Polymer injection system comprising multiple pumps and methods of using same

An injection system comprising:

• an extruder having an outlet;
• and
• a melt pump subsystem comprising at least a first melt pump and a second melt pump, wherein each melt pump of the first and second melt pumps has an inlet and an outlet, wherein the inlet of each of the first and second melt pumps is in fluid communication with the outlet of the extruder, wherein the first and second melt pumps are arranged in parallel so that flow from the outlet of the extruder divides between the first melt pump and the second melt pump, wherein the outlet of each of the first and second melt pumps is in fluid communication with a polymer transfer line so that flow leaving the outlets of each of the first and second melt pumps is combined in the polymer transfer line, wherein the polymer transfer line is configured to communicate the combined flow of the first and second melt pumps to a product forming device.