宁津县鑫丰化工有限公司

Ultra-high molecular weight polyethylene
English is, this is the highest quality polyethylene currently available that can be used in harsh working environments and for various purposes
. Very good applicability under many difficult application conditions. Ultra-high molecular weight is a unique feature of this polymer. It has a molecular weight of up to 10,000, while high-density polyethylene resin only has a molecular weight of 10,000 to 10,000. This difference ensures that ultra-high molecular weight polyethylene has sufficient strength to achieve wear resistance and impact resistance that other lower polymer products cannot have. Ultra-high molecular weight polyethylene's ultra-high molecular weight means that it does not melt and flows like a liquid, so the processing method is derived from powder metal technology. Traditional plastics processing techniques, such as injection molding blow molding and heat setting, cannot be applied to UHMWPE. Extrusion is the most common processing method used for this resin, which produces a tougher product.
Raw materials
According to the classification method of Phillips Petroleum Company in the United States, polyethylene with a molecular weight of more than 10,000 is called ultra-high molecular weight polyethylene (
). The German Hoechst Company, the American Hercules Company and the Japanese Mitsui Petrochemical Company are the three major production companies in the world. The main manufacturer in China is the Chemical Plant of Beijing Auxiliary Factory No. 2 and Shanghai Gaoqiao Petrochemical Company. The raw material of ultra-high molecular weight polyethylene board is ultra-high molecular weight polyethylene with a molecular weight of more than 10,000
Features
The extremely high molecular weight gives it excellent performance, and it is an affordable thermoplastic engineering plastic with excellent performance , it almost combines the advantages of various plastics, and has comprehensive properties such as wear resistance, impact resistance, self-lubrication, corrosion resistance, impact absorption, low temperature resistance, hygiene, non-toxic, not easy to adhere, not easy to absorb water, low density, and other unmatched by ordinary polyethylene and other engineering plastics. In fact, there is currently no single polymer material that has so many excellent properties.
Wear resistance
The wear resistance of plastics ranks the highest among plastics and exceeds that of some metals. The picture shows the comparison of wear resistance with other materials. It can be seen from the figure that compared with other engineering plastics, the mortar wear index of PTFE is only /, and compared with metal, it is / of carbon steel and / of brass. With such high wear resistance, it is difficult to test its wear resistance using the general plastic wear test method, so a mortar wear test device was specially designed. Wear resistance is proportional to molecular weight. The higher the molecular weight, the better the wear resistance.
Impact Resistance
The impact strength of times, the remainder of the sum. The impact resistance is so high that it is difficult to break it using ordinary impact testing methods. Its impact strength increases with the increase of molecular weight, reaches the maximum value when the molecular weight is 10,000, and then gradually decreases as the molecular weight continues to increase. It is worth pointing out that it can maintain excellent impact strength in liquid nitrogen (℃), a feature that other plastics do not have. Additionally, it becomes harder on repeated impacts to the surface.
Self-lubricating properties
It has extremely low friction coefficient and therefore has excellent self-lubricating properties. The table shows the comparison of friction factors with other engineering plastics. It can be seen from the table that the dynamic friction factor of is / under water lubrication conditions, which is second only to polytetrafluoroethylene with the best self-lubricating properties among plastics under non-lubrication conditions. When it works in sliding or rotating form , which has better lubricity than steel and brass after adding lubricant. Therefore, it is known as a friction material with very ideal cost/performance in the field of tribology.
Chemical resistance
It has excellent chemical resistance. In addition to strong oxidizing acids, it can withstand various corrosive media (acid, alkali and salt) and organic media (acid, alkali and salt) and organic media ( except tea solvents). When it is immersed in organic solvents at ℃ and ℃, there is no abnormality in the appearance, and there is almost no change in other physical properties.
Impact energy absorption
It has excellent impact energy absorption. The impact energy absorption value is the highest among all plastics, so it has good noise damping performance and excellent sound-cutting effect.
Low temperature resistance
It has excellent low temperature resistance and is still ductile at liquid helium temperature (℃), so it can be used as low temperature resistant parts in the nuclear industry.
