什么是裹背(bei)條，裹背(bei)條是通(tong)過(guo)皮殼(ke)機等機械(xie)用于精裝(zhuang)書(shu)(shu)(shu)本(ben)的書(shu)(shu)(shu)脊(ji)部分，使書(shu)(shu)(shu)貼連接得更(geng)加牢固。書(shu)(shu)(shu)脊(ji)制作弧(hu)長的計算，本(ben)器(qi)規(gui)格(ge)依(yi)書(shu)(shu)(shu)芯幅面大(da)小進行調定，以能將(jiang)書(shu)(shu)(shu)芯平穩地(di)送進夾書(shu)(shu)(shu)裝(zhuang)置內為標準。入本(ben)后的書(shu)(shu)(shu)冊不斜(xie)歪(wai)，四角垂直地(di)頂齊在夾書(shu)(shu)(shu)裝(zhuang)置的靠板、側規(gui)內。裁(cai)切尺寸(cun)正確一(yi)致(zhi)，其質量要求與(yu)規(gui)格(ge)誤差與(yu)一(yi)般切書(shu)(shu)(shu)相同。

夾(jia)書簽絲(si)(si)帶裝置安(an)放(fang)(fang)在(zai)切書機(ji)與扒(ba)圓起脊機(ji)之間(jian)(jian)。即(ji)將(jiang)切完的書芯，用分本器從(cong)中間(jian)(jian)分開，再由輸放(fang)(fang)絲(si)(si)帶器將(jiang)絲(si)(si)帶夾(jia)入中心紙書芯的中間(jian)(jian)靠訂(ding)縫一邊(bian)。絲(si)(si)帶夾(jia)在(zai)書芯內(nei)兩(liang)端各留出粘邊(bian)和使用的余地，再經切刀(dao)（剪(jian)刀(dao)式）將(jiang)其(qi)剪(jian)斷。

剪斷后(hou)的絲帶(dai)，裹(guo)背(bei)條芯(xin)(xin)(xin)(xin)部分被下面(mian)膠輥(gun)著膠、壓(ya)(ya)實完成(cheng)夾(jia)書(shu)(shu)簽(qian)絲帶(dai)過程。書(shu)(shu)簽(qian)絲帶(dai)的長(chang)度(du)(du)與一般手工加(jia)(jia)工長(chang)度(du)(du)基本相同，可依書(shu)(shu)冊幅面(mian)長(chang)度(du)(du)調定。扒(ba)圓(yuan)(yuan)(yuan)起(qi)脊(ji)(ji)操作及要求(qiu)。書(shu)(shu)芯(xin)(xin)(xin)(xin)經(jing)裁(cai)切、夾(jia)粘(zhan)絲帶(dai)（或(huo)(huo)不夾(jia)粘(zhan)絲帶(dai)）后(hou)，繼(ji)續傳送（或(huo)(huo)翻(fan)轉(zhuan)(zhuan)變位）并做90°翻(fan)轉(zhuan)(zhuan)，使(shi)平放書(shu)(shu)芯(xin)(xin)(xin)(xin)變為(wei)后(hou)背(bei)朝(chao)上（或(huo)(huo)朝(chao)下）而進入扒(ba)圓(yuan)(yuan)(yuan)起(qi)脊(ji)(ji)機。扒(ba)圓(yuan)(yuan)(yuan)起(qi)脊(ji)(ji)機的加(jia)(jia)工，其操作分為(wei)兩(liang)步，但機器的結構是連在一起(qi)的，均(jun)是先(xian)扒(ba)圓(yuan)(yuan)(yuan)后(hou)起(qi)脊(ji)(ji)。扒(ba)圓(yuan)(yuan)(yuan)。扒(ba)圓(yuan)(yuan)(yuan)起(qi)脊(ji)(ji)機在扒(ba)圓(yuan)(yuan)(yuan)時，由一組（或(huo)(huo)一對）圓(yuan)(yuan)(yuan)輥(gun)，將書(shu)(shu)芯(xin)(xin)(xin)(xin)壓(ya)(ya)緊(jin)后(hou)作相對旋轉(zhuan)(zhuan)動作），使(shi)書(shu)(shu)背(bei)扒(ba)成(cheng)適當規格圓(yuan)(yuan)(yuan)勢，加(jia)(jia)工成(cheng)圓(yuan)(yuan)(yuan)背(bei)書(shu)(shu)芯(xin)(xin)(xin)(xin)。書(shu)(shu)芯(xin)(xin)(xin)(xin)書(shu)(shu)背(bei)的形狀分為(wei)圓(yuan)(yuan)(yuan)背(bei)有(you)脊(ji)(ji)、圓(yuan)(yuan)(yuan)背(bei)無脊(ji)(ji)和方背(bei)（或(huo)(huo)稱(cheng)平背(bei)）三種。平裝裹(guo)背(bei)條書(shu)(shu)刊的書(shu)(shu)脊(ji)(ji)不高出書(shu)(shu)芯(xin)(xin)(xin)(xin)平面(mian)，而精(jing)裝書(shu)(shu)刊的書(shu)(shu)脊(ji)(ji)一般要高出書(shu)(shu)芯(xin)(xin)(xin)(xin)的平面(mian)。書(shu)(shu)脊(ji)(ji)分為(wei)真脊(ji)(ji)和假(jia)脊(ji)(ji)。

