Abstract: Polyethylene is produced by polymerization of ethylene alone or with comonomers or telogens (modifiers) in an elongated tubular reactor having an inlet and outlet and at least one reaction zone and one cooling zone in the presence of free radical or free oxygen yielding initiator at elevated temperatures and pressures by passing the reaction mixture through each of the reaction zones of the tubular reactor having internal diameters between about 0.5 and 3 inches at bulk fluid velocities sufficient so that the Flow Number in each reaction zone is greater than 3.3 ft..sup.2 /sec. Flow Number is defined as the bulk fluid velocity in ft./sec. times diameter in feet. With Flow Numbers in excess of 3.3 ft..sup.2 /sec. in the reaction zones, it has been found that the effective reaction volume in the reaction zone has been increased and, accordingly, a more efficient process for producing a high quality polyethylene.

Abstract: Polyethylene is produced by polymerization of ethylene alone or with comonomers and/or telogens (modifiers) in an elongated tubular reactor having an inlet and outlet and preferably containing four reaction zones. Conversions of up to 40% are achieved without loss of optical or physical product quality.