• Title/Summary/Keyword: Wicking

Search Result 62, Processing Time 0.024 seconds

Effects of Wicking on Solder Joint Profile in Gullwing Lead (워킹이 Gullwing 리드의 솔더 접합부 형상에 미치는 영향)

  • 최동필;유중돈;이태수;최상균
    • Journal of Welding and Joining
    • /
    • v.16 no.4
    • /
    • pp.117-124
    • /
    • 1998
  • During the reflow process in SMT, the molten solder has been observed to move upward and solidify along the gullwing lead, which is called the wicking phenomenon. In this paper, possible causes of the wicking are investigated, and its effects on the solder joint profile are quantitatively estimated by introducing the wicking constant. The free energy reduction by intermetallic formation between the copper and tin seems to be the major source of wicking action. The joint profiles of the gullwing lead are calculated using the previous finite element formulation incorporated with the wicking constant. The calculated results show reasonably good agreements with the experimental data when the wicking effects are considered.

  • PDF

Model-Based Simulation Analysis of Wicking Behavior in Hygroscopic Cotton Fabric

  • Hong, Cheol-Jae;Kim, Byung-Jick
    • Journal of Fashion Business
    • /
    • v.20 no.6
    • /
    • pp.66-78
    • /
    • 2016
  • Hygroscopic knitted cotton fabric was found to spontaneously absorb water showing a significantly wide concentration gradient in the absorption direction. A semi-empirical diffusion model was introduced to describe how the wicking behavior compared to the classical capillary model (Washburn's equation), which has been widely used in the textiles industry. The capillary sorption curve and the permeability coefficient, which are key variables for the model equations, were measured using an electronic balance. The concentration profile as a function of the wicking distance and the elapsed time was derived, based on the diffusion model. From the concentration profile, the wicking distance detectable by the human eye or a digital camera with the aid of an image-analysis system, could be described realistically as a function of the time. The classical capillary model could be modified by introducing the tortuous correction factor to match the diffusion model. Wicking models and data-processing techniques in the work could provide useful tools for objectively evaluating the textile's wicking performances.

Rapid Debinding of Low Pressure Injection Molded Parts by Wicking and Subsequent Thermal Pyrolysis (위킹 및 후속 열분해 탈지에 의한 저압 사출제의 가속탈지)

  • 최인묵;김민기;김상우;이해원;송휴섭;최성철
    • Journal of the Korean Ceramic Society
    • /
    • v.35 no.6
    • /
    • pp.635-639
    • /
    • 1998
  • When the low pressure injection molded parts are debinded by wicking and subsequent thermal pyrolysis the optimum transition point from wicking to thermal pyrolysis is just after the completion of the constant wicking rate period. Even when the partially debinded parts were heated at 5$^{\circ}C$/min after reaching the 1st falling rate period the debinding defects such as distortion and cracks were not found.

  • PDF

Experimental Study of Moisture-Wicking Fabric as Cooling Pad for Novel Rotary Direct Evaporative Cooler

  • Sang-Hwan Park;Jae-Weon Jeong
    • International Journal of High-Rise Buildings
    • /
    • v.12 no.4
    • /
    • pp.335-341
    • /
    • 2023
  • This study proposes a novel rotary direct evaporative cooler and investigates the potential of a moisture-wicking fabric as a cooling pad for the proposed evaporative cooler. The rotary direct evaporative cooler rotates the cooling pad to reduce the water and energy consumption of the pump compared to those of existing direct evaporative coolers. A moisture-wicking fabric is considered as the material of the cooling pad, because of its high moisture-wicking property, enhancing water evaporation. Experiments are performed under various inlet air conditions while measuring the air temperature, relative humidity, air velocity, and differential pressure. The evaporative cooling efficiency and impacts of the inlet air temperature and air velocity on the cooling performance are also evaluated. The results demonstrate the potential of the moisture-wicking fabric as cooling pad of direct evaporative cooler.

Moisture Transmission Characteristics of Fabric for High Emotional Garments -Moisture Transmission Characteristics according to Fiber Properties, Yarn Characteristics and Test Method- (고감성 의류용 직물의 수분이동특성 -섬유소재와 실 특성 및 실험방법에 따른 수분이동특성-)

  • Kim, SeungJin;Kim, Hyunah
    • Journal of the Korean Society of Clothing and Textiles
    • /
    • v.41 no.1
    • /
    • pp.28-42
    • /
    • 2017
  • Moisture transfer characteristics of high emotional garments are important to evaluate wear comfort. Wicking and drying measurement methods are also critical for perspiration absorption and quick dry fabric made of high functional fibers. In this study, the wicking and drying properties of high emotional fabrics made from hybrid composite yarns using CoolMax, Tencel, Bamboo staple fibers and PP. PET CoolMax filaments were also measured and analyzed according to various measuring methods. The wicking property of hybrid composite yarn fabrics by Bireck method was mostly influenced by the structure of hybrid yarns than the absorption rate of constituent fibers; however, both the hygroscopicity of fibers and the composite yarn structure affected the wicking property of the fabrics in the drop method. Concerning drying properties, the KSK 0815B method measuring distilled moisture weight was more relevant to explain the drying characteristics of hybrid yarn fabrics than the KSK 0815A method measuring the time to drying. This study revealed that the drying properties of hybrid yarn fabrics were influenced by the hygroscopicity of constituent fibers, wicking properties of constituent yarns and structure of composite yarns.

