• Journal of the Korean Wood Science and Technology
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• 제17권4호
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• pp.26-34
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• 1989

This study was carried out to manufacture bark board from oak bark by new processes and to examine the physical and mechanical properties of the board. This process with no addition of adhesive used higher pressure and temperature than the conventional one and was applied with or without paraformaldehyde. The results are as follows: 1. The new manufacturing process allowed a good bark board with high absorption coefficient. 2. The best manufacturing process for the mechanical properties of bark board was paraformaldehyde 10%-$250^{\circ}C$-100kg/$cm^2$-3 minutes, (bending strength 40kg/$cm^2$, internal bonding strength 2kg/$cm^2$) and the best manufacturing process for both the mechanical properties of bark board and economic point of view was $250^{\circ}C$-100kg/$cm^2$-3 minutes (bending strength 28kg/$cm^2$, internal bonding strength 1.52kg/$cm^2$). 3. Bark board showed specific gravities from 0.94 to 1.03 and air dried moisture content 9.2% to 11.7%, but Bark board needed paraffin wax emusion treatment. 4. The absorption coefficient of bark boards had two peaks along with frequency; one in 200-400 cps, the other 1200-2000 cps. The former was low but the latter great.

• 한국의류산업학회지
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• 제8권4호
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• pp.441-448
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• 2006

This research is the hair damage as treating a permanent wave before and after that is compared and analyzed the change of physical and mechanical properties. This is the survey of women's hair in 20 years old. On the basis of this we would like to analyze a extend of hair damage. Also, we would to show a basic data for hair damage prevention and hair improvement to keep the beautiful and healthy hair. The conclusion is as follow. : The swelling degree after the treatment was found to be greater than before permanent wave treatment. For the formational characteristics wave, untreated hair certainly had more elastic S curl wave than damaged hair in all the permanent wave treatments, and damaged hair and extremely damaged hair had less elasticity and had saggy S curl wave. The protein permanent and soft permanent wave had thicker, gorgeous, and better elastic wave than the regular permanent wave and direct heating permanent wave in all the hair condition. As the degree of damage on hair got greater, the tensile strength dramatically decreased and as the degree of damage got greater, the elongation was great as well. For treatment method, direct heating permanent wave showed the greatest effect, causing the most damage.

• Journal of the Korean Wood Science and Technology
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• 제33권2호통권130호
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• pp.40-55
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• 2005

This study was carried out to discuss the feasibility of wood and plastic wastes as the raw materials for wood particle-plastic composites. For this purpose, composites were manufactured from coarse and fine wood particles and polypropylene fibers by nonwoven web process. And the effect of wood particle size on the performance of the composites were analyzed according to ASTM D 1037-93. In the physical properties of composites, water absorption decreased with the increase of target density and polypropylene fiber content. And the composites with fine wood particles appeared to have slightly lower water absorption than those with coarse wood particles. Thickness swelling did not vary significantly with the increase of target density but increased with the increase of wood particle content. And the composites with fine wood particles were significantly lower in thickness swelling than those with coarse wood particles. In the mechanical properties of composites, dry and wet MOR showed the increasing tendency with the increase of polypropylene fiber content and target density. Dry and wet MOE showed the increasing tendency with the increase of target density but only wet MOE exhibited the increasing tendency with the increase of polypropylene fiber content. Composites with fine wood particles appeared to be generally higher in wet MOR and MOE than those with coarse wood particles. In conclusion, composites with fine wood particles showed generally higher performance than those with coarse ones. Also, composites were significantly superior to control particleboards in the performance, especially in water absorption and thickness swelling.

• 한국의류산업학회지
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• 제16권1호
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• pp.153-159
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• 2014

This study evaluates the changes of the subjective hand, preference, comfort and mechanical properties of tricot based artificial suede made from sea-island type micro fibers according to raising condition. The subjective hand and the preference of raised suede for jacket were rated by the 20's and 30's women experts according to raising cycles. Comfort properties were evaluated by air permeability, water vapor transmission, and thermal transmission. Mechanical properties were measured by the KES-FB system. The subjective hand of artificial suede was categorized into three hand factors: smoothness, warmness and thickness. Smoothness, warmness and thickness perception increased with raising cycles which affected hand preference and luxuriousness perception. The thickness and wale density of suede increased with the number of raising. Suede became more compact and less pliable and less stretchable due to increased fabric thickness; in addition, the surface of suede became smoother and compressive since the surface evenness of suede improved with smaller fiber fineness and an increased amount of naps covered the base fabric. Furthermore, water vapor transmission decreased and thermal insulation increased. The best raising conditions for artificial suede was four cycles in which artificial suede was preferred without changes in physical properties.

