外文翻譯---微孔膜防水透濕織物熱濕傳遞中織物表面凝結(jié)

1、<p>　　Condensation of Water Vapor on Waterproof Breathable Fabrics</p><p>　　Condensation occurs when the local vapor pressure rises above the saturation vapor pressure at the local temperature in theory

2、. 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 sta

3、ndard condition of temperature of 20°C and relative humidity of 65%. The result obtained from experiment showed that condensation could occur under the si</p><p>　　Keywords: condensation ;waterproof bre

4、athable fabric.</p><p>　　Introduction</p><p>　　The human body through the process of metabolism is constantly generating thermal energy and moisture, which exchange through the textile layers wi

5、th 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

6、 that the local vapor pressure rises above the saturation vapor pressure at the local temperature.</p><p>　　Keighley and Ruckman suggested from theory that the condensation occurring on the fabrics may be pr

7、edicted if a saturation line and water vapor concentration line is utilized .Keighley developed a method that involved measurement of water vapor concentration utilizing infrared absorption at the specific frequency of a

8、 strong water vapor absorption and Ruckman provided a solution to the problem of condensation on the inner surface of fabric by perforating metal cylinder simulating the perspiring </p><p>　　A1l above resear

9、ches focus on the effect of condensation on heat and water vapor transfer .Whilst no research has been conducted to study whether the condensation formed on the inner surface of a fabric .this paper described the details

10、 of the measuring apparatus investigated the mechanism of condensation occurred on the fabrics an d also presented typical measuring results for representative of fabrics included waterproof breathable fabrics.</p>

11、<p><b>　　Theories</b></p><p>　　Condensation occurs when the local vapor pressure rises above the saturation vapor pressure at the local temperature. The saturation line is described the wa

12、ter vapor pressure giving rise to 100%relative humidity at a specific temperature, as shown in Fig.1.</p><p>　　This is particularly likely to occur on waterproof fabrics since under such conditions the rate

13、of loss of water vapor from the clothing will be very low with a consequentially high water vapor pressure within the skin microclimate. The inevitable Condensation, which occurs under these circumstances, leads to disco

14、mfort with its associated consequence in wear.</p><p>　　From a physiological point, comfort can be defined as the state that maintains the skin at a temperature of 33±2°C and a relative;; humidity

15、of less than 100%. i.e. no liquid water on the skin surface. This state is controlled by the escape of body produced water vapor and the clothing ability to transmit the water vapor. Table l lists the amount of water vap

16、or produced by the body in different activities and indicates how much water vapor must be lost for comfort to be achieved. Fig.2 shows the</p><p><b>　　Samples</b></p><p>　　To invest

17、igate the condensation formed on the inner fabric surface,14 fabrics are listed in table 2. Three specimens shall be tested by the same method .They include the conventional fabrics, tightly woven fabrics; microporous fi

18、lm fabrics and nonporous film fabrics. Microporous film fabrics .such as PTFE laminated fabrics(known as breathable fabrics)have very small porous, which allow water vapor to diffuse through but prevent liquid water pene

19、tration. Water vapor can be absorbed by an other ty</p><p>　　Conclusion</p><p>　　To investigate the mechanism of condensation occurred on the fabrics, a new measuring apparatus were made to obta

20、in temperature and relative humidity simultaneously .The experiment conducted at the standard condition of temperature Of 20oc an d relative humidity of 65%. The result obtained from experiment showed that PTFE laminate

21、d fabrics except nylon gingham PTFE laminated fabric facilitate the loss of water vapor and therefore prevent condensation. However, the range of fabrics studied showe</p><p>　　作者：周小紅、殷寶璞、王善元</p><

22、p><b>　　國籍：中國</b></p><p>　　出處：東華大學學院報(英文版).第二期.卷19.2003.</p><p>　　微孔膜防水透濕織物熱濕傳遞中織物表面凝結(jié)</p><p>　　在理論上，凝結(jié)發(fā)生在當?shù)氐臍鉁叵庐敭數(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制，一種能同步獲得溫度和對應(yīng)的

23、濕度的測量設(shè)備被設(shè)計了出來。實驗是在溫度20℃相對濕度為65%的條件下進行的。實驗結(jié)果表明,冷凝可能在靠近飽和線的情況下發(fā)生，因為在測量溫度為周圍環(huán)境溫度20℃時，織物表面的溫度可能會低于水蒸氣的露點。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驗。這些織物可以消除冷凝，或防止運輸水蒸汽通過。</

