Co-Injection Molding and multi-cavity molding are very common processes for plastic manufacturing. These two systems are sometimes combined and applied to some structure products. The core penetration and flow balance control problems are very difficult to manage. The inside mechanism of co-injection multi-cavity system is not fully figured out yet. In this study, we have focused on the penetration phenomena of core-material in a co-injection multi-cavity molding. The dynamic penetration behavior of core is very sensitive to injection flow rate and skin/core ratio. The longest core penetration has been shown to change dramatically from one runner to the other. In addition, the core penetration behavior will display imbalance at the end of filling. The more core ratio it is, the longer core penetration flows through runner to cavity. However, due to the multi-cavity geometrical structure, the balance of the core penetration for multi-cavity is still challenging. Finally, the simulation is validated with some literature. The results showed that both simulation and experiment are in a good agreement in trend

1.
P.J.
Garner
and
D.F.
Oxley
,
British Patent 1
,
156
,
217
, (
25 June
,
1969
).
2.
V.
Goodship
and
J.C.
Love
,
Multi-Material Injection Molding, Rapra Review Reports 145
,
13
, pp.
1
31
(
2002
).
3.
S.-P.
Sun
,
C.-C.
Hsu
,
C.-T.
Huang
,
K.-C.
Huang
and
S.-C.
Tseng
, “
The Skin/Core Material Distribution of a Co-Injection Molding Process: The Effect of Processing Conditions and Material Selection
”,
SPE ANTEC Tech. Paper
,
Paper No. 1258422
(
2012
)
4.
Jimmy C.
Chien
,
Chao-Tsai
Huang
,
Wen-Hsien
Yang
, and
David C.
Hsu
, “
True 3D CAE Visualization of Intra-Cavity Filling Imbalance in INjection
”,
SPE ANTEC Tech. Paper
, pp
1153
1157
(
2006
).
5.
Ching-Chang
Chien
,
Yi-Hui
Peng
,
Wen-Li
Yang
, and
Rong-Yeu
Chang
, “
Effects of Melt Rotation on Warpage Phenomena in Injection Molding
”,
SPE ANTEC Tech. Paper
, pp
572
576
(
2007
).
6.
John P.
Beaumont
, Beaumont Runner Technologies, Inc. “
Intra-Cavity Filling Imbalances
Technical Brief
(Oct.
2001
)
7.
John P.
Beaumont
and
Jack H.
Young
, “
Mold Filling Imbalances in Geometrically Balanced Runner Systems
Journal of Injection Molding Technology
, Vol.
1
, No.
3
, pp
133
144
(
1997
).
8.
John P.
Beaumont
,
Runner and Gating Design HandBook
, (2nd ed,
Hanser
,
Munich
,
2004
), pp
63
110
.
9.
W.M.
Yang
,
H.
Yokoi
, “
Visual analysis of the flow behavior of core material in a fork portion of plastic sandwich injection moulding
”,
Polymer Testing
,
22
, pp
37
43
(
2003
).
This content is only available via PDF.
You do not currently have access to this content.