熱封時間主要由(you)制袋機的速度決定。
速度(du)(du)快，熱(re)(re)封(feng)(feng)(feng)(feng)時(shi)間(jian)(jian)就短；速度(du)(du)慢，熱(re)(re)封(feng)(feng)(feng)(feng)時(shi)間(jian)(jian)就長。熱(re)(re)封(feng)(feng)(feng)(feng)時(shi)間(jian)(jian)也是影(ying)(ying)響焊(han)縫封(feng)(feng)(feng)(feng)合(he)強度(du)(du)和(he)(he)外(wai)(wai)(wai)觀(guan)的(de)一(yi)(yi)個關鍵(jian)因(yin)素(su)。相同的(de)熱(re)(re)封(feng)(feng)(feng)(feng)溫(wen)度(du)(du)和(he)(he)壓力下，熱(re)(re)封(feng)(feng)(feng)(feng)時(shi)間(jian)(jian)長，則熱(re)(re)封(feng)(feng)(feng)(feng)層熔(rong)合(he)更(geng)充分(fen)，結合(he)更(geng)牢(lao)固；但(dan)熱(re)(re)封(feng)(feng)(feng)(feng)時(shi)間(jian)(jian)太長，容易造成焊(han)縫起(qi)皺變形，影(ying)(ying)響平整度(du)(du)和(he)(he)外(wai)(wai)(wai)觀(guan)。熱(re)(re)封(feng)(feng)(feng)(feng)后的(de)焊(han)縫若冷卻(que)不(bu)好(hao)，不(bu)但(dan)會影(ying)(ying)響焊(han)疑的(de)外(wai)(wai)(wai)觀(guan)平整度(du)(du)，而(er)且對熱(re)(re)封(feng)(feng)(feng)(feng)強度(du)(du)有一(yi)(yi)定(ding)的(de)影(ying)(ying)響，冷卻(que)過(guo)程就是通(tong)過(guo)在一(yi)(yi)定(ding)的(de)壓力下，用(yong)較低(di)的(de)溫(wen)度(du)(du)對剛熔(rong)融熱(re)(re)封(feng)(feng)(feng)(feng)后的(de)焊(han)縫進行(xing)定(ding)形。因(yin)此，壓力不(bu)夠，冷卻(que)和(he)(he)循環不(bu)暢，循環量不(bu)夠，水溫(wen)太高或冷卻(que)不(bu)及時(shi)，都會致使冷卻(que)不(bu)良，熱(re)(re)封(feng)(feng)(feng)(feng)強度(du)(du)降低(di)。