什么是裹(guo)背條，裹(guo)背條是通過皮殼機(ji)(ji)等機(ji)(ji)械用于精裝(zhuang)書(shu)(shu)本(ben)的(de)書(shu)(shu)脊部(bu)分，使書(shu)(shu)貼(tie)連接得(de)更加牢(lao)固。書(shu)(shu)脊制作弧長的(de)計算，本(ben)器規格(ge)依書(shu)(shu)芯幅面大(da)小進行(xing)調定，以能將(jiang)書(shu)(shu)芯平穩地送進夾書(shu)(shu)裝(zhuang)置內為標準。入本(ben)后(hou)的(de)書(shu)(shu)冊(ce)不斜(xie)歪(wai)，四(si)角(jiao)垂直地頂齊在夾書(shu)(shu)裝(zhuang)置的(de)靠板、側規內。裁切尺寸正確一(yi)致，其質量要求與(yu)規格(ge)誤差與(yu)一(yi)般切書(shu)(shu)相(xiang)同(tong)。

夾(jia)書(shu)簽絲(si)帶(dai)裝置安放在切書(shu)機與扒圓起脊機之間。即將切完的(de)(de)書(shu)芯(xin)(xin)，用(yong)分本(ben)器(qi)從中間分開，再(zai)由輸(shu)放絲(si)帶(dai)器(qi)將絲(si)帶(dai)夾(jia)入(ru)中心紙(zhi)書(shu)芯(xin)(xin)的(de)(de)中間靠訂縫一邊。絲(si)帶(dai)夾(jia)在書(shu)芯(xin)(xin)內(nei)兩端各留(liu)出粘邊和使用(yong)的(de)(de)余(yu)地，再(zai)經切刀（剪(jian)刀式）將其(qi)剪(jian)斷。

剪斷后(hou)的(de)(de)(de)絲(si)帶(dai)(dai)，裹(guo)背(bei)(bei)(bei)條芯(xin)(xin)(xin)部分(fen)被下面(mian)膠輥著(zhu)膠、壓實完成夾書(shu)(shu)(shu)(shu)(shu)簽絲(si)帶(dai)(dai)過程。書(shu)(shu)(shu)(shu)(shu)簽絲(si)帶(dai)(dai)的(de)(de)(de)長度與(yu)一(yi)般手工加(jia)(jia)工長度基本(ben)相(xiang)同，可依書(shu)(shu)(shu)(shu)(shu)冊幅(fu)面(mian)長度調定。扒(ba)(ba)圓起(qi)(qi)脊(ji)(ji)操作及要(yao)求。書(shu)(shu)(shu)(shu)(shu)芯(xin)(xin)(xin)經(jing)裁(cai)切、夾粘(zhan)絲(si)帶(dai)(dai)（或不夾粘(zhan)絲(si)帶(dai)(dai)）后(hou)，繼(ji)續傳送（或翻(fan)轉(zhuan)變(bian)位）并(bing)做(zuo)90°翻(fan)轉(zhuan)，使(shi)平(ping)放書(shu)(shu)(shu)(shu)(shu)芯(xin)(xin)(xin)變(bian)為(wei)(wei)后(hou)背(bei)(bei)(bei)朝上（或朝下）而(er)進入扒(ba)(ba)圓起(qi)(qi)脊(ji)(ji)機。扒(ba)(ba)圓起(qi)(qi)脊(ji)(ji)機的(de)(de)(de)加(jia)(jia)工，其操作分(fen)為(wei)(wei)兩步，但機器的(de)(de)(de)結(jie)構是(shi)連在一(yi)起(qi)(qi)的(de)(de)(de)，均是(shi)先扒(ba)(ba)圓后(hou)起(qi)(qi)脊(ji)(ji)。扒(ba)(ba)圓。扒(ba)(ba)圓起(qi)(qi)脊(ji)(ji)機在扒(ba)(ba)圓時(shi)，由(you)一(yi)組（或一(yi)對）圓輥，將(jiang)書(shu)(shu)(shu)(shu)(shu)芯(xin)(xin)(xin)壓緊后(hou)作相(xiang)對旋轉(zhuan)動作），使(shi)書(shu)(shu)(shu)(shu)(shu)背(bei)(bei)(bei)扒(ba)(ba)成適當(dang)規格圓勢，加(jia)(jia)工成圓背(bei)(bei)(bei)書(shu)(shu)(shu)(shu)(shu)芯(xin)(xin)(xin)。書(shu)(shu)(shu)(shu)(shu)芯(xin)(xin)(xin)書(shu)(shu)(shu)(shu)(shu)背(bei)(bei)(bei)的(de)(de)(de)形(xing)狀分(fen)為(wei)(wei)圓背(bei)(bei)(bei)有脊(ji)(ji)、圓背(bei)(bei)(bei)無脊(ji)(ji)和方背(bei)(bei)(bei)（或稱平(ping)背(bei)(bei)(bei)）三種。平(ping)裝(zhuang)裹(guo)背(bei)(bei)(bei)條書(shu)(shu)(shu)(shu)(shu)刊的(de)(de)(de)書(shu)(shu)(shu)(shu)(shu)脊(ji)(ji)不高出(chu)書(shu)(shu)(shu)(shu)(shu)芯(xin)(xin)(xin)平(ping)面(mian)，而(er)精裝(zhuang)書(shu)(shu)(shu)(shu)(shu)刊的(de)(de)(de)書(shu)(shu)(shu)(shu)(shu)脊(ji)(ji)一(yi)般要(yao)高出(chu)書(shu)(shu)(shu)(shu)(shu)芯(xin)(xin)(xin)的(de)(de)(de)平(ping)面(mian)。書(shu)(shu)(shu)(shu)(shu)脊(ji)(ji)分(fen)為(wei)(wei)真脊(ji)(ji)和假脊(ji)(ji)。

