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、yidingzhandubingjuyoulianghaokefangxingderongye,chengfangsiyuanye。yekeyoujunxiangrongyejuhezhijiededaofangsiyuanye。gaojuwuzairongjieqianxianfashengrongzhang,jirongjixianxianggaojuwuneibushenru,shidafenzizhijiandejulibuduanzengda,ranhourongjiexingchengjunyunderongye。zhenggeguochengsuoxushijianhenchang,rongzhangguochengdesududuirongjiesuduyouzhongyaoyingxiang。gaojuwurongyezaifangsizhiqian,xujinghunhe、過guo濾lv和he脫tuo泡pao等deng紡fang前qian準zhun備bei工gong序xu,以yi使shi紡fang絲si原yuan液ye的de性xing質zhi均jun勻yun一yi致zhi,除chu去qu其qi中zhong所suo夾jia帶dai的de凝ning膠jiao塊kuai和he雜za質zhi並bing脫tuo除chu液ye中zhong的de氣qi泡pao。在zai粘zhan膠jiao纖xian維wei生sheng產chan中zhong,紡fang前qian準zhun備bei還hai包bao括kuo熟shu成cheng工gong序xu,使shi粘zhan膠jiao具ju有you必bi要yao的de可ke紡fang性xing。
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. 濕shi法fa長chang絲si紡fang絲si機ji的de卷juan繞rao裝zhuang置zhi有you離li心xin罐guan式shi或huo筒tong管guan式shi。紡fang製zhi短duan纖xian維wei時shi通tong常chang采cai用yong紡fang絲si後hou處chu理li聯lian合he機ji,各ge紡fang絲si部bu位wei成cheng形xing後hou的de初chu生sheng纖xian維wei被bei集ji合he成cheng束shu,連lian續xu進jin行xing後hou處chu理li。
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。 |