• 복식문화연구
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• 제12권5호
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• pp.737-742
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• 2004

The purpose of this study is restoration for tearing strength of the durable press (DP) finished 100% cotton fabric by enzymatic treatment. Dimethylol Dihydroxy Ethylene Urea (DMDHEU) was used as a DP finish chemical. Enzymes (cellulase, pectinase, protease, lipolase) were selected based on their specific reaction activities. Ideal application of the enzymes for this work was to remove cross-links created by DMDHEU on the surface of the fibers to offer migration property between microstructures of cellulose, yet cross-links that exist inside of the fibers are still remained to impart effect of wrinkle resistance. Physical characteristics (tearing strength, wrinkle recovery, FT-IR) of enzyme treated samples were measured and compared. It was found out that, in case of enzyme treatment, most of enzymes didn't have a great effect on tearing strength, but, in case of Protease, tearing strength increased at DMDHEU 2% treatment. As a result of an experiment on wrinkle recovery of the textiles treated with enzyme making density of DMDHEU different whenever respective experiment was made, it was discovered that density of DMDHEU increased as wrinkle recovery increased and, in the relation to enzyme treatment especially in Lipase enzyme treatment, the lesser density of DMDHEU, the more wrinkle recovery increased.

• 한국의류학회지
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• 제22권4호
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• pp.525-534
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• 1998

Cotton fabrics were finished with mixture of BTCA(1,2,3,4,-butanetetracarboxylic acid) and polyalkyleneoxide-modified amino-functional silicone by pad-dry-cure process to achieve better DP performance with a higher retention of physical properties as compared to those of finished with BTCA alone. The results indicated that BTCA improved the wrinkle recovery but reduced significantly the tensile and tear strength of the treated fabrics. Whereas silicone imparted a lower wrinkle recovery, a lower loss of tensile strength than BTCA, in addition improved considerably the tear strength owing to reduction in inter-fiber and/or inter-yarn frictional forces. The concentration and curing temperature needed to enhance physical properties were as follows; for BTCA treatments 6%, at 18$0^{\circ}C$, for silicone treatments 1% at 14$0^{\circ}C$. This optimum concentration of silicone was observed by using the mixture of BTCA and silicone. The wrinkle recovery and DP rating of cotton fabrics treated with mixture of 4% BTCA and 1% silicone at a curing temperature of 17$0^{\circ}C$ was similar to those of treated with 6% BTCA at a curing temperature of 18$0^{\circ}C$, and other performance properties observed were; an increase in tensile strength, extension, toughness, abrasion resistance and moisture regain due to the reduction of BTCA concentration and curing temperature, futhermore an improvement in bending and surface properties due to the lubricating effect of silicone. On the other hand 1% aqueous silicone solution showed the lowest surface tension. Such nonionic surface activity resulted in a more uniform and rapid deposition of BTCA on the fiber or fabric.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.335-335
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• 2011

Instability of a thin film attached to a compliant substrate often leads to emergence of exquisite wrinkle patterns with length scales that depend on the system geometry and applied stresses. However, the patterns that are created using the current techniques in polymer surface engineering, generally have low aspect ratio of undulation amplitude to wavelength, thus, limiting their application. Here, we present a novel and effective method that enables us to create wrinkles with a desired wavelength and high aspect ratio of amplitude over wavelength as large as to 2.5:1. First, we create buckle patterns with high aspect ratio of amplitude to wavelength by deposition of an amorphous carbon film on a surface of a soft polymer poly(dimethylsiloxane) (PDMS). Amorphous carbon films are used as a protective layer in structural systems and biomedical components, due to their low friction coefficient, strong wear resistance against, and high elastic modulus and hardness. The deposited carbon layer is generally under high residual compressive stresses (~1 GPa), making it susceptible to buckle delamination on a hard substrate (e.g. silicon or glass) and to wrinkle on a flexible or soft substrate. Then, we employ glancing angle deposition (GLAD) for deposition of a high aspect ratio patterns with amorphous carbon coating on a PDMS surface. Using this method, pattern amplitudes of several nm to submicron size can be achieved by varying the carbon deposition time, allowing us to harness patterned polymers substrates for variety of application. Specifically, we demonstrate a potential application of the high aspect wrinkles for changing the surface structures with low surface energy materials of amorphous carbon coatings, increasing the water wettability.

• International Journal of Precision Engineering and Manufacturing-Green Technology
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• 제5권5호
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• pp.651-658
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• 2018

We comprehensively investigated the wrinkles of a stiff layer covering a spherical void embedded in a rubber matrix after the void experienced inflation or contraction. We developed an easy experimental way to realize the inflation and contraction of the voids. The inflation took place in a void right beneath the surface of the matrix and the contraction happened in a void at the bottom of the rubber matrix. In the inflation, the wrinkle at the center of the deformation was random, and the pattern propagated into rabyrinthine, herringbone, and then oriented parallel lines as the position was away from the center of the inflation to the edge. The cracks were concentric, which were perpendicular to the parallel wrinkled pattern. In the contraction, the wrinkle was simply concentric around the surface of the void without any crack. The cracks were found only near the center of the deformation. The strain distribution in the stiff layer after the inflation and contraction was theoretically analyzed with simulations that were in excellent agreement with the experimental results.

