• Title/Summary/Keyword: wrinkle

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Performance Improvement of Nonformaldehyde Wrinkle Resistant Finished Cotton Fabrics Treated with Dialdehydes

  • Park, Hyung-Min;Kim, Yong-Min
    • Fibers and Polymers
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    • v.2 no.4
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    • pp.190-195
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    • 2001
  • Additives, such as sodium perborate and borax, were examined in dialdehyde wrinkle resistant finishing of cotton. Results indicated that the whiteness index(WI) of cotton treated with dialdehyde and additive showed about 90% of WI of the untreated cotton but with decrease in wrinkle recovery angle (WRA) due to inhibition effect of these additives. Effect of additive on the WRA reduction was more prominent with glutaraldehyde than with glyoxal. Reduction in WRA of cotton treated with both dialdehydes and boron compound was minimized by simultaneous addition of formic acid in the bath. Addition of formic acid was also generally beneficial in maintaining WI retentions after 8 months storage. Furthermore, boron compounds were also effective in improving retentions of mechanical properties. By FTIR analysis the residual aldehyde group was detected on the dialdehyde-finished cotton, whereas no peak was shown by addition of boron compounds. This suggested that the residual aldehyde group was a main cause of fabric yellowing on the dialdehyde-finished cotton. Dialhehyde with boron compound, therefore, can be used to replace a conventional formaldehyde-containing wrinkle resistant finishing of cotton.

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Finite Element Analysis to Reduce the Wrinkle Initiation of Workpiece in Groove Rolling (공형압연에서 소재 주름흠 발생 감소를 위한 유한요소해석)

  • Na, D.H.;Cho, O.Y.;Lee, J.H.;Lee, Y.H.;Lee, Y.
    • Transactions of Materials Processing
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    • v.17 no.5
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    • pp.328-336
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    • 2008
  • A criterion which predicts wrinkle initiation on workpiece in groove rolling process based on finite element analysis is proposed. Fundamental idea considered in the criterion is using the difference between flat rolling which don't cause wrinkling at all and groove rolling which usually accompanies it. The proposed criterion assumes that irregular distribution of shear strain on workpiece during groove rolling is attributable to the initiation of wrinkling. The proposed criterion has been applied to roughing train in the rod mill of SEAH BESTEEL Inc. A new design of 2nd pass (square roll groove) was suggested, machined and applied. Results reveal that the proposed criterion could point out the location of wrinkle initiation and could reduce onset of wrinkle.

Development of On-line Bending Stiffness Tester (2) - Lab experiment - (종이 휨강성 자동 측정방식의 개발과 그 이용 (2) - 실험실 측정 -)

  • Seo, Yung-Bum;Jung, Suk-Myun;Jung, Tae-Young
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.39 no.4
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    • pp.21-28
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    • 2007
  • A simple method of on-line stiffness measurement using the wrinkling behavior of paper web between two rollers was presented. The theory and the equation were presented, and lab and mill tests were executed. We called the stiffness measured by Taber tester as 'Taber stiffness', and by tension wrinkling measurement as 'wrinkle stiffness', respectively. Lab experimental results showed Taber and wrinkle stiffness are almost equivalent. In the mill experiment, we could measure the stiffness in the wet state and in the dry state. The dry wrinkle stiffness was close to the taber stiffness, but the wet wrinkle stiffness was much lower than the corresponding taber stiffness.

Wrinkle Reduction Design Method of Triangular Solar Sail (삼각형 태양돛의 주름저감 설계방안)

  • Bae, Hongsu;Woo, Kyeongsik
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.41 no.12
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    • pp.940-949
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    • 2013
  • In this paper, wrinkle reduction design was studied for triangular sail. Wrinkles in the solar sail membrane can change the load path and surface topology which may have an adverse effect on propulsion performance and controllability. In this study, wrinkle reduction strategies of adjusting cable angle, catenary and catenary-wire schemes were considered and the design parameters for wrinkle reduction were systematically investigated.

Improving Wrinkle Resistance of Cotton Fabric by Montmorillonite

  • Yuen C.W.M.;Kan C.W.;Lee H.L.
    • Fibers and Polymers
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    • v.7 no.2
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    • pp.139-145
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    • 2006
  • Cotton fabric was treated with montmorillonite (MMT) so as to evaluate its effectiveness on improving its wrinkle resistance. The MMT in emulsion form was applied to cotton fabric by padding and finally the wrinkle resistance of the MMT-treated cotton fabric was improved. Furthermore, instrumental methods were used for studying the presence of MMT particles on the cotton fabric surface. It was noted that nano-scale MMT particles adhered on the fiber surface and the particle size played an important role in influencing the wrinkle resistance of the cotton fabric. The experimental results are discussed thoroughly in this paper.

