment, it is possible to convert existing equipment into FA Equipment by introducing programmable controllers, etc., rather than installing dedicated FA Equipment.

It is important to introduce appropriate FA Equipment on an appropriate scale according to the purpose and budget.

Functions of FA Equipment

FA Equipment has the following functions and roles, which are combined to automate the production plant:

1. Operation

Operation is to move a machine or equipment by human judgment. This is the act of moving a car by pressing the accelerator pedal, or moving a character in a video game by pressing a button on the controller. 

2. Control

Control is to control the movement of an object by a set of rules. In the case of driving a car, this means controlling the steering wheel so that the car stays between the lanes to avoid accidents.

 

3. Driving

To operate or control is to actually output to the outside world. In the case of driving a car, the action of rotating the tires is driving. 

4. Detecting

To control an operating object, it is necessary to trigger it to move. Even during operation, it is necessary to detect what state the machine is in. Sensors are used for this purpose.

5. Display

Indicates whether the machine is running normally and whether any abnormalities are occurring. It is very dangerous if a machine suddenly starts moving under some conditions even if it appears to be stopped at first glance. Therefore, the indicator is displayed by means of lamps, etc. so that people can see and understand it.

Advantages of FA Equipment

1. Cost

In the early days of a production factory, material processing, transportation, inspection, etc. are performed by human hands. Although this is implemented in any production factory, regardless of industry, the initial investment in equipment is higher than employee salaries, so it is necessary to consider the payback on the investment before introducing the equipment.

2. Quality

If the plant is able to respond to problems and perform daily maintenance, it will be able to produce higher quality products than if human labor is used. Also, for simple tasks, the time required is shorter than that of human workers, and it is possible to respond to large orders.

3. Safety

In places where the work environment is poor, there is an increased risk of injury and health hazards due to accidents when people are working. The introduction of industrial robots has the advantage of preventing work-related accidents and health hazards.

Current State of the FA Equipment Industry

In terms of performance trends in the domestic FA Equipment industry, shipments have been declining due to declining capital investment in semiconductor manufacturing and electronic equipment, the leveling off of smartphone demand around 2018, and the impact of trade friction between the U.S. and China in 2019. However, there are signs of recovery due to the prospect that this decline has bottomed out and rising demand for factory automation due to soaring global labor costs.

On the technological front, smart factories, in which FA Equipment is connected to the Internet and converted to IoT, are attracting attention, and the development of software to facilitate this is required.

What Is Resistance/Load?

Resistance is the action of restraining an external force.

Load resistance in industrial products suppresses the current flowing in an electric circuit. In a DC circuit, the resistance R is represented by R=V/I from the formula V=IR. If the voltage between points A and B is V and the current flowing is I, then the resistance between them is R. The unit is ohm (symbol: Ω) .

To change the perspective, if the voltage between points A and B is V and the value of the current is I, the value of R can be found by V/I when choosing the value of the resistance to be installed. In AC circuits, resistance is called impedance and is represented by the symbol Z. The unit of measurement is also ohm. R in a DC circuit can be replaced by Z and expressed as V = IZ.

In an AC circuit, the impedance component of a coil or capacitor is called reactance, which is inductive reactance in the case of a coil and capacitive reactance in the case of a capacitor, and both work to block the flow of current. In AC circuits with coils and capacitors, the calculation of impedance becomes more complex and includes a complex number of items expressed as a phase difference component from the resistance R.

Types of Resistance / Load

There are variable resistors as opposed to fixed resistors. Variable resistors have a structure in which the resistance increases in proportion to the distance between two points, and usually one side is fixed and the other side is slid to change the resistance.

There are two main types of structures: rotary type and linear type. The resistors mounted on a surface-mounted board by melting solder in a reflow oven are called chip resistors, while the types with lead wires are called chip resistors.

How to Select Resistance / Load

For lead wire type resistors, the most commonly used and relatively inexpensive carbon film resistors are selected by the resistor material.

However, the resistance value may be affected by the ambient temperature, resulting in current noise or poor frequency characteristics, in which case, a slightly more expensive metal film resistor type should be selected.

