Disclosed is a method of treatment of chronic obstructive pulmonary disease associated with chronic bronchitis in a patient at risk of exacerbations. The formed article is formed of a multicomponent polymer material comprising a continuous phase and a disperse phase; the continuous phase is made of a polybutylene succinate type andor polyethylene adipate type aliphatic polyester and the disperse phase is made of polylactic acid. The cylinder liners extend such that the end parts facing the cylinder head are arranged within the recessed parts of the cylinder head within the range of relative movement of the cylinder head with respect to the cylinder block.