A screw feeder is a mechanical device designed to precisely control the flow of powdered or granular materials. Its main component is a rotating spiral blade (commonly called a screw or auger) driven by a motor, which continuously transports the material from a storage bin such as a hopper or silo to the next process.

Compared with a typical screw conveyor, a screw feeder focuses more on flow control and metering accuracy rather than simple conveying. Therefore, it is widely used in situations where strict control of material dosage is required, such as chemical batching, food additive ratio, battery slurry preparation, and pharmaceutical powder mixing.