 I CAST ACRYLIC SHEETS
1.What is PMMA?
PMMA is a glassy polymer with an amorphous structure. It has a density of 1.19 g/cm3 and has a very low water absorption. The refractive index ranges from 1.49 to 1.51 depending on the type.
It is one of the earliest polymers and is well known around the world by a variety of trade names Lucite, Oroglas, Perspex and Plexiglas which vary with the country you are in. The original PMMA was seen as a replacement for glass in a variety of applications and is currently used extensively in glazing applications. The material is one of the hardest polymers, rigid, glass-clear with glossy finish and good weather resistance.
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 2. The history of PMMA
Polymethyl methacrylate, more commonly called acrylic or ‘Perspex’, was first produced commercially in the UK in 1934. Its shatter-resistant properties were soon in vast demand for aircraft canopies and all kinds of protective screens. |
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 3.Typical Applications
Optics: Dust covers for hi-fi equipment, sunglasses, watch glasses, lenses, magnifying glasses
Vehicles: Rear lights, indicators, tachometer covers, warning triangles
Electrical engineering: Lamp covers, switch parts, dials, control buttons
Office equipment: Writing and drawing instruments, pens
Medicine: Packaging for tablets, pills, capsules, suppositories, urine containers, sterilisable equipment.
Others: Leaflet dispensers, shatter-resistant glazing, shower cubicles, transparent pipelines, illuminated signs, toys. |
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| 4. Physical Property of Our PMMA |
| Property |
ASTM |
Unit |
Value |
| Optical |
| Light Transmittance |
D1003-61 |
% |
93 |
| Refractive Index |
D542-50 |
D542-50 |
1.49 |
| Thermal |
| Hot Forming Temp |
- |
oC |
140-180 |
| Heat Distortion Temp |
- |
oC |
87 |
| Coefficient of Liner Thermal Expansion |
D696-44 |
cm/cm/oC |
6x10m-5 |
| Specific Heat |
- |
cal/groC |
0.35 |
| Mechenical |
| Specific Gravity |
D792-60T |
|
1.2 |
| Tensile Strength Rupture |
D638-61T |
kg/cm2 |
760 |
| Modulus of Elasticity |
kg/cm2 |
3x104 |
| Elongation of Ruture |
% |
4.5 |
| Flexural Strength Rupture |
D790-63 |
kg/cm2 |
1,260 |
| Modulus of Elasticity |
kg/cm2 |
3x104 |
| Compressive Strength Yield |
D695-63T |
kg/cm2 |
1,260 |
| Modulus of Elasticity |
kg/cm2 |
3x104 |
| Shear Strength |
D732-46 |
kg/cm2 |
630 |
| Impact Strength |
D256-56 |
lb-ft/inch |
0.48 |
| Rockwell Hardness |
D785-62 |
kg/cm2 |
M-95 |
| Electrical |
| Surface Resistivity |
- |
ohm |
>1016 |
| Volume Resistivity |
D257-61 |
ohm cm |
>1515 |
| Dielectric Strength |
D149-64 |
kv/mm |
20 |
| Miscellaneous |
| Flammability |
D635-63 |
mm/min |
33 |
| Water Absorption(24Hrs) |
D570-63 |
% |
0.3 |
| Odor |
- |
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None |
| Taste |
- |
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None |
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