Effect of Molding Parameters on the Interface Morphology of Metal Co-Injection Molding

In the present study, the effect of injection temperature, velocity and delay time on the interface morphology of the co-injection molded plates was studied. The results showed that the core penetration parallel to the flow direction becomes less as the skin injection velocity and temperature increases and delay time decreases. Among the parameters, temperature was the most significant in affecting the interface morphology, followed by delay time, while injection velocity seemed to play no significant role. The results were analyzed by taking account of rheological properties of the two feedstocks. Calculations and comparisons of viscosity ratios encountered in experiments were made. It was demonstrated the differences in the rheological properties of the metal feedstocks involved are key factors in determining the interface morphology of the molded parts.

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The influence of blowing agent addition, talc filler content, and injection velocity on selected properties, surface state, and structure of polypropylene injection molded parts

Cellular Polymers ◽

10.1177/0262489319873642 ◽

2019 ◽

Vol 39 (1) ◽

pp. 3-30 ◽

Cited By ~ 2

Author(s):

Paweł Palutkiewicz ◽

Milena Trzaskalska ◽

Elżbieta Bociąga

Keyword(s):

Tensile Strength ◽

Impact Strength ◽

Filler Content ◽

Hold Time ◽

Injection Velocity ◽

Blowing Agents ◽

Blowing Agent ◽

Molded Parts ◽

Injection Molded ◽

Injection Cycle

The effects of blowing agent, talc, and injection velocity on properties of polypropylene molded parts were presented. Blowing agent was dosed to plastic in amounts 1–2% and talc 10–20%. The results of selected properties, such as weight, thickness, hardness, impact strength, tensile strength, and gloss, were presented. The article also presents microscopic investigations. The blowing agent and talc content have a large impact on mechanical properties and gloss of parts than addition of blowing agent. The use of the blowing agent in an amount of 2 wt% will allow the reduce injection cycle time by reducing the hold pressure and hold time. Addition of blowing agents lowers of tensile strength, hardness, impact strength, and significantly affected the gloss. Talc filler contributes to a significant increase in the weight of parts, a decrease in hardness, impact strength, and tensile strength. The injection velocity has no significant effect on parts properties.

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Measuring Fiber Length in the Core and Shell Regions of Injection Molded Long Fiber-Reinforced Thermoplastic Plaques

Journal of Composites Science ◽

10.3390/jcs4030104 ◽

2020 ◽

Vol 4 (3) ◽

pp. 104

Author(s):

Abrahán Bechara Senior ◽

Tim Osswald

Keyword(s):

Fiber Length ◽

Fiber Reinforced ◽

Characterization Methods ◽

The Core ◽

Glass Fiber Reinforced ◽

Molded Parts ◽

Concentration Changes ◽

Injection Molded ◽

Fibers Orientation ◽

Reinforced Thermoplastics

Long fiber-reinforced thermoplastics are an attractive design option for many industries due to their excellent mechanical properties and processability. Processing of these materials has a significant influence on their microstructure, which controls the properties of the final part. The microstructure is characterized by the fibers’ orientation, length, and concentration. Many characterization methods can capture the fiber orientation and concentration changes through the thickness in injection molded parts, but not the changes in fiber length. In this study, a technique for measuring fiber length in the core and shell regions of molded parts was proposed, experimentally verified, and used on injection molded 20 wt.% glass fiber-reinforced polypropylene plaques. The measured fiber length in the core was 50% higher than in the shell region. Comparison with simulation results shows disagreement in the shape of the through-thickness fiber length profile. Stiffness predictions show that the through-thickness changes in fiber length have little impact on the longitudinal and transverse Young’s modulus.

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Reducing the Burn Marks on Injection-Molded Parts by External Gas-Assisted Injection Molding

Polymers ◽

10.3390/polym13234087 ◽

2021 ◽

Vol 13 (23) ◽

pp. 4087

Author(s):

Jiquan Li ◽

Wenyong Liu ◽

Xinxin Xia ◽

Hangchao Zhou ◽

Liting Jing ◽

...

Keyword(s):

Image Processing ◽

Injection Molding ◽

Delay Time ◽

Quantitative Method ◽

Surface Defect ◽

Processing Method ◽

Traditional Methods ◽

Molded Parts ◽

Injection Molded ◽

Conventional Injection Molding

A burn mark is a sort of serious surface defect on injection-molded parts. In some cases, it can be difficult to reduce the burn marks by traditional methods. In this study, external gas-assisted injection molding (EGAIM) was introduced to reduce the burn marks, as EGAIM has been reported to reduce the holding pressure. The parts with different severities of burn marks were produced by EGAIM and conventional injection molding (CIM) with the same molding parameters but different gas parameters. The burn marks were quantified by an image processing method and the quantitative method was introduced to discuss the influence of the gas parameters on burn marks. The results show that the burn marks can be eliminated by EGAIM without changing the structure of the part or the mold, and the severity of the burn marks changed from 4.98% with CIM to 0% with EGAIM. Additionally, the gas delay time is the most important gas parameter affecting the burn marks.

