Condensation occurs when the local vapor pressure rises above the saturation vapor pressure at the local temperature in theory. A new measuring apparatus were made to obtain temperature and relative humidity simultaneously for the purpose of investigating the mechanism of condensation occurred on the fabrics. The experiment conducted at the standard condition of temperature of 20°C and relative humidity of 65%. The result obtained from experiment showed that condensation could occur under the situation closed to saturation line as the temperature on fabric may be lower than dew point of water vapor in the measuring box depending on the experiment conducted at an ambient environment temperature of 20°C. The range of fabrics studied showed that PTFE laminated fabrics except nylon gingham PTFE laminated fabric facilitates the loss of water vapor and therefore prevent condensation. It is necessary to develop studies from a wide range of fabrics, especially breathable fabrics and under bad experiment condition in order to develop fabrics, which could eliminate condensation, or transport water vapor through the fabric while remaining waterproof.
Keywords: condensation ;waterproof breathable fabric.
Introduction
The human body through the process of metabolism is constantly generating thermal energy and moisture, which exchange through the textile layers with its environment .As perspiration escapes from the human body when the water vapor transfer from clothing is low .condensation defined as water droplet collected on the inner surface of the clothing may occur, provided that the local vapor pressure rises above the saturation vapor pressure at

在理論上，凝結(jié)發(fā)生在當(dāng)?shù)氐臍鉁叵庐?dāng)當(dāng)?shù)氐恼羝膲毫ι仙礁哂陲柡驼羝膲毫Φ臅r候。為了研究發(fā)生在織物表面的冷凝機(jī)制，一種能同步獲得溫度和對應(yīng)的濕度的測量設(shè)備被設(shè)計了出來。實(shí)驗(yàn)是在溫度20℃相對濕度為65%的條件下進(jìn)行的。實(shí)驗(yàn)結(jié)果表明,冷凝可能在靠近飽和線的情況下發(fā)生，因?yàn)樵跍y量溫度為周圍環(huán)境溫度20℃時，織物表面的溫度可能會低于水蒸氣的露點(diǎn)。各種面料的研究表明,聚四氟乙烯層壓織物除外尼龍格子聚四氟乙烯層壓織物有利于水汽的損失，因此防止水汽凝結(jié)。為了開發(fā)織物，有必要更廣泛的開發(fā)和研究面料，特別是透氣織物和在惡劣的條件下實(shí)驗(yàn)。這些織物可以消除冷凝，或防止運(yùn)輸水蒸汽通過。
關(guān)鍵詞：凝結(jié); 防水; 透氣; 面料

引 言
人體在代謝的過程中，人體不斷和外界環(huán)境不斷做熱能和水分的交換通過織物。當(dāng)水蒸汽的運(yùn)輸在衣服中比較慢，伴隨人體的代謝物就會從體內(nèi)出來。冷凝定義為當(dāng)水滴在衣服的內(nèi)表面聚集時就發(fā)生，只要在在地方的溫度下水蒸汽的壓力高于飽和的水蒸汽的壓力情況下。