The invention relates to a process for producing polypropylene articles comprising a high relative content of the orthorhombic gamma-crystal modification by applying four consecutive process steps, namely (a) heating a polypropylene composition comprising a propylene random copolymer and an alpha-crystal nucleating agent to form a melt, (b) shearing said melt at a high apparent shear rate, (c) shaping said melt into an article, and (d) cooling said melt in a specific range of cooling rate to obtain polypropylene articles of high transparency
本发明涉及一种生产聚
丙烯制品的工艺,该工艺包括四个连续的工艺步骤,即(a)加热由
丙烯无规共聚物和α晶成核剂组成的聚
丙烯组合物以形成熔体,(b)以高表观剪切速率剪切所述熔体,(c)将所述熔体成型为制品,以及(d)在特定冷却速率范围内冷却所述熔体以获得高透明度的聚
丙烯制品。