熱封次數越多，熱封強度(du)越高，縱向熱封次數取(qu)決于(yu)縱向焊棒的有效長度(du)和袋(dai)長之比(bi)。
橫(heng)向熱(re)(re)(re)封(feng)(feng)(feng)(feng)(feng)次(ci)數由機(ji)臺橫(heng)向熱(re)(re)(re)封(feng)(feng)(feng)(feng)(feng)裝(zhuang)置的(de)(de)(de)組數決(jue)定。良(liang)好的(de)(de)(de)熱(re)(re)(re)封(feng)(feng)(feng)(feng)(feng)，要求熱(re)(re)(re)封(feng)(feng)(feng)(feng)(feng)次(ci)數至少(shao)達到(dao)兩(liang)次(ci)以上。相同(tong)結構(gou)和厚(hou)(hou)度(du)(du)的(de)(de)(de)復(fu)(fu)合(he)膜(mo)(mo)，復(fu)(fu)合(he)層(ceng)(ceng)間(jian)剝(bo)(bo)離度(du)(du)越(yue)高，熱(re)(re)(re)封(feng)(feng)(feng)(feng)(feng)強(qiang)(qiang)(qiang)度(du)(du)越(yue)大(da)；對于(yu)復(fu)(fu)合(he)剝(bo)(bo)離強(qiang)(qiang)(qiang)度(du)(du)低(di)的(de)(de)(de)產(chan)品，焊(han)縫(feng)破(po)壞(huai)往往是(shi)焊(han)縫(feng)處(chu)的(de)(de)(de)復(fu)(fu)合(he)膜(mo)(mo)先層(ceng)(ceng)間(jian)剝(bo)(bo)離，致(zhi)使由內面(mian)熱(re)(re)(re)封(feng)(feng)(feng)(feng)(feng)層(ceng)(ceng)獨立(li)承受破(po)壞(huai)拉(la)力，而面(mian)層(ceng)(ceng)材(cai)料失去補(bu)強(qiang)(qiang)(qiang)作用(yong)，致(zhi)使焊(han)縫(feng)的(de)(de)(de)熱(re)(re)(re)封(feng)(feng)(feng)(feng)(feng)強(qiang)(qiang)(qiang)度(du)(du)由此大(da)為降低(di)；若復(fu)(fu)合(he)層(ceng)(ceng)間(jian)剝(bo)(bo)離度(du)(du)強(qiang)(qiang)(qiang)，則不(bu)致(zhi)發生焊(han)邊處(chu)層(ceng)(ceng)問的(de)(de)(de)剝(bo)(bo)離，所測(ce)得(de)的(de)(de)(de)實際熱(re)(re)(re)封(feng)(feng)(feng)(feng)(feng)強(qiang)(qiang)(qiang)度(du)(du)就人(ren)得(de)多；在熱(re)(re)(re)封(feng)(feng)(feng)(feng)(feng)內層(ceng)(ceng)為PE或OPP時，熱(re)(re)(re)封(feng)(feng)(feng)(feng)(feng)強(qiang)(qiang)(qiang)度(du)(du)就比同(tong)樣厚(hou)(hou)度(du)(du)的(de)(de)(de)BOPP好得(de)多。