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Fiber Orientation in Injection-Compression Molded Short-Fiber-Reinforced Polypropylene Parts

Volume 14: Processing and Engineering Applications of Novel Materials ◽

10.1115/imece2009-13174 ◽

2009 ◽

Cited By ~ 1

Author(s):

Han-Xiong Huang ◽

Can Yang ◽

Kun Li

Keyword(s):

Fiber Orientation ◽

Flow Direction ◽

Processing Parameters ◽

Short Fiber ◽

Fiber Reinforced ◽

Compression Force ◽

Time Compression ◽

Compression Time ◽

Molded Parts ◽

Injection Molded

Four processing parameters, including compression force, compression time, compression distance, and delay time, were investigated in terms of their effects on the fiber orientation in injection-compression molded (ICM) short-fiber-reinforced polypropylene parts. The results reveal that the fiber orientation pattern in ICM parts is different from that in conventional injection molded parts. Compression force plays an important role in determining the fiber orientation, whereas the effect of compression time can be neglected. Moreover, the fiber orientation changes obviously in the width direction, with most fibers arranging orderly in the flow direction at positions near the mold cavity wall.

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Study of the effect on conductivity and its uniform distribution in injection molded composite polymer bipolar plate

e-Polymers ◽

10.1515/epoly.2007.7.1.1676 ◽

2007 ◽

Vol 7 (1) ◽

Author(s):

Chen Shia-Chung ◽

Shih Ming-Yi ◽

Lin Yi-Chang

Keyword(s):

Flow Direction ◽

Mold Temperature ◽

Bipolar Plate ◽

Surface Conductivity ◽

Temperature Control System ◽

Melt Flow ◽

Molded Part ◽

Molded Parts ◽

Fluid Channel ◽

Injection Molded

AbstractIn this study, PPS blended with as high as 50 wt% carbon fiber were injection molded. Effects of molding conditions as well as the melt flow condition parallel and perpendicular to fluid channel on the surface conductivity was investigated. It was found that mold temperature affects the surface conductivity of molded parts significantly. Using a variable mold temperature control system based on electromagnetic induction heating, the conductivity of the molded part increase by about 152% when the peak mold temperature increases from 120 °C to 210 °C. The channel layout also helps the fiber to orient more randomly leading to an increase in the conductivity. The channel design parallel to melt flow increases the conductivity by 152% and when it is perpendicular to melt flow, the conductivity increases by 95%. Channel layout perpendicular to melt flow direction provides more influence on the fiber reorientation than that of the parallel design.

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

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.97-101.1116 ◽

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.

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Microstructure Effect of Injection Molded Nanoparticle/Polymer Composites on their Resistivity

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.472-475.1059 ◽

2012 ◽

Vol 472-475 ◽

pp. 1059-1062 ◽

Cited By ~ 1

Author(s):

Bao Feng Zhang ◽

Ai Yun Jiang ◽

De Bo Liu ◽

Hai Hong Wu ◽

Jing Chao Zou

Keyword(s):

Polymer Composites ◽

Large Scale ◽

Flow Direction ◽

Injection Pressure ◽

Commercial Application ◽

Molded Parts ◽

Injection Molded ◽

Microstructure Effect ◽

The Relationship ◽

Microstructural Effect

Although the progress has been achieved in conductive Nanoparticle/Polymer Composites(NPC), but there are many problems to be solved before their commercial application in a large scale, especially on their processing technology. The barriers include the dispersion of nanoparticle, the effect of nanoparticle concentration and interface on the overall properties of materials. In order to improve the application of NPC, the microstructural effect of injection molded NPC on its resistivity was investigated to build the relationship between the processing conditions and the properties in this paper. Composites used in the experiment were carbon black(CB)/polypropylene(PP). The microstructures of the injection molded parts at different positions were investigated with Scanning Electrical Microscope, and corresponsive properties were tested. The results showed that the distribution of CB nanoparticles changed with the injection pressure and had significant effect on the conductivity of the part. With the increase of injection pressure CB particles strongly oriented towards the flow direction of the polymer and thickness of oriented layer increased, which improve conductivity of the composites. The results also showed that crystallization was enhanced because of existence of nanoparticles, which should have increased the mechanical properties of the composite and decreased its resistivity because of the interfacial action between CB particles and polymer matrix.

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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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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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