• Tribology and Lubricants
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• v.33 no.4
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• pp.148-152
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• 2017

The feel of writing is important to customers when they buy smart devices with stylus such as smartphones and tablet computers. With an aim to reproduce the tactile sensibility of writing instruments when people write on the glass display using a stylus, this study focuses on the frequency characteristics of writing instruments that can describe the vibrations of writing instruments sliding over counter surfaces. In addition, this study includes the effect of various factors influencing the friction of writing instruments such as lubricant, nib material, and contact type. We perform sliding experiments with six types of writing instruments and a sheet of paper to understand the relation between the friction conditions of the nib and the frequency characteristics. As this research focuses on the tactile perception of human skin when people use a writing instrument, the analysis of frequency characteristics is performed in the perceptible frequency range of mechanoreceptors in the human skin. As a result, three types of frequency characteristics are identified. Low frequency peaks are observed for a metal nib with ink; high frequency peaks are observed for a nib without ink; and, middle frequency peaks with a wide range of distribution occurs for fabric nibs with ink. Therefore, to implement the proper feel of writing, at least three types of vibrations have to be made.

• Transactions of the Korean Society of Automotive Engineers
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• v.25 no.3
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• pp.350-359
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• 2017

This paper presents a new holistic development approach for the carbon continuous-fiber composite frame of an automotive sunroof assembly. The original steel frame has been designed to get higher bending stiffness with its corrugated cross-sectional shape. The new approach uses the prepregs of a fast cure epoxy and PCM manufacturing processing. For higher productivity, the new frames feature a very simple plat cross sectional shape but achieve high bending stiffness through the laminate design. The sandwich structure with a PET foam core was presented. The frames were made of carbon UD laminae covered single carbon fabric on the outer surfaces. The fabrics provide torsional stiffness and also hold the carbon UD fibers floating in the low viscous epoxy resin of prepregs at the curing temperature during processing. The final product yields approximately 18 % savings in weight compared with the original.

• Carbon letters
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• v.12 no.4
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• pp.249-251
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• 2011

Carbon/epoxy woven composites are prominent wear-resistant materials due to the strength, stiffness, and thermal conductivity of carbon fabric. In this study, the effect of oilabsorption on the wear behaviors of carbon/epoxy woven composites was investigated. Wear tests were performed on dry and fully oil-absorbed carbon/epoxy woven composites. The worn surfaces of the test specimens were examined via scanning electron microscopy to investigate the wear mechanisms of oil-absorbed carbon/epoxy woven composites. It was found that the oil absorption rate was 0.14% when the carbon/epoxy woven composites were fully saturated. In addition, the wear properties of the carbon/epoxy woven composites were found to be affected by oilabsorption. Specifically, the friction coefficients of dry and oil-absorbed carbon/epoxy woven composites were 0.25-0.30 and 0.55-0.6, respectively. The wear loss of the oilabsorbed carbon/epoxy woven composites was $3.52{\times}10^{-2}\;cm^3$, while that of the dry carbon/epoxy woven composites was $3.52{\times}10^{-2}\;cm^3$. SEM results revealed that the higher friction coefficient and wear loss of the oil-absorbed carbon/epoxy woven composites can be attributed to the existence of broken and randomly dispersed fibers due to the weak adhesion forces between the carbon fibers and the epoxy matrix.

• Fibers and Polymers
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• v.6 no.4
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• pp.318-321
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• 2005

Demand for the fabric wipes is growing continuously. Wipes in industry are used for cleaning purpose. Cleaning involves rubbing action, so it is very important to know how much frictional force is encountered during the cleaning action. In this study the effects of normal load, sliding speed on frictional characteristics of nonwoven and woven wipes, both dry and wetted with different liquids, against glass and floor tile surfaces have been reported. With the increase in the normal load the coefficient of friction goes on decreasing for both nonwoven and woven wipes and this trend is observed in both dry and wet wipes. The coefficient of friction of both nonwoven and woven wipes against glass surface is in general higher than the floor tile surface. The wipes wetted with water shows an increase in coefficient of friction as compared to dry sample, but there is reduction in the coefficient of friction when the wipe samples are wetted with vegetable oil. In case of dry wipes, the coefficient of friction in case of nonwoven wipe is higher than the woven wipe. In case of woven wipes, the ranges of coefficient of friction either due to change in liquid type, normal load or sliding speed are in general smaller than that in case of nonwoven fabrics.

• Fashion & Textile Research Journal
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• v.11 no.3
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• pp.496-501
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• 2009

In this study, a kiwifruit-produced protease was used to improve the quality of the wool and silk fabrics. The wool and silk were treated with the actinidin from kiwifruit. Following this protease treatment, changes in the surface of a single yarn of the fabrics were observed via both an optical microscope and a scanning electron microscope (SEM). In order to determine the amount of dye uptake in the fabric, changes in the K/S value of the wool and silk were measured by spectrophotometric analysis. Also, we performed a tensile strength examination to determine variation in their mechanical properties. By increasing the protease treatment time to 48h, the dyeing properties of fabrics were enhanced, and the surfaces of the single yarns of the fabrics became smoother, because of the removal of soil and scale in them. However, no mechanical changes were detected in the fabrics. Thereby, we suggest that the kiwifruit-produced actinidin treatment can improve the quality of the fabrics.