真脊(ji)(ji)是利(li)用(yong)書(shu)(shu)(shu)(shu)背(bei)上下(xia)兩邊變(bian)形(xing)的(de)弧度高(gao)出書(shu)(shu)(shu)(shu)芯平面(mian)；假脊(ji)(ji)則是利(li)用(yong)紙板鑲在書(shu)(shu)(shu)(shu)背(bei)后形(xing)成的(de)書(shu)(shu)(shu)(shu)脊(ji)(ji)，書(shu)(shu)(shu)(shu)脊(ji)(ji)的(de)脊(ji)(ji)高(gao)等于(yu)封(feng)面(mian)紙板的(de)厚度。方背(bei)書(shu)(shu)(shu)(shu)芯。是指(zhi)書(shu)(shu)(shu)(shu)芯的(de)書(shu)(shu)(shu)(shu)背(bei)平直方正。書(shu)(shu)(shu)(shu)背(bei)不(bu)突出，與平裝書(shu)(shu)(shu)(shu)刊的(de)書(shu)(shu)(shu)(shu)背(bei)基(ji)本(ben)相似(si)。

背(bei)(bei)(bei)(bei)與書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)芯(xin)(xin)(xin)上(shang)下環襯互成直(zhi)角，由于精(jing)裝書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)芯(xin)(xin)(xin)是用(yong)鎖線訂(ding)(ding)訂(ding)(ding)連，每一個書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)帖(tie)的(de)(de)(de)(de)訂(ding)(ding)口折縫里面都(dou)用(yong)線串過(guo)，因此，書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)芯(xin)(xin)(xin)背(bei)(bei)(bei)(bei)脊(ji)比(bi)書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)帖(tie)其它部分要厚(hou)一些，書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)籍(ji)(ji)的(de)(de)(de)(de)帖(tie)數(shu)越多，書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)脊(ji)背(bei)(bei)(bei)(bei)與書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)芯(xin)(xin)(xin)其它部分厚(hou)度(du)的(de)(de)(de)(de)差別也越大。所以方背(bei)(bei)(bei)(bei)書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)芯(xin)(xin)(xin)的(de)(de)(de)(de)形式一般(ban)只用(yong)于厚(hou)度(du)約為(wei)20mm的(de)(de)(de)(de)精(jing)裝書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)籍(ji)(ji)。圓(yuan)背(bei)(bei)(bei)(bei)有(you)(you)脊(ji)書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)芯(xin)(xin)(xin)。圓(yuan)背(bei)(bei)(bei)(bei)有(you)(you)脊(ji)又稱圓(yuan)背(bei)(bei)(bei)(bei)真脊(ji)書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)芯(xin)(xin)(xin)。書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)芯(xin)(xin)(xin)背(bei)(bei)(bei)(bei)部呈圓(yuan)弧形，書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)脊(ji)高(gao)起有(you)(you)脊(ji)壟，堅硬挺實，這種書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)背(bei)(bei)(bei)(bei)的(de)(de)(de)(de)形式適合于裝訂(ding)(ding)較(jiao)厚(hou)的(de)(de)(de)(de)書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)籍(ji)(ji)，裝上(shang)書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)殼(ke)后(hou)有(you)(you)明顯的(de)(de)(de)(de)書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)槽(cao)，翻閱方便。目前我國(guo)的(de)(de)(de)(de)精(jing)裝書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)籍(ji)(ji)多采用(yong)這種圓(yuan)背(bei)(bei)(bei)(bei)有(you)(you)脊(ji)的(de)(de)(de)(de)加工形式。圓(yuan)背(bei)(bei)(bei)(bei)無(wu)脊(ji)書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)芯(xin)(xin)(xin)。圓(yuan)背(bei)(bei)(bei)(bei)無(wu)脊(ji)書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)芯(xin)(xin)(xin)又稱圓(yuan)背(bei)(bei)(bei)(bei)假脊(ji)，書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)芯(xin)(xin)(xin)背(bei)(bei)(bei)(bei)部呈圓(yuan)弧形，書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)背(bei)(bei)(bei)(bei)與書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)芯(xin)(xin)(xin)的(de)(de)(de)(de)厚(hou)度(du)相(xiang)同，堅實挺括，但沒(mei)有(you)(you)書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)裹(guo)背(bei)(bei)(bei)(bei)條(tiao)脊(ji)。這種形式的(de)(de)(de)(de)書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)芯(xin)(xin)(xin)，一般(ban)常與軟質書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)殼(ke)或塑料(liao)壓制而(er)成的(de)(de)(de)(de)書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)殼(ke)相(xiang)配(pei)套。中心紙有(you)(you)些機(ji)器(qi)(qi)(qi)還(huan)沒(mei)有(you)(you)沖(chong)圓(yuan)裝置，即將方背(bei)(bei)(bei)(bei)書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)先進行沖(chong)圓(yuan)加工，作初步(bu)定型。先根據書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)芯(xin)(xin)(xin)厚(hou)度(du)和中心紙幅面大小調定好夾書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)器(qi)(qi)(qi)及扒(ba)圓(yuan)輥（或沖(chong)圓(yuan)裝置）的(de)(de)(de)(de)規矩，再使書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)芯(xin)(xin)(xin)進入夾書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)器(qi)(qi)(qi)內并送到扒(ba)圓(yuan)輥之間，將書(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)(shu)背(bei)(bei)(bei)(bei)扒(ba)擠成一定圓(yuan)勢(shi)。