Process for producing polypropylene compounds with low CLTE

摘要

Process for producing a polypropylene composition comprising a heterophasic propylene copolymer and a plastomer, said process comprises the steps of
€¢ feeding the heterophasic propylene copolymer into an extruder,
€¢ applying shear stress in a first mixing zone on the heterophasic propylene copolymer,
€¢ adding downstream to the first mixing zone the plastomer to the heterophasic propylene copolymer,
€¢ applying shear stress in a second mixing zone on the heterophasic propylene copolymer and the plastomer (P),
€¢ discharging the polypropylene composition from the extruder ,
wherein further
the heterophasic propylene copolymer (HECO) comprises a polypropylene matrix and an elastomeric propylene copolymer being dispersed in said polypropylene matrix,
and
the elastomeric propylene copolymer and the plastomer are chemically different.