the shore durometer is a device for measuring the hardness of a material, typically of polymers, elastomers, and rubbers.. higher numbers on the scale indicate a greater resistance to indentation and thus harder materials. lower numbers indicate less resistance and softer materials.
indentation hardness tests are used in mechanical engineering to determine the hardness of a material to deformation. several such tests exist, wherein the examined material is indented until an impression is formed; these tests can be performed on a macroscopic or microscopic scale.
hardness is a measure of the resistance to localized plastic deformation induced by either mechanical indentation or abrasion.some materials e.g. metals are harder than others e.g. plastics, wood .macroscopic hardness is generally characterized by strong intermolecular bonds, but the behavior of solid materials under force is complex; therefore, there are different measurements of hardness .
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 .
polyethylene is of low strength, hardness and rigidity, but has a high ductility and impact strength as well as low friction. it shows strong creep under persistent force, which can be reduced by addition of short fibers. it feels waxy when touched. thermal properties
blade materials are those used to make the blade of a knife or other simple edged hand tool or weapon, such as a hatchet or sword.. the blade of a knife can be made from a variety of materials, the most common being carbon steel, stainless steel, tool steel and alloy steel.other less-common materials used in knife blades include: cobalt and titanium alloys, ceramics, obsidian, and plastic.
epdm has good low temperature properties, with elastic properties to temperatures as low as -40 c depending on the grade and the formulation. a roll of epdm flashing with fleece on the back, used for waterproofing roofs
high-strength low-alloy steel hsla is a type of alloy steel that provides better mechanical properties or greater resistance to corrosion than carbon steel.hsla steels vary from other steels in that they are not made to meet a specific chemical composition but rather specific mechanical properties.
the rubber designated grs government rubber styrene , a copolymer of butadiene and styrene, was the basis for u.s. synthetic rubber production during world war ii. by 1944, a total of 50 factories were manufacturing it, pouring out a volume of the material twice that of the world's natural rubber production before the beginning of the war. it .
history of synthetic rubber. the expanded use of bicycles, and particularly their pneumatic tires, starting in the 1890s, created increased demand for rubber.in 1909, a team headed by fritz hofmann, working at the bayer laboratory in elberfeld, germany, succeeded in polymerizing isoprene, the first synthetic rubber.. the first rubber polymer synthesized from butadiene was created in 1910 by .
low cis polybutadiene. using an alkyllithium e.g. butyllithium as the catalyst produces a polybutadiene called 'low cis' which typically contains 36% cis, 59% trans and 10% vinyl.
due to its low weight and high impact resistance, polycarbonate is the dominant material for making automotive headlamp lenses. however, automotive headlamps require outer surface coatings because of its low scratch resistance and susceptibility to ultraviolet degradation yellowing .
butyl rubber, sometimes just called 'butyl', is a synthetic rubber, a copolymer of isobutylene with isoprene.the abbreviation iir stands for isobutylene isoprene rubber. polyisobutylene, also known as 'pib' or polyisobutene, c 4 h 8 n, is the homopolymer of isobutylene, or 2-methyl-1-propene, on which butyl rubber is based. butyl rubber is produced by polymerization of about 98% of .
rulon is the trade name for a family of ptfe plastics produced by saint-gobain performance plastics. rulon plastics are known for their low coefficient of friction, excellent abrasion resistance, wide range of operating temperatures, and chemical inertness.common applications for rulon include seals, piston rings, bearings, and electrical insulation.
materials with low tear resistance sometimes have poor resistance to abrasion and when damaged will quickly fail this includes hard materials, since hardness is not related to tear resistance . tear resistance of different materials. substances with high tear resistance include epichlorohydrin, natural rubber and polyurethane.
polyvinyl chloride is formed in flat sheets in a variety of thicknesses and colors. as flat sheets, pvc is often expanded to create voids in the interior of the material, providing additional thickness without additional weight and minimal extra cost see closed-cell pvc foamboard . sheets are cut using saws and rotary cutting equipment.
machinability is the ease with which a metal can be cut permitting the removal of the material with a satisfactory finish at low cost. materials with good machinability free machining materials require little power to cut, can be cut quickly, easily obtain a good finish, and do not wear the tooling much.the factors that typically improve a material's performance often degrade its machinability.
silicone rubber offers good resistance to extreme temperatures, being able to operate normally from −100 to 300 c −148 to 572 f . silicone rubber has low tensile strength, poor wear and tear wear properties.