Figure 1 is a cross-section sketch of a proper hinge design. Note the use of radii to
improve melt flow and reduce notch sensitivity in the hinge area. Consider, too, the
suggested use of a radiused restriction. This will ensure bending at the thinnest point on
a straight line along the web centerline.
Figure 1 also indicates that shoulders on the two main bodies may be used to offset any
curvature of these parts on the perpendicular plane. These shoulders will also help
when both parts of the molding are quite deep. It is not possible to develop a web hinge
along a curved centerline.