Recycling plastics by two‐shot molding

Donovan, Ryan; Rabe, K. S.; Mammel, W. K.; Lord, H. A.

doi:10.1002/pen.760151103

Cited by 35 publications

(16 citation statements)

References 1 publication

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“…It is often desirable for the skin material to have a superior appearance, while the strength and rigidity of the part is strongly dependent upon the core material [2,3] . Typically, the core material will be less costly than the skin material, which can yield potential cost savings.…”

Section: Introductionmentioning

confidence: 99%

Simulation and Experimental Investigations of Material Distribution in the Sandwich Injection Molding Process

Patcharaphun

Mennig

2006

Polymer-Plastics Technology and Engineering

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In sandwich injection molding, two polymeric materials are sequentially injected into a mold to form a multilayer product with a skin and core structure. Different properties of these polymers and their distribution in the cavity greatly affect the applications of the moldings. In an ideal situation, the core material should be entirely encapsulated in the skin material. When the flow front of the core material overtakes that of the skin material, breakthrough occurs, resulting in a defective part. The focus of this study is to determine the effect of molding parameters on the skin/core material distribution. The commercial simulation package (Moldflow) has been extensively compared with experiments. Both simulated and measured results suggest that in order to obtain the optimum encapsulated skin/core structure in the sandwich injection molded parts, it is necessary to select a proper core volume fraction and suitable processing parameters. A good agreement between simulation and experimental results indicates that the Moldflow program can be used as a valuable tool for the prediction of melt-flow behavior during the sandwich injection process.

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Section: Introductionmentioning

confidence: 99%

Simulation and Experimental Investigations of Material Distribution in the Sandwich Injection Molding Process

Patcharaphun

Mennig

2006

Polymer-Plastics Technology and Engineering

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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%

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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“…The part model was created by CAD, imported in the 2D 1 2 simulation package and discretized with a triangular mesh of 11900 elements, having an average and maximum aspect ratios of 1.36 and 3.48 respectively. To get the core=skin distribution through the part thickness, the latter was divided into 20 layers, and the results on each of the layers were considered.…”

Section: Computer Simulationmentioning

confidence: 99%

“…The skin=core structure can be produced by a sequential process [1,2] : the skin material is injected first in the mould and sticks to the cold cavity walls giving rise to the usual fountain flow; prior to the skin material reaching the cavity end, the core material is injected into the mould, pushing forward the skin material and thus forming the layered structure. A third injection of the skin material is sometime performed, in order to complete the process and produce a part with an outer surface fully made of the skin material.…”

Section: Introductionmentioning

confidence: 99%

Effects of Process Parameters on the Skin/Core Distribution in Co-Injection: Experiments and Simulations Using a Simple Geometry

Briatico‐Vangosa

2011

Polymer-Plastics Technology and Engineering

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In this work the effect of processing parameters on core breakthrough and material distribution during co-injection in a model\ud mould has been studied. PMMA was used for the skin and ABS for the core. To identify the influences of the core volumetric fraction, its injection rate and temperature and the skin injection temperature a series of computer simulations and experimental tests were performed according to the design of experiments statistical approach. The results of statistical analysis performed on data coming from experiments and simulations are consistent, even if simulations overestimate the ABS content at which the breakthrough takes place

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Recycling plastics by two‐shot molding

Cited by 35 publications

References 1 publication

Simulation and Experimental Investigations of Material Distribution in the Sandwich Injection Molding Process

Simulation and Experimental Investigations of Material Distribution in the Sandwich Injection Molding Process

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

Effects of Process Parameters on the Skin/Core Distribution in Co-Injection: Experiments and Simulations Using a Simple Geometry

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