• Fashion & Textile Research Journal
• /
• v.11 no.2
• /
• pp.359-362
• /
• 2009

This study investigates the behavior of water vapor permeability of a layered system to find out a comfortable combination of a layered system for outdoor activities and examines the water vapor permeability of various types of outdoor clothing fabrics. The layered system includes the base layer such as sportswool and polyester/cotton fabrics, the middle layer such as single and double sided fleece fabrics, and the shell layer such as polyurethane-coated, PTFE-laminated and microfiber fabrics in this experiment. Results show that the layered system was applied, it was working together as a whole having some influence on each other layer, though every layer offered varying degree of water vapor permeability. Water vapor permeability of layered system exactly followed the same trend as the shell layer, which is all vapor permeable water repellent fabrics as a single layer. The rate of water vapor transfer through a layered system is mainly related to the type of vapor permeable water repellent fabrics used for the shell layer.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
• /
• v.5 no.1
• /
• pp.37-46
• /
• 1999

Water vapor permeability of films is commonly calculated from the water vapor transmission rate of the film measured using a permeability cup method which is essentially a gravimetric method. This method was originally developed for petroleum based plastic films with low water vapor permeability. In the case of hydrophilic bio-polymer films, the resistance caused by a stagnant air layer, which is developed between the underside of the film mounted on the cup and the surface of the desiccant saturated salt solution or distilled water, can be significant and, if neglected, ran lead to underestimation of water vapor transmission rates. Therefore, it is necessary to correct water vapor transmission rate data to accurately estimate the water vapor permeability of bio-polymer films.

• Fashion & Textile Research Journal
• /
• v.8 no.6
• /
• pp.709-712
• /
• 2006

The aim of this study is to find out comfortable combinations of layered system for outdoor activities through water vapor permeability. Layering fabrics is an effective way of controlling water transport properties in fabric systems for outdoor activities and analysis of these systems may be useful for designing comfortable clothing. Seven fabrics were chosen for the experiments: two fabrics for base layer, two for the middle layer and three for the shell layer. A total of 12 different layered systems, which are all possible combinations were established using selected fabrics. The water vapor permeability was measured using JIS L1099 under isothermal and non-isothermal conditions. It was found that layered system was working together as a whole having influence on each layer, though every layer offers varying degree of water vapor permeability. Furthermore, it was also found that an optimal combination of the three layered system does exist although the combination may differ according to the ways. The shell layer is the greatest effect of water vapor permeability under isothermal and non-isothermal conditions within layered system.

• Journal of the Korean Society of Industry Convergence
• /
• v.9 no.3
• /
• pp.229-233
• /
• 2006

The water vapor permeability of polypropylene spun bond non-woven fabrics were investigated with the water vapor permeability velocity at $20^{\circ}C$, $30^{\circ}C$ and $40^{\circ}C$ by applying the hygroscopic method. At each temperature 50, 65 and 80 %RH conditions were used. The results indicated that the water vapor permeability velocity increased with increasing the water vapor concentration difference between both sides of sample surfaces and it decreased with increasing the number of the piled-up fabrics and the apparent density.

• Journal of the Korea Furniture Society
• /
• v.19 no.6
• /
• pp.447-451
• /
• 2008

This study was carried out to know the difference of vapor transmission on the thickness of Paulownia wood(Paulownia tomentosa). The behavior of moisture transmission of wood thickness direction is generally estimated by vapor permeability and vapor transmission resistance. In general, Paulownia wood is known to use of inside material for furniture making, because of the excellent ability of vapor adsorption and/or desorption. Quarter sawing Paulownia wood material is prepared and the thickness is 6.0mm, 7.0mm, 8.0mm, 9.0mm, 10.0mm, respectively. The measurement of vapor transmission were conducted by the "cup method" in accordance with JIS(Japanese Industrial Standard) Z-0208. The experiment was made in the condition of 49.8mmHg vapor pressure difference and $40^{circ}C$ at constant temperature. From the experiment results, it was considered that Paulownia wood is very stable on moisture variation and any other material conditions. In this experiment we found that the vapor permeability and vapor permeance was reduced with the increase of wood thickness to vapor direction and vapor transmission resistance and specific vapor transmission resistance was increased with the increase of wood thickness to vapor direction. Besides moisture contents of adsorption and desorption side were about 5 percent and 14 percent, respectively. Mean value was 9.5 percent and about 10 percent in dry oven method. Moisture gradient was reduced with the increase of wood thickness for a small moisture difference of adsorption and desorption side.

