什么是"晶點(dian)"?
晶(jing)(jing)(jing)(jing)點實際上(shang)是"過度聚合(he)(he)物(wu)(wu)(wu)".即晶(jing)(jing)(jing)(jing)點部位(wei)聚合(he)(he)物(wu)(wu)(wu)的分子(zi)(zi)量，高于周(zhou)圍同種(zhong)(zhong)聚合(he)(he)物(wu)(wu)(wu)的分子(zi)(zi)量，由于分子(zi)(zi)量高，因此晶(jing)(jing)(jing)(jing)點部位(wei)聚合(he)(he)物(wu)(wu)(wu)具(ju)有較高熔(rong)(rong)點，在熔(rong)(rong)化時(shi)，熔(rong)(rong)體具(ju)有較高的粘度，晶(jing)(jing)(jing)(jing)點部位(wei)聚合(he)(he)物(wu)(wu)(wu)在吹成(cheng)薄(bo)(bo)膜(mo)(mo)時(shi)，不(bu)能與周(zhou)圍的同種(zhong)(zhong)聚合(he)(he)物(wu)(wu)(wu)相互均(jun)勻地分散/混和，并在熔(rong)(rong)體吹成(cheng)薄(bo)(bo)膜(mo)(mo)后，先于周(zhou)圍的同種(zhong)(zhong)聚合(he)(he)物(wu)(wu)(wu)凝固.因此，研成(cheng)"箭(jian)頭"狀或球狀過度聚合(he)(he)物(wu)(wu)(wu)的凝固體.習慣(guan)上(shang)被稱為"晶(jing)(jing)(jing)(jing)點"。