There is also a wire-wound resistor type that excels in heat resistance, but because of its inductance component, it must be used with caution in high-frequency circuits. On the other hand, there are also metal resistor types with small inductance components and resistors with fuse functions, so it is important to select the appropriate type that meets the requirements of circuit design.

What Are Conveyors ?

Conveyors are devices used to transport and send materials from one work station to another.

The difference between a conveyor device and conveyor equipment is that a conveyor device is used as a tool to carry or a device to put an object on. Some can be used as a stand-alone piece of conveyor equipment, while others are used in combination with something else.

Types of Conveyors and Devices

This section introduces two types of conveyor equipment and devices.

1. Conveyor Equipment

• Carts
  This is a conveyor device that carries objects to be transported by placing them on a platform with wheels. This is a typical conveyor device used in various situations such as by movers, construction companies, stores, etc.
• Pallets
  Pallets come in a variety of shapes and sizes, including board, box, and basket-shaped pallets. They are also made of a wide variety of materials, such as wood, resin, and metal.
• Containers
  These are box-shaped transport containers that are usually loaded onto large transport vehicles such as freight trains, ships, and airplanes for transportation.

2. Conveyor Devices

• Conveyor
  Conveyors are used to transport items continuously or intermittently. They range from short-distance to medium- to long-distance conveyors. There are also a wide variety of conveyor systems, including belt conveyor systems and roller conveyor systems.
• Robots
  Robots are conveying equipment that transports or transfers materials to the correct position. Recently, some robots are equipped with a camera recognition function that automatically corrects the position without teaching the position.
• Pick & Place
  This transfer device transfers smaller parts from one position to another. A cam mechanism enables high-speed transfer as it performs a series of movements by circling a motor: grabbing the part, transferring it to the transfer point, releasing the part, and returning it to its original position.

Emergency Transfer Equipment

While the above were mainly used in manufacturing and industrial conveyors, a stretcher is a more familiar type of conveyor. Stretchers are mainly used in the event of a disaster, accident, or sudden illness, and are used to transport people. Two people, one in the front and one in the back, carry a person who has become immobile on the stretcher. There are also cart-type stretchers with wheels, which are equipped in hospitals and ambulances.

What Are Power Supplies?

Power Supplies are components or devices that supply electrical energy.

Examples include electrical outlets, computer batteries, and dry cell batteries. Electronic circuits, motors, processors, and other electronic components that are responsible for the operation of electrical products cannot operate without a defined supply of electrical energy (voltage or current) from power supplies.

Such components that consume electrical energy are called load devices. On the other hand, a device that converts the electrical energy supplied by the Power Supplies into the appropriate voltage or current required by the load device is called a power supply device.

Power Supplies ICs

Power Supplies ICs are power supply devices that control the exchange of power between the power supply and the load device.

A load device cannot operate unless it receives a specified supply of electrical energy. For example, if the required voltage of a load device is 5[V] and the power supply is 12[V] or 1.5[V], these voltages must be converted to 5[V] and supplied. Power supply ICs are responsible for converting electrical energy in this way.

1. AC/DC Converter

Most of the time when you plug an electrical device into an outlet, you connect a cord with an AC adapter. Normally, an AC voltage is output from the outlet, but most electronic devices operate on DC voltage and need to be converted from AC (alternating current) to DC (direct current).

2. Charge Control IC

Controls charging of lithium-ion batteries. 

3. DC/DC Converter

A DC/DC converter is inserted in front of each component to convert the voltage, since each component (CPU, display, storage, etc.) must be supplied with the corresponding voltage. Increasing the voltage is called a step-up and decreasing the voltage is called a step-down. 

4. Linear Regulator

Linear regulators are inserted in front of components (e.g., speakers) whose performance is degraded by voltage noise to supply more stable voltage.

Power Supplies Devices

In addition to power supply devices used by users as products, variable and stable power supplies are needed during the R&D phase of products as they are experimented with under various conditions. Some power supplies are also installed in factories and corporate facilities as backup power supplies in case of power outages. Power supplies specifically include the following:

1. Regulated DC Power Supplies

A device that outputs a constant voltage, constant current, or both from an AC voltage input. There are also classifications such as fixed type with constant output and variable type that can freely change the output.