24、p><p>　　關(guān)鍵詞：凝結(jié); 防水; 透氣; 面料</p><p><b>　　引 言</b></p><p>　　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。當水蒸汽的運輸在衣服中比較慢，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

25、況下。</p><p>　　Keighley 和Ruckman 在理論上提出，利用飽和蒸汽線和水蒸汽濃度線防止在織物上產(chǎn)生凝結(jié)的措施。Keighley利用紅外測試水蒸汽的濃度，Ruckman試制了打孔的滾筒模擬人體發(fā)汗，并測量通過織物散發(fā)的水蒸汽量。最近，Ren和Ruckman 利用潑水法模擬在織物表面產(chǎn)生凝結(jié)，對不同的防水透濕織物的透濕性進行測試，研究凝結(jié)對織物透濕性能的影響。一種向織物熱表面噴水的方法的引進是

26、模擬水滴的凝結(jié)。雖然織物的防水性和可透氣性集中在這些織物是否可以減少熱壓力和不舒適度與此同時在風雨里提供一定的保護。</p><p>　　以上關(guān)于凝結(jié)的研究主要集中在凝結(jié)對熱、濕傳遞的影響，而至今為止，無論是理論還是實驗，缺少對織物表面凝結(jié)形成的判斷與研究。本文將介紹一種同時測量溫度與濕度的織物微氣候測試裝置，并對典型的一些織物在模擬人體出汗的環(huán)境中進行測試，對防水透濕織物表面凝結(jié)進行物理指標的表征，對防水透濕織

27、物表面凝結(jié)成因進行研究。</p><p><b>　　理論</b></p><p>　　冷凝是在當?shù)氐臏囟认庐數(shù)氐乃羝麎毫ι仙秊轱柡退羝麎毫r。飽和線是描述在特定的溫度下水蒸汽的壓力上升到100%的相對濕度，見圖1。</p><p>　　這些在防水織物上很容易發(fā)生，當在從衣物的水分壓力遺失率很低而皮膚的水分壓力比較高的情況下。凝結(jié)的必然,發(fā)

28、生在這種情況下,與其相關(guān)的后果,導(dǎo)致在佩戴不適。</p><p>　　表1 由各種活動產(chǎn)生的近似新陳代謝的水蒸汽</p><p>　　從生理角度，舒適可以定義為一種狀態(tài)，這種狀態(tài)為體表的溫度為33±2℃且相對濕度小于100%，沒有液態(tài)水在體表。這種狀態(tài)是由人體產(chǎn)生并散發(fā)的水分和衣服傳遞水分的能力所決定的。表1列出各種活動的水汽產(chǎn)生量，并表明多少水汽必須遺失要達到舒適。圖2顯示了一

29、種水分傳送機制在不同的織物中的模式，并顯示冷凝是依賴織物的性能。水分越是難以通過織物傳送，就有越多的水分在織物的內(nèi)表面聚集。</p><p>　　圖2 不同織物的水蒸汽轉(zhuǎn)移機制</p><p><b>　　樣本</b></p><p>　　調(diào)查在織物內(nèi)表面的冷凝，14種織物已列在表2。三個樣本的檢驗方法應(yīng)該相同，它們包括傳統(tǒng)面料,緊密織物，微孔

30、膜織物面料和無孔薄膜。微孔膜面料，例如聚四氟乙烯層壓織物（稱為透氣面料）有很小的多孔，它允許水蒸氣通過,但為防止液體透水。水蒸汽可以被其他的可透氣織物所吸收（無孔親水性薄膜面料）然后通過排到外界散失。緊梭織使用所謂的細旦纖維，可以防止水分的穿透。</p><p><b>　　表2檢測的織物</b></p><p><b>　　結(jié)束語</b><

31、;/p><p>　　為了研究發(fā)生在織物表面的冷凝機制，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。實驗是在溫度20℃相對濕度為65%的條件下進行的。所得的實驗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損失，因此防止冷凝。但是各種面料的研究表明，凝結(jié)可能發(fā)生在靠近飽和線的情況下。所以必要對大量的織物進行研究，尤其是透氣面料和在惡劣的條件下實驗，以發(fā)展消除冷凝的和能在防水時進行水蒸氣傳輸?shù)目?/p>