【吹塑(su)機(ji)原(yuan)理】吹塑(su)機(ji)工作(zuo)原(yuan)理 吹塑(su)機(ji)運(yun)作(zuo)原(yuan)理是什么？

吹塑機，將(jiang)液體(ti)塑(su)(su)膠(jiao)噴出(chu)來之(zhi)后，利用機(ji)器吹(chui)(chui)出(chu)來的(de)風(feng)力，將(jiang)塑(su)(su)體(ti)吹(chui)(chui)附到一(yi)(yi)定形狀(zhuang)的(de)模腔(qiang)，從而制成產品，這種(zhong)機(ji)器就叫做吹(chui)(chui)塑(su)(su)機(ji)。 塑(su)(su)料在螺桿擠出(chu)機(ji)中被(bei)熔化并定量(liang)擠出(chu)，然后通過口膜成型(xing)，再有風(feng)環吹(chui)(chui)風(feng)冷卻，然后有牽引機(ji)按(an)一(yi)(yi)定速度牽引，卷繞機(ji)將(jiang)其(qi)卷繞成卷。

1、吹塑機工作原理

在(zai)吹塑薄(bo)膜(mo)生(sheng)產(chan)過程中，薄(bo)膜(mo)厚(hou)薄(bo)均(jun)(jun)勻度是一(yi)個很關鍵的指標，其(qi)中縱向厚(hou)薄(bo)均(jun)(jun)勻度可(ke)以(yi)通過擠出(chu)和(he)牽(qian)引速(su)度穩(wen)定(ding)性加以(yi)控(kong)制(zhi)，而(er)薄(bo)膜(mo)橫向厚(hou)薄(bo)均(jun)(jun)勻度一(yi)般依耐于(yu)模頭(tou)精密制(zhi)造(zao)，且隨著生(sheng)產(chan)工藝(yi)參(can)數變化而(er)變化，為了提高薄(bo)膜(mo)橫向厚(hou)薄(bo)均(jun)(jun)勻度，須(xu)引進自(zi)(zi)動(dong)(dong)(dong)橫向厚(hou)薄(bo)控(kong)制(zhi)系統(tong)，常用(yong)(yong)控(kong)制(zhi)方法有自(zi)(zi)動(dong)(dong)(dong)模頭(tou)（熱(re)膨脹(zhang)螺絲控(kong)制(zhi)）和(he)自(zi)(zi)動(dong)(dong)(dong)風(feng)環，這(zhe)里主要介紹自(zi)(zi)動(dong)(dong)(dong)風(feng)環原理與應(ying)用(yong)(yong)。

基本原理

自(zi)動(dong)風(feng)(feng)(feng)環結構上采用雙風(feng)(feng)(feng)口方(fang)式，其中下(xia)風(feng)(feng)(feng)口風(feng)(feng)(feng)量(liang)保持恒定(ding)，上風(feng)(feng)(feng)口圓周上分為若干個(ge)風(feng)(feng)(feng)道(dao)，每個(ge)風(feng)(feng)(feng)道(dao)由風(feng)(feng)(feng)室(shi)、閥門、電機(ji)等組成，由電機(ji)驅動(dong)閥門調整(zheng)風(feng)(feng)(feng)道(dao)開口度，控制每個(ge)風(feng)(feng)(feng)道(dao)風(feng)(feng)(feng)量(liang)大小。

控制過程中，由測厚(hou)探頭檢(jian)測到薄(bo)(bo)膜(mo)厚(hou)薄(bo)(bo)信號(hao)傳(chuan)送到計算(suan)機，計算(suan)機把厚(hou)薄(bo)(bo)信號(hao)與當前設定(ding)平(ping)均厚(hou)度(du)(du)進(jin)行對比，根據厚(hou)薄(bo)(bo)偏(pian)差量以及曲(qu)線變(bian)(bian)化趨勢進(jin)行運算(suan)，控制電(dian)機驅動(dong)(dong)閥門移動(dong)(dong)，當薄(bo)(bo)膜(mo)偏(pian)薄(bo)(bo)時，電(dian)機正向(xiang)移動(dong)(dong)，風(feng)口關小(xiao)；相(xiang)反，電(dian)機反向(xiang)移動(dong)(dong)，風(feng)口增(zeng)大(da)，通過改變(bian)(bian)風(feng)環(huan)圓周上各點(dian)風(feng)量大(da)小(xiao)，調(diao)整(zheng)各點(dian)冷(leng)卻(que)速度(du)(du)，使薄(bo)(bo)膜(mo)橫向(xiang)厚(hou)薄(bo)(bo)偏(pian)差控制在目標的范圍。

