Multiple feeds of catalyst metals to a polyester production process

A process for feeding metals to one or more melt phase process lines for the production of a polyester polymers comprising: A. providing a first feed stream, said first feed stream having a first molar ratio and comprising a mixture of metal A and a different metal B; B. providing a second feed stream, said second feed stream comprising metals of a kind which are less than all the kinds of metals in the first feed stream, or a metal of a kind which is not a metal in said first feed stream, or all of the same kind of metals in said first feed stream but at a second molar ratio different than said first molar ratio; and C. feeding said first stream to one or more melt phase process lines at an addition point on each line and feeding said second feed stream either: (i) into one or more of the melt phase process lines upstream or downstream of the addition point of the first feed stream into the melt phase lines or (ii) to the first feed stream leading to the one or more melt phase process lines, combining said first and second feed streams to provide a combined feed stream, and feeding the combined feed stream into one or more of the melt phase process lines.