Patent ID: 7874723

Claim:
A method of determining the melt mass flow rate of an ethylene polymer in the polymerization of ethylene or of ethylene with further comonomers, wherein the polymerization is carried out at temperatures of from 140° C. to 350° C. and pressures of from 40 MPa to 350 MPa in a reactor to form the ethylene polymer, and wherein the ethylene polymer is subsequently cooled in a heat exchanger, said method comprising: a) establishing a correlation between the thermal conductivity of the ethylene polymer in the heat exchanger and the melt mass flow rate of the ethylene polymer, with individual measurements each being carried out at an essentially constant melt mass flow rate, b) measuring the thermal conductivity of the ethylene polymer in the heat exchanger; and c) calculating the melt mass flow rate from the thermal conductivity measured in b) and the correlation established in a).