• 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.

• 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%.

• 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.

• 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.

• 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.

• Fashion & Textile Research Journal
• /
• v.25 no.1
• /
• pp.119-126
• /
• 2023

This study aimed to determine the effects of relative humidity and fiber properties on the moisture permeability of multilayer systems by measuring water vapor transmission in the overlapping condition of various fabrics. The results confirmed that the property of the fabric in contact with the humid environment affects the moisture permeability. If the layer facing the humid environment is hydrophobic and the layer facing the dry environment is superhydrophobic, water vapor transmission increases by up to 17.8% compared to the opposite conditions. Comparing the correction values of the water vapor transmission reflecting the thickness of the specimen under the multilayer condition showed that permeability was higher when the hydrophilic or hydrophobic layer was facing the humid environment. The opposite was true from the "push-pull" effect of absorption mechanism. In the case of moisture permeability, the more hydrophilic the surface facing the humid environment, the more permeable that water vapor diffuses and passes through. It was concluded that the "pull-push" effect, in which water vapor diffuses widely through the hydrophilic facing a humid environment and then passes through the hydrophobic layer, contributes to the improvement of permeability. Permeability differed according to the multilayer overlapping condition. When the relative humidity was high, the "pull-push" effect was insignificant. This is caused by water droplets absorption after the partial migration of water due to condensation. These results suggest that the overlapping conditions and properties of fabrics should vary depending on heavy sweating or not.

• Proceedings of the SAREK Conference
• /
• 2008.06a
• /
• pp.754-757
• /
• 2008

To maintain the indoor air quality, many ventilation systems and technologies have been developed in the highly insulated and air tight buildings. In this study, a porous construction material, which is applicable to passive ventilation system, is developed and measured the performances of the permeability and the resistance of water vapor, and the dust collection efficiency. The average coefficient of water vapor permeability shows $3.6\;g/m^2{\cdot}h{\cdot}mmHg$, which is slightly higher than Hanji ($2.4{\sim}3.2\;g/m^2{\cdot}h{\cdot}mmHg$) and the average water vapor resistance factor shows $0.303\;g/m^2{\cdot}h{\cdot}mmHg/g$, which is slightly smaller than Hanji($0.309{\sim}0.315\;g/m^2{\cdot}h{\cdot}mmHg/g$). The pressure drop of the porous construction material is smaller than the HEPA filter and the minimum dust collection efficiency shows 82.8% in the range of $2{\sim}9\;cm/s$.