6. Isothermal mold filling simulations for developing liquid composite molded parts

The morphology of polymer blends plays a critical role in determining the properties of the blends and performance of resulting injection-molded parts. However, it is currently impossible to predict the morphology evolution during injection molding and the final micro-structure of the molded parts, as the existing models for the morphology evolution of polymer blends are still limited to a few simple flow fields. To fill this gap, this paper proposed a novel model for droplet morphology evolution during the mold filling process of polymer blends by coupling the models on macro- and meso-scales. The proposed model was verified by the injection molding experiment of PP/POE blends. The predicted curve of mold cavity pressure during filling process agreed precisely with the data of the corresponding pressure sensors. On the other hand, the model successfully tracked the moving trajectory and simulated morphology evolution of the droplets during the mold-filling process. After mold-filling ended, the simulation results of the final morphology of the droplets were consistent with the observations of the scanning electron microscope (SEM) experiment. Moreover, this study revealed the underlying mechanism of the droplet morphology evolution through the force analysis on the droplet. It is validated that the present model is a qualified tool for simulating the morphology evolution of polymer blends during injection molding and predicting the final microstructure of the products.

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Control Volume Finite Element Method for Mold Filling Simulation

International Polymer Processing ◽

10.3139/217.950082 ◽

1995 ◽

Vol 10 (1) ◽

pp. 82-87 ◽

Cited By ~ 6

Author(s):

T. J. Wang ◽

L. J. Lee ◽

W. B. Young

Keyword(s):

Finite Element Method ◽

Finite Element ◽

Control Volume ◽

Mold Filling ◽

Filling Simulation ◽

Control Volume Finite Element ◽

Element Method

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Modeling and Simulation of High Reynolds' Number Flows During Reaction Injection Mold Filling

International Polymer Processing ◽

10.3139/217.940279 ◽

1994 ◽

Vol 9 (3) ◽

pp. 279-285 ◽

Cited By ~ 3

Author(s):

Rahima K. Mohammed ◽

Tim A. Osswald ◽

Timothy J. Spiegelhoff ◽

Esther M. Sun

Keyword(s):

Reynolds Number ◽

Modeling And Simulation ◽

High Reynolds Number ◽

Mold Filling ◽

Injection Mold ◽

High Reynolds ◽

Reynolds Number Flows

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Defects in Resin Transfer Molded Plaques Due to Resin Age Distribution During Mold Filling

International Polymer Processing ◽

10.3139/217.960284 ◽

1996 ◽

Vol 11 (3) ◽

pp. 284-290 ◽

Cited By ~ 1

Author(s):

N. S. Losure ◽

K. Jayaraman ◽

C. A. Petty

Keyword(s):

Age Distribution ◽

Mold Filling

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Analysis of the Mold Filling Process with Phase Change Considering the Non-steady Effect

International Polymer Processing ◽

10.3139/217.960058 ◽

1996 ◽

Vol 11 (1) ◽

pp. 58-67 ◽

Cited By ~ 1

Author(s):

M. S. Kim ◽

W. I. Lee ◽

J. S. Lee

Keyword(s):

Phase Change ◽

Mold Filling ◽

Filling Process

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Effect of ethanol on the mold filling-time and mechanical properties of woven glass fiber reinforced epoxy filled with TiO2 nanoparticles

Journal of Industrial Textiles ◽

10.1177/1528083720971345 ◽

2020 ◽

pp. 152808372097134

Author(s):

Sherif M Youssef ◽

M Megahed ◽

Soliman S Ali-Eldin ◽

MA Agwa

Keyword(s):

Mechanical Properties ◽

Composite Laminates ◽

Cost Effective ◽

Mold Filling ◽

High Viscosity ◽

Ansys Fluent ◽

Glass Fiber Reinforced ◽

Filling Time ◽

Ethanol Addition ◽

Woven Glass Fiber

Vacuum resin infusion (VRI) is a promising technique for manufacturing complicated structural laminates. This high viscosity of nanofilled resin increases the filling time and leads to an incomplete mold filling. The mold filling time can be reduced either by making the fiber dimensions smaller than the mold (gaps around the fibers) or by adding ethanol to nanofilled epoxy. However, ethanol addition influences the mechanical properties of composite laminates. In this study, different amounts of ethanol (0.5 wt. % and 1 wt. %) were used as a diluent to both neat epoxy and epoxy filled with (0.25 wt. %) of titanium dioxide (TiO2) nanoparticles. From results, it was found that ethanol addition saves the time for neat and nanofilled epoxy by 47.1% and 24.1%, respectively. It was found that adding 0.5 wt. % of ethanol to 0.25wt. % of TiO2 nanoparticles (GT0.25E0.5) enhances the tensile and flexural strength by 30.8% and 55.9%, respectively compared with neat specimens. Furthermore, the tensile and flexural moduli increased by 62% and 72.3%, respectively. Furthermore, the mold filling time was investigated experimentally and validated numerically using ANSYS FLUENT software. The mold filling time prediction using ANSYS FLUENT can be used to avoid resin gelation before the incomplete mold filling and thus can be considered a cost-effective methodology. The results showed that the gaps around the fibers reduce the time by 178% without affecting the mechanical properties.

