月: 2022年12月

What Is a Polyurethane Glove?

A polyurethane glove is made from polyurethane, a type of plastic known for its resilience surpassing that of rubber.

These gloves offer superior durability against chemicals compared to natural rubber gloves, making them ideal for handling organic solvents. They also boast significant thermal resistance, suitable for extended outdoor work periods.

However, they are generally more costly than gloves made from natural rubber, nitrile rubber, or polyvinyl chloride. The range includes options from thin to thick, and from disposable to reusable, catering to various requirements.

Uses of Polyurethane Gloves

Polyurethane gloves find use across diverse fields such as plating, solvent painting, cleaning, scientific research, printing, and chemical manufacturing. They are characterized by their high solvent resistance, exceptional elasticity, and suitability for detailed tasks, even when thick. Such tasks include the assembly and sorting of precision machinery.

These gloves are compatible with organic solvents like toluene, xylene, benzene, methanol, and ethyl acetate. Yet, they lack resistance to specific solvents, including cyclohexanone, dimethylformamide (DMF), and methylene chloride. Prior verification of the gloves’ solvent resistance is necessary when dealing with organic solvents.

Moreover, their high resistance to weather elements like wind, rain, sunlight, and temperature fluctuations makes them fit for prolonged outdoor tasks, such as in agriculture.

Principle of Polyurethane Gloves

Polyurethane is synthesized from diols and diisocyanates, found in polyesters and polyethers, through polymerization. The resultant polyurethane bonds are further strengthened by hydrogen bonding.

This bonding endows polyurethane with rubber-like qualities, enhancing its mechanical strength, elasticity, and resistance to friction, thereby often being referred to as polyurethane rubber.

Aside from gloves, polyurethane’s robust properties make it a preferred material for industrial belts, solid tires, rubber rollers, shoe soles, and paints.

Types of Polyurethane Gloves

1. Thick Type

Thick polyurethane gloves are recognized for their mechanical strength, elasticity, abrasion resistance, and solvent resistance. They are typically reusable, not intended for single use, and available in long versions that extend to the elbow.

2. Backless Type

Backless gloves feature a polyurethane coating only on the palm, leaving the back of the hand uncoated. This uncoated area is often made from breathable materials like nylon or mesh, ensuring a snug fit and allowing for precise tasks as if working with bare hands. However, the low solvent resistance of nylon and mesh means these gloves are unsuitable for tasks involving organic solvents.

Other Information on Polyurethane Gloves

1. Polyurethane Allergy

Isocyanates in polyurethane can cause allergic reactions, including rashes, irritation, and asthma, upon inhalation or contact. This condition is also referred to as spandex allergy in the US, where polyurethane is commonly known as spandex.

2. Polyurethane Elastomer

Though a plastic, polyurethane’s mechanical strength and elasticity have led to its classification as a “polyurethane rubber” or more formally, a polyurethane elastomer. These elastomers are categorized into thermosetting and thermoplastic types, each behaving differently upon heating. Thermosetting types harden and do not revert to their original state, whereas thermoplastic types soften when heated and solidify upon cooling, allowing them to be molded into various shapes.

What Is a Plastic Case?

A plastic case is made of resin, commonly known as plastic. These cases utilize various materials such as polypropylene, polystyrene, PET, and acrylic, offering a wide selection of container sizes and thicknesses. The case’s durability and weight depend on the material, thickness, and size. It’s essential to select a case that suits the intended use.

Generally, plastic cases are lighter and more affordable than other types of cases. They serve diverse purposes, from home storage solutions like wardrobe boxes to product storage in factories and sample containment in laboratories.

Uses of Plastic Cases

1. General Household

For general household use, lightweight and transparent plastic cases, such as wardrobe boxes, are prevalent.

2. Manufacturing Sites

Manufacturing sites employ thick and durable plastic cases for product storage and as returnable containers.

3. Specialty Applications

The application of plastic cases varies widely. For instance, waterproof and dustproof cases protect communication devices and breakers, while chemical-resistant cases are ideal for laboratories prone to chemical exposure. Additionally, these cases are utilized for transporting sensitive items like semiconductors and silicon substrates.

Characteristics of Plastic Cases

Due to the inherent electrical charge in plastics, plastic cases are prone to static electricity buildup. This makes them unsuitable for storing static-sensitive items such as electronic devices and semiconductors. Conductive cases are recommended for storing or transporting these products.

