• Composites Research
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• v.26 no.3
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• pp.155-159
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• 2013

This paper reviewed the continuous fiber tow spreading technologies and its applications. The effect of the continuous fiber tow spreading in manufacturing process of continuous fiber reinforced thermoplastic composite was introduced theoretically. The fiber tow spreading technologies were categorized according to the spreading medium and its order during manufacturing process. The general principles, the applications, and the merits and demerits of fiber tow spreading technologies were introduced. Furthermore, the proposal for future direction of research on this issue was considered in this study.

• Composites Research
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• v.33 no.6
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• pp.390-394
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• 2020

The carbon fiber has been damaged via tow spreading process for carbon fiber spread tow. The fiber damage is caused by friction between equipment and fibers or between fibers and fibers in the process of spreading. As a result, mechanical properties are decreased due to differences in process via material and equipment condition. Therefore, minimizing fiber damage have to be considered in the process. In this study, the change in carbon fiber pneumatic spreading process was observed by according to the filament count, sizing content of carbon fiber and process variables in spreading equipment (fiber tension at the beginning, air temperature in spreading zone, vacuum pressure in spreading zone). Tensile strength was evaluated using samples prepared under optimal conditions for each of the carbon fiber varieties, and mechanical properties were reduced due to damage on the carbon fiber.

• Journal of the Korean Wood Science and Technology
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• v.33 no.4 s.132
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• pp.60-65
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• 2005

This study was carried out to investigate the sheet properties of Indian mallow Hanji, made by different pulping methods, such as alkali and sulfomethylated pulpings, and different stock compositions, various mixing ratios of bast fiber and wood core fibers. Indian mallow Hanjis made with 60% of woody core pulps were shown better Chinese ink spreading distance than those of the others. The Chinese ink spreading distance of the Indian mallow Hanjis made from bast fiber pulp only were unsuitable for Hwaseonji. The Chinese ink spreading distance of Indian mallow Hanji was closely related to the mixing ratio of long fiber and short fiber. Especially sulfomethylated pulping method was superior to alkali pulping method.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.363-363
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• 2010

The high capillarity of a plastic fiber network having superhydrophilic Si-DLC coating is studied. Although the superhydrophilic surface maximize wetting ability on the flat surface, there remains a requirement for the more wettable surface for various applications such as air-filters or liquid-filters. In this research, the PET non-woven fabric surface was realized by superhydrophilic coating. PTE non-woven fabric network was chosen due to its micro-pore structure, cheap price, and productivity. Superhydrophobic fiber network was prepared with a coating of oxgyen plasma treated Si-DLC films using plasma-enhanced chemical vapor deposition (PECVD). We first fabricated superhydrophilic fabric structure by using a polyethylene terephthalate (PET) non-woven fabric (NWF) coated with a nanostructured films of the Si-incorporated diamond-like carbon (Si-DLC) followed by the plasma dry etching with oxygen. The Si-DLC with oxygen plasma etching becomes a superhydrophilic and the Si-DLC coating have several advantages of easy coating procedure at room temperature, strong mechanical performance, and long-lasting property in superhydrophilicity. It was found that the superhydrophobic fiber network shows better wicking ability through micro-pores and enables water to have much faster spreading speed than merely superhydrophilic surface. Here, capillarity on superhydrophilic fabric structure is investigated from the spreading pattern of water flowing on the vertical surface in a gravitational field. As water flows on vertical flat solid surface always fall down in gravitational direction (i.e. gravity dominant flow), while water flows on vertical superhydrophilic fabric surface showed the capillary dominant spreading.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2002.10a
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• pp.245-248
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• 2002

Research on the high performance and strength thermoplastic/continuous fiber composites was performed. New concept of impregnating die for developing continuous strand and prepreg tape of engineering plastic/glass fiber was introduced and estimated. Fully impregnated prepreg strand and tape was successfully manufactured through the new pin structure of impregnating die and control of spreading variable. Also design variables for stability of increasing processing speed were shown. And tensile strength of prepreg tape manufactured in this study was much higher than composites made by other competition company.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.37 no.5 s.113
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• pp.1-7
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• 2005

The objective of this work was to investigate the effect of spreading behavior of the sizing agents (AKD or dialkyl ketone) on the sizing development of AKD-sized paper. There was a direct relationship between the spreading behavior of the sizing agents and their melting points. Both AKD and dialkyl ketone showed no substantial spreading until the temperature reaches to their melting points. Consequently, dialkyl ketone did not provide sizing development when the paper was heat-treated below $75^{\circ}C$, while AKD provided sizing effect even the paper heated at $50^{\circ}C$. The ketone, however, provided rather higher sizing effect than that of AKD, when the paper was heat-treated over $100^{\circ}C$. This result means that the ketone also gives sizing development to paper, moreover the ketone could give higher sizing effect to paper than AKD when it was melted and well spreaded on the fiber surface. While the ketone introduced to papers from hydrolyzed AKD emulsion could not contribute to sizing development.