• Korean Chemical Engineering Research
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• 제46권1호
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• pp.23-36
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• 2008

고분자-점토 나노복합체는 소량의 점토를 사용하여 큰 기계적 물성향상을 나타내 많은 관심을 끌고 있는 분야이다. 층상 구조를 갖고 있는 점토를 고분자 matrix에 분산하는 과정으로 요약할 수 있는 고분자-점토 나노복합체 제조는 친수성 점토 표면을 조절하는 기술, 점토의 물리적 성질을 이용하는 무기재료에 관한 지식, 고분자 합성, 고분자 유변학, 고분자 용액 거동, 기계적 물성이 복합적으로 작용하는 계이다. 이러한 복잡성을 설명하기 위해, 이 총설에서 점토 종류와 그 특성을 설명하였다. 또한 점토 특성과 고분자-점토 나노복합체 제조 방법의 연관성에 대해 설명하고, 제조된 복합체의 구조 분석과 방법에 대해 설명하였다. 그리고 복합체의 특징적인 물성을 분류한 후 그 물성과 복합체의 구조를 연관하여 살펴보았다. 마지막으로 최근의 연구 경향과 향후 연구 경향을 제시하였다.

• 한국의류산업학회지
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• 제2권2호
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• pp.132-137
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• 2000

This study was carried out to evaluate the distribution of mechanical and thermal properties of 14 sorts of tencel fabrics. Three kinds of cellulosic fabrics such as cotton 100%, cotton/tencel 50/50% and rayon 100% were used to compare with tencel fabrics. Furthermore, for the comparison of thermal properties, these fabrics were repeatedly washed 1, 3, 5, 10, 15 and 20 times respectively. The mechanical properties were measured by the KES-FB system and Thereto Labo II type was employed to measure the thermal properties of warmth retaining and contact warm/cool feeling($q_{max}$). The experimental results were analysed statistically to relate the mechanical and thermal properties. Tencel showed sufficient ability to recover from bending deformation and drapability comparing with other cellulosic fabrics and had a silhouette which goes along with the body.

• 한국염색가공학회지
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• 제10권5호
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• pp.1-12
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• 1998

This study surveys the mechanical properties such as bending and shear properties to the weight reduction rate of PET fabrics. For this purpose, 12 kinds of satin and 18 kinds of plain weave fabrics are prepared with change of the physical properties of weft yarn(T.P.M., density, and denier) The weight reduction rate was 0％, 12％, 25％, and 30％. Bending rigidity and hysteresis, shear rigidity and hysteresis were measured and discussed with theoretical values in relation with weft twist, yarn linear density, weft fabric density and weave structures.

• International Journal of Advanced Culture Technology
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• 제3권1호
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• pp.86-89
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• 2015

Sugar cane, renewable fiber resources, were used for roof tile production. Urea formaldehyde, phenol formaldehyde and isocyanate resin were used as binders in this study. Roof tile specimens with 400 mm wide, 400 mm long and 5 mm thick were prepared by compression molding. Physical and mechanical properties of the specimens were analyzed by water absorption, thickness swelling, thermal conductivity, density, modulus of rupture and modulus of elasticity. From the results, water absorption at 1 and 24 hours was 19-47 % and 38-57 %, respectively. Thickness swell at 24 hours was 15-29%. Thermal conductivity was 0.016, 0.017 and 0.019 W/m.K when using isocyanate, urea formaldehyde and phenol formaldehyde, respectively. Density of the specimens was 770-860 kg/m3. Modulus of rapture was 255-280 MPa. Modulus of elasticity was 5.1-7.6 GPa. Physical and mechanical properties of the specimens indicated that they would be applied for roof tile and construction.

• 한국염색가공학회지
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• 제25권3호
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• pp.206-214
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• 2013

There has been an increasing demand for high performance and energy-saving of blind. In order to develop the eco-friendly blind textiles, heat treatment process has been utilized for LM(Low Melting) polyester fabrics and the changes of the physical properties of the treated fabrics were examined according to temperature of heat treatment. Morphology, surface reflectance, contact angle, luster, thermal property and mechanical property of heat treated LM polyester fabrics were investigated. As results, morphology analysis of thermal treated fabrics confirmed that degree of fusion of LM polyester yarns improved with increase of temperature. Surface reflectance of thermal treated fabrics decreased with increase of temperature. Luster and contact angle of a water droplet on thermal treated fabrics increased slightly with increase of temperature. The mechanical properties of the fabrics by KES-FB system were found to be temperature-dependent and especially, bending and shear properties among them were highly related to temperature.

• 한국암반공학회:학술대회논문집
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• 한국암반공학회 2007년도 춘계학술발표회 논문집
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• pp.130-139
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• 2007

We have carried out numerical compression experiments to estimate the mechanical properties (Mohr-Coulomb and elastic) of corestone-bearing saprolites in Beolgyo area. The studied saprolite, consisting of mechanically much stronger corestone and weaker matrix, is a weathering product of the Precambrian granitic gneiss in the Youngnam massif. Since the saprolite consists of larger corestones with diameter up to 2m, it is impossible to directly measure the mechanical properties by physical experiments. We have measured the mechanical properties of corestone and matrix from naturally occurring saprolite and have used them as a reference for our numerical model. Then, we mixed each material and carried out biaxial compression tests while varying the volume percentage of corestones from 0 to 57%. We found that both cohesion and internal friction angle increase with the volume percentage of corestones while elastic modulus remains constant. We found the results from numerical experiments are in contradiction to what is known from physical experiments using artificial saprolites. This may be due to a possibility that the sharp and discrete nature of interface between corestone and matrix in physical experiments differs from the gradual interfacial nature in numerical modelling and natural saprolites.