The NORYL family of modified PPE resins consists of amorphous blends of PPO polyphenylene ether (PPE) resin and polystyrene. They combine the inherent benefits of PPE resin (affordable high heat resistance, good electrical insulation properties, excellent hydrolytic stability and the ability to use non-halogen fire retardant packages), with excellent dimensional stability, good processibility and low density.
Originally developed in 1966 by General Electric Plastics (now owned by SABIC). NORYL is a registered trademark of SABIC Innovative Plastics IP B.V.
NORYL resins are a rare example of a homogeneous mixture of two polymers. Most polymers are incompatible with one another, so tend to produce separate phases when mixed. The two polymers compatibility in NORYL resins is due to the presence of a benzene ring in the repeat units of both chains.
An impeller is a rotating component of a centrifugal pump, usually made of iron, steel, bronze, brass, aluminium or plastic, which transfers energy from the motor that drives the pump to the fluid being pumped by accelerating the fluid outwards from the center of rotation. The velocity achieved by the impeller transfers into pressure when the outward movement of the fluid is confined by the pump casing. Impellers are usually short cylinders with an open inlet (called an eye) to accept incoming fluid, vanes to push the fluid radially, and a splined, keyed, or threaded bore to accept a drive-shaft.
The impeller made out of cast material in many cases may be called rotor, also. It is cheaper to cast the radial impeller right in the support it is fitted on, which is put in motion by the gearbox from an electric motor, combustion engine or by steam driven turbine. The rotor usually names both the spindle and the impeller when they are mounted by bolts.