Observation of the polymer melt flow in injection molding process using co-injection molding technique

Chen, S.C.; Hsu, K. F.; Huang, Jianguo

doi:10.1016/0735-1933(94)90049-3

Cited by 11 publications

(6 citation statements)

References 6 publications

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“…To understand the internal sandwich structure formation and the melt flow behavior in coinjection molding, it is important to design properly the coinjection‐molding process. Only limited experimental studies on coinjection molding have been reported 3–19. Most previous experimental investigations highlighted the importance of the role of the viscosity ratio between skin and core materials, as well as the rate of injection.…”

Section: Introductionmentioning

confidence: 99%

“…In addition, Kadota et al17 performed sequential coinjection molding of polystyrene/polypropylene to investigate the structure gradients as a function of the process history and injection sequence. The skin–core–skin sequential coinjection‐molding process was also used as a method for visualization by Chen et al18, 19 to investigate polymer melt flow behavior and the fountain flow effect.…”

Section: Introductionmentioning

confidence: 99%

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Interface development and encapsulation in simultaneous coinjection molding of disk. II. Two‐dimensional simulation and experiment

Lee

Isayev

2003

J of Applied Polymer Sci

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Two-dimensional simulation and experimental studies of flow-rate-controlled coinjection molding were carried out. Skin polymer was injected first, and then both skin and core polymers were injected simultaneously into a center-gated disk cavity through a two-channel nozzle to obtain an encapsulated sandwich structure. The physical modeling and simulation developed, reported in Part I of this series, were based on the Hele-Shaw approximation and the kinematics of the interface to describe the multilayer flow, and the interface development was used to predict the skin/core distribution in the moldings. The effects of rheological properties and processing conditions on the material distribution, penetration behavior, and breakthrough phenomena were investigated. The predicted and measured results were found to be in a good agreement.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Interface development and encapsulation in simultaneous coinjection molding of disk. II. Two‐dimensional simulation and experiment

Lee

Isayev

2003

J of Applied Polymer Sci

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“…The potential of thermoplastic or elastomer injection over-moulding processes has attracted the attention of many researchers. Chen et al (1994) studied multi-material injection moulding and bi-injection moulding processes using an amorphous polymer for the skin polymer and a second colour of the same polymer for the core. They investigated the melting flux evolution of both polymers and the distribution of skin and core materials in the final component [24].…”

Section: Introductionmentioning

confidence: 99%

“…Chen et al (1994) studied multi-material injection moulding and bi-injection moulding processes using an amorphous polymer for the skin polymer and a second colour of the same polymer for the core. They investigated the melting flux evolution of both polymers and the distribution of skin and core materials in the final component [24]. Lee, Isayev, and White (1998) investigated the evolution of the interface between each phase of a sandwich structure during an injection moulding process.…”

Section: Introductionmentioning

confidence: 99%

Experimental and numerical investigations of bi-injection moulding of PA66/LSR peel test specimens

2020

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Bi-injection moulding is a widely used process to manufacture engineering products and consumer goods. Typically, a thermoplastic is combined with rubber or another thermoplastic to create colour differences or hard and soft areas, respectively. The aim of this study was to optimise the injection parameters and processing conditions for the moulding of twocomponent standard peel test specimens with suitable functional properties. In this work, all parameters of thermo-rheo-kinetic behaviour were identified to predict the entire filling stage and the effect of a liquid silicone rubber cross-linking reaction during the injection moulding process. The models of Carreau-Yasuda and Isayev-Deng regarding the thermal dependence assumed by Arrhenius' law were used. In our study, over-injection moulding is simulated and examined using finite element software (Cadmould 3D) to investigate the thermo-rheo-kinetic behaviour and the adhesion of liquid silicone rubber during the filling mould process in over-moulding. Numerical simulation results were then compared with the experimental results, and good agreement was obtained.

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“…Its formation of the most uniform skin/core structure was discussed under isothermal and nonisothermal flow conditions during sequential injection of two melts [3][4][5][6]. Furthermore, polymer melt flow behavior inside the mold cavity was investigated by visualization of the sequential COIM process [3,7]. The structure gradients were studied as a function of the process history and injection sequence during the COIM and it was found that a slower injection speed for core would cause core spreading uniformly in the flow direction [8].…”

Section: Introductionmentioning

confidence: 99%

Real‐time diagnosis of co‐injection molding using ultrasound

Cheng

Ono

Jen

2007

Polymer Engineering & Sci

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Co‐injection molding, also known as sandwich molding, is a process in which two or more polymers are laminated together in a mold cavity. Integrated ultrasonic sensors embedded into a mold insert of a co‐injection‐molding machine have been used for real‐time, nonintrusive, and nondestructive diagnosis of co‐injection‐molding processes. Diagnosis of core arrival, core flow speed, part solidification, part detachment from the mold, thickness of skin and core, and core length at the mold was demonstrated. It is found that core flow speed and peak cavity pressure monotonically increased and decreased with the core volume percentage, respectively. Thicknesses of the skin and core of the molded part were estimated using the presented ultrasonic technique during molding with an accuracy better than ±17%. In addition, the core length had correlation with core thickness, core flow speed, and peak cavity pressure. Among them, the core thickness measured by the ultrasonic technique had the better correlation. This technique enables process optimization, the maximum process efficiency, and in‐process quality assurance of the molded parts. POLYM. ENG. SCI., 47:1491–1500, 2007. © 2007 Society of Plastics Engineers

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Observation of the polymer melt flow in injection molding process using co-injection molding technique

Cited by 11 publications

References 6 publications

Interface development and encapsulation in simultaneous coinjection molding of disk. II. Two‐dimensional simulation and experiment

Interface development and encapsulation in simultaneous coinjection molding of disk. II. Two‐dimensional simulation and experiment

Experimental and numerical investigations of bi-injection moulding of PA66/LSR peel test specimens

Real‐time diagnosis of co‐injection molding using ultrasound

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