Toray "Lumirrorâ" polyester
film, is made from polyethylene terephthalate which has
the following molecular structure:
This polymer is formed by the polycondensation reaction
of terephthalic acid and ethylene glycol. "Lumirrorâ"
is made by extruding the polymer in a melted state into
a sheet form, stectching it in the machine and transverse
directions, and then subjucting it to a heat setting treatment.
USE OF "Lumirrorâ"
has many applications as exemplified below:
High-voltage electric equipment
plates of flexible, printed circuits, tapes and cables.
of micas, nonwoven fabrics, glass fabrics, polyethylene,
aluminum foils, metallized materials, etc.
Adhesive tapes for electrical insulation.
"Lumirrorâ" has high tensile
strength along with proper elongation and good edge-tearing
resistance making it suitable for use in electrical insulation.
Its mechanical properties as well as other properties are
well balanced both in the machine and transverse directions.
In addition to the inherent hight insulation quality of polyester
films, "Lumirrorâ" has the
excellent dielectric strenght of 8,000 volts for 1 mil film
60Hz/sec., ASTM D-149-64), without virtually any insulating
Withstands Heat and Cold
The melting point of "Lumirrorâ"
Its applicable temperature range is from -70°C
and it can withstand the temperature as high as 180°C
for a relativelly short time, It does not contain any plasticizer
that very often degrades other films to an oozy state, therefore
it maintains its electrical insulating property for long.
It will remain flexible under a wide range of climatic conditions.
"Lumirrorâ" shows a relatively
low thermo-shrinkage rate and good dimensional stability against
Resistant to Chemicals "Lumirrorâ"
will not be affected by any kind of oil and most of chemicals
and solvents. It can well withstand, therefore, the vanish
impregnating and curing process of motors, transformers, etc.
However, it is not so resistant to alkali or hydrolysis at
temperature because of polyester film's inherent characteristics.