Mercerization in Degassed Sodium Hydroxide Solution

  • Kim Seung-Il;Lee Eui-So;Yoon Heung-Soo
    • Fibers and Polymers
    • /
    • v.7 no.2
    • /
    • pp.186-190
    • /
    • 2006
  • The application of a degassing system to mercerization process was investigated. It was found that the physical properties of cotton fabrics mercerized in the degassed NaOH solution were superior to those mercerized in NaOH solution. The degree of penetration of the degassed water was examined by measuring wicking height. The wicking height in the degassed water without the wetting agent is higher than that of the saturated water with 0.1 % of wetting agent.

Experimental Study on Development for Separation and Reinforcement Geotextiles with Horizontal Wicking Drain Property (수평방향의 위킹 배수 특성을 지닌 분리·보강용 지오텍스타일 개발을 위한 실험적 연구)

  • Kim, Hong-Kwan;Ahn, Min-Soo
    • Journal of the Korean Geosynthetics Society
    • /
    • v.18 no.4
    • /
    • pp.215-224
    • /
    • 2019
  • According to the recent civil engineering construction work site which is a complex process, development of multi-functional geotextiles is required. In this study, the characteristics of five different modified cross-section fiber yarns for the selection of wicking yarns were analyzed and yarns that can achieve target properties were selected. Experimental prototype geotextiles suitable for horizontal wicking drain property and reinforcement was developed and its tensile strength, 2% secant modulus, vertical water permeability, AOS, friction characteristics by the direct shear method, and vertical/horizontal wicking test were analyzed. These tests are conducted to verify the performance of the geotextiles with horizontal wick drain property, separation and reinforcement developed in this study. As a results of the indoor soil box test, it was confirmed that the geotextiles using the wicking yarn sufficiently exhibited the function of discharging excess pore water in the horizontal direction.

Surface Modification of PET Irradiated by Ultra-Violet (Part II) - Transformation of moisture properties and physical Properties - (UV조사를 통한 PET의 표면개질(제2보) -수분특성 및 물리적 특성 변화-)

  • Choi Hae Young;Lee Jung Soon
    • Journal of the Korean Society of Clothing and Textiles
    • /
    • v.29 no.5 s.142
    • /
    • pp.617-625
    • /
    • 2005
  • The purpose of this study was to develop functional and environment-friendly polyester fabric by irradiating Ultra-Violet, which was produced by the low-pressure mercury lamp. UV irradiation was conducted with various treatment times and distances. Also, pretreatments of solvents and photoinitiator were used to improve the surface modification effects. The effects of UV irradiation on the moisture regain were found to increase gradually with increase of UV treatment time and decrease of treatment distance. Compared the effects of UVC and UVA, UVC was more effective than UVA. Moisture regain and wicking of PET was increased after UV treatment in our experimental condition. And owing to increasing of moisture regain, static charge was decreased. Pretreatment of solvents such as methanol, ethyl ether and addition of photoinitiator such as Benzophenone accelerated surface modification. The moisture regain was increased but wicking was decreased with pretreatment and addition of photoinitiatior. Therefore it is considered as inappropriate f3r clothing because of wicking effects. Yellowness, tensile strength and elasticity slightly decreased after UV irradiation.

Effect of Wickability on Low Temperature Dyeing of Wool (염액의 wicking성이 양모의 저온 염색에 미치는 영향)

  • Dho, Seong-Kook
    • Fashion & Textile Research Journal
    • /
    • v.9 no.1
    • /
    • pp.113-118
    • /
    • 2007
  • It is well recognized that the wicking of liquids in a textile fabric takes place mainly through a capillary system composed of the individual fibers. Considering typical dyeing stages, it is thought that a high dye uptake on the fabric probably depends on the wickability. Three kinds of barely water soluble ketones, acetophenone(A), 2-pentanone(2P) and 3-pentanone(3P) were separately dissolved in methanol(M) and then each was mixed with aqueous solution of C. I. Red Acid 114. Wicking heights of dyeing solutions were measured under such conditions that the effect of gravity was negligible. The result could be graphed as a series of straight lines having the form s = $kt^{1/2}$, where s was distance traveled by the solutions, t was time, and k was slope of the line. The surface tension(${\gamma}$) of the ketones had more signifcant effect on the wickability compared to the viscosity(${\eta}$) of them. The greater wickability resulted in the higher dye uptake on the fabric and the order of wickabilty was equal to that of the surface tension(${\gamma}$) and dye uptake on the fabric, A>3P>2P>M.

Dyeing Properties of CDP Fiber(III) - Dyeing and Solvent Wicking and Physical Properties of Micro CDP Fiber - (CDP 섬유의 염색성(III) -극세 CDP섬유의 염색성, Solvent wicking성 및 물성-)

  • Kim, Young-Hee;Jeong, Dong-Seok;Lee, Mun-Cheul
    • Textile Coloration and Finishing
    • /
    • v.17 no.5 s.84
    • /
    • pp.1-12
    • /
    • 2005
  • Polyester fibers can be modified into cationic dyeable polyester fibers(CDP) by the copolymerization of terephthalic acid and 5-sodium sulphoisophthalic acid with ethylene glycol. The advantage of CDP on most cationic dyes is the conspicuous brilliance due to a narrow steep absorption band and the wash fastness and etc. Weight reduction by alkali hydrolysis, dyeing and solvent wicking properties of fabrics with cationic dyes, and change of fine structure were investigated. To obtain optimum splitting process parameters for dyeing and physical properties of micro CDP fiber, splitting method under various conditions was carried out. By means of SEM, it was confirmed that the splitting process of the micro CDP fiber be achieved at the weight reduction. A comparatively greater quantity of dye is necessary to dye microfiber than conventional fiber. The fastness and solvent wicking of regular CDP fiber is higher than that of micro CDP fiber.