There is an effective trick for getting a significantly greater amount of air out of a runner system, and that is to machine a
flash trap, as shown in Fig.
However, a disk will function as a "
flash trap." That is a thin web of material, usually added down the sides of a runner to prevent flashing.
Geometry constraints did not allow for the option of
flash traps so weld aesthetics were also important.
Another important design consideration is incorporating joint
flash traps to manage excess resin displaced by the welding process, particularly with ultrasonics.