熱(re)封時間主要(yao)由制袋機的(de)速度決定。
速度(du)快(kuai)，熱(re)(re)封(feng)(feng)(feng)時(shi)(shi)(shi)間(jian)就短；速度(du)慢(man)，熱(re)(re)封(feng)(feng)(feng)時(shi)(shi)(shi)間(jian)就長。熱(re)(re)封(feng)(feng)(feng)時(shi)(shi)(shi)間(jian)也(ye)是影(ying)響(xiang)焊縫封(feng)(feng)(feng)合強(qiang)(qiang)度(du)和外(wai)觀的(de)一個關鍵(jian)因素。相同的(de)熱(re)(re)封(feng)(feng)(feng)溫(wen)度(du)和壓(ya)力(li)下，熱(re)(re)封(feng)(feng)(feng)時(shi)(shi)(shi)間(jian)長，則熱(re)(re)封(feng)(feng)(feng)層熔合更充分，結合更牢固；但熱(re)(re)封(feng)(feng)(feng)時(shi)(shi)(shi)間(jian)太(tai)長，容易造成焊縫起(qi)皺變形，影(ying)響(xiang)平(ping)整(zheng)度(du)和外(wai)觀。熱(re)(re)封(feng)(feng)(feng)后的(de)焊縫若冷卻不(bu)(bu)好，不(bu)(bu)但會影(ying)響(xiang)焊疑的(de)外(wai)觀平(ping)整(zheng)度(du)，而且(qie)對熱(re)(re)封(feng)(feng)(feng)強(qiang)(qiang)度(du)有一定(ding)(ding)的(de)影(ying)響(xiang)，冷卻過程就是通(tong)過在一定(ding)(ding)的(de)壓(ya)力(li)下，用較低的(de)溫(wen)度(du)對剛熔融熱(re)(re)封(feng)(feng)(feng)后的(de)焊縫進行定(ding)(ding)形。因此，壓(ya)力(li)不(bu)(bu)夠(gou)，冷卻和循(xun)環(huan)不(bu)(bu)暢，循(xun)環(huan)量不(bu)(bu)夠(gou)，水溫(wen)太(tai)高或冷卻不(bu)(bu)及時(shi)(shi)(shi)，都會致使冷卻不(bu)(bu)良，熱(re)(re)封(feng)(feng)(feng)強(qiang)(qiang)度(du)降低。