Injection Stretch Blow Moulded Articles

A method comprising preparing an injection stretch blow moulded article from a high density polyethylene (HDPE) resin, wherein the HDPE comprises:

• two polyethylene fractions comprising fraction A and fraction B, fraction A being substantially free of comonomer and having a lower weight average molecular weight and a higher density than fraction B, each fraction prepared in different reactors of two reactors connected in series in the presence of a metallocene-containing catalyst system,
• wherein the metallocene is selected from at least one of the following formula (I) or (II):
• wherein each R is the same or different and is selected from hydrogen or XR′v in which X is chosen from carbon, silicon, germanium, oxygen or nitrogen, and each R′ is the same or different and is chosen from hydrogen or a hydrocarbyl of from 1 to 20 carbon atoms and v+1 is the valence of X;
• wherein R″ is a structural bridge between the two indenyl or tetrahydrogenated indenyls to impart stereorigidity that comprises a C1-C4 alkylene radical, a dialkyl germanium, silicon or siloxane, or an alkyl phosphine or amine radical;
• wherein Q is a hydrocarbyl radical having from 1 to 20 carbon atoms or a halogen;
• and wherein M is a transition metal Group 4 of the Periodic Table or vanadium;
• wherein the HDPE resin has a bimodal molecular weight distribution (MWD), defined by the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn), of from 2 to 20, a density, measured following the method of standard test ASTM 1505 at a temperature of 23° C., of from 0.950 to 0.965 g/cm3, and a melt index MI2, measured following the method of standard test ASTM D 1238 at a temperature of 190° C. and under a load of 2.16 kg, of from 0.5 to 5 g/10 min.