The ultem tm family of amorphous thermoplastic polyetherimide pei resins offers outstanding elevated thermal resistance, high strength and stiffness, and broad chemical resistance. Environmental stress cracking esc is considered a lead ing cause of plastic part failure. Natural ultem sheet great for applications that require improved stiffness, glass fiber filled grades with filler levels of 10% 40% are available, however the 30% glass fill is the most. Quantum polymer maintains a large inventory of ultem 2300 extruded rods and. Resistance to this mode of failure can be best gauged through constanttensileload testing, while taking into account the differences in yield point among various polyethylenes. Environmental stress cracking can take place through continuous crack growth or via a stepwise progressive mechanism of cracking and arrest, depending on the molecular structure of the plastic, the composition of the chemical agent, the level of stress, and other environmental conditions. Technical resources craftech industries highperformance. China recycled gf30 polyetherimide ultem pei resin plastic. The results show crack growth in solvents at very low g i levels as compared with tests in air. Environmental stress cracking of poly3hydroxibutyrate.
Stresses that cause environmental cracking arise from residual cold work, welding, grinding, thermal treatment, or may be externally applied during service and, to be effective, must be tensile as opposed to compressive. Stresses that cause environmental cracking arise from residual cold work, welding, grinding, thermal treatment, or may be externally applied during service and, to be effective. Stress cracking is a frequent problem in plastic applications. Environmental cracking or environmentally assisted cracking eac is the cracking of a material wherein an interaction with its environment is a causative factor in conjunction with tensile stress authors note. During stress corrosion cracking, the material is relatively unattacked by the corrosive agent, but fine cracks form within it. It has been estimated that 15% of all failures of plastic materials in commercial use are related to environmental stress cracking esc 3. Throughout a semicrystalline polymer, there may be small packets of crystals contained within the amorphous matrix, with some polymer chains being so long that they can be in two different crystals at the same time. The tensile stress may be applied externally or may simply be a consequence of residual, or moldedin, stresses. Ultem machining sentinel plastics experts in all plastic. Environmental stress cracking of polyvinyl chloride in. Environmental stress cracking in polyethylene takes place because of interlamellar failure, which in turn is caused by relaxation of tie molecules.
Since variance of any of these factors can change the environmental stress crack resistance of the container, the test results are representative only of a given test performed under defined conditions in the laboratory. Sabic ultem 2300f2310f natural black peipolyetherimide resin. China sabic ultem pei resin 2210 natural pei 22107301. Craftech manufactures precision machined and molded plastic fasteners and components in a wide range of plastic materials from commodity to exotic. Environmental stress cracking is a failure mechanism whereby a plastic material cracks due to contact with an incompatible chemical agent while under tensile stress. It is a physical process driven by the applied stress but accelerated by. Environmental stress cracking esc is a common phenomenon that affects commercially available polymeric materials exposed to liquid agents under external loading, and it is one of the most common. According to astm d883, stress cracking is defined as an external or internal crack in a plastic caused by tensile stresses less than its shortterm mechanical. The following is a selection of plastic materials that are regularly processed in our manufacturing facility. Ultem 2300 2300r 2300f 2300fc sabic pei resins, find complete details about ultem 2300 2300r 2300f 2300fc sabic pei resins,pei resin 1010 from other plastic raw materials supplier or manufacturerhuaian ruanke trade co. Environmental stress cracking esc is one of the most important causes of polymer premature failure, occurring when a combination of mechanical load and an aggressive fluid is applied.
It became apparent that environmental stress failure was an achilles heel for these otherwise high performance materials and exposure to application environments needed to be strongly considered. Plastics will exhibit environmental stress cracking when exposed to an aggressive chemical environment if and only if a tensile stress is present. Stress corrosion cracking is a phenomenon where a synergistic action of corrosion and tensile stress leads to brittle fracture of normally ductile materials at generally lower stress levels. The ultem resin family of amorphous thermoplastic pei polyetherimide resins offers outstanding elevated thermal resistance, high strength, stiffness and broad chemical resistance. Environmental stress cracking apparatus model 4606 the rayran environmental stress cracking apparatus determines the susceptibility of ethylene plastics to stresscracking when exposed to different environments such as soaps, wetting agents, oils and detergents.
Prevent failure by understanding why plastic parts crack. These materials are available in transparent and opaque. When it does burn, it generates exceptionally low smoke that is no more toxic than wood smoke. Even when exposed to alcohols, acids, solvents, aliphatic hydrocarbons, and automotive and aircraft fluids, ultem retains its strength and resists cracking. Astm d2561 17 standard test method for environmental stress. Solvent stress cracking studies have been carried out in o.
Ultem pei stock shapes are inherently flame resistant with low smoke emission. But there are methods for getting to the root of the problem. Quantum polymer maintains a large inventory of ultem 2300 extruded rods and plates. Environmental stress cracking apparatus testing machines. Its environmental stress and crack resistance make it an excellent plastic for any. Esc is the consequence of a combination of mechanical stress and exposure to an aggressive chemical. Ultem injection molding ultem plastic molding resin. These materials are available in transparent and opaque custom colors, as well as glass filled grades. Pei resins are used in medical and chemical applications due to their heat resistance, solvent.
