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Shore A Hardness
The Shore durometer is a device for measuring the hardness of a material, typically of polymers. Higher numbers on the scale indicate a greater resistance to indentation and thus harder materials. Lower numbers indicate less resistance and softer materials. The term is also used to describe a material's rating on the scale, as in an object having a "'Shore durometer' of 90." The scale was defined by Albert Ferdinand Shore, who developed a suitable device to measure hardness in the 1920s. It was neither the first hardness tester nor the first to be called a ''durometer'' ( ISV '' duro-'' and '' -meter''; attested since the 19th century), but today that name usually refers to Shore hardness; other devices use other measures, which return corresponding results, such as for Rockwell hardness. Durometer scales There are several scales of durometer, used for materials with different properties. The two most common scales, using slightly different measurement systems, are the AST ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bont High Roller G4 110mm 85A And 83A
Bont may refer to: * Bont F.C., a Welsh association football team * Bonţ, village in Fizeșu Gherlii Commune, Cluj County, Romania * Y Bont, nickname for Pontarddulais, a town in Swansea, Wales * BONT, NASDAQ symbol for The Bon-Ton Stores, Inc. * BoNT, abbreviation for botulinum toxin * Debbie Bont, Dutch handball player * Alexander Bont, fictional character in the Marvel Comics universe * Robert Bont * Henry Bont * Marcus Bontempelli, an Australian rules footballer known by his nickname 'The Bont'. {{disambig, surname ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Force
In physics, a force is an influence that can cause an Physical object, object to change its velocity unless counterbalanced by other forces. In mechanics, force makes ideas like 'pushing' or 'pulling' mathematically precise. Because the Magnitude (mathematics), magnitude and Direction (geometry, geography), direction of a force are both important, force is a Euclidean vector, vector quantity. The SI unit of force is the newton (unit), newton (N), and force is often represented by the symbol . Force plays an important role in classical mechanics. The concept of force is central to all three of Newton's laws of motion. Types of forces often encountered in classical mechanics include Elasticity (physics), elastic, frictional, Normal force, contact or "normal" forces, and gravity, gravitational. The rotational version of force is torque, which produces angular acceleration, changes in the rotational speed of an object. In an extended body, each part applies forces on the adjacent pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyurethane
Polyurethane (; often abbreviated PUR and PU) is a class of polymers composed of organic chemistry, organic units joined by carbamate (urethane) links. In contrast to other common polymers such as polyethylene and polystyrene, polyurethane term does not refer to the single type of polymer but a group of polymers. Unlike polyethylene and polystyrene, polyurethanes can be produced from a wide range of starting materials resulting in various polymers within the same group. This chemical variety produces polyurethanes with different chemical structures leading to many List of polyurethane applications, different applications. These include rigid and flexible foams, and coatings, adhesives, Potting (electronics), electrical potting compounds, and fibers such as spandex and polyurethane laminate (PUL). Foams are the largest application accounting for 67% of all polyurethane produced in 2016. A polyurethane is typically produced by reacting a polymeric isocyanate with a polyol. Since a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High-density Polyethylene
High-density polyethylene (HDPE) or polyethylene high-density (PEHD) is a thermoplastic polymer produced from the monomer ethylene. It is sometimes called "alkathene" or " polythene" when used for HDPE pipes. With a high strength-to-density ratio, HDPE is used in the production of plastic bottles, corrosion-resistant piping, geomembranes and plastic lumber. HDPE is commonly recycled, and has the number "2" as its resin identification code. In 2008, the global HDPE market reached a volume of more than 30 million tons. Properties HDPE is known for its high strength-to-density ratio. The density of HDPE ranges from 930 to 970 kg/m3. Although the density of HDPE is only marginally higher than that of low-density polyethylene, HDPE has little branching, giving it stronger intermolecular forces and tensile strength (38 MPa versus 21 MPa) than LDPE. The difference in strength exceeds the difference in density, giving HDPE a higher specific strength. It is also harder and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hard Hat
A hard hat is a type of helmet predominantly used in hazardous environments such as industrial or construction sites to protect the Human head, head from injury due to falling objects (such as tools and debris), impact with other objects, and electric shock, as well as from rain. Suspension bands inside the helmet spread the helmet's weight and the force of any impact over the top of the head. A suspension also provides space of approximately 30 mm (1.2 inches) between the helmet's shell and the wearer's head, so that if an object strikes the shell, the impact is less likely to be transmitted directly to the skull. Some helmet shells have a mid-line reinforcement ridge to improve impact resistance. The Rock-climbing equipment#Helmet, rock climbing helmet fulfills a very similar role in a different context and has a very similar design. A bump cap is a lightweight hard hat using a simplified suspension or padding and a chin strap. Bump caps are used where there is a possibi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ebonite
Ebonite is a brand name for a material generically known as hard rubber or vulcanite, obtained via vulcanizing natural rubber for prolonged periods. Ebonite may contain from 25% to 80% sulfur and linseed oil. Its name comes from its intended use as an artificial substitute for ebony wood. The material has also been called ''vulcanite'', although that name formally refers to the mineral vulcanite. Charles Goodyear's brother, Nelson Goodyear, experimented with the chemistry of ebonite composites. In 1851, he used zinc oxide as a filler. Hugh Silver was responsible for giving it its name. Properties The sulfur percentage and the applied temperatures and duration of vulcanizing are the main variables that determine the technical properties of the hard rubber polysulfide elastomer. The occurring reaction is basically addition of sulfur at the double bonds, forming intramolecular ring structures, so a large portion of the sulfur is highly cross-linked in the form of intramolecul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
