Polyester Properties

1. Optical Transmission in the visible region of window glass.

2. Refractive Index 1.64 to 4.67

3. Melting Point 250 - 265 centigrade

4. Water vapour permeability, slight, 0.7g/m2 24 hrs/mm at 37.9 centigrade and 90% rh

5. Tensile Tear Strength (23 mu) 2800 kg/cm2 at 25 centigrade (Higher than any other plastic film)

6. Propagated Tear Strength (23mu) 7.36N/mm

7. Initial Tear Strength (23mu) 250N/mm (Very much higher than PVC or Cellulose Acetate)

8. Folding Strength (23mu) 14,000 measured by M.I.T. at 1kg loading at 25 centigrade

9. Fungus Resistance, inert

10. Flammability, slow to self-extinguishing

11. 1000 Microns = 1mm , so the higher the value, the thicker the polyester film.