HDPE is High density Poly ethylene .There are Various technologies of HDPE Production ,Gas Phase , Liquid and Slurry Phase.The Slurry Phase has 2 technology provider Mistsui and Basell polyolefins...Basell employs low pressure slurry process using n-Hexane ,Ethylene as monomer , butene-1 as co monomer , Hydrogen as chain regulating agent with Zieger Natta Catalyst .