To prevent dust and dirt from adhering to the case, consider using cases with locking lids, especially in environments where cleanliness is paramount.

Types of Plastic Cases

1. ABS Resin

ABS resin, a copolymer of three monomers, is known for its exceptional impact resistance and suitability for protecting contents from external shocks. Its high abrasion resistance ensures durability, even with frequent use. Although somewhat less resistant to weathering, ABS resin’s durability can be enhanced through painting or coating. It finds widespread application in household goods, electronic device cases, and automotive parts.

2. PC Resin

PC resin, notable for its high transparency and weather resistance, is comparable to glass. This makes it ideal for optical equipment, lighting fixtures, protective smartphone cases, and tablet screen protectors. PC resin’s heat and chemical resistance further extend its use to durable industrial products and automotive parts. Despite its high quality, PC resin’s cost may necessitate comparison with other materials when budget is a consideration.

3. PP Resin

PP resin is lightweight and boasts excellent chemical resistance, heat resistance, and electrical insulation, making it ideal for chemical containers, electronic component cases, and automotive interior parts. Its low cost and ease of processing make PP resin suitable for mass production. Additionally, its high recyclability highlights its environmental friendliness, although it may not be the best choice for high-temperature environments.

4. PE Resin

PE resin is flexible, durable, and exceptionally lightweight, widely used in outdoor equipment, sports gear, and military cases. Its excellent cold resistance ensures functionality in low-temperature conditions. Chemically stable and resistant, PE resin is also highly water-resistant, ideal for overseas transport and adverse weather conditions. However, prolonged outdoor exposure can lead to degradation from ultraviolet rays, warranting caution.

Additional Information on Plastic Cases

Material Considerations

Plastic cases, known for their lightweight and portability, come in various sizes and thicknesses for diverse applications. The choice of materials, including polypropylene, polystyrene, PET, and acrylic, affects the case’s durability, load resistance, and weather resistance. Selection should be based on the specific application needs. Notably, plastic cases generally do not resist organic solvents well. For environments with potential chemical contact, selecting a case made from highly chemical-resistant material, such as fluorinated resin, is crucial.

What Is a Switch Box?

A switch box is a component designed to house electrical connections and devices like switches and outlets. It facilitates the organization and protection of wiring systems and can be mounted in various ways, including embedded within or exposed on a wall.

Uses of Switch Boxes

Switch boxes are versatile, serving to install electrical fixtures securely. They accommodate the connections for switches and outlets, allowing for organized and safe electrical setups. The choice of switch box depends on the installation environment, such as wooden or concrete structures, and can support multiple devices in a single location.

Principle of Switch Boxes

The design and installation of switch boxes vary based on the building material and whether they are placed inside or outside, embedded or exposed. Options include easily mountable boxes for wooden structures and sealed steel plate boxes for concrete installations to prevent penetration by concrete. Exposed boxes, typically metal, are used where the box remains visible and may require environmental resistance.

Types of Switch Boxes

1. Embedded Type

Designed for integration into walls, these boxes are suited for various construction materials and come in multiple depths to accommodate different installation needs. Material options include steel plate and resin, with finishes like electrogalvanization or electrodeposition coating.

2. Exposed Type

Used mainly for retrofitting, exposed switch boxes are made from materials such as steel, cast iron, and resin. They feature conduit connection ports for wire insertion and are available in various dimensions to support multiple switches.

3. Special Type

Specialized for particular applications, these include mobile switch boxes for close machine operation, operating switch boxes for machine control in a handheld format, and distribution switch boxes for power supply and alarm signaling to devices. They are constructed from materials like polycarbonate resin and steel, offering features like flame resistance and waterproofing.

What Is a Copper Pipe Fitting?

Copper tubing, known for its excellent workability and corrosion resistance, is commonly used in household plumbing.

Copper pipe fittings are specialized connectors for copper pipes, available in several types. For copper pipes, soldering or brazing is a common method for joining, which involves low-temperature techniques to connect pipes.

Other fitting types include one-touch fittings that easily join by inserting copper pipes, and screw-tightened fittings.

Uses of Copper Pipe Fittings

Copper is economical, offering corrosion resistance and workability at a low cost. It’s widely used in residential water supply, hot water systems, and in medical and air conditioning applications.

For water supply, copper may leach from pipes. Thus, some pipes are tin-coated to prevent leaching. Copper pipe fittings are essential for extending and branching copper piping, with the most suitable type chosen based on cost and application.

