• Title, Summary, Keyword: physical properties

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Effects of Processing Parameters on the Physical Properties of Spunbounded and Melt Blown Nonwovens (스펀본드와 멜트블로운 부직포의 물리적 성질)

  • 서학은;김은애
    • Textile Science and Engineering
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    • v.36 no.7
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    • pp.529-538
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    • 1999
  • The processing parameters of spunbonding and melt blowing technologies are major factors determining the physical properties of the resulted nonwovens. In this study, the effects of basis weight and calendering temperature on the physical properties of spunbonded nonwovens were examined. Twelve spunbonded polypropylene nonwovens were fabricated from three different calendering temperatures and four different basis weights. To evaluate the effects of basis weight on the physical properties of melt blown nonwovens, four polypropylene nonwovens having different basis weights were produced. A statistical model fitting by regression was employed to estimate the physical properties. Four physical properties of the spunbonded webs were simultaneously optimized to estimate the optimum calendering temperature and basis weight values for a strong, extensible, breathable and flexible nonwoven. Also, the linear relationships among the properties were examined by Pearson coefficients. The results indicated that the physical properties of the nonwovens were greatly influenced by the calendering temperatures and basis weights. The ratios of the strengths in machine direction and in cross direction were greatly influenced by the basis weights. This study suggested one way to optimize the processing parameters for the interpretation and prediction of the properties of nonwoven fabrics.

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Force-Deformation Characteristics of the Fruit Flesh (과실(果實)의 힘-변형(變形) 특성(特性))

  • Kim, M.S.;Park, J.M.;Choi, D.S.
    • Journal of Biosystems Engineering
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    • v.17 no.2
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    • pp.156-170
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    • 1992
  • The force-deformation relationship gives the basic physical properties of the fruits such as the bioyield point, the rupture point, and the deformations at the bioyield point and the rupture point. These informations are very important to study the stress-strain relationships of the fruits. This study was conducted to analyze those physical properties according to the sampling position of the fruits, and to determine the bioyield point, the rupture point, and the deformations at the bioyield point and the rupture point of the fruits for two different storage conditions(low temperature and normal temperature) and the storage period, and to investigate the effect of loading rate on those physical properties, the hysteresis on the loading-unloading condition and the degree of elasticity of the fruits. The results of the study were as follows : 1. The physical properties(BS, US, BD, and RD) of the test specimen selected from the different sampling positions were quite different. The values of the physical properties were shown smallest ones at the cheek of the fruits, and the statistical test results of the physical properties between the cheek from the other two positions of the fruits showed that there were significant difference at the 1 % level between them. 2. The effect of loading rate on the physical properties of the fruits was relatively large, all the considered physical propertis of the fruits increased with the loading rate, but the hysteresis loss decreased with it. 3. The physical properties of the fruits according to the storage conditions and period showed different, and the bioyield deformation and the rupture deformation of the fruits increased with the storage period, but the bioyield strength and the ultimate strength of the fruits decreased with it. The effect of the storage conditions on the those physical properties showed that the normal temperature storage condition was a little higher than the low temperature storage condition. 4. As a whole, it was shown that the bioyield strength and the ultimate strength of the pear decreased a little faster than those of the apple, and the bioyield deformation and rupture deformation of the pear increased a little faster than those of apple at the two storage conditions.

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Physical properties of composite resins for dental restorative (치과 수복재용 복합레진의 물리적 특성에 대한 연구)

  • Kim, Ji Yeob;Lee, Kwang-Rae
    • Journal of Industrial Technology
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    • v.35
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    • pp.35-39
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    • 2015
  • One of the purposes of the study was to investigate and compare the physical properties(depth of light cure, degree of conversion, water absorption) of 4 kinds of composit resins prepared in this lab; Bis-GMA based, Bis-EMA based, Bis-GMA/UDMA based, and Bis-EMA/UDMA based composit. Another aim was to compare the physical properties of the composit resins with those of the commercialized products(Charmfil flow(Denkist), Quadrant flow(CAVEX)) in market. All of the composit resins and the commercialized products showed almost same values of the physical properties. It was found that all of the composit resins prepared in this lab satisfied the physical properties specified in ISO 4049.

