One of the factors limiting the throughput of injection molding is cooling time, which
is the most significant part of the total cycle time. The cooling efficiency of molds
can be considerably improved with additive manufacturing techniques. A 3D printed
injection mold with conformal cooling channels reduces cooling time by 30–40 %. However,
the cooling efficiency of these molds can be further improved with a multi-material
approach and the use of materials with excellent thermal and mechanical properties.
In this study, we propose a hybrid mold insert made of steel and copper, produced
with the combination of Laser Powder Bed Fusion (L-PBF) and casting. The steel shell
that contains conformal cooling channels was printed by L-PBF. Then this shell was
cast with copper. We found that the hybrid mold insert we developed has lower residual
cooling time and heat extraction is more uniform than the conventional printed steel
insert. The developed hybrid mold insert enables a reduction of residual cooling time
by 15 %.