The material is an unfilled polyetherimide, made by g. Environmental stress cracking of polypropylene springerlink. Investigations on environmental stress cracking resistance. Jansen stork technimet new berlin, wisconsin e nvironmental stress cracking esc is a phenomenon in which a plastic resin is degraded by a chemical agent while under stress, and it is the leading cause of plastic component failure. Environmental stress cracking esc is the premature cracking of a polymer due to the combined action of a stress and a fluid. Environmental stress cracking esc is not the result of the continual battle that the plastics industry has in convincing environmentalists and politicians that plastics can be the solution to environmental problems and not the cause. Environmental stress cracking esc is one of the most common causes of unexpected brittle failure of thermoplastic polymers known at present. Ultem is an unreinforced grade offering a heat deflection temperature of 200c 392f at 264 psi and a ul 94 flammability rating of vo at 0. To avoid problems, select your material with care and employ the fundamental rules of good design and processing. Environmental stress cracking the the chemical agent does. Glass filled grades appear tan or greenish in color. Plastic failure through environmental stress cracking.
Pei resins are used in medical and chemical applications due to their heat resistance, solvent resistance and flame resistance. Evaluating environmental stress cracking of medical plastics. China recycled gf30 polyetherimide ultem pei resin plastic pellets, find details about china pei resin, pei granule from recycled gf30 polyetherimide ultem pei resin plastic pellets jiangsu aimi tech co. Environmental stress cracking apparatus model 4606 the rayran environmental stress cracking apparatus determines the susceptibility of ethylene plastics to stress cracking when exposed to different environments such as soaps, wetting agents, oils and detergents. According to astm d883, stress cracking is defined as an external or internal crack in a plastic caused by tensile stresses less than its shortterm mechanical strength. The bent strip test is a constant strain test, but polyethylene relaxes when strained. Because of this, environmental stress cracking and creep rupture are parallel failure mechanisms. Ultem exhibits inherent flame resistance and is extremely difficult to ignite.
Ultem pei stock shapes display property retention and resistance to environmental stress cracking when exposed to a wide variety of chemicals. The phenomenon is well know by polymer producers and product designers but its mechanisms are not very well understood. Environmental stress cracking resistance of polyethylene. Due to ultem s high mechanical strength and heat resistant composition, it is ideal for use in harsh environmental conditions needing chemical resistant features and high temperature resistance. Materials for access to our material data sheet library, please click here. Environmental stress crack resistance of polyethylene.
Environmental cracking is also known as caustic embrittlement, which refers to the cracking in riveted boiler plates made from steel, or as environmentallyassisted cracking eac. Ultem resin sabic ultem emco industrial plastics. Ultem 2300 2300r 2300f 2300fc sabic pei resins buy pei. Environmental stress cracking esc is one of the most common causes of unexpected brittle failure of thermoplastic especially amorphous polymers known at present. Stocked in ultem rods and sheets, natural and black and ultem 2300 a 30% glass filled version in natural a dark amber and black. It is associated with the phenomenon of crazing and solvent plasticization of the polymer.
Environmental stress crack resistance of polyethylene stress crack reagent concentration in the case of the most commonly used stress crack reagent, igepal co630, as the concentration of water in the stress cracking media increases, the faster the esc onset. Select material names below for a brief description and access. Stock shapes extruded from ultem 2300 offer outstanding elevated thermal resistance, high strength and stiffness, and broad chemical resistance. Environmental stress cracking is involved with some 25% of plastic part failures.
Definition of environmental stress cracking esc environmental stress cracking esc in plastics means the failure at about room temperature due to continuously acting external andor internal stresses in the presence of surface active substances known as stress cracking agents such as alcohols, soaps, dyes, agents containing moisture. It is the premature embrittlement and subsequent cracking of a plastic due to the simultaneous and synergistic action of stress and contact with a chemical agent. When the material is under certain conditions of stress, these reagents can. Environmental stress cracking is a failure mechanism very similar to slow crack growth in terms of shape. Pei resin, pei granule, pei pellets manufacturer supplier in china, offering sabic ultem pei resin 2210 natural pei 22107301 black, factory price weight loss orlistat raw test steroids raw powder, recycled gf30 polyetherimide ultem pei resin plastic pellets and so on. Environmental stress cracking the the chemical agent. Environmental stress cracking can take place through continuous crack growth or via a stepwise progressive mechanism of cracking and arrest, depending on the molecular structure of the plastic, the composition of the chemical agent, the level. This stress relaxation allows testing to run without failure for very long periods 1,500 hours. Environmental stress cracking article about environmental.
1113 221 218 1154 1296 1435 660 719 471 446 143 1441 107 1346 134 1162 307 863 1450 913 1412 263 1181 486 28 1479 794 1369 897 470 535 785 196