真脊(ji)是(shi)利用書(shu)(shu)(shu)背(bei)上下兩邊(bian)變形(xing)(xing)的(de)弧度高出書(shu)(shu)(shu)芯平面(mian)；假脊(ji)則是(shi)利用紙(zhi)板(ban)鑲在(zai)書(shu)(shu)(shu)背(bei)后形(xing)(xing)成的(de)書(shu)(shu)(shu)脊(ji)，書(shu)(shu)(shu)脊(ji)的(de)脊(ji)高等于封面(mian)紙(zhi)板(ban)的(de)厚(hou)度。方(fang)背(bei)書(shu)(shu)(shu)芯。是(shi)指(zhi)書(shu)(shu)(shu)芯的(de)書(shu)(shu)(shu)背(bei)平直方(fang)正。書(shu)(shu)(shu)背(bei)不突出，與平裝書(shu)(shu)(shu)刊的(de)書(shu)(shu)(shu)背(bei)基本相似。

背(bei)(bei)與(yu)書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)芯(xin)(xin)上下(xia)環襯互(hu)成直角，由(you)于精(jing)裝(zhuang)(zhuang)(zhuang)書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)芯(xin)(xin)是用(yong)鎖線訂訂連，每一(yi)(yi)個書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)帖的(de)(de)訂口折(zhe)縫里面都用(yong)線串過，因此，書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)芯(xin)(xin)背(bei)(bei)脊(ji)比書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)帖其它部分要厚(hou)(hou)一(yi)(yi)些，書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)籍的(de)(de)帖數越多，書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)脊(ji)背(bei)(bei)與(yu)書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)芯(xin)(xin)其它部分厚(hou)(hou)度(du)的(de)(de)差別也越大(da)。所以(yi)方(fang)背(bei)(bei)書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)芯(xin)(xin)的(de)(de)形(xing)式一(yi)(yi)般只用(yong)于厚(hou)(hou)度(du)約為20mm的(de)(de)精(jing)裝(zhuang)(zhuang)(zhuang)書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)籍。圓(yuan)(yuan)背(bei)(bei)有(you)脊(ji)書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)芯(xin)(xin)。圓(yuan)(yuan)背(bei)(bei)有(you)脊(ji)又稱(cheng)圓(yuan)(yuan)背(bei)(bei)真脊(ji)書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)芯(xin)(xin)。書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)芯(xin)(xin)背(bei)(bei)部呈圓(yuan)(yuan)弧(hu)形(xing)，書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)脊(ji)高起(qi)有(you)脊(ji)壟(long)，堅(jian)硬挺實，這種(zhong)書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)背(bei)(bei)的(de)(de)形(xing)式適合于裝(zhuang)(zhuang)(zhuang)訂較厚(hou)(hou)的(de)(de)書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)籍，裝(zhuang)(zhuang)(zhuang)上書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)殼(ke)(ke)后(hou)有(you)明(ming)顯的(de)(de)書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)槽，翻閱方(fang)便。目前我國(guo)的(de)(de)精(jing)裝(zhuang)(zhuang)(zhuang)書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)籍多采用(yong)這種(zhong)圓(yuan)(yuan)背(bei)(bei)有(you)脊(ji)的(de)(de)加工(gong)形(xing)式。圓(yuan)(yuan)背(bei)(bei)無(wu)脊(ji)書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)芯(xin)(xin)。圓(yuan)(yuan)背(bei)(bei)無(wu)脊(ji)書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)芯(xin)(xin)又稱(cheng)圓(yuan)(yuan)背(bei)(bei)假(jia)脊(ji)，書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)芯(xin)(xin)背(bei)(bei)部呈圓(yuan)(yuan)弧(hu)形(xing)，書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)背(bei)(bei)與(yu)書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)芯(xin)(xin)的(de)(de)厚(hou)(hou)度(du)相同，堅(jian)實挺括，但(dan)沒有(you)書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)裹(guo)背(bei)(bei)條脊(ji)。這種(zhong)形(xing)式的(de)(de)書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)芯(xin)(xin)，一(yi)(yi)般常(chang)與(yu)軟(ruan)質書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)殼(ke)(ke)或(huo)塑料壓制而(er)成的(de)(de)書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)殼(ke)(ke)相配(pei)套。中(zhong)心(xin)紙有(you)些機器還沒有(you)沖(chong)(chong)圓(yuan)(yuan)裝(zhuang)(zhuang)(zhuang)置(zhi)，即將方(fang)背(bei)(bei)書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)先進行沖(chong)(chong)圓(yuan)(yuan)加工(gong)，作初(chu)步定(ding)型。先根據書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)芯(xin)(xin)厚(hou)(hou)度(du)和中(zhong)心(xin)紙幅面大(da)小調定(ding)好夾書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)器及扒圓(yuan)(yuan)輥（或(huo)沖(chong)(chong)圓(yuan)(yuan)裝(zhuang)(zhuang)(zhuang)置(zhi)）的(de)(de)規矩(ju)，再(zai)使書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)芯(xin)(xin)進入夾書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)器內并送到(dao)扒圓(yuan)(yuan)輥之間，將書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)背(bei)(bei)扒擠成一(yi)(yi)定(ding)圓(yuan)(yuan)勢。