Have you ever thought about proportional relationships in sag bending (forming)? Here examples of inverse and direct relationships in the sag bending process:

Inversely Proportional Relationships:

- Viscosity vs. Glass Temperature: As glass temperature rises, viscosity decreases, facilitating the bending / forming process.

- Sagging vs. Edge Size: As sagging (cross curvature) increases, edge size decreases—and vice versa.

- Mold Counterweight vs. Side Sagging: Less counterweight on the mold leads to larger side/wing sagging; increasing counterweight reduces side sagging. This applies to skeleton systems applying their own weight also.

- Radius of Glass Curvature vs. Secondary Images: A smaller curvature radius increases likelihood of secondary image appearance and magnitude.

Directly Proportional Relationships:

- Bending Time vs. Windshield Edge Size: Extended bending time above the transition temperature results in increased sagging, as the glass sags under its own weight.

- Overlapping vs. Edge Stress: Reduced overlap can lead to lower compressive edge stress reduction; glass shifting leaving little to no overlap can collapse edge compression.

- Curvature of Glass vs. Transmission Distortion: Greater curvature increases the amount of optical distortion present in the glass.

These, only few basic examples to demonstrate understanding the fundamental relationships can help you refining bending process.