Hygienic and non-toxic
Hygienic and non-toxic, it can be used in contact with food and drugs.
Non-stickiness
The surface adsorption capacity is very weak, and its anti-stick ability is second only to the best non-stick among plastics, so the surface of the product is not easy to stick to other materials.
Water absorption
The water absorption rate is very low and is generally less than 0,000, so it generally does not need to be dried before molding.
Density
Compared with other engineering plastics, the density is relatively low.
Tensile strength
Due to the necessary structural characteristics toward stretch orientation, it has unparalleled ultra-high tensile strength, so it can be produced by gel spinning method with ultra-high elastic modulus and Strong fiber, its tensile strength is as high as tensile elastic modulus as high as its fiber specific strength is the highest among all fibers that have been commercialized so far, which is three times greater than carbon fiber, three times greater than steel wire, and greater than aramid fiber.
Aging resistance
Ultra high molecular weight polyethylene has good aging resistance, can be used longer and saves costs.
Energy Absorption
Utilizing the energy absorption characteristics of ultra-high molecular weight polyethylene, it can be widely used in the mechanical equipment industry and used on steel surfaces to reduce friction and improve efficiency.
Flame retardant
Ultra-high molecular weight polyethylene is made flame retardant by adding flame retardants.
Application fields of products
Industrial applications of ultra-high molecular weight polyethylene products
Due to its good wear resistance, environmental protection, anti-static buffering, high wear resistance, moisture resistance, corrosion resistance, easy processing, shock absorption, no noise, economical and economical It has deformation resistance, impact resistance and self-lubricating properties, so it is very suitable for making various wear-resistant mechanical parts, such as supporting wheel bushings, nozzles and stirring blades. It has a wide range of applications.
Application examples
Transportation machinery
Guide rail conveyor belt transmission device slider seat fixed plate flow production line timing star wheel
Food machinery
star wheel bottle delivery counting screw filling machine Bearings, bottle grabbing machine parts, gaskets, guide pins, cylinder gears, rollers, sprockets, handles
Papermaking machinery
Suction tank cover, deflector pulley, scraper, bearings, leaf mouth, filter, oil reservoir, anti-wear strip, felt cleaning machine
Textile machinery
Open-width machine shock absorber baffle connector crankshaft connecting rod shuttle rod sweeper needle deflector bearing swing rear beam
Construction machinery agricultural machinery
Bulldozer pushes up the sheet material automatically Unloading truck compartment lining tractor pear knife lining
Chemical machinery
Valve body pump body gasket filter gear nut sealing ring nozzle cock bushing bellows
port machinery and ship machinery
ship Components Side roller wear-resistant blocks for bridge cranes and other spare parts
General machinery
Various gears, bearing bushes, sliding plates, clutch guides, brakes, hinges, elastic couplings, roller rollers, fasteners, lifting tables and sliding Components
Dyeing and finishing
Exhaust dyeing machine bearing scraper sliding plate gasket seal tenter guide plate
Stationery and sports supplies
Snow lining power sled skating rink pavement ice rink protection rack
Medical supplies
Rectangular outer material parts, artificial joints, prostheses, etc.
Others
Shielding plate electroplating parts for cryogenic machinery atomic energy power stations, ultra-low temperature mechanical parts
Production technology
Due to ultra-high The viscosity of molecular weight polyethylene in the molten state is as high as *, the fluidity is extremely poor, and its melt index is almost zero, so it is difficult to process with general mechanical processing methods. In recent years, the processing technology of ultra-high molecular weight polyethylene has developed rapidly. Through the transformation of ordinary processing equipment, ultra-high molecular weight polyethylene has developed from the initial pressing and sintering molding to extrusion blow molding and injection
br/>Molding and other special methods of molding.
General processing technology
Press sintering
Press sintering is the most original processing method of ultra-high molecular weight polyethylene
. The production efficiency of this method is quite low and it is prone to oxidation and degradation. In order to improve production efficiency, direct electric heating can be used.
〔〕In addition, the company has developed an ultra-high-speed sintering processing method
〔〕Using a blade mixer, the maximum speed of blade rotation can reach /, so that the material can be mixed in just a few seconds. rise to processing temperature.