• Transactions of the Korean Society of Machine Tool Engineers
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• v.14 no.1
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• pp.73-80
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• 2005

Injection molding is the most widely used process for the industrial forming of plastic articles. During an injection molding process of composites, the fiber-matrix separation and fiber orientation are caused by the flow of molten polymer/fiber mixture. As a result, the product tends to be nonhomogeneous and anisotropic. Hence, it is very important to clarify the relations between separation orientation and injection molding conditions. So far, there is no research on the measurement of fiber orientation using image processing. In this study, the effects of fiber content ratio and molding condition on the fiber orientation-angle distributions are studied experimentally. Using the image processing method, the fiber orientation distribution of welding parts in injection-molded products is assessed. And the effects of fiber content and injection mold shapes on the fiber orientation in case of fiber reinforced polymeric composites are studied experimentally.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.15 no.4
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• pp.1-7
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• 2006

Injection molding is a very important industrial process for the manufacturing of plastics objects. During an injection molding process of composites, the fiber-matrix separation and fiber orientation are caused by the flow of molten polymer/fiber mixture. As a result, the product tends to be nonhomogeneous and anisotropic. Hence, it is very important to clarify the relations between separation orientation and injection molding conditions. So far, there is no research on the measurement of fiber orientation using image processing. In this study, the effects of fiber content ratio and molding condition on the fiber orientation-angle distributions are studied experimentally. Using the image processing method, the fiber orientation distribution of weld-line in injection-molded products is assessed. And the effects of fiber content and injection mold-gate conditions on the fiber orientation are also discussed.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.186-191
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• 2004

we can say that the increasing range of the value of GMT Sheet's tensile strength in the direction of fiber orientation is getting wider as the fiber content increases. It shows that the value of GMT Sheet's tensile strength in the direction of fiber orientation 90 is similar with the value of pp's intensity when fiber orientation function is J= 0.7, regardless of the fiber content. Tensile strength of GMT Sheet is affected by the fiber orientation distribution more than by the fiber content.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2001.05a
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• pp.201-204
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• 2001

A Confocal Laser Scanning Microscope (CLSM) is applied to determine three-dimensional fiber orientation states in injection-molded short fiber composites. Since the CLSM optically sections the composites, more than two planes either on or below the surface of composites can be obtained. Therefore, three dimensional fiber orientation states are determined without destruction. To predict the orientation states, velocity and temperature fields are calculated by using a hybrid FEM/FDM method. The change of orientation state during packing stage is also considered by employing a compressible Hele-Shaw model. The predicted orientation states show good agreement with measured ones. However, some differences are found at the end of cavity. They may result from other effects, which are not considered in the numerical analysis.

• Journal of Ocean Engineering and Technology
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• v.10 no.3
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• pp.34-43
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• 1996

In this study basic equations of fiber orientations is cimpared with experimental results. It is found that fiber orientations of short fiber reinforced polymeric composite under compression molding are governed by slope of flow speed in x-y direction. Fiber orientation angle of mold is also found to increase with closure speed and the compression ratio. At the middle of the mold, the slope of flow speed is larger in x-direction than in y-direction. At the wall of the mold, the shope of flow speed in y-direction occurs due to the effect of friction, hence affects the fiber orientation. The effect of partial flow, which incurs y-direction orientation causes to increase the fiber orientation angle at the fore part of the flow.

• Journal of Welding and Joining
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• v.24 no.5
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• pp.43-48
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• 2006

This paper is concerned with a fracture strength study of composite adhesive lap joints. The tests were carried out on specimen joints manufactured hybrid stacked composites such as the polyester and bamboo natural fiber layer. The main objective of the work was to test the fracture strength using hybrid stacked composites with a polyester and bamboo natural fiber layer. Tensile and peel strength of hybrid stacked composites are tested before appling adhesive bonding. From results, Natural fiber reinforced composites have lower tensile strength than the original polyester. and The load directional orientation and small amount and low thickness of bamboo natural fiber layer have a good effect on the tensile and peel strength of natural fiber reinforced composites. The failure strength of these materials applied adhesive bonding is also affected by fiber orientation and thickness of bamboo natural fiber layer. There for, Fiber orientation of bamboo natural fiber layer have a great effect on the tensile-shear strength of natural fiber reinforced composites including adhesive bonded joints.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.22 no.6
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• pp.639-646
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• 2009

High-flow steel-fiber reinforced mortar may induce a certain fiber orientation distribution in the process of placing and thus have an influence on the tensile properties. In this paper, the variation of the fiber orientation distribution according to the flow of high-flow steel-fiber reinforced mortar was estimated in numerical simulation. The analytical results present that the major variation of fiber orientation distribution is made within 150mm of flow distance, thereafter the tendency of the fiber orientation distribution is not noticeable even though the peak of distribution density in the orientation parallel to the flow direction get bigger along the distance. Considering the close relation between the fiber orientation and the tensile behavior of composite, prediction of fiber orientation distribution make it possible to predict the variation in the tensile behavior of high-flow steel-fiber reinforced mortar according to the flow.

• Korea-Australia Rheology Journal
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• v.14 no.4
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• pp.175-188
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• 2002

We review the modeling and simulation of fiber orientation during injection molding processes of short fiber reinforced thermoplastics. Generally, a group of fibers are described in terms of probability distribution function or orientation tensor. Various closure approximation models to express higher order tensor in terms of Bower order tensors are reviewed. Rheology of fiber suspensions, multiple fiber-fiber interaction and numerical technique for the prediction of fiber orientation are also considered for concentrated situations.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.422-425
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• 2003

Investigated whether fiber orientation distribution of twisted yarn composites and the fiber content are 0$^{\circ}$ and 90$^{\circ}$ direction tensile strength and some correlation. Tensile strength of 0$^{\circ}$ directions of twisted yarn composites increased changelessly being proportional the fiber content and fiber orientation function get into anisotropic in isotropic. But, tensile strength ratio by separation of fiber filament of 90$^{\circ}$ directions tensile strength decreased when tensile load is imposed for width direction of reinforcement fiber. 0$^{\circ}$ and 90$^{\circ}$ direction tensile strength ratio value of a twisted yarn composites not receive almost effect of the fiber content of fiber orientation function J = 0.4 lows. Although do, 20 wt% of the fiber content is high about 0$^{\circ}$ and 90$^{\circ}$ direction tensile strength ratio about 1.6~2 than 10 wt% from J = 0.4. Therefore. could know that effect of the fiber content is dominate.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.457-460
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• 2000

Injection molding is the most widely used process for the industrial forming of plastic articles. During an injection molding process of composites, the fiber-matrix separation and fiber orientation are caused by the flow of molten polymer/fiber mixture. As a result, the product tends to be nonhomogeneous and anisotropic. Hence, it is very important to clarify the relations between separation·orientation and infection molding conditions. So far, there is no research on the measurement of fiber orientation using image processing. In this study, the effects of fiber content ratio and molding condition on the fiber orientation-angle distributions are studied experimentally. Using the image processing method, the fiber orientation distribution of welding parts in injection-molded products is assessed. And the effects of fiber content and injection mold shapes on the fiber orientation in case of fiber reinforced polymeric composites are studied. experimentally.