In injection molding, when gas generated from molten resin becomes deposited in the gas-vents of molds, burns and short-shot are formed on products. In this study, we developed a mold for evaluating gas-vent performance, and proposed a quantitative evaluation method of gas-vent performance by supplying a known gas to gas-vent grooves where mold deposits increase during continuous molding. We applied this method for gas-vent grooves with three kinds of gaps and quantitatively inspected the effective cross-sections of the gas-vent grooves by flow rate Q and time T when gas pressure was reduced by half. Furthermore, we applied this method to the continuous molding process and detected the changes in Q and T with shots, calculated the clogging ratio of the effective cross-sectional area of the gas-vent groove, and confirmed that changes in the gas-vent performance can be evaluated quantitatively.

Topics
Materials synthesis and processing
1.
K.
 
Fujimaki
,
H.
 
Yokoi
,
Preprints of Seikei-Kakou Autumnal Meeting 2012
,
319
–
320
(
2012
)
2.
H.
 
Yokoi
,
T.
 
Shimizu
,
Preprints of Seikei-Kakou Annual Meeting 2014
,
295
–
269
(
2014
)
3.
K.
 
Matsuzaka
,
H.
 
Yokoi
,
Preprints of Seikei-Kakou Autumnal Meeting 2017
,
97
–
98
(
2017
)
4.
Y.
 
Senda
,
SEI technical review
,
176
(
1
),
1
–
7
(
2010
)
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© 2019 Author(s).
2019
Author(s)