• 제목/요약/키워드: water-vapor permeability

검색결과 188건 처리시간 0.022초

Effect of Coating Methods on the Properties of Poly(lactide)-coated Paperboard: Solution Coating vs. Thermo-compression Coating

  • Rhim, Jong-Whan
    • Food Science and Biotechnology
    • /
    • 제18권5호
    • /
    • pp.1155-1160
    • /
    • 2009
  • Poly(lactide) (PLA)-coated paperboards were prepared by solution coating and thermo-compression coating methods and their effect of coating on the packaging properties such as tensile, water resistance, water vapor barrier, and heat sealing properties was tested. Compared with uncoated control paperboard, tensile strength (TS) of PLA-coated paperboard increased profoundly (2.2-2.6 folds) with slight increase in elongation at break (E). Water absorptiveness (WA) of the paperboard decreased 74-170 folds and water vapor permeability (WVP) decreased 6.3-22.1 folds by coating with PLA, which indicates an increase in the hydrophobicity of the surface of paperboard. Compared with polyethylene (PE)-coated paperboard, both PLA-coated paperboard exhibited 2.3 time higher heat sealing strength. In addition, the PLA-coated paperboards showed equal or higher wet TS than PE-coated paperboard. All the test results showed that the paperboard coated by the thermo-compression coating method was similar to or better than those of coated by the solution coating method.

Preparation of Carrageenan-based Antimicrobial Films Incorporated With Sulfur Nanoparticles

  • Saedi, Shahab;Shokri, Mastaneh;Rhim, Jong-Whan
    • 한국포장학회지
    • /
    • 제26권3호
    • /
    • pp.125-131
    • /
    • 2020
  • Carrageenan-based functional films were prepared by adding two different types of sulfur nanoparticles (SNP) synthesized from sodium thiosulfate (SNPSTS) and elemental sulfur (SNPES). The films were characterized using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction spectroscopy (XRD), and thermal gravimetric analysis (TGA). Also, film properties such as UV-visible light transmittance, water contact angle (WCA), water vapor permeability (WVP), mechanical properties, and antibacterial activity were evaluated. SNPs were uniformly dispersed in the carrageenan matrix to form flexible films. The addition of SNP significantly increased the film properties such as water vapor barrier and surface hydrophobicity but did not affect the mechanical properties. The carrageenan/SNP composite film showed some antibacterial activity against foodborne pathogenic bacteria, L. monocytogenes and E. coli.

편성물의 섬유의 종류, 실의 굵기 및 니트타입에 따른 투습완충능력 (Effect of Fiber Content, Yarn Size and Construction of Knit Fabrics on the Buffering Capacity against Water Vapor)

  • 유화숙;허윤숙;김은애
    • 한국의류학회지
    • /
    • 제20권1호
    • /
    • pp.228-238
    • /
    • 1996
  • The purpose of this study was to evaluate the effect of chacteristics of knit fabrics on the microclimate of the skin simulating system. To determine the effect of characteristics of knit fabrics, vapor state of sweat pulse was simulated in the closed system. Different contents of fibers such as cotton, wool and polyester with different yarn size and knit types were chosen for specimens. The changes of humidity and temperature of air layer in the simulated systems were measured. Buffering indices, $K_d$ and $\beta_r$, were determined by considering $\alpha_p, \DeltaP_{max}, t_{max}, and tan\beta$. Physical properties of knit fabrics such as thickness, porosity, air resistance and moisture vapor transport were measured. Results showed that vapor pressure of wool was lower than cotton or polyester This was attributed to the hydrophilicity of wool which absorbed moisture rather quickly and retained in the knit fabric. The time to decrease vapor pressure was faster for polyester than cotton or wool. As a result, $K_d$ was in the order of wool> polye, item> cotton. $\beta_r$ of wool was rower than cotton or polyester due to its lowers porosity and slower desorption rate. For the yarn size, $K_d$ was in the order of 80's> 60's> 30's; thinner and lighter yarn showed better water vapor transport property. For knit type, buffering capacity of single jersey was better than interlock knit fabric. Statistical analysis showed that the air permeability was the most influential factor far the water vapor transport properties.

  • PDF

고밀도 직물의 반복세탁 및 세탁조건에 따른 투습.발수성 변화 (Changes in Moisture Permeability and Waterproofness of High-density Fabric by Repeated Laundering and Condition)

  • 노의경;한정은;김은애
    • 한국의류학회지
    • /
    • 제34권11호
    • /
    • pp.1798-1811
    • /
    • 2010
  • This research evaluates the changes in the comfort-related properties of high-density fabric, such as moisture permeability and waterproofness, in order to assess the relative importance of laundry conditions for clothing properties after repeated laundering and suggest the best laundering conditions for high-density fabric through the identification of the most influential factor. A commercial high-density fabric was washed 25 times in a drum-type washer using nine different laundry conditions based on profiles derived from a fractional factorial design. To evaluate the changes in the comfort-related properties of the fabric, pore size, air permeability, water vapor transport, water repellency, and water resistance were measured. The comfort-related properties of the fabric deteriorated after repeated laundering by the damaged surface finish; in addition, the damaged surface also changed the pore size. As a result, the water repellency and water resistance decreased. The detergent was the most responsible factor to change the properties among the four factors of detergent, hardness, temperature, and RPM. The best laundering conditions for the fabric was a neutral detergent, soft water of 70ppm, a temperature of $15^{\circ}C$, and 30rpm.

