Particle-level simulation for the prediction of short fiber orientation in injection molding

The short fiber orientation (SFO) distribution in the water-assisted injection molding (WAIM) is more complicated than that in traditional injection molding due to the new process parameters. In this work, an improved fiber orientation tensor method was used to simulate the SFO in WAIM. The result was compared with the scanning electron micrograph, which was consistent with the experiments. The effect of six process parameters, including filling time, melt temperature, mold temperature, delay time, water pressure, and water temperature, on the SFO along the melt flow direction were studied through orthogonal experimental design, range analysis, and variance analysis. An artificial neural network was used to establish the nonlinear agent model between the process parameters and A11 representing the fiber orientation in melt flow direction. Results show that water pressure, melt temperature, and water temperature have significant effects on SFO. The three-dimensional (3D) response surfaces and contour plots show that the values of A11 decrease with the increase in water pressure and melt temperature and increase as the water temperature rises.

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Numerical simulation of fiber orientation in injection molding of short-fiber-reinforced thermoplastics

Polymer Engineering & Science ◽

10.1002/pen.760350707 ◽

1995 ◽

Vol 35 (7) ◽

pp. 604-618 ◽

Cited By ~ 62

Author(s):

S. T. Chung ◽

T. H. Kwon

Keyword(s):

Numerical Simulation ◽

Injection Molding ◽

Fiber Orientation ◽

Short Fiber ◽

Fiber Reinforced ◽

Reinforced Thermoplastics ◽

Fiber Reinforced Thermoplastics

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Short Fiber Orientation in Injection Molding

Sen i Gakkaishi ◽

10.2115/fiber.47.p74 ◽

1991 ◽

Vol 47 (2) ◽

pp. P74-P78 ◽

Cited By ~ 1

Author(s):

HIRAKU TAKEDA

Keyword(s):

Injection Molding ◽

Fiber Orientation ◽

Short Fiber

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Numerical study of short fiber orientation in simple injection molding processes

10.1063/1.4914262 ◽

2015 ◽

Author(s):

I. Modhaffar ◽

K. Gueraoui ◽

H. El-tourroug ◽

S. Men-la-yakhaf

Keyword(s):

Injection Molding ◽

Fiber Orientation ◽

Numerical Study ◽

Short Fiber

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Predictions of fiber concentration in injection molding simulation of fiber-reinforced composites

Journal of Thermoplastic Composite Materials ◽

10.1177/0892705717738302 ◽

2017 ◽

Vol 31 (11) ◽

pp. 1529-1544 ◽

Cited By ~ 3

Author(s):

Huan-Chang Tseng ◽

Rong-Yeu Chang ◽

Chia-Hsiang Hsu

Keyword(s):

Injection Molding ◽

Fiber Orientation ◽

Short Fiber ◽

Core Structure ◽

Particle Migration ◽

Migration Behavior ◽

Fiber Concentration ◽

Numerical Predictions ◽

Injection Molding Simulation ◽

Injection Molded

The microstructures of injection-molded short fiber composites, involving fiber orientation and fiber concentration, strikingly influence flow behaviors and mechanical properties. Through the use of certain commercial software, reported numerical predictions of fiber orientation for the shell–core structure have been obtained to date. However, no work has been done on fiber concentration prediction available in processing simulations. In the theoretical field of suspension rheology, the suspension balance (SB) model has proven successful in capturing particle migration behavior under the simple Couette shear flow of “spherical” particle suspension, hence the attempt to verify the SB model applied in the “like-rod” suspensions. To predict flow-induced variations of fiber concentration, the SB model is implemented in 3-D-injection molding simulation with more general flows. It is remarkable for the shell–core structure is explored to reflect the relationship between fiber orientation and fiber concentration.

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Injection molding of short fiber thermoplastic bio-composites: Prediction of the fiber orientation

Journal of Composite Materials ◽

10.1177/0021998320938454 ◽

2020 ◽

Vol 54 (30) ◽

pp. 4787-4797

Author(s):

Fatima-Zahra Semlali AouraghHassani ◽

Mounir El Achaby ◽

Mohammed-Ouadi Bensalah ◽

Denis Rodrigue ◽

Rachid Bouhfid ◽

...

Keyword(s):

Experimental Data ◽

Mechanical Properties ◽

Injection Molding ◽

Fiber Orientation ◽

Orientation Angle ◽

Short Fiber ◽

Thermoplastic Polymer ◽

Molded Part ◽

Practical Tool ◽

Orientation Pattern

Injection molding of short fiber reinforced thermoplastic polymer results in a preferential fiber orientation in the part, which leads to an anisotropy in the material mechanical properties. To anticipate the molded part performances, it is necessary to predict the fiber orientation pattern. Our goal is to have a practical tool that accurately predicts fiber orientation patterns, and to use that information to estimate the final product properties. Consequently, an efficient way to determine the flow induced fiber orientation for different flow cases under real injection molding conditions is presented. The proposed approach allows the average orientation angle prediction in a section by considering the close interaction between the fibers and the flow rheology, the fibers aspect ratio and the mold geometry. Finally, to validate the model, experimental data were taken with different matrices, fibers and mold geometries, where good agreements (R2 ≥ 0.8) were obtained for the fiber orientations measurements.

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Warpage Reduction of Glass Fiber Reinforced Plastic Using Microcellular Foaming Process Applied Injection Molding

Polymers ◽

10.3390/polym11020360 ◽

2019 ◽

Vol 11 (2) ◽

pp. 360 ◽

Cited By ~ 5

Author(s):

Hyun Kim ◽

Joo Sohn ◽

Youngjae Ryu ◽

Shin Kim ◽

Sung Cha

Keyword(s):

Injection Molding ◽

Glass Fiber ◽

Fiber Orientation ◽

Mechanical And Thermal Properties ◽

Micro Ct ◽

Fiber Reinforced ◽

Foaming Process ◽

Microcellular Foaming ◽

Glass Fiber Reinforced ◽

The Impact

This study analyzes the fundamental principles and characteristics of the microcellular foaming process (MCP) to minimize warpage in glass fiber reinforced polymer (GFRP), which is typically worse than that of a solid polymer. In order to confirm the tendency for warpage and the improvement of this phenomenon according to the glass fiber content (GFC), two factors associated with the reduction of the shrinkage difference and the non-directionalized fiber orientation were set as variables. The shrinkage was measured in the flow direction and transverse direction, and it was confirmed that the shrinkage difference between these two directions is the cause of warpage of GFRP specimens. In addition, by applying the MCP to injection molding, it was confirmed that warpage was improved by reducing the shrinkage difference. To further confirm these results, the effects of cell formation on shrinkage and fiber orientation were investigated using scanning electron microscopy, micro-CT observation, and cell morphology analysis. The micro-CT observations revealed that the fiber orientation was non-directional for the MCP. Moreover, it was determined that the mechanical and thermal properties were improved, based on measurements of the impact strength, tensile strength, flexural strength, and deflection temperature for the MCP.

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