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Polycarbonate is a tough, dimensionally stable, transparent thermoplastic
that has many applications which demand high performance properties. This
versatile thermoplastic maintains its properties over a wide range of
temperatures, from -20°C to 140°C
It has the highest impact resistance of any thermoplastic, transparent up
to 32mm thick in special grades, outstanding dimensional and thermal
stability, exceptional machine ability, stain resistant and non-toxic with
low water absorption. Polycarbonate is optically clear, providing total
luminous transmittance and a very low haze factor. The high impact
strength makes it resistant to repeated blows, shattering and spalling.
Impact strength:
Un notched polycarbonate is virtually unbreakable, making it extremely safe
in areas where parts may be exposed to impact. When exposed to repeated
heavy blow, the material tends to cold form rather than shatter.
Electrical:
Polycarbonate is excellent for electrical applications, because of its
high dielectric strength and high volume resistivity which decreases only
slightly as temperature or humidity is increased.
Machinability:
Parts can be easily machined from standard metal working tools. No special
tools are needed, and finished parts can be polished to a high gloss.
Water or water-soluble cutting oils should be used when machining
polycarbonate, since some standard cutting oils will attack the material.
Polycarbonate can be machined on standard metalworking or woodworking
equipment. Its unique properties permit it to be machined without
chipping, splitting, or breaking.
Annealing:
In some instances where extensive machining is required, an annealing of
semi-finished parts is highly recommended. Annealing can be accomplished
by heating parts at 120°C in a desiccated
air circulating oven for one hour per 25mm of thickness. After heating,
the oven should be turned off and allowed to cool to room temperature
spontaneously.
Bonding:
Polycarbonate can be mechanically bonded by standard methods. It can also
be cemented by using a solvent such as methylene chloride or adhesives
such as epoxy, urethane and silicone. Polycarbonate and also be
ultrasonically or vibrational welded.
Removing paint or other materials:
Fresh paint may be removed by rubbing lightly with a cleaning material
such as isopropyl alcohol. Then the sheet should be washed immediately
with a mild soap or detergent in warm water, and rinsed thoroughly with
clean water. Grease and glazing compound may similarly be removed from the
surface with the above mentioned cleaning materials. Weathered paint may
be lifted off the sheet with masking tape. Razor blades or other sharp
scraping tools should never be used.
Formability:
Standard polycarbonate sheet can be heat formed with proper pre-drying.
Polycarbonate sheet may also be cold formed under special conditions.
Cleaning:
Is best done with warm soapy water, specialised plastic cleaners and
polishes, such as, Sheenmaster, Plexus, Novus #1 or Meguiars #18 may
remove slight scratches. Products such as
abrasive or highly alkaline cleaners, acetone, carbon tetrachloride,
benzene or petrol should not be used, and the sheet should not be cleaned
in hot sun or at high temperatures.
Scratch Removal:
Sheenmaster, Plexus, Novus #1 and #2 or Meguiars #18 and #17 may remove
hairline scratches and minor abrasions. Any polish, however, should be
tested first on a sample area of the polycarbonate sheet.
Decorating:
Polycarbonate products will accept painting, printing, or vacuum
metallising as decorating methods.
UV Stabilisation:
Standard grade Polycarbonate sheet, tube and rod is not UV stabilised,
however, sheet is available in UV stabilised and mar resistant grades.
Applications:
Lenses, high temperature and pressure windows, face shields. Industrial
equipment, guards and housings. Medical equipment components. Instrument
components, electrical insulators and connectors. Windows in pressure
chambers, automotive parts.
Materials available:
Standard Grade:
Clear and tinted sheet. 2440 x 1220 or 2440 x 1830 sheet up to 13mm thick
UV and Mar resistant sheet:
Clear and tinted sheet. 2440 x 1220 or 2440 x 1830 sheet up to 32mm thick
Rod and Tube is available in natural clear.
Typical Properties of Polycarbonate
Property
|
ASTM
|
Value
|
General
|
|
|
| Specific gravity |
D 792 |
1.20 |
| Tensile strength,
Ultimate |
D 638 |
9,000 psi. |
| Elongation at break |
D 638 |
130% |
| Tensile modulus |
D 638 |
3.1x10~5 psi. |
| Rockwell hardness |
D 785 |
R118 |
| Impact strength
(73° F) (notched) |
D 256 |
17.0 ft-lb/inch |
| Flexural strength |
D 790 |
14,200 psi |
| Flexural modulus |
D 790 |
3.4x 10~5 psi. |
| Wear factor against
steel 40 psi 50fpm |
|
2500x10~10 |
| Coefficient of
friction 40psi 50fpm |
|
0.38 Dynamic |
Thermal
|
|
|
| Melting point |
|
155° C |
| Heat deflection at
66 psi |
D 648 |
140° C |
| Heat deflection at
264 psi |
D 648 |
130° C |
| Max serving
temperature for short term |
|
135° C |
| Max serving
temperature for long term |
|
115° C |
| Thermal
conductivity |
C 177 |
1.35
Btu-inch/hr-ft~2- ° F |
| Specific heat |
|
0.30 Btu/lb- ° F |
| Coefficient of
linear thermal expansion |
D 696 |
3.7x10~5 |
| Temp range for
thermal expansion |
|
0-95° C |
Electrical
|
|
|
| Dielectric constant
at 60Hz (23° C) |
D 150 |
3.2 |
| Dissipation factor
at 60Hz (23° C) |
D 150 |
0.001 |
| Volume resistivity |
D 257 |
10~17 ohm-cm |
| Dielectric strength |
D 149 |
380 v/MIL |
Miscellaneous
|
|
|
| Water absorption -
24 hours |
D 570 |
0.15% |
| Water absorption -
saturation |
D 570 |
0.35% |
| Density |
D 792 |
0.0434 lb/inch~3 |
| Flammability |
UL 94 |
V-2 |
| Weathering
Resistance |
|
Limited resistance |
| |
|
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These values are representative of those obtained under standard ASTM
conditions and should not be used to design parts which function under
different conditions.
For more information on Light Transmission of polycarbonate sheet, see
our Light Transmission page. Download this page as a PDF file
Download Polycarbonate MSDS 
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