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Density 1.24 - 1.25 g/cm 3
Glass transition temperature (Tg) 187 - 190 °C
Max / Min continuous Service temperature 160 - 180 °C / -100 °C
Processed by Injection moulding, extrusion, extrusion blow moulding methods
Processing temperature: 340 to 390°C
Drying is needed: 3 hours at 135°C to 165°C, % of water < 0.04
As many amorphous polymer, melt viscosity in quite high. Polysulfone exhibits
good melt strength which facilitates extrusion processes.
Injection Moulding: A mould temperature of 100-120°C is recommended. Screws
of L/D around 25 are recommended.
Extrusion: temperature: 370-400°C, L/D around 20 is recommended
PSUs are transparent, amorphous thermoplastic with high mechanical strength and
rigidity. Reinforcement improves toughness and further enhances dimensional
stability, but turns materials opaque. They have high permanent operating
temperature; outstanding high creep strength over a wide range of temperatures.
Its exhibit good electrical properties with a high dielectric strength and a low
dissipation factor, posses self-extinguishing ability, low moisture absorption and
are resistance to greases, hot water, steam, many solvents and chemicals.
They can be machined, joined by gluing or welding (frictional, thermal and
ultrasonic) and can be painted, metallised or electroplated.
The glass transition temperature of PSU is lower than that of PES and PPSU: it is
just in-between PC (150 °C) and of PES / PPSU /PEI (220°C). PES has better creep
resistance, smoke emission on burning characteristics and a higher HDT than PSU;
whereas PSU absorbs less water and is cheaper than PES.
Strengths: Good resistance to repeated steam sterilization, gamma and E-beam
radiation, good mechanical and creep properties in a large temperature range,
resistance to oxidation, outstanding compression resistance, Good FR and
electrical properties.
Limitations: High cost, not recommended for service temperatures above 170°C,
attacked by polar solvents such as Ketones, Chlorinated solvents, Aromatic
hydrocarbons, high melt viscosity: tendency toward jetting, drying is required before
processing, poor weatherability, Subject to stress cracking
Applications: Medical devices, for repeated sterilized instruments like medical
respirators, humidifiers, dental reamers and dialysis equipment, appliances,
microwave grilles, dishwasher, automotive headlight reflectors, oil pump pistons,
electrical components, fuses, fuel system components, coffee, dispensers, Toaster
parts, electronic circuit boards, capacitor films, switches and connectors, hot water
fittings, manifolds, Insulation foam, Gas separation, drinking water filtration membranes
43) Polyethersulphone (PESU):
Is an amorphous, slightly yellowish transparent thermoplastic, having
characteristics similar to those of PSU. However, PES has better chemical
resistance as well as higher impact strength when compared to PSU.
Density 1.37 - 1.46 g/cm 3
Glass transition temperature 210 - 230 °C

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