Study of Ultrasonic Injection Molding
Date Issued
2010
Date
2010
Author(s)
Fang, Ting-Wei
Abstract
This research is devoted to investigating the effects of ultrasonic vibration in the filling and packing behaviors of the Polycarbonate (PC) melt in flat plates and plates with microstructures.
First, with and without ultrasonic vibration, the filling behaviors of PC melt in the cavities of flat plates of 1.0 mm and 0.5 mm thick with aid of short-shots. This study discovered that the length and weights of short-shots in filling the 1mm-thick cavities increased with ultrasonic vibration, compared to these without ultrasound. On the other hand, little improvements were observed in the filling of the thin-wall parts of 0.5 mm thick. The effects ultrasonic vibration in extending the gate freeze time were systematically investigated. Ultrasonic vibration could significantly prolongs the gate freeze time and extends the packing process. It was found that the amplitude of ultrasonic vibration must exceed a particular level for the effect of ultrasonic vibration to be significant. The ultrasonic vibration in this study showed no effects in reducing residual stress. This maybe due to the limit of our facility and implementation.
In the other part of this research, the replication of V-groove microstructures in the plates of 1 mm thick were also investigated. It was found that ultrasonic vibration improves replication of microstructrues. The effects of vibration in injection molding with different injection speeds, packing pressures and mold temperatures have been studied. The improvements in enhancing the degree of replication are significant, especially at low packing pressure.
This study demonstrates that ultrasonic vibration improves the filling and packing of flat and v-grooved plates, showing the potential of using the ultrasonic vibration in enhancing the molding capacity of injection molding.
Subjects
Ultrasonic injection molding
Filling behavior
Microstructures
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
ntu-99-R97522724-1.pdf
Size
23.53 KB
Format
Adobe PDF
Checksum
(MD5):af198f45b121bbbae51dccde3e792d80