濕法無紡布:是(shi)將(jiang)置(zhi)於(yu)水(shui)介(jie)質(zhi)中(zhong)的(de)纖(xian)維(wei)原(yuan)料(liao)開(kai)鬆(song)成(cheng)單(dan)纖(xian)維(wei),同(tong)時(shi)使(shi)不(bu)同(tong)纖(xian)維(wei)原(yuan)料(liao)混(hun)合(he),製(zhi)成(cheng)纖(xian)維(wei)懸(xuan)浮(fu)漿(jiang),懸(xuan)浮(fu)漿(jiang)輸(shu)送(song)到(dao)成(cheng)網(wang)機(ji)構(gou),纖(xian)維(wei)在(zai)濕(shi)態(tai)下(xia)成(cheng)網(wang)再(zai)加(jia)固(gu)成(cheng)布(bu)。
濕法紡絲 wet spinning
化學纖維主要紡絲方法之一,簡稱濕紡。濕紡包括的工序是:(1)製備紡絲原液;(2)將原液從噴絲孔壓出形成細流;(3)原液細流凝固成初生纖維;(4)初生纖維卷裝或直接進行後處理。
將成纖高聚物溶解在適當的溶劑中,得到一定組成、一(yi)定(ding)粘(zhan)度(du)並(bing)具(ju)有(you)良(liang)好(hao)可(ke)紡(fang)性(xing)的(de)溶(rong)液(ye),稱(cheng)紡(fang)絲(si)原(yuan)液(ye)。也(ye)可(ke)由(you)均(jun)相(xiang)溶(rong)液(ye)聚(ju)合(he)直(zhi)接(jie)得(de)到(dao)紡(fang)絲(si)原(yuan)液(ye)。高(gao)聚(ju)物(wu)在(zai)溶(rong)解(jie)前(qian)先(xian)發(fa)生(sheng)溶(rong)脹(zhang),即(ji)溶(rong)劑(ji)先(xian)向(xiang)高(gao)聚(ju)物(wu)內(nei)部(bu)滲(shen)入(ru),使(shi)大(da)分(fen)子(zi)之(zhi)間(jian)的(de)距(ju)離(li)不(bu)斷(duan)增(zeng)大(da),然(ran)後(hou)溶(rong)解(jie)形(xing)成(cheng)均(jun)勻(yun)的(de)溶(rong)液(ye)。整(zheng)個(ge)過(guo)程(cheng)所(suo)需(xu)時(shi)間(jian)很(hen)長(chang),溶(rong)脹(zhang)過(guo)程(cheng)的(de)速(su)度(du)對(dui)溶(rong)解(jie)速(su)度(du)有(you)重(zhong)要(yao)影(ying)響(xiang)。高(gao)聚(ju)物(wu)溶(rong)液(ye)在(zai)紡(fang)絲(si)之(zhi)前(qian),須(xu)經(jing)混(hun)和(he)、guolvhetuopaodengfangqianzhunbeigongxu,yishifangsiyuanyedexingzhijunyunyizhi,chuquqizhongsuojiadaideningjiaokuaihezazhibingtuochuyezhongdeqipao。zaizhanjiaoxianweishengchanzhong,fangqianzhunbeihaibaokuoshuchenggongxu,shizhanjiaojuyoubiyaodekefangxing。
紡絲原液被循環管道送至紡絲機,通過計量泵計量,然後經燭形濾器、連接管而進入噴絲頭(帽)。噴絲頭一般采用黃金與鉑的合金或鉭合金材料製成。在噴絲頭上有規律地分布若幹孔眼,孔徑為0.05~0.08毫hao米mi。從cong噴pen絲si孔kong眼yan中zhong壓ya出chu的de原yuan液ye細xi流liu進jin入ru凝ning固gu浴yu,原yuan液ye細xi流liu中zhong的de溶rong劑ji向xiang凝ning固gu浴yu擴kuo散san,凝ning固gu劑ji向xiang細xi流liu滲shen透tou,從cong而er使shi原yuan液ye細xi流liu達da到dao臨lin界jie濃nong度du,在zai凝ning固gu浴yu中zhong析xi出chu而er形xing成cheng纖xian維wei。濕shi紡fang中zhong的de擴kuo散san和he凝ning固gu是shi物wu理li化hua學xue過guo程cheng,但dan某mou些xie化hua學xue纖xian維wei在zai濕shi紡fang過guo程cheng中zhong還hai同tong時shi發fa生sheng化hua學xue變bian化hua。例li如ru粘zhan膠jiao纖xian維wei,纖xian維wei素su黃huang酸suan納na分fen解jie成cheng為wei纖xian維wei素su再zai生sheng纖xian維wei。
