熱封時間(jian)主要由制袋(dai)機(ji)的速度決(jue)定。
速(su)度(du)(du)(du)(du)快，熱(re)(re)封(feng)(feng)(feng)(feng)(feng)(feng)時(shi)間(jian)(jian)就短(duan)；速(su)度(du)(du)(du)(du)慢，熱(re)(re)封(feng)(feng)(feng)(feng)(feng)(feng)時(shi)間(jian)(jian)就長。熱(re)(re)封(feng)(feng)(feng)(feng)(feng)(feng)時(shi)間(jian)(jian)也是影(ying)響(xiang)焊(han)(han)縫封(feng)(feng)(feng)(feng)(feng)(feng)合強(qiang)度(du)(du)(du)(du)和(he)外(wai)(wai)觀的(de)(de)一個關(guan)鍵因(yin)素。相同的(de)(de)熱(re)(re)封(feng)(feng)(feng)(feng)(feng)(feng)溫度(du)(du)(du)(du)和(he)壓力(li)(li)下，熱(re)(re)封(feng)(feng)(feng)(feng)(feng)(feng)時(shi)間(jian)(jian)長，則熱(re)(re)封(feng)(feng)(feng)(feng)(feng)(feng)層熔合更(geng)充分，結合更(geng)牢固；但熱(re)(re)封(feng)(feng)(feng)(feng)(feng)(feng)時(shi)間(jian)(jian)太(tai)長，容易造成焊(han)(han)縫起皺變(bian)形，影(ying)響(xiang)平(ping)整(zheng)度(du)(du)(du)(du)和(he)外(wai)(wai)觀。熱(re)(re)封(feng)(feng)(feng)(feng)(feng)(feng)后的(de)(de)焊(han)(han)縫若冷卻(que)不(bu)(bu)(bu)好，不(bu)(bu)(bu)但會(hui)影(ying)響(xiang)焊(han)(han)疑(yi)的(de)(de)外(wai)(wai)觀平(ping)整(zheng)度(du)(du)(du)(du)，而(er)且(qie)對熱(re)(re)封(feng)(feng)(feng)(feng)(feng)(feng)強(qiang)度(du)(du)(du)(du)有一定(ding)的(de)(de)影(ying)響(xiang)，冷卻(que)過程就是通過在一定(ding)的(de)(de)壓力(li)(li)下，用較(jiao)低的(de)(de)溫度(du)(du)(du)(du)對剛熔融熱(re)(re)封(feng)(feng)(feng)(feng)(feng)(feng)后的(de)(de)焊(han)(han)縫進行(xing)定(ding)形。因(yin)此，壓力(li)(li)不(bu)(bu)(bu)夠(gou)(gou)，冷卻(que)和(he)循環(huan)不(bu)(bu)(bu)暢，循環(huan)量(liang)不(bu)(bu)(bu)夠(gou)(gou)，水溫太(tai)高或冷卻(que)不(bu)(bu)(bu)及(ji)時(shi)，都會(hui)致使冷卻(que)不(bu)(bu)(bu)良，熱(re)(re)封(feng)(feng)(feng)(feng)(feng)(feng)強(qiang)度(du)(du)(du)(du)降低。