What happens to the thermoplastic material immediately after being extruded?

After being extruded, the thermoplastic material adheres to the layer below it, contributing to the layer-by-layer build-up that characterizes Fused Deposition Modeling (FDM). This bonding occurs due to the high temperature of the extruded filament, which allows it to soften and fuse with the underlying material. As the extruder nozzle deposits the molten plastic, the heat enables inter-molecular connections to take place, strengthening the overall structure as additional layers are added.

This bonding process is essential for achieving a robust final part, as it ensures that successive layers are held together effectively, resulting in improved mechanical properties and dimensional accuracy of the printed object. If proper bonding does not occur, the layers may separate, leading to weak points in the finished product.

The other choices do not accurately describe the immediate behavior of the material after extrusion. For instance, the material does not shrink or vaporize; rather, it expands slightly as it exits the nozzle but primarily forms strong bonds with the layers beneath as it cools and solidifies.