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Thermoforming:
The process of heating a thermoplastic sheet to a working
temperature and then forming it into a finished shape
by means of heat or pressure. (Modern Plastics Encyclopedia
1995).
Thermoplastic:
(1) Capable of being repeatedly softened by heat and
hardened by cooling.
(2) A material that will repeatedly soften when heated
and harden when cooled. Typical of the thermoplastic
family are the styrene polymers and copolymers, acrylics,
cellulosics, polyethylenes, polypropylene, vinyls and
nylons. (Plastics Engineering Handbook of The Society
of the Plastics Industry, Inc., edited by Michael L.
Berins, 1991).
Thermoset:
A material that will undergo or has undergone a chemical
reaction through the application of heat and pressure,
catalysts, ultraviolet light, etc., leading to a relatively
infusible state. Typical of the plastics in the thermosetting
family are the aminos (melamine and urea), most polyesters,
alkyds, epoxies, and phenolics. (Plastics Engineering
Handbook of The Society of the Plastics Industry, Inc.,
edited by Michael L. Berins, 1991).
Tacticity
The orderliness of the succession of configurational
repeating units in the main chain of a regular macromolecule
(or oligomer or block).
Tear Resistance
The force required to tear completely across a specifically
nicked rubber test specimen, or right angle test specimen,
by elongating at a specific rate. See ASTM Method D
624.
Tear strength
Film must have certain resistance to tear loading. Tear
strength indicates the average force required to propagate
tearing through a specified length of the film sample.
This test is suitable for investigation of orientation
balance of the film. Normally tear strength is measured
in two directions, parallel and transverse to the extrusion
direction of the film.
Telomer
A substance composed of macromolecules or oligomer molecules
having few, usually terminal, reactive functional groups
enabling, under appropriate conditions, the formation
of larger macromolecules
Thermogravimetry (TG,
TGA)
Thermogravimetry (TG, TGA) can be used to measure any
reaction involving mass change. TG analysis is often
complementary test to DSC, the weight loss curve giving
a picture of the make-up of the material by showing
the temperatures at which individual components volatilize.
Thermomechanical Analysis
(TMA)
Thermomechanical Analysis (TMA) is is a technique for
monitoring changes of physical dimensions (expansion,
schrinkage, penetration) while the temperature of the
sample is changed.
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Plastic
Brief
