熱(re)封時間主(zhu)要由制袋(dai)機(ji)的速(su)度決定。
速(su)(su)度(du)快(kuai)，熱(re)封(feng)(feng)(feng)(feng)時(shi)間(jian)(jian)就短；速(su)(su)度(du)慢(man)，熱(re)封(feng)(feng)(feng)(feng)時(shi)間(jian)(jian)就長(chang)。熱(re)封(feng)(feng)(feng)(feng)時(shi)間(jian)(jian)也是(shi)影(ying)響焊縫封(feng)(feng)(feng)(feng)合強(qiang)度(du)和外(wai)(wai)(wai)觀(guan)的(de)(de)一(yi)個關鍵(jian)因素。相同的(de)(de)熱(re)封(feng)(feng)(feng)(feng)溫(wen)(wen)度(du)和壓力下(xia)，熱(re)封(feng)(feng)(feng)(feng)時(shi)間(jian)(jian)長(chang)，則(ze)熱(re)封(feng)(feng)(feng)(feng)層(ceng)熔(rong)合更充分，結合更牢(lao)固；但(dan)熱(re)封(feng)(feng)(feng)(feng)時(shi)間(jian)(jian)太長(chang)，容易造(zao)成焊縫起(qi)皺變形，影(ying)響平(ping)(ping)整度(du)和外(wai)(wai)(wai)觀(guan)。熱(re)封(feng)(feng)(feng)(feng)后(hou)的(de)(de)焊縫若冷卻不(bu)好，不(bu)但(dan)會(hui)影(ying)響焊疑的(de)(de)外(wai)(wai)(wai)觀(guan)平(ping)(ping)整度(du)，而且對熱(re)封(feng)(feng)(feng)(feng)強(qiang)度(du)有一(yi)定的(de)(de)影(ying)響，冷卻過(guo)程就是(shi)通(tong)過(guo)在一(yi)定的(de)(de)壓力下(xia)，用較低的(de)(de)溫(wen)(wen)度(du)對剛(gang)熔(rong)融(rong)熱(re)封(feng)(feng)(feng)(feng)后(hou)的(de)(de)焊縫進行定形。因此，壓力不(bu)夠(gou)，冷卻和循環不(bu)暢，循環量不(bu)夠(gou)，水溫(wen)(wen)太高或冷卻不(bu)及時(shi)，都(dou)會(hui)致使冷卻不(bu)良，熱(re)封(feng)(feng)(feng)(feng)強(qiang)度(du)降低。