熱(re)(re)封(feng)次數(shu)越多(duo)，熱(re)(re)封(feng)強度越高(gao)，縱向熱(re)(re)封(feng)次數(shu)取決于縱向焊(han)棒(bang)的有效長度和袋長之比(bi)。
橫向熱(re)封(feng)(feng)(feng)(feng)(feng)次數由(you)機臺橫向熱(re)封(feng)(feng)(feng)(feng)(feng)裝置的(de)(de)組數決定。良好的(de)(de)熱(re)封(feng)(feng)(feng)(feng)(feng)，要求熱(re)封(feng)(feng)(feng)(feng)(feng)次數至少(shao)達到兩次以(yi)上。相(xiang)同結構和厚度(du)(du)(du)(du)的(de)(de)復(fu)合(he)膜(mo)，復(fu)合(he)層(ceng)(ceng)(ceng)間剝離(li)(li)度(du)(du)(du)(du)越高，熱(re)封(feng)(feng)(feng)(feng)(feng)強(qiang)(qiang)(qiang)(qiang)度(du)(du)(du)(du)越大；對于(yu)復(fu)合(he)剝離(li)(li)強(qiang)(qiang)(qiang)(qiang)度(du)(du)(du)(du)低(di)的(de)(de)產品，焊(han)縫破(po)壞(huai)往往是焊(han)縫處(chu)(chu)的(de)(de)復(fu)合(he)膜(mo)先層(ceng)(ceng)(ceng)間剝離(li)(li)，致(zhi)使由(you)內(nei)面熱(re)封(feng)(feng)(feng)(feng)(feng)層(ceng)(ceng)(ceng)獨立(li)承受破(po)壞(huai)拉力，而(er)面層(ceng)(ceng)(ceng)材料失去補強(qiang)(qiang)(qiang)(qiang)作用(yong)，致(zhi)使焊(han)縫的(de)(de)熱(re)封(feng)(feng)(feng)(feng)(feng)強(qiang)(qiang)(qiang)(qiang)度(du)(du)(du)(du)由(you)此大為降(jiang)低(di)；若復(fu)合(he)層(ceng)(ceng)(ceng)間剝離(li)(li)度(du)(du)(du)(du)強(qiang)(qiang)(qiang)(qiang)，則(ze)不致(zhi)發生焊(han)邊處(chu)(chu)層(ceng)(ceng)(ceng)問的(de)(de)剝離(li)(li)，所測得的(de)(de)實際熱(re)封(feng)(feng)(feng)(feng)(feng)強(qiang)(qiang)(qiang)(qiang)度(du)(du)(du)(du)就(jiu)人得多；在熱(re)封(feng)(feng)(feng)(feng)(feng)內(nei)層(ceng)(ceng)(ceng)為PE或OPP時，熱(re)封(feng)(feng)(feng)(feng)(feng)強(qiang)(qiang)(qiang)(qiang)度(du)(du)(du)(du)就(jiu)比同樣厚度(du)(du)(du)(du)的(de)(de)BOPP好得多。