Polymer composition for moulded article

A cap or closure comprising a polyethylene composition, wherein said polyethylene composition comprises

• a) at least 89.0 wt. % of a multimodal polyethylene polymer;
• b) optionally 0.01 to 10.0 wt.-% of a colour pigment or a colour masterbatch comprising a colour pigment;
• c) 0.01 to 1.0 wt.-% of a nucleating agent of formula (I)
• or 0.01 to 1.0 wt.-% of a nucleating agent of formula (II)
• wherein
• A=mono- or bicyclic aryl group;
• each X is independently a —CO—NH— group or —NH—CO— group;
• R1 to R3 are each independently a C1-C20 alkyl optionally substituted by one or more hydroxyl groups;
• C2-C20 alkenyl optionally substituted by one or more hydroxyl groups;
• C2-C20 alkyl interrupted by oxygen or sulfur;
• C3-C12 cycloalkyl optionally substituted by one or more C1-C20 alkyl;
• C3-C12 cycloalkyl-C1-6-alkylene- wherein the C3-12 cyclokalkyl is optional substituted by one or more C1-C20 alkyl groups.