The key to the melt gear pump’s ability to deliver precise metering lies in the combination of its positive displacement principle and precision manufacturing processes.
First, in terms of operating principle, the melt gear pump is a positive displacement pump. Inside the pump, a pair of high-precision gears mesh tightly; for every revolution, the volume of melt that can be delivered within the sealed chamber formed by the gear teeth and the pump body is theoretically constant. This means there is a strict linear proportional relationship between the pump’s output flow rate and its rotational speed. Therefore, by precisely controlling the motor speed through variable frequency drive (VFD) speed regulation, the output flow rate can be linearly controlled—this is the physical basis for achieving precise metering.
Second, the melt gear pump plays a critical role as a pressure stabilizer within the system. In extrusion production lines, the upstream extruder often generates pressure fluctuations. The melt pump utilizes the meshing of the gears to form a rotating barrier that effectively prevents upstream pressure and flow fluctuations from being transmitted downstream. Regardless of how the inlet pressure varies, it ensures a stable, pulsation-free outlet flow, which is crucial for the production of high-precision films, profiles, or fibers.
Furthermore, high-precision manufacturing is essential for accurate metering. The gear clearances and bearing side plate fits inside the pump housing are precision-machined to achieve extremely high volumetric efficiency, minimizing “internal leakage” (backflow) of the melt under high-temperature and high-pressure conditions. The use of high-temperature tool steel or special alloys, combined with wear-resistant components, ensures that the clearance remains stable over the long term under high-temperature and high-pressure conditions.
As a professional manufacturer of melt pumps, Tianjin Ruicheng Pump Industry Co., Ltd. specializes in the RC series of high-precision melt pumps, rubber melt pumps, reactor bottom pumps, and high-temperature, high-pressure melt pumps. Ruicheng Pump Industry’s melt discharge pumps utilize high-temperature tool steel and a mechanical diaphragm design, offering high-temperature resistance, corrosion resistance, and durability. They effectively ensure constant-pressure delivery and flow stability under complex operating conditions, providing reliable equipment support for precision extrusion in the plastics, rubber, chemical fiber, and petroleum industries.