• Journal of the Optical Society of Korea
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• v.7 no.3
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• pp.180-187
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• 2003

A theoretical presentation by using a three-dimensional finite difference beam propagating method (3-D FD-BPM) for the evanescent coupling is offered with respect to the refractive indexes between a side-polished optical fiber and an infinitely planar waveguide with a conductor cladding (PWGCC). The PWG is suspended at a constant distance from an unclad fiber core and attached with a perfect conductor (PEC) on one side. The coupling and propagation of light are found to depend on both the relationship between the refractive index values of two structures and the configuration of the side-polished fiber used in the PWGCC. The spreading of light in the unconfined direction of a PWGCC is presented with the distribution of electric fields in xy - plane and the absolute amplitude of electric fields along the x and y axis. The power of the light propagation in a fiber decreases exponentially along the fiber axis as it is transferred to the PWGCC, where it is carried away.

• Composites Research
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• v.28 no.5
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• pp.249-253
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• 2015

This paper reports a study on a method for achieving lightweight thermoplastic laminate composites referred to as tow spreading technology. Thickness of an unspread 12 K carbon fiber tow is reduced by increasing the tow width from 7 mm to 20 mm. The polypropylene (PP) film was used to stabilize and impregnate the spread tow, covering it into a partially consolidated prepreg: 12 K carbon fiber spread tow/PP. Laminates were fabricated from the spread tow prepreg and control laminate composites were produced from unspread tow prepreg consisting of 12 K carbon fiber and PP. The void content, tensile and flexural properties of the composite laminates were investigated. Consequently, the spread tow laminate composite exhibited lower void content and improved mechanical properties.

• Journal of the Optical Society of Korea
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• v.7 no.1
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• pp.20-27
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• 2003

A theoretical presentation of evanescent coupling is offered with respect to the refractive indexes between a side-polished optical fiber and an infinitely planar waveguide with a conductor cladding (PWGCC). The PWG is suspended at a constant distance from an unclad fiber core and attached with the perfect conductor (PEC) on one side. The behavior of the distributed couple. is examined using a coupled mode model, which takes account of the two dimensions of the waveguide configuration. The coupling and propagation of light were found to depend on both the relationship between the refractive index values of each structure and the configuration of the side-polished fiber used in the PWGCC. The spreading of light in the unconfined direction of the PWGCC is described in terms of a simple geometrical interpretation of the synchronization condition that is in agreement with a previous investigation of the problem based on the coupled-mode theory (CMT). The power of the light propagation in the fiber decreased exponentially along the fiber axis as it was transferred to the PWGCC, where it was carried away.

• Korean Journal of Materials Research
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• v.20 no.7
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• pp.392-400
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• 2010

The electrospinning process was established as a promising method to fabricate nano and micro-textured scaffolds for tissue engineering applications. A BCP-loaded PCL micro-textured scaffold thus can be a viable option. The biocompatibility as well as the mechanical properties of such scaffold materials should be optimized for this purpose. In this study, a composite scaffold of poly ($\varepsilon$-caprolactone) (PCL)-biphase calcium phosphate (BCP) was successfully fabricated by electrospinning. EDS and XRD data show successful loading of BCP nano particles in the PCL fibers. Morphological characterization of fibers shows that with a higher loaded BCP content the fiber surface was rougher and the diameter was approximately 1 to 7 ${\mu}m$. Tensile modulus and ultimate tensile stress reached their highest values in the PCL- 10 wt% BCP composite. When content of nano ceramic particles was low, they were dispersed in the fibers as reinforcements for the polymer matrix. However, at a high content of ceramic particles, the particles tend to agglomerate and lead to decreasing tensile modulus and ultimate stress of the PCL-BCP composite mats. Therefore, the use of nano BCP content for distribution in fiber polymer using BCP for reinforcement is limited. Tensile strain decreased with increasing content of BCP loading. From in vitro study using MG-63 osteoblast cells and L-929 fibroblast like cells, it was confirmed that electrospun PCL-BCP composite mats were biocompatible and that spreading behavior was good. As BCP content increased, the area of cell spreading on the surface of the mats also increased. Cells showed the best adherence on the surface of composite mats at 50 wt% BCP for both L-929 fibroblast-like cells and MG-63 osteoblast cell. PCL- BCP composites are a promising material for application in bone scaffolds.