Numerical Simulation and Experimental Study of Warpage of Injection-Molded Parts

2005 ◽  
Vol 44 (4) ◽  
pp. 603-617 ◽  
Author(s):  
Huamin Zhou ◽  
Dequn Li
Keyword(s):  
Numerical Simulation ◽  
Experimental Study ◽  
Molded Parts ◽  
Injection Molded

Numerical simulation and experimental validation of residual stress induced constrained shrinkage of injection molded parts

Polimery ◽  
2008 ◽  
Vol 53 (04) ◽  
pp. 304-310 ◽  
Author(s):  
TAHER AZDAST ◽  
AMIR HOSSEIN BEHRAVESH ◽  
KIUMARS MAZAHERI ◽  
MOHAMMAD MEHDI DARVISHI
Keyword(s):  
Numerical Simulation ◽  
Residual Stress ◽  
Experimental Validation ◽  
Molded Parts ◽  
Injection Molded

An Experimental Study of Polymer-Filler Redistribution in Injection Molded Parts

1994 ◽  
Vol 13 (2) ◽  
pp. 98-110 ◽  
Author(s):  
N. Dontula ◽  
N.S. Ramesh ◽  
G.A. Campbell ◽  
J.D. Small ◽  
A.L. Fricke
Keyword(s):  
Experimental Study ◽  
Polymer Filler ◽  
Molded Parts ◽  
Injection Molded

An Experimental Study of Metal Co-Injection Molding with Sequential Injection

2010 ◽  
Vol 97-101 ◽  
pp. 1116-1119
Author(s):  
Hao He ◽  
Yi Min Li ◽  
Jian Guang Zhang
Keyword(s):  
Experimental Study ◽  
Injection Molding ◽  
Phase Distribution ◽  
Relative Viscosity ◽  
Injection Velocity ◽  
Sequential Injection ◽  
Dissimilar Metal ◽  
Molded Parts ◽  
Injection Molded ◽  
Primary Variable

An experimental study of co-injection molding which involves sequential injection of dissimilar metal feedstocks into a mold has been carried out. The effect of skin temperature and injection velocity on the material distribution of co-injection molded plates has been studied. It was found that the molding temperature was important in controlling skin-core distribution, while injection velocity seemed to play no significant role. The experimental results were analyzed by taking account of the relative viscosity of the two melts. It was demonstrated that the differences in rheological properties of the metal feedstocks involved are the primary variable determining the phase distribution of the molded parts.

Experimental Study on the Warpage and Tensile Strength of Additively Manufactured Semi-Crystalline Polyamide 6

2019 ◽  
Author(s):  
Konstantin Struebig ◽  
Andreas Schröffer ◽  
Tim C. Lueth
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Tensile Tests ◽  
Polyamide 6 ◽  
High Tendency ◽  
Manufacturing Method ◽  
Crystalline Polymers ◽  
Basic Model ◽  
Molded Parts ◽  
Injection Molded

Abstract Semi-crystalline polymers offer great mechanical properties and are ubiquitously found in everyday life. Despite of this, they are not yet widespread among additive manufacturing processes, due to their high tendency to warp. This leads to unstable build processes and dimensionally inaccurate parts, which greatly reduces their usability. This paper describes the findings of an experimental study designed to identify relevant parameters that affect the warpage and investigate the influence of the manufacturing method on the mechanical properties of semi-crystalline PA6. The first experiment investigates the effect of water absorption over time, measuring weight and curling of 64 specimens over three weeks. The second part of this study focuses on the changes in geometry caused by the warpage by evaluating a basic model for simple part geometries. At last, a tension test was conducted and the results were compared to injection molded parts of the same material. The results indicate, that while the absorption of water plays an important role in the warpage of hydrophilic polymers like PA6, other environmental factors also have a significant influence. The model evaluation showed, that the warpage geometry of the tested parts can be approximated with only three parameters for very simple parts, if there are no irregularities in the manufacturing process. The tensile tests revealed, that the additively manufactured specimens reach up to 85.9% of the strength of the injection molded reference parts, most likely due to imperfect filling and reduced density. Overall, this study provides an insight into the challenges of additively manufacturing semi-crystalline polymers and the potential of PA6 as a tougher alternative to the common materials.

scholarly journals Spontaneous buckling of thin-walled injection-molded parts

Mechanik ◽  
2019 ◽  
Vol 92 (1) ◽  
pp. 7-9
Author(s):  
Przemysław Poszwa ◽  
Paweł Brzęk ◽  
Wiktor Hoffmann
Keyword(s):  
Numerical Simulation ◽  
Experimental Validation ◽  
Industrial Applications ◽  
Theoretical Background ◽  
Wide Range ◽  
Molded Parts ◽  
Injection Molded ◽  
Thin Walled ◽  
Plastic Parts ◽  
Injection Molded Plastic

Injection molding technology has a wide range of industrial applications, especially in packaging and casing production. In this paper the spontaneous buckling of thin-walled injection molded plastic parts was described. Theoretical background along with numerical simulation and experimental validation of this phenomenon were presented.

Effects of Polymer-Filler Properties on the Warpage of Injection Molded Automobile Door

2011 ◽  
Vol 239-242 ◽  
pp. 2511-2514
Author(s):  
Qiu Hui Liao ◽  
Xiao Xun Zhang ◽  
Qin Chao Ruan
Keyword(s):  
Numerical Simulation ◽  
Experimental Investigation ◽  
Major Axis ◽  
Mold Design ◽  
Experimental Measurements ◽  
Thermal Displacement ◽  
Polymer Filler ◽  
Molded Parts ◽  
Injection Molded ◽  
Good Agreement

The accurate prediction of warpage of injection molded parts is important to achieve successful mold design with high precision. In this study, effects of polymer-filler properties, such as filler aspect ratio (L/D), filler modulus parallel to major axis (E1) and filler modulus perpendicular to major axis (E2), on warpage displacement of automobile door were studied quantitatively by experimental investigation and numerical simulation. The numerical results are in good agreement with the experimental measurements. It is also found that: (1) the thermal displacement decreases as E1 and E2 decrease, (2) the PVT displacement is not influenced by change of L/D, E1 and E2, (3) the orientation effect displacement is neglected small when L/D=1 and E1= E2, and it also increases as L/D and E1/E2 increase.

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