控制方案

自動(dong)風(feng)環是一(yi)種在線實時(shi)控(kong)(kong)(kong)(kong)(kong)制(zhi)系(xi)(xi)統(tong)，系(xi)(xi)統(tong)被控(kong)(kong)(kong)(kong)(kong)對象為分(fen)布在風(feng)環上的若干(gan)個(ge)電機。由(you)(you)風(feng)機送來的冷(leng)卻氣流經(jing)風(feng)環風(feng)室恒壓后分(fen)配到每個(ge)風(feng)道上，由(you)(you)電機驅動(dong)閥門(men)(men)作開合運動(dong)以(yi)調(diao)整風(feng)口(kou)及(ji)風(feng)量(liang)(liang)(liang)的大小，改(gai)(gai)變(bian)(bian)模(mo)頭出料(liao)處膜坯的冷(leng)卻效(xiao)果，從(cong)而控(kong)(kong)(kong)(kong)(kong)制(zhi)薄膜厚(hou)度，從(cong)控(kong)(kong)(kong)(kong)(kong)制(zhi)過程看，薄膜厚(hou)度變(bian)(bian)化(hua)(hua)與電機控(kong)(kong)(kong)(kong)(kong)制(zhi)量(liang)(liang)(liang)之(zhi)間找不(bu)到明確(que)關(guan)系(xi)(xi)，不(bu)同(tong)厚(hou)度薄膜以(yi)及(ji)閥門(men)(men)不(bu)同(tong)位置厚(hou)薄變(bian)(bian)化(hua)(hua)與控(kong)(kong)(kong)(kong)(kong)制(zhi)量(liang)(liang)(liang)之(zhi)間程非(fei)線性(xing)(xing)(xing)無(wu)規律(lv)變(bian)(bian)化(hua)(hua)，每調(diao)整一(yi)個(ge)閥門(men)(men)時(shi)對相(xiang)鄰(lin)點影響都很(hen)(hen)大，且調(diao)整有滯后性(xing)(xing)(xing)，使(shi)(shi)不(bu)同(tong)時(shi)刻之(zhi)間又互相(xiang)關(guan)聯，對于這種高(gao)度非(fei)線性(xing)(xing)(xing)、強耦合、時(shi)變(bian)(bian)性(xing)(xing)(xing)和(he)控(kong)(kong)(kong)(kong)(kong)制(zhi)不(bu)確(que)定性(xing)(xing)(xing)系(xi)(xi)統(tong)，其精確(que)數學(xue)模(mo)型(xing)幾乎無(wu)法建(jian)立(li)，即使(shi)(shi)能(neng)(neng)建(jian)立(li)數學(xue)模(mo)型(xing)，也非(fei)常復雜，難以(yi)求解(jie)，以(yi)致(zhi)沒(mei)實用(yong)價(jia)值，而傳統(tong)控(kong)(kong)(kong)(kong)(kong)制(zhi)對較確(que)定控(kong)(kong)(kong)(kong)(kong)制(zhi)模(mo)型(xing)控(kong)(kong)(kong)(kong)(kong)制(zhi)效(xiao)果較好，而對于高(gao)度非(fei)線性(xing)(xing)(xing)，不(bu)確(que)定性(xing)(xing)(xing)，復雜反(fan)饋信息(xi)控(kong)(kong)(kong)(kong)(kong)制(zhi)效(xiao)果很(hen)(hen)差(cha)甚至(zhi)無(wu)能(neng)(neng)為力(li)。鑒(jian)于此(ci)我們選擇了模(mo)糊(hu)控(kong)(kong)(kong)(kong)(kong)制(zhi)算法。同(tong)時(shi)采用(yong)改(gai)(gai)變(bian)(bian)模(mo)糊(hu)量(liang)(liang)(liang)化(hua)(hua)因子方式更好適應(ying)系(xi)(xi)統(tong)參數的改(gai)(gai)變(bian)(bian)。