O-ring
An O-ring, also known as a packing or a toric joint, is a mechanical gasket in the shape of a torus; it is a loop of elastomer with a round cross section (geometry), cross-section, designed to be seated in a groove and compressed during assembly between two or more parts, forming a seal (mechanical), seal at the interface. The O-ring may be used in static applications or in dynamic applications where there is relative motion between the parts and the O-ring. Dynamic examples include rotating pump shafts and hydraulic cylinder pistons. Static applications of O-rings may include fluid or gas sealing applications in which: (1) the O-ring is compressed resulting in zero clearance, (2) the O-ring material is vulcanized solid such that it is permeation, impermeable to the fluid or gas, and (3) the O-ring material is resistant to degradation by the fluid or gas. The wide range of potential liquids and gases that need to be sealed has necessitated the development of a wide range of O-r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skateboard
A skateboard is a type of sports equipment used for skateboarding. It is usually made of a specially designed 7–8-ply maple plywood deck and has polyurethane wheels attached to the underside by a pair of skateboarding trucks. The skateboard moves by pushing with one foot while the other foot remains balanced on the board, or by Pump (skateboarding), pumping one's legs in structures such as a bowl or half pipe. A skateboard can also be used by standing on the deck while on a downward slope and allowing gravity to propel the board and the rider. If the rider's leading foot is their left foot, they are said to ride "regular". Conversely, they are said to ride "goofy" if their leading foot is their right foot. The two main types of skateboards are the longboard and shortboard. The shape of the board is also important: the skateboard must be concaved to perform tricks. History Skateboarding, as it exists today, was probably born sometime in the late 1940s, or early 1950s, when ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Roller Skates
Roller skates are boots with wheels mounted to the bottom, allowing the user to travel on hard surfaces similarly to an ice skater on ice. The first roller skate was an inline skate design, effectively an ice skate with a line of wheels replacing the blade. In modern usage, the term typically refers to skates with two pairs of wheels on shared axles like those of skateboards (early versions of which were made using roller skate parts). Skates with this configuration are also known as "quad skates" or "quads" and, like skateboards, steer by tilting the skate to one side, which causes the axles to turn inward. History While the first reported use of wheeled skates was on a London stage in 1743, the first patented "roller skate" was introduced in 1760 by Belgian inventor John Joseph Merlin. They were hard to steer and stopping was difficult due to the fact that they did not have any type of braking mechanism and as such they failed to gain popularity. Merlin demonstrated his i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tire Tread
The tread of a tire or track refers to the rubber on its circumference that makes contact with the road or the ground. As tires are used, the tread is worn off, limiting its effectiveness in providing traction. A worn tire can often be retreaded. The word tread is often used casually to refer to the pattern of grooves molded into the rubber, but those grooves are correctly called the tread pattern, or simply the pattern. The grooves are not the tread, they are in the tread. This distinction is especially significant in the case of racing slicks, which have much tread but no grooves. Tires Street tires The grooves in the rubber are designed to allow water to be expelled from beneath the tire and prevent hydroplaning. The proportion of rubber to air space on the road surface directly affects its traction. Design of tire tread has an effect upon noise generated, especially at freeway speeds. Generally there is a tradeoff of tread friction capability; deeper pattern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rubber Band
A rubber band (also known as an elastic, gum band or lacky band) is a loop of rubber, usually ring or oval shaped, and commonly used to hold multiple objects together. The rubber band was patented in England on March 17, 1845, by Stephen Perry (inventor), Stephen Perry. Most rubber bands are manufactured out of natural rubber as well as for latex free rubber bands or, especially at larger sizes, an elastomer, and are sold in a variety of sizes. Notable developments in the evolution of rubber bands began in 1923 when William H. Spencer obtained a few Goodyear inner tubes and cut the bands by hand in his basement, where he founded Alliance Rubber Company. Spencer persuaded the ''Akron Beacon Journal'' as well as the ''Tulsa World'' to try wrapping their newspapers with one of his rubber bands to prevent them from blowing across lawns. He went on to pioneer other new markets for rubber bands such as: agricultural and industrial applications and a myriad of other uses. Spencer obtai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sorbothane
Sorbothane is the brand name of a synthetic viscoelastic urethane polymer used as a shock absorber and vibration damper. It is manufactured by Sorbothane, Inc., based in Kent, Ohio. History Sorbothane was invented and patented in 1982 by Dr. Maurice Hiles, a British inventor. It was prepared by mixing polyol and isocyanate. His research into the energy dissipation properties of human soft tissue disclosed a structure very similar to an interpenetrating polymer network. This led to his synthesis of the first commercial simultaneous interpenetrating network, now called Sorbothane. Dr. Hiles wrote in his patent "The resulting solid polymer behaves like a quasi-liquid, being readily deformed by an applied force and slow to recover, although in the absence of such a force it takes up a defined shape and volume". In 1976, he contacted the National Research Development Corporation (NRDC) about his invention; the NRDC spent almost £10,000 in helping him to improve and patent the polymer. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
