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A comparison of seven filling to packing switchover methods for injection molding
Author(s) -
Kazmer David O.,
Velusamy Suganya,
Westerdale Sarah,
Johnston Stephen,
Gao Robert X.
Publication year - 2010
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.21731
Subject(s) - switchover , nozzle , materials science , molding (decorative) , position (finance) , process (computing) , standard deviation , mechanical engineering , process capability , computer science , composite material , mathematics , reliability engineering , engineering , statistics , work in process , operations management , finance , economics , operating system
The effectiveness of seven methods for controlling switchover from the filling to packing stage were investigated, including: (1) screw position, (2) injection time, (3) machine pressure, (4) nozzle pressure, (5) runner pressure near the sprue, (6) cavity pressure near the gate, and (7) cavity temperature at the end of flow. The activation threshold for each of the seven switchover methods was iteratively determined so as to produce similar part weights relative to a standard process. A design of experiments was implemented for each of the seven switchover methods that perturbs the process settings by an amount equal to six standard deviations of the standard process so as to replicate the expected long‐term process variation. The results suggest that conventional switchover methods (e.g., screw position) had lower short‐term variation, but other methods were more robust with respect to rejecting long‐term process variation. The merits of different dimensional measurements for quality control are also discussed relative to the society of the plastics industry (SPI) standard tolerances. POLYM. ENG. SCI., 50:2031–2043, 2010. © 2010 Society of Plastics Engineers