Principle of Copper Pipe Fittings

While stainless steel is more durable, copper piping offers a cost-effective and durable alternative. PVC piping, though low-cost, is less durable, particularly in narrower diameters where it’s prone to breakage. Copper strikes a balance between cost and durability.

Fittings connected by solder are brazed, with a simple design. The solder’s tin creates an alloy with copper, facilitating connections. Brazing requires a torch and skill, as it can’t be done near flammable materials.

Screw-tightened and plug-in fittings offer convenient alternatives. The copper pipe simply inserts into the fitting, and an O-ring seals the joint, preventing leaks when matched correctly in size.

What Is a Milling Machine Chuck?

A milling machine chuck is a tooling tool that grips various cutting tools such as end mills and drills and can be attached to the spindle of a machining center or milling machine.

There are various types, from highly rigid types for heavy-duty cutting to slim types for light-duty cutting, according to the shape of the machining center or the purpose of machining.

Some milling shacks have 2- or 3-sided contact surface restraints between the milling shack and the machining center to prevent touching due to high-speed spindle rotation and to ensure accuracy.

Uses of Milling Machine Chucks

Some milling machine chucks are equipped with convenient mechanisms, such as a spindle type that can increase the rotation speed several times and a center-through variety that can supply cutting fluid to cutting tools through the cutting fluid inside the milling chuck.

The shank, which comes in various types, is the part of the milling machine chucks that attach to the machine.

NT shanks are used for general-purpose milling machines, while BT shanks or HSK standard shanks are used for NC machines and machining centers.

Principle of Milling Machine Chucks

Milling machine chuck shanks are classified into No. 30, No. 40, and No. 50 according to size.

The BT shank is mainly used in machining centers and is the most common shank in Japan and overseas. The HSK shank is also primarily used in machining centers. The difference between the HSK shank and the BT shank is that the shank is shorter and does not have a pull bolt. The NT shank is similar in shape to the BT shank but does not have a flange for the ATC (automatic tool change) function. It is used on machines that do not have an ATC function, such as general-purpose milling machines.

What Is a Feeler Gauge?

A feeler gauge, a thin plate-shaped tool, is a gauge (scale) for measuring thin gaps between machines and height adjustment dimensions.

A filler gauge is a metal plate less than 1 mm thick, rolled like tape, and cut to the desired length.

A similar tool is the Thickness Gauge, which consists of multiple plates (leaves) of different thicknesses bundled together like a fan, and the thickness can be changed, while a feeler gauge usually has a fixed thickness.

Uses of Feeler Gauges

Feeler gauges are used for delicate height adjustment of jigs and molds, adjustment of internal gaps in automobile engines, and fine adjustment of machine tools. Metals such as aluminum, brass, copper, and stainless steel are used, and some are hardened. The thickness of these products is relatively easy to process, and many have excellent corrosion resistance because oil adhesion and contamination are expected depending on the environment in which they are used.

In addition, the tape type is generally used by cutting only the necessary amount. The shape and material of feeler gauges are used according to the application.

Principle of Feeler Gauges

This tool measures dimensions in fixed, narrow gaps (1 mm or less) that cannot be measured with other measuring instruments.

While the Siknes mentioned above gauge can be used for a wide range of measurements, such as selecting the desired thickness from multiple thin fan-shaped metal plates or combining them to insert them into a gap between machine parts, the feeler gauges are, in principle, designed to evaluate only a certain fixed thickness, making it convenient for continuously and repeatedly evaluating products with a single standard gap, such as in a factory. Therefore, it is convenient for continuous and repetitive product evaluation of a single standard gap in a factory, for example.

Therefore, it is essential to carefully check the thickness dimension (mm) when purchasing feeler gauges since it is used, for example, for final evaluations of internal combustion engines at factories where the target gap dimensions have already been determined or for preparing multiple types of feeler gauges with different thicknesses in some cases. They are usually 1 m rolls, however, various lengths are also available.

Some tape-type products can be used as shim tape after cutting. Since feeler gauges are generally metallic, they are excellent conductors of electricity and heat and may be processed for specific applications and used as simple gauges.

What Is a Milling Machine Chuck?

A milling machine chuck is a specialized tool holder designed for securing various cutting tools, such as end mills and drills, to the spindle of machining centers or milling machines. These chucks come in different types, tailored for specific applications, ranging from heavy-duty to light-duty cutting, and are selected based on the machining center’s design and the machining task at hand.

