The polyethene obtained when the etheneis prepared in the presence of hydrocarbon solvent and catalyst is

High density polythene(HDPE)  is formed when addition polymerization of ethene takes place in the presence of  a hydrocarbon solvent and in the presence of a catalyst such as triethyl-aluminum and titanium salts (Ziegler-Natta catalyst) at a temperature of 335 K to 345 K and under a pressure of 6-7 atmospheres. High density polythene (HDP) thus produced, consists of linear molecules and has a high density due to close packing.