2、吹塑機吹塑工藝

吹(chui)(chui)塑(su)(su)(su)(su)(su)(su)(su) (blow moulding )也稱中(zhong)空(kong)吹(chui)(chui)塑(su)(su)(su)(su)(su)(su)(su)，一種發(fa)展迅速(su)的(de)(de)(de)塑(su)(su)(su)(su)(su)(su)(su)料加工(gong)(gong)方(fang)法。熱(re)(re)塑(su)(su)(su)(su)(su)(su)(su)性(xing)樹脂經擠出或注(zhu)射成(cheng)型(xing)(xing)得到(dao)的(de)(de)(de)管狀塑(su)(su)(su)(su)(su)(su)(su)料型(xing)(xing)坯，趁(chen)熱(re)(re)（或加熱(re)(re)到(dao)軟化狀態(tai)），置于對開模(mo)中(zhong)，閉(bi)模(mo)后立即在(zai)型(xing)(xing)坯內(nei)通入壓縮空(kong)氣，使(shi)塑(su)(su)(su)(su)(su)(su)(su)料型(xing)(xing)坯吹(chui)(chui)脹(zhang)而緊貼在(zai)模(mo)具內(nei)壁上，經冷卻脫模(mo)，即得到(dao)各種中(zhong)空(kong)制(zhi)品。吹(chui)(chui)塑(su)(su)(su)(su)(su)(su)(su)薄膜的(de)(de)(de)制(zhi)造工(gong)(gong)藝在(zai)原理上和(he)中(zhong)空(kong)制(zhi)品吹(chui)(chui)塑(su)(su)(su)(su)(su)(su)(su)十分相似，但它不使(shi)用模(mo)具，從塑(su)(su)(su)(su)(su)(su)(su)料加工(gong)(gong)技(ji)術(shu)分類的(de)(de)(de)角度，吹(chui)(chui)塑(su)(su)(su)(su)(su)(su)(su)薄膜的(de)(de)(de)成(cheng)型(xing)(xing)工(gong)(gong)藝通常列入擠出中(zhong)。吹(chui)(chui)塑(su)(su)(su)(su)(su)(su)(su)工(gong)(gong)藝在(zai)第(di)二(er)次世界大戰期間，開始用于生(sheng)產低密度聚(ju)(ju)(ju)乙烯(xi)(xi)小瓶。50年代后期，隨著高(gao)密度聚(ju)(ju)(ju)乙烯(xi)(xi)的(de)(de)(de)誕生(sheng)和(he)吹(chui)(chui)塑(su)(su)(su)(su)(su)(su)(su)成(cheng)型(xing)(xing)機(ji)的(de)(de)(de)發(fa)展，吹(chui)(chui)塑(su)(su)(su)(su)(su)(su)(su)技(ji)術(shu)得到(dao)了(le)廣(guang)泛(fan)應用。中(zhong)空(kong)容(rong)器的(de)(de)(de)體積(ji)可達數(shu)千升，有(you)的(de)(de)(de)生(sheng)產已(yi)采(cai)用了(le)計算機(ji)控(kong)制(zhi)。適用于吹(chui)(chui)塑(su)(su)(su)(su)(su)(su)(su)的(de)(de)(de)塑(su)(su)(su)(su)(su)(su)(su)料有(you)聚(ju)(ju)(ju)乙烯(xi)(xi)、聚(ju)(ju)(ju)氯乙烯(xi)(xi)、聚(ju)(ju)(ju)丙烯(xi)(xi)、聚(ju)(ju)(ju)酯等，所得之(zhi)中(zhong)空(kong)容(rong)器廣(guang)泛(fan)用作工(gong)(gong)業包(bao)裝容(rong)器。

根(gen)據(ju)型坯制(zhi)作方法，吹(chui)塑(su)可(ke)分為(wei)擠出吹(chui)塑(su)和注(zhu)射吹(chui)塑(su)，新發展起來(lai)的(de)有多層吹(chui)塑(su)和拉伸(shen)吹(chui)塑(su)。