위장 날염된 선택 투과성 화생방 직물의 제조 공정연구 및 성능평가 (A Study on Processes and Performance Evaluation for IR Camouflage Printed Selectively Permeable Membrane Fabrics)

  • 정용균;문상현;강재성;서현관;박현배
    • 한국염색가공학회지
    • /
    • 제26권1호
    • /
    • pp.13-21
    • /
    • 2014
  • The object of this research is to perform the basic research for the development of selectively permeable membrane fabrics which is suitable for korean military in sense of embattlement. As a key factor of selectively permeable membrane fabrics which is suitable for korean military, this study selected the best PVA thickness and membrane selection for DMMP protection, pre-treatment method for conformational stability of face fabric and water/oil repellent process condition. Especially as the PVA coating thickness of the fabrics increase, peneration of DMMP decrease including water vapor permeation is lower. This study shows how physical features and permeability of chemical agents can be influenced by pre-treatment methods, the selection of selectively permeable membrane, the thickness of PVA etc. Results showed that outer shell / PVA / e-PTFE materials possessed performance with superior water vapor permeation (Over $3,000g/m^2/day$) and protective capability against DMMP vapor ($0.6{\mu}g/cm^2{\cdot}16hr$).

풍속 존재 시 쾌적보온성 의복의 온열특성에 관한 연구 (A Study on the Insulation of Thermal Clothing Under Dynamic Air Condition)

  • 송민규;권명숙
    • 복식
    • /
    • 제58권9호
    • /
    • pp.29-37
    • /
    • 2008
  • The purpose of this study was to investigate insulation of thermal clothing under still and dynamic air conditions(with 2.1m/sec air velocity) and decrease of insulation in both conditions, to analyze correlations among them, and to estimate insulation and decrease of insulation using factors, such as fabric insulation, fabric weight, clothing weight, air permeability, and water vapor resistance. A total of 25 kinds of clothing were tested(9 types for suits, 6 types of jacket, 5 types for shirts, and 5 types for trousers). The results of this study were as follows; Thermal resistance of clothing under the dynamic air condition decreased comparing to that of clothing under still air condition in all types of clothing. Decrease in shirts was the biggest(47.5%), followed by suits(39.51%), trousers(37.48%), and jackets(34.49%) in sequence. Thermal resistance of clothing under dynamic air condition showed very high correlation(0.98, p<0.01) with that of clothing under still air condition, followed by thermal resistance of fabric(0.86, p<0.01). Decrease in thermal resistance of clothing showed the highest correlation with air permeability. It didn't show correlation with other factors. Regression analysis showed that fabric thickness would be useful factor for estimating thermal resistance of clothing and air permeability also would be useful factor for estimating decrease in thermal resistance of clothing.

Enhancement of Oxygen and Moisture Permeability with Illite-Containing Polyethylene Film

  • Seong, Dong Min;Lee, Hyesun;Chang, Jeong Ho
    • 한국세라믹학회지
    • /
    • 제56권6호
    • /
    • pp.601-605
    • /
    • 2019
  • This work reports the preparation of ceramic hybrid films with illite-polyethylene composites analyzed as a function of concentration of added illite in polyethylene. The enhancement of oxygen and water-vapor transmission rate of illite-polyethylene film was evaluated to determine its influence on the freshness in fruit packaging. Particle size of illite materials was controlled in the range of 1~10 ㎛ and then mixed with LDPE to form the masterbatch. Ceramic hybrid films were prepared through a blown film making process. To determine the dispersity and abundancy of illite materials in the polyethylene matrix, various characterizations of illite-PE hybrid masterbatch and films were performed using SEM, TGA, and FT-IR. The oxygen and water-vapor transmission rate of illite-polyethylene film was found to be two times higher than that of LDPE film.

Characteristics of Films Based on Chitosans Isolated from Todarodes pacificus

  • Chung, Dong-Hwa;Kim, Sang-Moo;Kim, Won-Tae;Shin, Il-Shik;Park, Hoon
    • Food Science and Biotechnology
    • /
    • 제14권3호
    • /
    • pp.433-436
    • /
    • 2005
  • Chitosans were obtained with varying deacetylation times using the ${\beta}$-chitin isolated from Todarodes pacificus, and their deacetylation degrees and average molecular weights were determined. Films prepared with the squid chitosans were characterized by estimating their tensile strengths, percent elongations, water vapor permeabilities, degree of swelling, and temperatures of glass transition and thermal decomposition. The results suggest that the squid chitosan films were comparable to common crustacean chitosan films in regard of mechanical, moisture barrier, and thermal properties, although further, multilateral investigations are necessary to make a more definitive conclusion.

우럭 껍질 젤라틴 복합필름의 특성 (Characterization of Rockfish Skin Gelatin Composite Films)

  • 백송이;김혜리;송경빈
    • 한국식품영양과학회지
    • /
    • 제46권3호
    • /
    • pp.394-399
    • /
    • 2017
  • 플라스틱 포장 폐기물로 인한 환경오염을 해결하기 위한 대안으로 생분해성 필름이 많이 연구되어 왔다. 본 연구에서는 우럭 껍질 젤라틴(RFG)과 nano-clay(Cloisite $Na^+$, 10A)의 복합필름의 특성에 관하여 연구하였다. 우럭 껍질로부터 젤라틴을 추출하여 sorbitol을 가소제로서 첨가한 단백질 필름을 제조하였고, 제조된 RFG 필름의 tensile strength(TS), water vapor permeability(WVP), water solubility(WS)는 각각 15.0 MPa, $2.70{\times}10^{-9}g\;m/m^2\;s\;Pa$, 53.8%였다. RFG에 nano-clay를 첨가한 복합필름은 TS가 증가하고 WVP와 WS는 감소하였다. XRD 분석과 SEM 측정 결과를 통하여 RFG/nano-clay 복합필름 내부에 박리형 구조를 형성함을 확인할 수 있었다. 결론적으로 본 연구 결과 RFG/nano-clay 복합필름은 생분해성 포장재로 적용될 수 있음을 시사한다.