不(bu)干膠(jiao)標(biao)簽印刷制版(ban)工藝(yi):
專業標簽印(yin)刷涵蓋了幾種主要(yao)的印(yin)刷方式(shi),在制版(ban)階段(duan).根據不同(tong)(tong)的產品性質,選擇不同(tong)(tong)的印(yin)刷方式(shi),針對(dui)不同(tong)(tong)的印(yin)刷方式(shi),制版(ban)工藝也有(you)所不同(tong)(tong)。本文以(yi)柔性版(ban)制版(ban)工藝為例作(zuo)簡(jian)要(yao)介紹。
柔性版制版工藝流程為:原稿一(yi)(yi)菲林(陰片)一(yi)(yi)曝光(guang)一(yi)(yi)沖洗(xi)一(yi)(yi)烘干一(yi)(yi)后處理。
1.原(yuan)稿。適合柔(rou)性(xing)印刷(shua)的原(yuan)稿設計應具備如(ru)下特點:色數(shu)多.但疊印少;不要求再(zai)現特別小的細(xi)節;網線不太(tai)高,但能(neng)取得(de)彩(cai)色印刷(shua)效果;可以聯機(ji)做(zuo)包裝加工(gong)。
2.菲(fei)(fei)林(lin)(陰片)。符合制版需要,圖文(wen)清晰、尺(chi)寸大小規格準(zhun)確;用磨砂菲(fei)(fei)林(lin),要求(qiu)菲(fei)(fei)林(lin)四角密(mi)(mi)度一致;使用藥膜正(zheng)字(zi);用透射密(mi)(mi)度儀量度,白(bai)位密(mi)(mi)度為0.06以下(xia);黑位密(mi)(mi)度為3.5以上。
3.曝光(guang)包(bao)括背曝光(guang)和主曝光(guang)。
①背曝(pu)(pu)光(guang)。感(gan)光(guang)樹脂版的(de)(de)支(zhi)撐(cheng)膜(mo)向上(shang)、保護膜(mo)向下(xia)平(ping)鋪于曝(pu)(pu)光(guang)抽屜中接受曝(pu)(pu)光(guang)。紫外光(guang)線透過支(zhi)撐(cheng)膜(mo)使(shi)感(gan)光(guang)粘接層固(gu)化.以(yi)建立穩固(gu)的(de)(de)底基,也可控制洗(xi)版深度,加強支(zhi)撐(cheng)膜(mo)與感(gan)光(guang)樹脂層的(de)(de)結合力。背曝(pu)(pu)光(guang)時(shi)間根據需(xu)要的(de)(de)底基厚(hou)度確定。
②主曝(pu)(pu)(pu)光(guang)(guang)(guang)。又(you)稱(cheng)正面(mian)(mian)(mian)曝(pu)(pu)(pu)光(guang)(guang)(guang),感光(guang)(guang)(guang)樹(shu)脂版(ban)(ban)材支撐膜(mo)朝(chao)下(xia),保護(hu)膜(mo)朝(chao)上。平(ping)鋪在(zai)曝(pu)(pu)(pu)光(guang)(guang)(guang)抽屜中.將保護(hu)膜(mo)連續一次撕下(xia),再將菲林(lin)藥(yao)(yao)膜(mo)面(mian)(mian)(mian)貼(tie)在(zai)感光(guang)(guang)(guang)樹(shu)脂版(ban)(ban)材上面(mian)(mian)(mian).把真(zhen)空(kong)膜(mo)平(ping)蓋于菲林(lin)(非藥(yao)(yao)膜(mo)面(mian)(mian)(mian)),抽真(zhen)空(kong),使(shi)(shi)菲林(lin)與感光(guang)(guang)(guang)樹(shu)脂層(ceng)貼(tie)合緊密(mi)。紫(zi)外(wai)線(xian)透(tou)過真(zhen)空(kong)膜(mo)及菲林(lin)透(tou)光(guang)(guang)(guang)部(bu)分(fen)(fen),使(shi)(shi)版(ban)(ban)材感光(guang)(guang)(guang)部(bu)分(fen)(fen)聚合固化。主曝(pu)(pu)(pu)光(guang)(guang)(guang)時間(jian)長(chang)短由版(ban)(ban)材型(xing)號和光(guang)(guang)(guang)源強弱(ruo)確(que)定。曝(pu)(pu)(pu)光(guang)(guang)(guang)時間(jian)過短會使(shi)(shi)圖(tu)文坡度太直,線(xian)條(tiao)彎曲,小(xiao)字、小(xiao)點部(bu)分(fen)(fen)被(bei)洗(xi)(xi)掉,反之(zhi)曝(pu)(pu)(pu)光(guang)(guang)(guang)時間(jian)過長(chang)會敷版(ban)(ban),字跡模糊(hu)。如果在(zai)同一張印版(ban)(ban)上有大、小(xiao)宇,粗、細(xi)(xi)線(xian)條(tiao).可視情況用(yong)黑膜(mo)遮蓋分(fen)(fen)別曝(pu)(pu)(pu)光(guang)(guang)(guang).細(xi)(xi)小(xiao)部(bu)分(fen)(fen)不會因(yin)沖洗(xi)(xi)丟(diu)失,以確(que)保印版(ban)(ban)質(zhi)量。主曝(pu)(pu)(pu)光(guang)(guang)(guang)操作要點。
4.沖洗。將未(wei)感光(guang)部分洗刷溶解(jie),保留(liu)光(guang)聚合的浮(fu)雕。洗版(ban)時(shi)(shi)間長(chang)短(duan)根據印版(ban)厚(hou)薄和印紋深淺決定,洗版(ban)時(shi)(shi)間太短(duan),版(ban)上(shang)會留(liu)下未(wei)感光(guang)的樹脂(zhi)而(er)影響(xiang)制版(ban)深度,洗版(ban)時(shi)(shi)間過長(chang)會使版(ban)材膨脹,導致精細部分變形或脫落(luo)。
5.烘干(gan)。去除洗版(ban)溶(rong)劑,使印(yin)版(ban)恢復原(yuan)來尺寸厚(hou)(hou)度(du)。烘烤溫(wen)度(du)在50—60℃之間(jian)。烘烤時(shi)(shi)(shi)間(jian)依版(ban)材厚(hou)(hou)薄(bo)和洗版(ban)時(shi)(shi)(shi)間(jian)的(de)長(chang)短確定,一般厚(hou)(hou)版(ban)兩小(xiao)時(shi)(shi)(shi),薄(bo)版(ban)一小(xiao)時(shi)(shi)(shi)。烘烤時(shi)(shi)(shi)間(jian)過長(chang),烘版(ban)溫(wen)度(du)過高將(jiang)會使印(yin)版(ban)變脆而(er)影響印(yin)刷壽命。烘烤溫(wen)度(du)過低將(jiang)延長(chang)烘干(gan)時(shi)(shi)(shi)間(jian),烘烤時(shi)(shi)(shi)間(jian)過短,印(yin)刷時(shi)(shi)(shi)會出現爛版(ban)現象(xiang)。
6.后處理。即除(chu)粘與后曝光(guang)。使感光(guang)樹(shu)脂徹底硬(ying)(ying)化(聚合(he))達到應有(you)的硬(ying)(ying)度(du)指標,并消除(chu)印(yin)版(ban)粘性,以利于油(you)墨傳遞。后處理時間由測試(shi)所得,目的在于不龜裂、不粘著。