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Changes of Physical and Mechanical Properties of Firefighter Protective Clothing After Radiant Heat Exposure (노출시간과 열강도에 따른 복사열 노출후의 소방보호복의 물리적 특성과 역학적 특성변화)

  • ;N.Pan;G.Sun
    • Journal of the Korean Society of Clothing and Textiles
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    • v.23 no.6
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    • pp.853-863
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    • 1999
  • the change of physical properties (thickness, weight, air permeability) and mechanical properties(abrasion resistance breaking load and displacement) of samples were determined after heat exposure by a RPP tester. The effect of exposure time and heat flux intensity on the changes and the relationship between physical properties and mechanical properties were investigated. FR treated cotton Kevlar/PBI and Nomex with different structureal characteristics were chosen for specimens. The changes of physical properties and mechanical properties were calculated based on their initial values before heat exposure. The longer exposure time and the high heat flux intensity the more changes of those properties. Heat flux intensity was more effective on the changes, The showed to be affected by an interplay of shrinkage and pyrolysis products loss. The changes of thickness and abrasion resistance showed to be higher for plain weave fabric and those of air permeabiliyt and breaking load and displacement for twill weave fabric. While FR treated cotton which have high RPP value experienced serious and detrimental changes after heat exposure Kevlar/PBI which has low RPP value showed no high changes. In conclusion it could be confirmed that when total performance of a protective clothing is estimated retention capability of physical and mechanical properties after heat exposure as well as RPP value must be considered.

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Physical Properties of Polyester, Tencel and Cotton MVS Blended Yarns with Yarn counts and Blend Ratio (PET, Tencel, Cotton MVS 혼방사의 섬도와 혼용률에 따른 물성 특성)

  • Sa, A-Na;Lee, Jung Soon
    • Fashion & Textile Research Journal
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    • v.17 no.2
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    • pp.287-294
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    • 2015
  • This study investigates the physical properties of Murata Vortex Spinning (MVS) blended yarn with yarn count(20's, 30's, 40's) and blend ratio(Polyester 100, Polyester70:Cotton30, Polyester50:Cotton50, Polyester30:Cotton70, and Polyester50:Tencel40:Cotton10). This study evaluated tenacity, elongation, bending rigidity, bending hysteresis, hairiness coefficient, irregularity and twist number. The structure of MVS blended yarn influenced stress, strain, bending rigidity, bending hysteresis and the hairiness coefficient of MVS blended yarn decreased as the yarn count increased. MVS blended yarn consists of core and sheath. The core of MVS blended yarn is composed of a parallel fiber with a wrapping fiber that covers thecore fiber. This special structure of the MVS blended yarn effects the physical properties of the yarn; in addition, the mechanical properties of the component fibers influenced the stress, strain, bending rigidity, bending hysteresis and hairiness coefficient of MVS blended yarn with the blend ratio. Polyester decreases and cotton increases resulted in decreased physical properties. A similar polyester content increased the tencel and physical properties. Appropriate physical properties and a variety of touch expression can be realized through a correct blend ratio.

Physical and Mechanical Properties of Methyl Methacrylate-Impregnated Wood from Three Fast-Growing Tropical Tree Species

  • Hadi, Yusuf Sudo;Massijaya, Muh Yusram;Zaini, Lukmanul Hakim;Pari, Rohmah
    • Journal of the Korean Wood Science and Technology
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    • v.47 no.3
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    • pp.324-335
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    • 2019
  • Timber from plantation forests has inferior physical and mechanical properties compared to timber from natural forest because it is mostly from fast-growing tree species that are cut at a young age. Filling cell voids with methyl methacrylate (MMA) can improve the wood properties. The purpose of this study was to determine the physical and mechanical properties of MMA-impregnated wood from three fast-growing wood species, namely jabon (Anthocephalus cadamba (Roxb.) Miq.), mangium (Acacia mangium Willd) and pine (Pinus merkusii Jungh. & de Vriese). Wood samples were either immersed in MMA monomer or impregnated with it and then heated to induce the polymerization process. Jabon, which was the lowest density wood, had the highest polymer loading, followed by pine and mangium. The physical and mechanical properties of samples were affected by wood species and the presence of MMA, with higher-density wood having better properties than wood with a lower density. Physical and mechanical properties of MMA wood were enhanced compared to untreated wood. Furthermore, the impregnation process was better than immersion process resulting the physical and mechanical properties. Based on MOR values, the MMA woods were one strength class higher compared to untreated wood with regard to Strength Classification of Indonesian Wood.