• Fibers and Polymers
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• 제2권4호
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• pp.184-189
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• 2001

Continuous photografting/crosslinking of polyethyleneglycol dimethacrylate oligomers onto cotton using a water-soluble benzophenone photoinitiator was investigated. Photografting increased with increasing irradiation dose, oligomer concentration and photoinitiator concentration. Maximum grafting efficiency of DM 400 and 600 were 83% and 79%, respectively. the photografting increased the wrinkle resistance of cotton implying surface crosslinking of cotton. bothsurface crosslinking and bulk crosslinking of cotton were accomplished via dual curing of a mixed formulation containing both a thermally curable component (BTCCA/SHP) and a UV-curable component. The wrinkle resistance of the crosslinked cotton was found to be higher when cured by thermal curing due to the facile post-polymerization of the UV active component. The presence of crosslinks in the dually crosslinked cotton was verified with FT-IR and thermogravimetric analysis.

• 소성∙가공
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• 제25권5호
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• pp.295-300
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• 2016

Recently, Ultra High Strength Steel (UHSS) sheet metal has been widely used to improve lightweight structures in the automobile industry. Because UHSS sheets have high strength but low elongation, it is difficult to control winkle and thinning for complex shaped products. The draw beads on die surface were introduced in this study to reduce wrinkle and thinning. The positions and strength values of draw beads were selected as design variables and optimized using finite element analysis. The beads positions and strength of a mold for B-pillar part were designed with the proposed optimization method. The accuracy of die design from optimization was verified by comparing with the results from 3-D scanned geometry.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2013년도 춘계학술대회 논문집
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• pp.619-620
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• 2013

• 한국한의학연구원논문집
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• 제18권3호
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• pp.119-126
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• 2012

1. Objectives Sasang constitutional medicine is unique in Korean traditional medicine. It diagnoses and treats patients based on his/her Sasang constitution (SC). Skin properties have been used as an effective diagnostic component in the classification of SC types in clinics. In this paper, we investigated the SC-based health relevance of skin elasticity and wrinkle properties. 2. Methods The skin elasticity and wrinkle of forearm and dorsal hand were measured in 299 elderly female subjects. To determine the subject's Sasang constitution, we adopted the classification results from a newly developed SC diagnostic tool. The health states of the subjects were scored by two Korean traditional medical doctors, by whom each subject was categorized either into the healthy state or the unhealthy state. 3. Results As a result, the elasticity hysteresis of forearm (E_HYS), the visco-elasticity (VE_MEAN), and the wrinkle frequency energy of backhand (W_HAND) showed significant differences between Taeum-in group and Soeum-in group. In case of the Soeum-in on unhealthy state, VE_MEAN was decreased significantly (p<.05). W_HAND and W_ARM_H of the healthy Taeum-in were less than those of the unhealthy Taem-in. 4. Conclusions In this study we showed that, for an elderly female population, skin elasticity and viscosity were significantly different not only between each SC type but also between healthy group and unhealthy group in each constitution. In particular, Soeum-in subjects were inferred to be superior in retaining skin softness when they were healthy, and Taeum-in subjects were easy to lose their firmness of skin surface when they became unhealthy.

• Elastomers and Composites
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• 제51권4호
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• pp.342-349
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• 2016

Characteristics of the swelling-induced wrinkles on the surfaces of natural rubber (NR) film were investigated. The wrinkle structure was generated by swelling of NR film pre-stretched and firmly bonded onto an aluminum substrate in hexane. A novel experimental method was adopted to replicate the swelling-induced wrinkles on the NR film using an epoxy-hardener system. To get insight into the wrinkle parameters; the wrinkle length (L), wrinkle distance (D), wrinkle height (H) and the angle between two consecutive wrinkles (${\theta}$), the cross-sections of the replicas obtained from saturated swollen NR film were examined using an optical microscopy (OM). From the OM images, the wrinkling parameters were measured as a function of the thickness of NR film from 0.42 to 1.76 mm. Also, it was evaluated that the effects of swelling time on the wrinkling parameters. The length (L), distance (D) and height (H) of wrinkles increased as the thickness of the NR film and the swelling time increased. However, the angle between the wrinkles (${\theta}$) showed a sharp decrease up to a swelling time of 200 minutes and slightly decreased afterwards.

• 대한화장품학회지
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• 제43권3호
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• pp.247-254
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• 2017

Optical Coherence Tomography (OCT)는 광 산란과 간섭 현상을 이용하여 비침습적으로 생체조직의 표면 및 내부 구조를 이미지화 할 수 있는 영상기술이다. OCT 기술은 질병의 조기진단과 같은 의료 분야에서 활발히 활용되어 왔으나 미용을 위한 피부진단으로의 적용은 아직 초기단계라 할 수 있다. 본 연구에서는 OCT를 피부효능평가에 도입하여 피부결 및 주름 평가에 활용 가능성을 살펴보았다. 모사판(replica)을 대상으로 한 평가에서 PRIMOS와 유사한 패턴을 보여 주었고 주름을 모사한 3차원 모델을 이용한 평가에서는 PRIMOS에 비해 측정각에 따른 오차가 적음을 확인할 수 있었다. 그리고 커버력 화장품을 이용한 사용 전후의 평가에 있어서도 이를 구분할 정도의 해상도를 보였다. 이러한 평가를 통해 OCT의 미세주름평가에서의 가능성을 알 수 있었고 향후 더 구체화된 연구를 통해 그 활용가능성에 대한 신뢰도를 높일 예정이다.