Wall Slip of Linear Polymer Melts During Ultrasonic-assisted Micro-injection Molding

2018 ◽  
Vol 59 (S1) ◽  
pp. E7-E13 ◽  
Author(s):  
Shan Gao ◽  
Zhongjun Qiu ◽  
Junhao Ouyang ◽  
Yujun Yang
Keyword(s):  
Injection Molding ◽  
Polymer Melts ◽  
Wall Slip ◽  
Linear Polymer ◽  
Micro Injection Molding ◽  
Ultrasonic Assisted

Effects of Wall Slip on Filling Flow for Polymer Melt in Micro Injection Molding

2014 ◽  
Vol 609-610 ◽  
pp. 617-622 ◽  
Author(s):  
Jian Zhuang ◽  
Ya Jun Zhang ◽  
Da Ming Wu ◽  
Li Zhu Liu ◽  
Cheng Jun Sun ◽  
...  
Keyword(s):  
Injection Molding ◽  
Slip Velocity ◽  
Polymer Melt ◽  
Wall Slip ◽  
Diameter Ratio ◽  
Micro Injection Molding ◽  
Slip Mechanism ◽  
Inlet Flow Rate ◽  
Section Size ◽  
Slip Coefficients

Effect of wall slip on melt filling flow behaviors in micro injection molding are investigated based on analysis of wall slip mechanism for polymer melt flowing at filling stage. By means of comparisons, slip coefficients in different microchannels are confirmed. With finite element method, the relationship between slip velocity and inlet flow rate or length-diameter ratio is analyzed. The results indicate that the wall slip happen for polymeric melt in microchannels, and slip coefficients are related with the size characteristics of microchannels. Moreover, wall slip velocity has the size effect and increase with the decrease of the section size of microchannels, which cause melt velocity distribution to smooth. At the same time, slip velocity is proportional to length-diameter ratio of microchannel, namely when wall shear stress is uniform, the slip velocity rises with increasing length-diameter ratio of microchannel.

Wall Slip of Bidisperse Linear Polymer Melts

2014 ◽  
Vol 47 (9) ◽  
pp. 3154-3160 ◽  
Author(s):  
S. Mostafa Sabzevari ◽  
Itai Cohen ◽  
Paula M. Wood-Adams
Keyword(s):  
Polymer Melts ◽  
Wall Slip ◽  
Linear Polymer

scholarly journals Vacuum Venting Enhances the Replication of Nano/Microfeatures in Micro-Injection Molding Process

2016 ◽  
Vol 4 (2) ◽  
Author(s):  
Seong Ying Choi ◽  
Nan Zhang ◽  
J. P. Toner ◽  
G. Dunne ◽  
Michael D. Gilchrist
Keyword(s):  
Injection Molding ◽  
Quantitative Study ◽  
Vacuum Pressure ◽  
Injection Molding Process ◽  
Anodized Aluminum ◽  
Molding Process ◽  
Micro Injection Molding ◽  
Sample Shape ◽  
Final Sample ◽  
Qualitative And Quantitative Study

Vacuum venting is a method proposed to improve feature replication in microparts that are fabricated using micro-injection molding (MIM). A qualitative and quantitative study has been carried out to investigate the effect of vacuum venting on the nano/microfeature replication in MIM. Anodized aluminum oxide (AAO) containing nanofeatures and a bulk metallic glass (BMG) tool mold containing microfeatures were used as mold inserts. The effect of vacuum pressure at constant vacuum time, and of vacuum time at constant vacuum pressure on the replication of these features is investigated. It is found that vacuum venting qualitatively enhances the nanoscale feature definition as well as increases the area of feature replication. In the quantitative study, higher aspect ratio (AR) features can be replicated more effectively using vacuum venting. Increasing both vacuum pressure and vacuum time are found to improve the depth of replication, with the vacuum pressure having more influence. Feature orientation and final sample shape could affect the absolute depth of replication of a particular feature within the sample.

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