Analysis of wrinkle Initiation on Workpiece in Groove Rolling - Finite Element Analysis (공형압연에서 소재 주름흠 발생 해석 - 유한요소해석)

  • Na, D.H.;Cho, O.Y.;Lee, J.H.;Lee, Y.H.;Lee, Y.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2008.05a
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    • pp.415-418
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    • 2008
  • We propose a criterion which predicts wrinkle initiation on workpiece in groove rolling process based on finite element analysis. Fundamental idea introduced in the criterion is to examine the difference between flat rolling which don't' cause wrinkling at all and groove rolling which usually accompanies it. The proposed criterion assumes that irregular distribution of shear strain on workpiece during groove rolling is attributable to the initiation of wrinkling. The proposed criterion has been applied to roughing train in the rod and bar mill of SEAH BESTEEL Inc. A new design for 2nd pass (square roll groove) was suggested, machined and applied. Results reveal that the proposed criterion in this study could point out the location of wrinkle initiation during groove rolling and could reduce onset of wrinkle on final products.

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Thickness Effect on Wrinkle-Crease Interaction for Thin Membrane (접힌자국이 있는 멤브레인에서 두께에 따른 주름거동의 변화)

  • Woo, Kyeong-Sik
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.38 no.5
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    • pp.421-426
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    • 2010
  • In this paper, the thickness effect on the wrinkle-crease interaction behavior of corner-loaded creased square membranes was studied using geometrically nonlinear post-buckling analysis. The membranes were modeled using shell elements, and the meshes were seeded with semi-random geometrical imperfection to instigate the buckling deformation. Results indicated that the wrinkle-crease interaction behavior was significantly dependent on the membrane thickness. Both the global and local wrinkles developed earlier as the thickness decreased. It was also found that the wrinkling behavior depended on the initial deployment angle in which the local wrinkle initiation occurred earlier, while the global wrinkle formation was delayed as the angle increased.

Analysis Methods of Wrinkle Prediction for Thin Membrane (얇은 막재료의 주름해석 기법)

  • Bae, Hongsu;Woo, Kyeongsik
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.41 no.11
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    • pp.865-873
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    • 2013
  • In this paper, numerical methods for wrinkle prediction of thin membrane were studied by finite element analysis. Techniques using membrane and shell elements were applied for triangular membrane. In case of membrane element method, the wrinkling was accounted for by the wrinkle algorithm of property modification, which was implemented to ABAQUS as a user subroutine. In case of shell method, geometrically nonlinear post-buckling analysis was performed to obtain the wrinkle deformation explicitly. The wrinkling deformation was induced by seeding the mesh with a random geometric imperfection. The results were investigated focusing on the mesh convergence and the solution accuracy.

Anti-Wrinkle Effect of Ulmus davidiana Extracts (유근피 추출물의 피부개선효과)

  • Kim, Young-Ock;Seo, Yong-Chang;Lee, Hyeon-Yong;Oh, Sook-Myung;Lee, Sang-Won;Kim, Hyung-Don
    • Korean Journal of Medicinal Crop Science
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    • v.19 no.6
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    • pp.508-513
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    • 2011
  • The bark of the root and stem of Ulmus davidiana var. japonica has been used as a traditional Korean medicine to treat inflammatory disorders. This plant reportedly shows antioxidant, anticancer, and anti-inflammatory effects. In this study, we investigated the protective effects of Ulmus davidiana var. japonica ethanolic extract (UDE) on UVB irradiation-induced wrinkle in hairless mice. We evaluated for their free radical-scavenging activities against 1,1-diphenyl-2-picrylhydrazyl (DPPH) and the anti-elastase activities, and for their anti-matrix metalloproteinase-1 (MMP-1) activity in human skin fibroblast cells. In the wrinkle measurement and image analysis of skin replicas, the results showed that UDE significantly inhibited wrinkle formation caused by chronic UVB irradiation. These results suggest that UDE has anti-wrinkle activity.

Anti-wrinkle effect of bone morphogenetic protein receptor 1a-extracellular domain (BMPR1a-ECD)

  • Yoon, Byung-Hak;Jeon, Yun-Hui;Hwang, Byunghee;Kwon, Hyuknam;Choe, Senyon;Yang, Zungyoon
    • BMB Reports
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    • v.46 no.9
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    • pp.465-470
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    • 2013
  • Bone morphogenetic proteins (BMPs) have diverse and important roles in the proliferation and differentiation of adult stem cells in our tissues. Especially, BMPs are well known to be the main inducers of bone formation, by facilitating both proliferation and differentiation of bone stem cells. Interestingly, in skin stem cells, BMPs repress their proliferation but are indispensable for the proper differentiation into several lineages of skin cells. Here, we tested whether BMP antagonists have an effect on the prevention of wrinkle formation. For this study we used an in vivo wrinkle-induced mouse model. As a positive control, retinoic acid, one of the top anti-wrinkle effectors, showed a 44% improvement compared to the non-treated control. Surprisingly, bone morphogenetic protein receptor 1a extracellular domain (BMPR1a-ECD) exhibited an anti-wrinkle effect which was 6-fold greater than that of retinoic acid. Our results indicate that BMP antagonists will be good targets for skin or hair diseases.