• Journal of the Korean Society of Clothing and Textiles
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• v.35 no.10
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• pp.1264-1270
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• 2011

This study is to optimize the conditions for the treatment of polyamide fabrics using laccase. The pH, temperature, treatment time, and concentration were varied; their effects were evaluated by measuring the number of primary amide groups by the uptake of an acid dye measured by K/S of dyed polyamide fibers. The hydrophilicity of the fabrics was evaluated in terms of moisture regain and wettability. The effects of the mediator, ABTS, on the laccase activity were also evaluated. The optimal treatment conditions were identified as a pH of 4.5, temperature of $30^{\circ}C$, treatment time of 6 hours, and concentration of 10% of the weight of the fabric (o.w.f.). ABTS facilitated the activity of laccase on the polyamide fabrics. Voids and cracks on the surfaces of the laccase-treated polyamide fabrics were responsible for improved wettability. The results proved that laccase treatment improved the hydrophilicity of polyamide fibers without decreasing their strength.

• Journal of the Korean Society of Clothing and Textiles
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• v.27 no.1
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• pp.134-142
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• 2003

Performances of Taekwondo fabrics were evaluated in respect of fiber component. yarn count, weave structure and wearing comfort. As a beginning step, we investigated the present situation of Taekwondo wears by questionnaire from pro and amateur Taekwondo players. Samples employed in this study were cotton/nylon blend fabric that was newly woven for this study as well as fabrics of current Taekwondo wears for sale in the market. Their fundamental properties measured were such as air permeability, water vapor transport. wickability, absorption rate, Qmax values, thermal conductivity, durability, hand value, and etc. In addition, subjective wearing sensations were evaluated using Taekwondo wears made of those fabrics. From the results of the objective measurement and the subjective wearing test, we estimated the total fitness of fabrics as a Taekwondo wear. From the questionnaire we could see that pro players and amateurs wanted highly absorbing, quick drying, and soft-tough and complained abrasive surfaces and static elasticity of current fabrics. In view of the results so far achieved, nylon blended fabrics newly woven in this study, showed better comfort-related properties from both of the objective and subjective tests. It was also represented that finer yams enhanced water absorption and touch, and fabrics with rough surface such as honeycomb weave was superior in wearing comfort as well as aesthetic appearance.

• Advanced Composite Materials
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• v.17 no.4
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• pp.359-372
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• 2008

The moisture absorption behavior of carbon fiber-reinforced plastic (CFRP) and its effect on dimensional stability were examined. Moisture diffusivity in CFRP was determined by measuring a specimen's weight during the moisture absorption test. Three types of CFRP specimens were prepared: a unidirectionally reinforced laminate, a quasi-isotropic laminate and woven fabric. Each CFRP was processed into two geometries - a thin plate for determination of diffusivity and a rod with a square cross-section for the discussion of two-dimensional diffusion behavior. By solving Fick's law expanded to 3 dimensions, the diffusivities in the three orthogonal directions were obtained and analyzed in terms of the anisotropy of CFRP moisture diffusion. Coefficients of moisture expansion (CMEs) were also obtained from specimen deformation caused by moisture absorption. During moisture absorption, the specimen surfaces showed larger deformation near the edges due to the distribution of moisture contents. This deformation was reasonably predicted by the finite element analysis using experimentally determined diffusivities and CMEs. For unidirectional CFRP, the effect of the fiber alignment on CME was analyzed by micromechanical finite element analysis (FEA) and discussed.

• The Research Journal of the Costume Culture
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• v.27 no.1
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• pp.11-19
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• 2019

The mass production after the industrialisation and the fast changing fashion cycles in today's world resulted in buying clothes and home textiles more than we need and discarding them before they complete their life cycles. This causes vast amounts of textile waste that creates environmental issues. Upcycling is the creative process of transforming clothing and textile waste by reusing deadstock or used fabric to create new garments and products. It holds importance in terms of sustainability, reducing waste and environmental pollution. During the process of upcycling, certainly the creativity and innovation are the key words because to reuse a product to a better value needs a creative mind, aesthetic consciousness, innovative look and knowledge and it is quite different from a normal design procedure. There is a delicate level of aesthetics which carries the reused materials to a higher value. The handling of the materials, knowing how to manipulate the waste material, the techniques available to apply to surfaces, the concept of two and three dimension on textiles and clothing, contributions of other branches of art such as sculpture and painting all help the designer to reach a higher aesthetic value in the upcycled product in this process. In the study; it was aimed to raise awareness, to attract attention to sustainable fashion and also to contribute to sustainable development as an upcycling design project realized with students in textile and fashion design education taken as an example.

• Journal of the Korea Fashion and Costume Design Association
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• v.23 no.2
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• pp.155-163
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• 2021

This design proposal research is meaningful as Jogakbo can retain the traditional value of the it's design as it becomes a contemporary design proposal. As a specific method of research, history was been investigated to find meaning and formative characteristics defined through prior research under the theme of Jogakbo. Ideas, such as silhouettes, details for design, and the making domestic and foreign designer examples were obtained. The fabric used for the works were recycled from past leather works. All materials are sheep skin. There were various processed surfaces used to avoid monotony. Jogakbo's cotton composition focused on free and radial patterns. The pattern was manufactured using a flat and 3D combination, and the selection of items was mainly made with a simple and light silhouette, so that Jogakbo's details, such as dresses, slip dress, and vests could stand out. Color is an important factor in Jogakbo. However, traditions which are relics of the times, do not need to be preserved in their original form. If changes are inherited with reasonable grounds and directions in line with the changing times, the significance and values are retained are sufficient. It is hoped that these design development studies will continue in the future so that our precious cultural heritage can continue to change and develop positively.