2. AC Regulated Power Supplies

There are those with AC stabilizers that maintain constant voltage and waveforms, and those with frequency converter functions that maintain constant frequency. Some are used as Uninterruptible Power Supplies (UPS) to protect equipment and PCs in the event of power outages due to disasters.

What Is a Spring?

Springs are mechanical elements that utilize elasticity. The property of a material that extends or contracts when a force is applied and returns to its original shape when the force is removed is called elasticity.

Springs are used in various places and parts of the body of an object, such as as cushions to soften impacts, to restore a position using the force to return to its original form, and as instruments such as spring gauges.

Types of Springs

In addition to coiled springs, some other types are rod-shaped springs or plate-shaped springs.

1. Coiled Spring

Coiled springs are the most well-known type of spring, and are made by winding the spring material around in a circle. Its most common use is within a cushion. There are different types of coil springs, such as compression coil springs that contract when pressed in, and tension springs that stretch when pulled.

2. Leaf Springs

A plate spring is a spring made of spring material in the shape of a plate. When force is applied, it bends, but returns to its original shape when the force is released. Treadplates used in vaulting boxes are also a type of spring.

3. Torsion Bars

Torsion bars are bar-shaped springs. When force is applied, the bar bends and returns to its original shape when the force is released. It is characterized by its higher strength than a leaf spring.

4. Dish Spring

A dish spring is made by forming a spring material into a cone like a shallow dish and making a hole in the center. They are often used by stacking a number of them rather than using them individually. Depending on its usage, it may be used for pushing force or as a pulling force. The strength of the force is proportional to the number of disc springs stacked on top of each other.

Selection of Springs

In order to select a spring, it is necessary to determine various factors, and the factors to be determined vary depending on the type of spring.

For example, when selecting a coil spring, the following elements need to be determined:

• Outer diameter and inner diameter of spring
• Free length
• Wire diameter
• Material

The diameter and free length of springs are related to size, while the wire diameter and material are related to strength and repulsive force. Similarly, when selecting a disc spring, it is necessary to determine the following factors:

• Outer diameter and inner diameter of springs
• Plate thickness
• Material
• Number of sheets used

What Are Sanitary Conditions?

Sanitary conditions refers to the practices and conditions that prioritize cleanliness and hygiene, preventing the spread of disease and maintaining a healthy environment.

Ensuring sanitary conditions follows guidelines for products used in manufacturing lines, testing and research, and other situations where a high level of cleanliness is required. In the real estate and construction industries, sanitary conditions are also used as a generic term for spaces with water supply and drainage systems for sanitation, such as bathrooms, washrooms, and toilets, excluding kitchens. It also includes accessories and equipment and facilities attached to the water supply space.

Thus, sanitary products called can be broadly classified into two categories: those dedicated to use in manufacturing and production sites and in testing and research, and those related to water supply and drainage facilities.

Types of Sanitary Equipment (Manufacturing and Production Sites, Testing and Research)

Typical products used in situations where cleanliness is required are sanitary piping, which is used in production lines for food, pharmaceuticals, semiconductors, etc.

Sanitary piping consists of sanitary pipes and sanitary fittings. The special structure and surface/inner surface finish prevent liquid accumulation and contamination, and disassembly, cleaning, and assembly are easy, thus preventing bacteria and foreign matter from entering the piping.

Sanitary rooms are often provided at these manufacturing sites to prevent human contamination. Hand washing stations, alcohol sanitizers, jet towels, rollers, foot washing pits, air showers, etc. are installed to prevent the introduction of foreign substances, including hair.

Similarly, special labware such as sanitary beakers are used in testing and research settings to prevent contamination. Most of these products are made of stainless steel and have excellent chemical resistance and corrosion resistance.

Types of Sanitary Equipment (Water Supply and Drainage Equipment)

Products related to water supply and drainage equipment include not only bathtubs, washbasins, faucets, showerheads, shower handles, etc., which are exposed to the outside, but also pipes, valves, pumps, ball taps, packing, gaskets, etc., which are used for piping. In addition, towel holders, towels and mats installed in bathrooms, washrooms, and toilets may also be referred to as sanitary products.