Cavity orientation can have an effect on machine selection, material utilization, and tooling costs, because it affects the size and dimensions of the mold base and mold runner system (see Dimensions of the Plastic Forming Region and Runner System Model).

By default, a cavity’s orientation (relative to the machine platen) minimizes the effect of gravity on the action of slides. The cavity is oriented so that the motion of the majority of slides is horizontal, that is, parallel to the mold base width direction, the platen width direction, and the factory floor.

Note that in the above illustration, the draw direction is directly towards the viewer. In this case, the cavity shorter dimension (which equals part width--see GCD Extraction for Plastic Molding) is aligned with the length dimension of the machine platen and the length dimension of the mold base.

If there are no slides, or if the slide locations imply no gravitationally preferred orientation (that is, if the number of horizontally-moving slides is the same in either orientation), then by default the cavity is oriented so as to minimize mold base width, as in the illustration below. (This is also true for vertical Insert Injection Molding machines—see Machines for Assembly Molding—since, for vertical machines, gravity is not a factor in the placement of slides.)

Users can override the default cavity orientation with the setup option Cavity Orientation (see User Inputs for Plastic Molding).

The setup option allows users to select one of the following:

The main Plastic Molding processes define custom outputs that specify the slide locations:

If the part is oriented so that the draw diection is towards the viewer and the parting line’s length direction is to the right, then North, South, East, and West are arranged as on a map:

(Note the draw direction and parting line’s length direction are specified as unit vectors by the Parting Line GCD properties Draw Direction and Length Direction.)