濕法紡絲速度(指卷取初生纖維的第一導絲盤速度)youyushourongjiheninggujishuangkuosansuduheningguyudeliutizulidengxianzhi,yinciyuanbirongfangsuduweidi。diyidaosipandexiansuduyufangsiyuanyedejichusuduzhibichengweipensitoulashenbi。shifanglashenbiyibanweifuzhi、零,或是很小的正值,目的是提高成形過程的穩定性。
紡絲原液是兼具粘性和彈性的彈粘體。原液從噴絲孔壓出時,有孔口脹大效應(巴勒斯效應),使擠出細流的直徑大於噴絲孔孔徑。濕紡過程中,脹大比一般為1~2。
在zai第di一yi導dao絲si盤pan的de拉la伸shen力li作zuo用yong下xia,擠ji出chu細xi流liu在zai越yue過guo最zui大da直zhi徑jing後hou逐zhu漸jian變bian細xi,細xi化hua過guo程cheng一yi直zhi持chi續xu到dao原yuan液ye細xi流liu完wan全quan固gu化hua為wei止zhi。濕shi紡fang中zhong細xi流liu直zhi徑jing的de變bian化hua不bu僅jin是shi拉la伸shen形xing變bian的de結jie果guo,而er且qie還hai與yu質zhi量liang傳chuan遞di過guo程cheng有you關guan。從cong噴pen絲si頭tou到dao固gu化hua點dian的de一yi段duan紡fang程cheng為wei纖xian維wei成cheng形xing區qu,是shi纖xian維wei結jie構gou形xing成cheng的de關guan鍵jian區qu域yu。
濕shi紡fang初chu生sheng纖xian維wei由you於yu含han有you大da量liang液ye體ti而er處chu於yu溶rong脹zhang狀zhuang態tai。大da分fen子zi具ju有you很hen大da的de活huo動dong性xing,而er且qie取qu向xiang度du很hen低di,其qi形xing態tai結jie構gou與yu紡fang絲si工gong藝yi條tiao件jian關guan係xi極ji為wei密mi切qie。選xuan擇ze和he控kong製zhi紡fang絲si工gong藝yi條tiao件jian,可ke製zhi得de不bu同tong橫heng截jie麵mian形xing狀zhuang或huo特te殊shu毛mao細xi孔kong結jie構gou和he特te殊shu性xing能neng的de纖xian維wei。 濕紡有各種不同的成形方式,紡絲機也有各種不同的結構。例如有單浴法或雙浴法,有深浴法或淺浴法,有漏鬥成形或管中成形等.
shifachangsifangsijidejuanraozhuangzhiyoulixinguanshihuotongguanshi。fangzhiduanxianweishitongchangcaiyongfangsihouchulilianheji,gefangsibuweichengxinghoudechushengxianweibeijihechengshu,lianxujinxinghouchuli。
濕紡不僅需要種類繁多、體積龐大的原液製備和紡前準備設備,而且還要有凝固浴、循環及回收設備,其工藝流程複雜、廠房建築和設備投資費用大、紡fang絲si速su度du低di,因yin此ci成cheng本ben較jiao高gao。製zhi造zao切qie段duan纖xian維wei時shi可ke采cai用yong數shu萬wan孔kong的de噴pen絲si頭tou或huo集ji裝zhuang噴pen絲si頭tou來lai提ti高gao生sheng產chan能neng力li。一yi般ban隻zhi有you不bu能neng用yong熔rong體ti紡fang絲si的de合he成cheng纖xian維wei,例li如ru聚ju丙bing烯xi腈jing纖xian維wei和he聚ju乙yi烯xi醇chun纖xian維wei,才cai適shi於yu用yong高gao聚ju物wu溶rong液ye濕shi紡fang生sheng產chan切qie段duan纖xian維wei和he長chang絲si束shu。
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