The Studies of Correlation between Wrinkle and Mechanical Properties of Fabric (직물의 구김과 역학적성질과의 상관성 연구)

  • 김승진;장동호
    • Textile Science and Engineering
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    • v.20 no.1
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    • pp.11-18
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    • 1983
  • To determine the degrees of the contribution of the various physical properties of the fabrics to their crease recovery, correlations between the 16 physical properties and crease recovery were experimentally analyzed on the 165 worsted sample fabrics by the KES-F System and the Monsanto crease recovery tester. Step-Wise Regression and Correlation Analyses were used to examine correlations between crease recovery and these physical properties. The regression formula was derived to estimate crease recovery from the given physical properties. Correlation coefficients between the estimates obtained by the formula and the experimental results were calculated. And the degrees of the contribution of the 16 physical properties to crease recovery were classified.

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Effect of Air-jet Texturing Processing Parameters on Physical Properties of New Synthetic Polyester Filament (에어젯트 텍스쳐 제조공정조건이 신합섬용 폴리에스테르사의 물성에 미치는 영향)

  • 김승진;한원희
    • Textile Science and Engineering
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    • v.32 no.7
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    • pp.679-689
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    • 1995
  • The physical properties of air-jet texturing yarn with various processing conditions are investigated in this paper. Physical and mechanical properties of air-jet textured yams manufactured with Hemma Jet T311 type are measured with various processing conditions such as overfeed, air pressure and dry/wet effect. Polyester filaments used are 75d/36f semi dull, which is used for core, and 75d/72f semi dull, which is used for effect in the yarn, respectively. The other polyester filaments used are 40d/24f, which is high shrinkable yam and 50d/24f, which is cation fibre, both are used for core in the yam. Physical properties measured are yarn linear density, yarn stability(instability and decay) by the stress-strain dlayim, loop structure by SEM. Mechanical properties measured are tenacity, modulus, ym, compression, and bending property. These physical and mechanical properties are analysed and discussed with various processing parameters such as overfeed, air pressure and dry/wet condition.

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Effect of Refining on the Stress-Strain Characteristics and Physical Properties of Paper (고해가 종이의 응력-변형 특성 및 물성에 미치는 영향)

  • Won, Jong-Myoung
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.38 no.4
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    • pp.10-16
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    • 2006
  • The study was carried out to investigate how the refining of pulps affects the stress-strain characteristics and physical properties of paper. SwBKP and HwBKP were refined with Hollender laboratory beater to obtain three levels of freeness(500, 400 and 300 ml CSF) at the different consistencies(0.5% and 1.0%). The effects of fines were also evaluated. The stresses and strains of papers made from SwBKP and HwBKP were increased with refining. The absolute value of strain in paper made from SwBKP was higher than those of paper made from HwBKP. We also found that the presence of fines increased the stress and strain significantly in both pulp types. The refining at lower pulp consistency gave higher stress and strain properties. Most physical properties of paper were improved with refining, but the effect of refining consistency depended on the characteristics of each physical properties.

Physuical characteristics of crushed aggregates in Korea (한반도 산림골재의 물성특성)

  • 양동윤
    • Economic and Environmental Geology
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    • v.32 no.1
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    • pp.1-11
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    • 1999
  • In the last decade, the supply of natural aggregates has been continuously increased due to the other types of aggregates. In general, aggregates constitute 70-80% of the total volume of concrete, so the quality of aggregates is main factor controlling physical characteristics of concrete. For this reason, physical properties of aggregate according to different rock types were studied. The majority of crushed aggregates is taken out of granite, gneiss, sandstone, andesite, basalt and so forth. The physical properties of these rock types were tested and most of them fell within the acceptable limit on the base of Korean standard regulation. The major lithology of the crushed aggregates is granite and gneiss, both of which are marked for more than 50% of total lithology thpes in Korea. A to the physical properties of granite, the high specific gravity coincides with low porosity, low absorption ratio, while the abrasion and soundness index show, in general, no specific trend. It has been assumed that slight differences of the physical properties of granite aggregates are related with those of the mineral composition, grain size, and so on. In comparison to granite, the physical properties of gneiss have little correlation one after another. This trend is related to different mineral composition, grain size and typical sheet fractures typically prevailing in the texture of gneiss. Spatial pattern of physical properties shows that high specific gravity of granite coincides only with low porosity and absorption ratio in all provinces except Cheolla province, and high specific gravity of gneiss coincides with low porosity and absorption ratio only in Cheolla and Gandwon provinces.

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