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、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。
zaidiyidaosipandelashenlizuoyongxia,jichuxiliuzaiyueguozuidazhijinghouzhujianbianxi,xihuaguochengyizhichixudaoyuanyexiliuwanquanguhuaweizhi。shifangzhongxiliuzhijingdebianhuabujinshilashenxingbiandejieguo,erqiehaiyuzhiliangchuandiguochengyouguan。congpensitoudaoguhuadiandeyiduanfangchengweixianweichengxingqu,shixianweijiegouxingchengdeguanjianquyu。
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)。 |