Separate purpose from structure
“Melt metering pump” describes a purpose; “gear pump” describes a structure. A melt metering pump can use a gear-type design. The two are not mutually exclusive categories, and a name alone does not decide which is more precise.
What to check before discussing a configuration
- Material and process conditions: material grade, processing temperature, target flow rate and system pressure.
- Equipment match: existing extrusion system, interfaces, controls and installation conditions.
- Evaluation goals: the problem to improve, measurement methods and acceptable results.
Judge from system results
Metering does not replace a full check of temperature, extrusion, die head, mold and cooling. Whether to configure a pump and how to verify it should be answered in a technical proposal; bottle wall-thickness accuracy must not be inferred from the pump name. The proposal should state the configuration, evaluation metrics and verification conditions so results can be compared with the process before the change.