Glossary - Introduction to Polymeric Composites with Rice Hulls - page 155

Mechanical mixing head - a mixing device with a power-driven rotor and impeller.
Mer - a basic unit in a plastic and the repeating structural unit in a polymer.
Mesh pack - a set of fine steel mesh placed at the head of an extruder to prevent
foreign matter entering.
Metering - the calibrated flow of a composite mix through the extruder.
Metering system - the pumping system used to accurately control the flow of a mix.
Methylene chloride - a chlorinated hydrocarbon commonly used as a secondary
blowing agent and as a cheap cleaning solvent in the plastics industry.
Mill - in industry a 'hammer mill' is used to produce fine particles.
Mixer - a mechanical device that can mix two or more materials together
homogenously.
Modified pre-polymer - a polymer system that has been modified by diluting the
catalyst system with plasticisers and additives.
Modulus of elasticity - the ratio of stress-to-strain in a material that is elastically
deformed.
Monitoring - checking of a process at various stages of production and afterwards.
Mould packing - small percentage of excess total liquid poured to counter weight
loss due to gas.
Mould release agents - chemical compounds applied to the insides of a mould to
prevent cured products from sticking to the mould.
Moulding - whereby a mix is put into a mould cavity to mould a shaped product
(used in injection or compression moulding).
N
Nominal throughput range - a throughput or flow rate capacity of a particular
machine designed to handle normal formulations.
Nozzle - a very general term used to describe the discharge opening or discharge
port of the mixing head.
Nucleation - generation of small uniform bubbles by an injection of air or other
liquid chemicals to improve quality or for light weight.
O
Organotin catalysts - a family of foam catalysts used to help in blowing and gelation.
Overfill - the amount of unwanted excess of a composite mix poured into a mould
intentionally or otherwise.
P
Permeability - the rate at which a liquid or gas can penetrate through a material.
Pin impeller - a rotating mixing blade having a straight shaft having a series of
round, square or hexagonal shaped 'pins' mounted at right angles to the shaft.
Other variations are possible.