The Polycarbonate Hemisphere Moulding Problem
September 21st, 1998
Interim Prosyma Research Ltd report to Video Controls
S F Bush
Introduction
This is a brief report to Video Controls on the position after the third trial conducted during August 1998.
The samples examined on May 19 showed optical distortion particularly on a polar angle θ of about 30-40o, and azimuthal angle φ of approximately 45-135 and 225 to 315o. There was also significant distortion around the pole N.
The distortion observed seemed likely to be due to two factors:
- Unrelaxed molecules causing internal strain and local differences in refractive index.
- Thickness variation due to local shrinkage differences.