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A Study on the Birefringence Measurement in Injection Molded Parts Using Two Different Laser Sources and R-G-B Separation of White Light

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.326-328.187 ◽

2006 ◽

Vol 326-328 ◽

pp. 187-190

Author(s):

Jong Sun Kim ◽

Chul Jin Hwang ◽

Kyung Hwan Yoon

Keyword(s):

White Light ◽

Low Cost ◽

Main Idea ◽

Injection Molding Process ◽

Molding Process ◽

Laser Method ◽

High Productivity ◽

Molded Parts ◽

Injection Molded ◽

Plastic Parts

Recently, injection molded plastic optical products are widely used in many fields, because injection molding process has advantages of low cost and high productivity. However, there remains residual birefringence and residual stresses originated from flow history and differential cooling. The present study focused on developing a technique to measure the birefringence in transparent injection-molded optical plastic parts using two methods as follows: (i) the two colored laser method, (ii) the R-G-B separation method of white light. The main idea of both methods came from the fact that more information can be obtained from the distribution of retardation caused by different wavelengths. The comparison between two methods is demonstrated for the same sample of which retardation is up to 850 nm.

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Injection Molding and Near-Complete Densification of Monolithic and Al2O3 Fiber-Reinforced Ti2AlC MAX Phase Composites

Materials ◽

10.3390/ma14133632 ◽

2021 ◽

Vol 14 (13) ◽

pp. 3632

Author(s):

Sylvain Badie ◽

Rimy Gabriel ◽

Doris Sebold ◽

Robert Vaßen ◽

Olivier Guillon ◽

...

Keyword(s):

Injection Molding ◽

Graphite Powder ◽

Max Phase ◽

Powder Injection ◽

Fiber Reinforced ◽

Ceramic Fibers ◽

Plasma Sintering ◽

Molded Parts ◽

Al2o3 Fiber ◽

Induced Velocity

Near-net shape components composed of monolithic Ti2AlC and composites thereof, containing up to 20 vol.% Al2O3 fibers, were fabricated by powder injection molding. Fibers were homogeneously dispersed and preferentially oriented, due to flow constriction and shear-induced velocity gradients. After a two-stage debinding procedure, the injection-molded parts were sintered by pressureless sintering at 1250 °C and 1400 °C under argon, leading to relative densities of up to 70% and 92%, respectively. In order to achieve near-complete densification, field assisted sintering technology/spark plasma sintering in a graphite powder bed was used, yielding final relative densities of up to 98.6% and 97.2% for monolithic and composite parts, respectively. While the monolithic parts shrank isotropically, composite assemblies underwent anisotropic densification due to constrained sintering, on account of the ceramic fibers and their specific orientation. No significant increase, either in hardness or in toughness, upon the incorporation of Al2O3 fibers was observed. The 20 vol.% Al2O3 fiber-reinforced specimen accommodated deformation by producing neat and well-defined pyramidal indents at every load up to a 30 kgf (~294 N).

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Silane-Functionalized Sheep Wool Fibers from Dairy Industry Waste for the Development of Plasticized PLA Composites with Maleinized Linseed Oil for Injection-Molded Parts

Polymers ◽

10.3390/polym12112523 ◽

2020 ◽

Vol 12 (11) ◽

pp. 2523

Author(s):

Franciszek Pawlak ◽

Miguel Aldas ◽

Francisco Parres ◽

Juan López-Martínez ◽

Marina Patricia Arrieta

Keyword(s):

Linseed Oil ◽

Microstructural Analysis ◽

Dairy Industry ◽

Poly Lactic Acid ◽

Industry Waste ◽

Wool Fibers ◽

Molded Parts ◽

Silane Modification ◽

Injection Molded ◽

Sheep Wool

Poly(lactic acid) (PLA) was plasticized with maleinized linseed oil (MLO) and further reinforced with sheep wool fibers recovered from the dairy industry. The wool fibers were firstly functionalized with 1 and 2.5 phr of tris(2-methoxyethoxy)(vinyl) (TVS) silane coupling agent and were further used in 1, 5, and 10 phr to reinforce the PLA/MLO matrix. Then, the composite materials were processed by extrusion, followed by injection-molding processes. The mechanical, thermal, microstructural, and surface properties were assessed. While the addition of untreated wool fibers to the plasticized PLA/MLO matrix caused a general decrease in the mechanical properties, the TVS treatment was able to slightly compensate for such mechanical losses. Additionally, a shift in cold crystallization and a decrease in the degree of crystallization were observed due to the fiber silane modification. The microstructural analysis confirmed enhanced interaction between silane-modified fibers and the polymeric matrix. The inclusion of the fiber into the PLA/MLO matrix made the obtained material more hydrophobic, while the yellowish color of the material increased with the fiber content.

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