Visualization of Melt-Flow Behavior Inside the Runner in Ultra High Speed Injection Molding

2006 ◽  
Vol 21 (5) ◽  
pp. 464-472 ◽  
Author(s):  
S. Hasegawa ◽  
H. Yokoi
Keyword(s):  
Injection Molding ◽  
High Speed ◽  
Flow Behavior ◽  
Melt Flow ◽  
Ultra High Speed

Effect of Welding Speed on Melt Flow Behavior in High Speed Laser Welding Process

2013 ◽  
Vol 40 (5) ◽  
pp. 0503001
Author(s):  
裴莹蕾 Pei Yinglei ◽  
单际国 Shan Jiguo ◽  
任家烈 Ren Jialie
Keyword(s):  
Laser Welding ◽  
Welding Speed ◽  
High Speed ◽  
Flow Behavior ◽  
Welding Process ◽  
Melt Flow ◽  
Laser Welding Process

Rheological behavior of PS polymer melt under ultra high speed injection molding

2012 ◽  
Vol 31 (7) ◽  
pp. 864-869 ◽  
Author(s):  
Shia-Chung Chen ◽  
Won-Hsion Liao ◽  
Jung-Peng Yeh ◽  
Rean-Der Chien
Keyword(s):  
Injection Molding ◽  
Rheological Behavior ◽  
High Speed ◽  
Polymer Melt ◽  
Ultra High Speed

Observation of Polypropylene (PP) Melt Flow on Macro and Micro Cavities during Filling Phase of Injection Molding

2011 ◽  
Vol 314-316 ◽  
pp. 1273-1277
Author(s):  
M. Azuddin ◽  
Z Taha ◽  
Imtiaz Ahmed Choudhury
Keyword(s):  
Injection Molding ◽  
High Speed ◽  
Electrical Discharge Machining ◽  
Mold Cavity ◽  
Melt Flow ◽  
Observation Window ◽  
Custom Made ◽  
Micro Parts ◽  
Filling Phase ◽  
Plastic Parts

The flow of plastic melt in macro and micro parts during the filling phase of injection molding is an interesting area to discover. The visualization technique is a common method used to understand the phenomena of polymer flow in mold cavity. Various shapes and sizes were fabricated on aluminum molds embedded with Polymethyl Methacrylate (PMMA) as observation window. Electrical discharge machining (EDM) and micro mechanical machining method were employed to fabricate plastic parts shape on aluminum mold cavity. This paper focuses and discusses in detail on the Polypropylene (PP) melt flow injected using a custom made vertical injection molding machine. The PP melt flow can be clearly seen through the PMMA window and captured using high speed camera. The captured images are then compared with result from commercially available plastic injection molding software, Autodesk MoldFlow. It was found that there is good agreement for macro plastic parts but not for the micro parts. It can be concluded that, the analysis software has less capability in predicting the flow of melt plastic in micro parts.

Application of ultrasonic-assisted injection molding for improving melt flowing and floating fibers

2016 ◽  
Vol 36 (2) ◽  
pp. 119-128 ◽  
Author(s):  
Yi-Jen Yang ◽  
Chung-Ching Huang ◽  
Jie Tao
Keyword(s):  
Injection Molding ◽  
Glass Fiber ◽  
Flow Behavior ◽  
Line Strength ◽  
Pressure Sensors ◽  
Weld Line ◽  
Flow Characteristics ◽  
Local Heat ◽  
Melt Flow ◽  
Ultrasonic Assisted

Abstract In this study, we investigated the use of ultrasonic technology in assisted injection molding and mold designs. We used an ultrasonic device installed in a mold to vibrate a melt directly, thereby converting kinetic energy into thermal energy. In addition, we developed three flat specimens of different thicknesses (3, 1, and 3-1-3 mm) produced by ultrasonic-assisted injection molds. An ultrasonic oscillation device 45 mm in diameter was placed in the cavity and used to vibrate a polycarbonate or a polycarbonate with 30% glass fiber melt at a frequency of 20 kHz. Furthermore, cavity pressure sensors were positioned at the front and rear of the vibration region for analyzing the melt flow behavior under ultrasonic-assisted injection molding conditions. Because of the absorption of ultrasonic energy, local heat was generated inside the resin, thus forming an oscillatory flow during the packing and holding stages, improving the flow characteristics of the melt, and changing the melt flow behavior around the skin layer to reduce the molecular orientation and high shear effect. The freezing rate of the melt was also reduced to eliminate the glass fiber streaks, floating fibers, and fiber orientation, particularly for thinner parts; the hesitation phenomena were then improved to increase the weld line strength.

Pressure Effects on Rheological Behavior of Melt Polymers – A Discussion in Relation to Polymer Processing

1986 ◽  
Vol 7 (1) ◽  
pp. 47-76 ◽  
Author(s):  
Yasushi Oyanagi ◽  
Kazuhisa Kubota
Keyword(s):  
Shear Stress ◽  
Injection Molding ◽  
Rheological Properties ◽  
Flow Behavior ◽  
Experimental Studies ◽  
Polymer Processing ◽  
Pressure Effects ◽  
Deformation Pattern ◽  
Melt Flow ◽  
Bulk Compressibility

Abstract Polymers have large bulk compressibility in the molten state /1/ and their rheological properties are largely affected by pressure applied in polymer processing. The volumetric strain induced by pressure consists of instantaneous and retarded elastic strains, both of which are proportional to pressure, and recover reversibly when pressure is removed. In many crystalline polymers, as observed by B. Maxwell for polyethylene, retarded elastic strain is large, and due mostly to pressure crystallization. This paper describes results of experimental studies relating pressure effects on rheological properties of melt polymers with polymer processing and bulk properties of products. The following items are discussed: pressure induced shear stress, analysis of local deformation pattern, critical shear stress for melt flow fracture, relationship between power law index and bulk compressibility, effects of hydrostatic pressure on melt flow behavior, pressure efficiency of injection molding, jetting phenomena, shrinkage in injection moldings, residual strain, and super-high-pressure injection molding process.

Effects of ultrasonic injection molding conditions on the plate processing characteristics of PMMA

2018 ◽  
Vol 38 (9) ◽  
pp. 905-914
Author(s):  
Yi-Jen Yang ◽  
Chung-Ching Huang
Keyword(s):  
Injection Molding ◽  
Manufacturing Industry ◽  
Flow Behavior ◽  
Pressure Sensors ◽  
Flow Characteristics ◽  
Local Heat ◽  
Skin Layer ◽  
Polymer Processing ◽  
Melt Flow ◽  
Diverse Field

AbstractPolymer processing is a crucial and diverse field in the manufacturing industry. We investigated the process characteristics and effects of injection molding using ultrasonic vibration. An ultrasonic device was installed in an injection mold; polymer was directly vibrated during injection. An ultrasonic oscillation device 45 mm in diameter was placed in the cavity and used to vibrate a poly(methyl methacrylate) melt at 19 kHz. The amplitude of the acoustic unit was set at 15 μm for the measurements. Moreover, cavity pressure sensors were positioned at the front and rear sides of the vibration region to determine the melt flow behavior under ultrasonic-assisted injection molding conditions. Because of the absorption of ultrasonic energy, local heat was generated inside the resin, thus improving the flow characteristics of the melt. Moreover, the melt flow behavior around the skin layer was changed; the molecular orientation and high shear effect were reduced. Furthermore, the freezing rate of the melt was reduced; thus, the amount of melt pressure lost through the cavity was decreased and the residual stress inside the injection-molded component generated during the photoelastic stress analysis was lower.

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