Glossary - Introduction to Polymeric Composites with Rice Hulls - page 158

Solvent - a substance, usually liquid, used to dissolve another substance.
Solvent flush - the cleaning of mixing tanks, chambers or mixing heads after each
production cycle. Done manually or automatically.
Solvent flush timers - timers used to control auto flushing systems.
Specific gravity - the density (mass per unit volume) of any material divided by
that of water.
Splashing - a splattering that occurs if a mixed liquid is poured into a mould or
onto a moving conveyor.
Spreader - a device used to assist in placement of a uniformly distributed layer of
mixed liquids.
Stabilisers - additives such as antioxidants and ultraviolet absorbers that help to
maintain the quality of a foam. Silicone stabilisers add stability and control
the semi-liquid foaming mass.
Stannous octoate - one of the commonly used organotin catalysts used in the
manufacture of flexible foams.
Stannous oleate - an organotin catalyst less active than stannous octoate.
Static fatigue - the loss in load-bearing properties of a composite sample after
being under constant compression.
Stator blades - non-rotating or non-moving baffles in a mixing chamber that assist
mixing components.
Stoichemistry - the relationship of the various combining weights of several
interacting chemicals.
Stream - the flow of liquid of one of the components in a formula.
Surfactants - chemical compounds used in a foam formulation to help and control
cell formation during foaming.
Surface active agent - an additive to a foam formulation that helps or hinders the
formation of a fine, uniform cell structure in the resulting foam.
Swelling - excess moisture in a composite mix causes swelling of extrudate during
extrusion.
Synergism - the property exhibited by a blend of some materials having a greater
effectiveness or chemical activity as a mixture than would ordinarily be
expected from the sum of their independent abilities.
System - an ambiguous term used to describe almost any combination or
method of mechanical parts or chemicals that have some relationship
with each other.
T
Tachometer - a device used to indicate the speed of a mechanism (usually the
number of revolutions per minute).
Tacky surface - the condition of the surface of a processed composite that is still
sticky. This feature could be due to insufficient cure time or faulty weighing or
a faulty formulation.