Some milling machine chucks feature two or three-sided contact surface restraints to minimize displacement caused by high-speed spindle rotation, enhancing precision during operations.

Uses of Milling Machine Chucks

Certain milling machine chucks are equipped with advanced mechanisms like a spindle type that amplifies rotation speed and a center-through design that allows the delivery of cutting fluid directly to the cutting tools through the chuck. The part of the chuck that connects to the machine, known as the shank, varies in type. NT shanks are common in general-purpose milling machines, whereas BT shanks or HSK standard shanks are used in NC machines and machining centers.

Principle of Milling Machine Chucks

Milling machine chuck shanks are categorized by size: No. 30, No. 40, and No. 50. The BT shank, predominantly used in machining centers, is the most common type both in Japan and internationally. The HSK shank, also primarily for machining centers, differs from the BT shank in its shorter length and the absence of a pull bolt. The NT shank, similar to the BT shank but lacking a flange for automatic tool change (ATC) functionality, is typically used in machines without ATC, such as general-purpose milling machines.

What Is a Countersunk Head Screw?

Countersunk head screws, also known as flat head screws, feature a tapered head that narrows towards the screw side, resembling a dish when viewed from the side. Unlike flat head nails, which have a flat top face, the top face of a countersunk head screw is rounded. These screws have a relatively small nominal head diameter and typically feature a slotted or cross-shaped drive.

Uses of Countersunk Head Screws

Figure 1. Example of Using Countersunk Head Screws

Countersunk head screws are primarily used as fasteners in applications with female threads, such as door closers, knobs, and hinges. They are designed to fit into a tapered counterbore in the fastened object, ensuring the screw head does not protrude beyond the object’s surface, as illustrated in Figure 1.

While similar in application to round countersunk head nails, which have a rounded top face, countersunk head screws feature a flat head that can prevent snagging on cross-holes.

Principle of Countersunk Head Nails

Countersunk head screws, like their nail counterparts, are secured by screwing into a tapped female thread without the need for a nut. They are tightened using a Phillips-head or flat-blade screwdriver inserted into the cross-hole or slot. The length of these screws is measured from the top of the head to the end, in contrast to ordinary bolts, which are measured excluding the bolt head.

Types of Countersunk Head Screws

Figure 2. Types, Materials, and Shapes of Countersunk Head Screws

Countersunk head screws are categorized by head hole shape and material strength.

1. Classification by Hole Shape of Countersunk Screw Head

Different headhole shapes accommodate specific tools for tightening. The two main types are Cross (Phillips) and Suri-Wari (Flat). Phillips types are common, with a slightly concave pressure surface, while Pozidriv types feature almost vertical sides. Flat holes, or minus holes, accommodate a flathead screwdriver.

Figure 3. Hole and Tool Geometry of the Head of Countersunk Head Screws

Hexagonal and Torx holes are also available, providing higher tightening force and requiring specific tools for operation.

2. Classification by Material (Strength Classification)

Materials for countersunk head screws include steel, stainless steel, and nonferrous metals, each classified by strength and applicable standards.

Other Information on Countersunk Head Screws

Standards for countersunk head screws include ISO 7046, among others. It’s important to match the screw to the female thread’s standard to ensure compatibility. Additionally, countersunk head screws come in various sizes, typically from M2 to M8, with recommended lengths ranging from 4 to 60 mm.

What Is a Gradiometer?

A gradiometer, often referred to as an inclinometer, is an instrument designed to measure angles of inclination relative to the horizontal plane. It is commonly used for assessing the slope of surfaces like roofs and inclined terrain. While levels are a common tool in many toolboxes, gradiometers are more specialized and are typically used by professionals such as carpenters and service engineers.

There are two primary types of gradiometers: the bubble tube gradiometer, which is affordable and widely used for basic measurements, and the laser gradiometer, preferred by professionals for more precise measurements.

Uses of Gradiometers

Gradiometers have various applications in construction, civil engineering, and surveying. They are instrumental in determining the angles of inclined surfaces, such as those found in steel structures. Some models feature a magnet on the back, allowing them to attach to metallic surfaces like rebar for stability during measurements.

The bubble tube gradiometer relies on visually reading the position of bubbles within a liquid-filled tube, making it less precise than laser models, which are used for more exacting surveys.

Principle of Gradiometers

The bubble tube gradiometer consists of a small cylindrical glass tube with a liquid and a small air bubble. When this tube is aligned perpendicular to gravity, the bubble settles at the tube’s center, indicating a horizontal alignment. This tube is mounted on a base, enabling the measurement of horizontal planes and angles of inclination.

