What is the principle of FDM technology of 3D printing technology, it is best to have a graphic description

Fused Deposition Modeling (FDM technology; Fused Deposition Modeling ):

The filamentary material (here mainly refers to engineering plastics) is fused and then extruded by the nozzle layer by layer to form the accumulation of a rapid prototyping method, this process does not use a laser, engraving knife, but the use of nozzles. (The mature 3D printer on the market now is basically this forming technology, forming materials such as PLA, ABS, PC, nylon, synthetic rubber, paraffin, etc.; now on the market is mainly PLA, ABS materials are mainly) Main features: molding equipment is small in size, easy to maintain, easy to operate, safe, low cost.