Which process deposits melted polymer via a moving nozzle?

• A. Selective Laser Sintering (SLS)
• B. Stereolithography (SLA)
• C. Direct metal laser sintering (DMLS)
• D. Fusion deposition modelling (FDM)

Answer: (D)

This item is about how material is placed in the build process. In Fusion Deposition Modeling, a thermoplastic material is fed into a heated nozzle where it melts and then the nozzle moves to lay down molten polymer along the intended path. The material is deposited layer by layer, and as each bead cools and bonds to the previous layer, the part takes shape. This approach relies on the nozzle delivering melted polymer directly to the print surface.

The other methods use different mechanisms. Selective Laser Sintering uses a laser to fuse powder spread over the bed, not extrude melted material through a nozzle. Stereolithography uses a vat of liquid resin that is cured by light, again without a moving nozzle depositing melted material. Direct metal laser sintering also fuses metal powder with a laser, not extrudes it through a nozzle.

So the process that deposits melted polymer via a moving nozzle is Fusion Deposition Modeling.