To measure an inclined surface, the gradiometer is placed on the object, and the tube is rotated until the bubble centers in the tube, indicating the angle of inclination. The tube typically has reference lines for fine adjustments, allowing users to align the bubble within these lines for accurate readings.

Some gradiometers allow angle readings without rotating the bubble tube, offering an alternative measurement approach.

What Is a Hinge Pin?

A hinge pin is a crucial component in hinge systems, primarily used for enabling the opening and closing of doors, lids, and other movable parts. It is attached to the edge of the component that needs to pivot and is inserted into a corresponding hole in the frame or body, functioning as a pivot point.

Specifically, a “hinge pin” refers to a rod-like pin that rotates within the hole of the receiving component, facilitating smooth movement.

Uses of Hinge Pins

Hinge pins find diverse applications, including indoor mechanisms, vertical-opening window locks, box lids, fitness equipment, and other fixtures. They are also integral to hydraulic door stoppers and manual paper cutters, where they aid in the movement of parts. In heavy-duty applications, such as tool cabinet doors and coin-operated lockers, hinge pins provide enhanced durability and frequent usage capability.

Principle of Hinge Pins

When installed correctly with durable materials like stainless steel or hardened steel, hinge pins offer semi-permanent performance, barring issues like rust or dust accumulation. The basic mechanism is straightforward: a rod (the hinge pin) rotates inside a cylindrical receptacle. This simple design allows for various connection types and adaptability to different applications.

For example, in office paper cutters, the operational part and the fixed part are joined with a type of hinge pin connection known as a ‘split stop.’ Stronger connections, like the ‘key stopper,’ offer greater stability. There are also various fastening types, including set-ring, set-screw, and nut-fastening, each differing in serviceability.

Hinge pins are also commonly used in less visible applications, such as commercial refrigerators and car bodies, including hood and trunk mechanisms which often combine hinge pins with door catches.

What Is a Conveyor Roller?

 

A conveyor roller is a device that facilitates the movement of materials by arranging cylindrical rollers perpendicular to the travel direction. This system significantly reduces the effort required to transport loads by enabling them to roll, thus speeding up the movement of large quantities of items.

Uses of Conveyor Rollers

Conveyor rollers are commonly used in manufacturing facilities and logistics to move large volumes of goods efficiently. Their capability to maintain a consistent speed significantly cuts down on manual labor. While they are ideal for transporting rigid items like cardboard boxes, softer items may face challenges in transfer and could potentially become lodged under the rollers.

The friction on the load is drastically reduced, making the conveyor system a safer alternative to manual or machine transport, essential for factory safety.

Principle of Conveyor Rollers

Comprising rollers, a shaft, bearings, seals, and a frame, roller conveyors allow for smooth rotation around the shaft, supported by ball bearings. Depending on the usage environment, seals may be added to the bearings for protection.

Diverse types of rollers include straight, grooved, and tapered designs, with the roller pitch ensuring material support by at least two rollers. Electrically driven conveyors may use motors integrated into the rollers or external chains or belts for movement.

Characteristics of Conveyor Rollers

1. No Power Required

Manual conveyors, also known as free conveyors, operate without electricity, allowing for horizontal installation or inclined setups for self-propulsion.

2. Variety

Available in steel, aluminum, and resin, rollers come in various diameters and widths, and with different bearings to accommodate light to heavy loads. They can be straight or curved and designed for manual, self-propelled, or electric operation.

3. Environmentally Friendly

Certain conveyors avoid using hazardous substances identified by the EU, featuring non-chrome surface treatments, trivalent chromate bearings, powder-coated frames, and bolts and nuts, contributing to environmental sustainability.

Types of Conveyor Rollers

Conveyor rollers are categorized into free (gravity) conveyors and driven conveyors, distinguished by the use of motor power for load transport.

1. Free Conveyor

Gravity conveyors use the force of gravity to move loads on an incline, requiring no electricity. Installation and maintenance costs are low, with the angle of inclination adjusted based on the load type and weight to ensure efficient transport.

2. Driven Conveyor

Driven conveyors, powered by motors, are suited for stable load movement but may not be ideal for very small objects due to potential gaps between rollers. Drive options include chain drives, built-in motor rollers, accumulating rollers, and V-belt drives, each catering to different power needs and applications.