• Journal of the Korean Wood Science and Technology
• /
• v.20 no.3
• /
• pp.21-27
• /
• 1992

The amount of moisture transmitted under four different humidity conditions was measured in earlywood and latewood for Cryptomeria japonica(LT specimens). The results obtained are summarized as follows. The vapor permeability in eariywood was about three times larger than that of latewood. The vapor permeabilities in earlywood and late wood depended on the average moisture content of the wood. This indicates that moisture transmission is influenced by vapor permeability or vapor-transmission resistance, but the values obtained by experiments do not have great adaptability for practical situations because of changes in the experimental conditions. There fore, it is necessary to know the moisture content along the flow direction in order to explain the moisture transmission of wood. The vapor permeability was calculated using the density in air dried wood. These were then compared with the experimental values. The vapor permeabilities calculated with this density in the radial direction(LR specimen) had a good tendency to agree with the experimental values, but not so in tangential direction(LT specimen).

• Fashion & Textile Research Journal
• /
• v.19 no.4
• /
• pp.493-503
• /
• 2017

This study investigated water vapor permeability of the 73 breathable fabrics for sports-wear according to the materials, finishing methods and fabric structural parameters. The water vapor permeability by KS K 0594 method of PET breathable fabric was superior than that of nylon one, in addition, water vapor permeability of coated or laminated breathable fabrics were higher than those of hot melt or dot laminated fabrics. The water vapor permeability of breathable fabric was dependent on the thickness, weight and density, which was consistent with measuring method. However, water vapor permeability according to materials and finishing method showed different results according to measuring method. The correlation coefficient of WVP of PET breathable fabrics between ISO and KS K measuring methods was -0.83 and the correlation coefficient of WVP of coated breathable fabrics was -0.72 and -0.71 for KS K and ASTM and -0.72 for KS K and ISO in hot melt laminated breathable fabrics. According to regression analysis, WVP of PET breathable fabric by both KSK and ISO measuring methods was highly dependent upon on the density and weight. In addition, WVP of hot melt laminated breathable fabric was highly dependent upon thickness, weight and density. Therefore, relevant measuring method for WVP of breathable fabrics has to be adopted to measure precise breathability.

• Fashion & Textile Research Journal
• /
• v.22 no.1
• /
• pp.112-118
• /
• 2020

This paper examined the water repellency, water proofing and water vapor permeability of twelve types of woven fabrics for sports wear clothing. Their physical properties were compared and discussed with the fabric structural parameters and surface finishing effect. A water repellent property of 100% was obtained in the coated or laminated water repellent finished fabrics; in addition, cotton/nylon breathable composite fabrics treated with a laminated finishing and with low fabric density showed a 90% water repellency. Water proofing fabric above 6,000 mm H₂O hydraulic pressure was achieved by coated or laminated finishing; however, high density fabric or medium-level coated fabrics exhibited 100% water repellent and low water proofing characteristics. Superior water vapor permeability characteristics with good water repellency and proofing properties were achieved at the 2.5 layered low density and with 0.7 - 0.9 cover factor nylon fabrics treated with hydrophilic laminated finishing. The regression analysis for examining the effects of fabric structural parameters and surface finishing such as coating and laminating to the water vapor permeability exhibited a high determination coefficient of fabric structural parameters of 63.5%; in addition,, main factors among fabric structural parameters appeared to be cover factor and fabric thickness per weight. Coating and Laminating factors exhibited determination coefficient of water vapor permeability parameters of 36.5%.

• Korean Journal of Food Science and Technology
• /
• v.21 no.2
• /
• pp.235-237
• /
• 1989

Water vapor permeability of plastic films was measured by Electric tester and Cup tester and the data of the two were compared. Regardless of the testing method, water vapor permeability measured by two methods showed consistent results. By these methods, water vapor permeability of polyethylene film was $21.25g/m^2$. 24h and $5.4g/m^2$. 24h for 0.045mm and 0.08mm thickness, respectively. The water vapor permeability of casted polypropylene film was 14.93 and $14.90g/m^2$. 24h for Electric tester and Cup tester, respectively. In conclusion, the data obtained by Cup tester was consistent with those of the Electric tester. The Cup tester was certified to perform the water vapor pormeability testing method.

• International Journal of Concrete Structures and Materials
• /
• v.2 no.2
• /
• pp.83-90
• /
• 2008

Permeability to vapor and water among other performances required for finishing materials is dealt with in this study. The relative moisture content of concrete coated/covered with a finishing material was experimentally investigated while changing the environmental conditions including temperature, relative humidity, and rainfall. An organic paint (water-based urethane), organic synthetic resin emulsion-type film coating (film coating E), and inorganic porcelain tiles were selected as the finishing materials. When compared from the aspect of vapor and water permeability, the vapor permeability and water permeability of water-based urethane were high and low, respectively; those of film coating E were high and high, respectively; and those of porcelain tiles were low and low, respectively. This means that the moisture state of concrete structures is governed not only by the environmental conditions but also by the performance of finishing materials. It is therefore of paramount importance to appropriately select a finishing material to address the specific deteriorative factors involved in the concrete structure to be finished.