Shenzhen Alu Rapid Prototype Precision Co., Ltd.

The extruder is one of the most important parts of a fused filament fabrication (FFF/FDM) 3D printer. It’s essentially the component that feeds, melts, and precisely deposits the plastic filament to build your object layer by layer.

Main jobs of the extruder:

1.Feeds the filament  

A motorized gear (usually a hobbed bolt or geared drive) grabs the filament and pushes it forward at a very controlled rate.

There are two main types of feeding systems:Direct drive: The motor and gears are right on the print head (shorter path, better for flexible filaments).

Bowden: The motor is mounted on the frame and pushes filament through a PTFE tube to the hot end (lighter print head, faster movement).

2.Melts the filament (hot end)  

The filament enters the hot end, which consists of:A heater block (with a cartridge heater and thermistor/temperature sensor).

A heat break (a thin zone that keeps heat from traveling upward).

A nozzle (usually 0.4 mm diameter, but can be smaller or larger).

The heater block melts the plastic (typically to 190–250 °C for PLA, higher for ABS, PETG, etc.) so it becomes a viscous liquid.

3.Deposits the molten plastic  

The pressure created by the continuously fed filament forces the molten plastic out of the tiny nozzle in a thin, continuous bead.

The printer moves this nozzle in the X/Y plane to draw each layer, and the bed or head moves in Z to start the next layer.

In simple terms:

The extruder is like a very precise, computer-controlled hot glue gun that pushes plastic filament through a tiny heated nozzle and “draws” your 3D model one layer at a time.