What is the UHMWPE fiber?
Ultra-high molecular weight polyethylene is unbranched linear polyethylene with a molecular weight of over 1.5 million. Common molecular weights are 1-6 million, up to 10 million, with chain lengths and molecular weights 10-20 and 20-30 times that of HDPE respectively.
Modulus: 91～140N/tex.
Elongation: 3.5% to 3.7%.
Density: 0.920～0.964g/cm3
Heat distortion temperature: 85℃, melting point 130～136℃.
What are UHMWPE fiber properties?
1, Low density: UHMWPE density is 56% lower than PTFE, 33% lower than POM, 30% lower than PBTP, relative to other engineering plastics density are low. It can float in the water.
2, Good abrasion resistance: UHMWPE abrasion resistance is directly proportional to the molecular weight, the higher the molecular weight, the better its abrasion resistance.
3, Very low friction factor (0.05 ~ 0.11), so excellent self-lubricating properties.
4, High specific strength, high specific modulus. Specific strength is more than ten times that of steel wire of the same cross-section, and specific modulus is second only to that of special-grade carbon fibre.
5, Good chemical resistance: based on UHMWPE is a saturated molecular group structure, chemical stability is very high, in addition to strong oxidising acid, in a certain temperature and concentration range can withstand a variety of corrosive media (acids, alkalis, salts) and organic media (except the solvent of the Tantalum). 20 ℃ and 80 ℃ of the 80 kinds of organic solvents in the impregnation of 30d, the appearance of the appearance of no anomalous phenomena, and other physical properties are also almost no changes.
6, Low elongation at break, large work at break, has a strong ability to absorb energy, and thus has outstanding impact resistance and cutting resistance.
7, Anti-ultraviolet radiation, anti-neutron and γ-ray, than the high energy absorption, low dielectric constant, high electromagnetic wave transmittance.
What are the applications of UHMWPE fiber?
Defence
Because of the fibre’s good impact resistance, than the energy absorption, in the military can be made of protective clothing, helmets, bulletproof materials, such as helicopters, tanks and ships, armour protection plate, radar protection shell cover, missile cover, bulletproof vests, anti-stabbing clothing, shields, etc., which is the most notable application of bulletproof vests. It has the advantage of lightness and flexibility, and the bulletproof effect is better than aramid. In addition, ultra-high molecular weight polyethylene fibre composites than the bullet impact load value of U/p is 10 times that of steel, glass fibre and aramid more than 2 times. Overseas bulletproof and riot helmets made of resin composites reinforced with this fibre have become a substitute for steel helmets and aramid reinforced composite helmets.
Aviation
In aerospace engineering, because of the fibre composites are lightweight, high strength and good impact resistance, they are suitable for various aircraft wing tip structures, airship structures and buoy aircraft. The fibre can also be used as deceleration parachutes for space shuttle landing and ropes for suspending heavy loads on aircraft, replacing traditional steel cables and synthetic fibre ropes, which are developing at an exceptionally fast pace.
Civilian
(1) Ropes, cables and cables: the ropes, cables, sails and fishing gear made of this fibre are suitable for marine engineering, which is the initial use of this fibre. It is commonly used in negative force ropes, heavy load ropes, salvage ropes, tow ropes, sailing ropes and fishing lines. Ropes made from this fibre have a breaking length under dead weight that is eight times that of steel rope and twice that of aramid. The ropes are used as fixed anchor ropes for supertankers, offshore operating platforms, lighthouses, etc. It solves the problems of reduced strength and breakage of cables caused by corrosion, hydrolysis, UV degradation, etc. encountered in the past by using steel cables, and the problems of frequent replacement caused by corrosion, hydrolysis, UV degradation, etc. encountered in the past by using nylon and polyester cables.
(2) sports equipment supplies: in sporting goods have been made helmets, skis, sailboards, fishing rods, rackets and bicycles, gliding boards, ultra-lightweight aircraft parts, etc., its performance is better than traditional materials.
(3) Used as biomaterials: the fibre-reinforced composite materials for dental materials, medical grafts and plastic sutures, etc., its biocompatibility and durability are better, and has a high degree of stability, does not cause allergies, has been used for clinical applications. It is also used in medical gloves and other medical measures.
(4) Industrially, the fibre and its composite materials can be used as pressure-resistant containers, conveyor belts, filtering materials, automobile buffer boards, etc.; architecturally, it can be used as walls, partition structures, etc., and it can be used as reinforced cement composite materials to improve the toughness of cement and enhance its impact resistance. It can be used to make safety protection products such as anti-cutting gloves.