Blow molding
Extrusion of a parison (hollow melt tube) which is forced to a mold caving by internal pressure and cooled down to form a hollow article. Used for the production of bottles, wide-mouth containers, petrol tanks etc.

A polyethylene with a relatively high molecular weight fraction and a relatively low molecular weight fraction is called bimodal polyethylene. The comonomer contents of the two fractions are often different.