US Patent 9902790 Producing polyolefin products

A method of polymerizing olefins is disclosed. The method comprises contacting ethylene and at least one comonomer with a catalyst system to produce a polyolefin polymer that is multimodal. The catalyst system comprises a first catalyst that promotes polymerization of the ethylene into a low molecular weight (LMW) portion of the polyolefin polymer and a second catalyst that promotes polymerization of the ethylene into a high molecular weight (HMW) portion of the polyolefin polymer. The first catalyst and at least a portion of the second catalyst are co-supported to form a commonly-supported catalyst system and at least a portion of the second catalyst is added as a catalyst trim feed to the catalyst system.