熱封時間主(zhu)要由(you)制(zhi)袋機(ji)的速度決(jue)定。
速度(du)(du)(du)(du)快，熱(re)(re)封(feng)(feng)(feng)時(shi)(shi)間(jian)(jian)(jian)就短；速度(du)(du)(du)(du)慢，熱(re)(re)封(feng)(feng)(feng)時(shi)(shi)間(jian)(jian)(jian)就長。熱(re)(re)封(feng)(feng)(feng)時(shi)(shi)間(jian)(jian)(jian)也(ye)是(shi)影(ying)(ying)響焊縫封(feng)(feng)(feng)合強度(du)(du)(du)(du)和(he)外(wai)觀的一個關鍵因素。相(xiang)同的熱(re)(re)封(feng)(feng)(feng)溫(wen)度(du)(du)(du)(du)和(he)壓力(li)下，熱(re)(re)封(feng)(feng)(feng)時(shi)(shi)間(jian)(jian)(jian)長，則熱(re)(re)封(feng)(feng)(feng)層熔合更(geng)充(chong)分(fen)，結合更(geng)牢固；但(dan)熱(re)(re)封(feng)(feng)(feng)時(shi)(shi)間(jian)(jian)(jian)太(tai)長，容(rong)易造成焊縫起皺變(bian)形，影(ying)(ying)響平(ping)整(zheng)度(du)(du)(du)(du)和(he)外(wai)觀。熱(re)(re)封(feng)(feng)(feng)后的焊縫若冷卻(que)不(bu)好，不(bu)但(dan)會(hui)影(ying)(ying)響焊疑的外(wai)觀平(ping)整(zheng)度(du)(du)(du)(du)，而(er)且對(dui)熱(re)(re)封(feng)(feng)(feng)強度(du)(du)(du)(du)有一定(ding)的影(ying)(ying)響，冷卻(que)過程(cheng)就是(shi)通過在一定(ding)的壓力(li)下，用(yong)較低的溫(wen)度(du)(du)(du)(du)對(dui)剛熔融熱(re)(re)封(feng)(feng)(feng)后的焊縫進行定(ding)形。因此，壓力(li)不(bu)夠，冷卻(que)和(he)循環不(bu)暢，循環量不(bu)夠，水溫(wen)太(tai)高或冷卻(que)不(bu)及時(shi)(shi)，都會(hui)致使(shi)冷卻(que)不(bu)良(liang)，熱(re)(re)封(feng)(feng)(feng)強度(du)(du)(du)(du)降(jiang)低。