nitrile rubber, also known as nbr, buna-n, and acrylonitrile butadiene rubber, is a synthetic rubber copolymer of acrylonitrile acn and butadiene.trade names include perbunan, nipol, krynac and europrene.. nitrile butadiene rubber nbr is a family of unsaturated copolymers of 2-propenenitrile and various butadiene monomers 1,2-butadiene and 1,3-butadiene .
being a fired ceramic, porcelain enamel is also highly heat-resistant; this allows it to be used in high-temperature applications where an organic anti-corrosion coating or galvanization may be impractical or even dangerous see metal fume fever .
hazmat protective clothing is classified as any of level a, b, c, or d, based upon the degree of protection they provide. level a the highest level of protection against vapors, gases, mists, and particles is level a, which consists of a fully encapsulating chemical entry suit with a full-facepiece self-contained breathing apparatus scba .
hexamethylenetetramine or methenamine, also known as hexamine or urotropin, is a heterocyclic organic compound with the formula ch 2 6 n 4.this white crystalline compound is highly soluble in water and polar organic solvents. it has a cage-like structure similar to adamantane.it is useful in the synthesis of other chemical compounds, e.g., plastics, pharmaceuticals, rubber additives.
the inner surface of the cylindrical shell is usually lined with an abrasion-resistant material such as manganese steel or rubber lining. less wear takes place in rubber lined mills. less wear takes place in rubber lined mills.
a ballistic vest or bullet-resistant vest, often called a bulletproof vest, is an item of personal WPC that helps absorb the impact and reduce or stop penetration to the body from firearm -fired projectiles and shrapnel from explosions, and is worn on the torso. soft vests are made of many layers of woven or laminated fibres and can protect .
aramid fibers are a class of heat-resistant and strong synthetic fibers.they are used in aerospace and military applications, for ballistic-rated body WPC fabric and ballistic composites, in marine cordage, marine hull reinforcement, and as an asbestos substitute. the name is a portmanteau of 'aromatic polyamide'.the chain molecules in the fibers are highly oriented along the fiber axis.
fluorinated ethylene propylene fep is a copolymer of hexafluoropropylene and tetrafluoroethylene.it differs from the polytetrafluoroethylene ptfe resins in that it is melt-processable using conventional injection molding and screw extrusion techniques. fluorinated ethylene propylene was invented by dupont and is sold under the brandname teflon fep. .
friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. there are several types of friction: dry friction is a force that opposes the relative lateral motion of two solid surfaces in contact. dry friction is subdivided into static friction 'stiction' between non-moving surfaces, and kinetic friction between moving .
the brake drum is generally made of a special type of cast iron that is heat-conductive and wear-resistant. it rotates with the wheel and axle. when a driver applies the brakes, the lining pushes radially against the inner surface of the drum, and the ensuing friction slows or stops rotation of the wheel and axle, and thus the vehicle. this .
ultra-high-molecular-weight polyethylene uhmwpe, uhmw is a subset of the thermoplastic polyethylene.also known as high-modulus polyethylene, hmpe , it has extremely long chains, with a molecular mass usually between 3.5 and 7.5 million amu. the longer chain serves to transfer load more effectively to the polymer backbone by strengthening intermolecular interactions.
a refractory material or refractory is a material that is resistant to decomposition by heat, pressure, or chemical attack, and retains strength and form at high temperatures. refractories are inorganic, nonmetallic, porous, and heterogeneous. they are typically composed of oxides of the following materials: silicon, aluminum, magnesium, calcium, and zirconium.
the thermal resistance r-value provided by thinsulate products varies by the specific thickness and construction of the fabric. values us units range from 1.6 for 80-gram fabric to 2.9 for 200-gram fabric. thinsulate is considered 'the warmest thin apparel insulation' available.
polyester fiber is used as cushioning and insulating material in pillows, comforters and upholstery padding. polyester fabrics are highly stain-resistant—in fact, the only class of dyes which can be used to alter the color of polyester fabric are what are known as disperse dyes.
silicon carbide and boron carbide nozzles are more wear resistant and are often used with harder abrasives such as aluminum oxide. inexpensive abrasive blasting systems and smaller cabinets use ceramic nozzles. in a pressure blast system, the abrasive is stored in the pressure vessel then sealed.
it is also found processed into fibers in toothbrushes, false eyelashes and is used in the keycaps of some high end computer keyboards because the texture is highly resistant to wear and discoloration due to uv radiation. pbt can also be made into yarn. this has a natural stretch similar to lycra and can be incorporated into sports wear. due to its chlorine resistance it is commonly found in swimwear.
a leachate is any liquid that, in the course of passing through matter, extracts soluble or suspended solids, or any other component of the material through which it has passed.. leachate is a widely used term in the environmental sciences where it has the specific meaning of a liquid that has dissolved or entrained environmentally harmful substances that may then enter the environment.
in this form, it is also used in plumbing, electrical cable insulation, imitation leather, flooring, signage, phonograph records, inflatable products, and many applications where it replaces rubber. with cotton or linen, it is used in the production of canvas. pure polyvinyl chloride is a white, brittle solid.
since the lining is the portion of the braking system which converts the vehicle's kinetic energy into heat, the lining must be capable of surviving high temperatures without excessive wear leading to frequent replacement or outgassing which causes brake fade, a decrease in the stopping power of the brake .