Large, thin plate-shaped parts usually are strengthened with structura
l ribs. Ribs also serve as gas channels with gas-assisted technology.
The layout and geometry of these gas-channel ribs are critical to the
gas-assisted injection molding (GAIM) process. In this study, the effe
cts of rib geometry, including aspect ratio and fillet geometry, on th
e GAIM process are investigated. Experimental results indicate that in
creasing the rib width widens the allowable operation range and thus i
mproves the moldability. Adding fillets to the rib corner significantl
y enhances the moldability. Adding fillets also reduces the loss of ri
gidity due to void formation in the rib. A curved fillet improves mold
ability and rigidity more than one that is straight.