How does a 3- D printer work?

图片发自App

With technology changes, three-dimensional printers have been widely used to build up models, which work a bit like conventional inkjet printers, but with the ‘ink’ replaced by another feed material—mostly the plastic. How does it work? Let’s take a closer look.

To print out the finish of the product, you first need a three-dimensional digital model, which contains piles of cross-sectional layers. The pattern of each layer is filled by the feed material which is melted and then extruded through the nozzle under digital control—a method known as fused depositional modeling (FDM). As for the best feed material for 3D printing, ABS, a composite of a hard plastic with a synthetic rubber stands out for its useful property: it melts at a little over 100℃, a temperature can be reached without too much heat inside the printer, and cools down at room temperature.

Following the pattern from the digital file, the feed material is spewed out and deposited precisely on each layer. The nozzle moves with the printer head across two horizontal rafts, while the baseplate on which models are printed moves in the perpendicular direction horizontally, thus setting the x and y coordinates and ensuring each point on the layer can be touched. The printer paints one layer at a time, and the precisely vertical movement of the printer bed allows another layer to pile on-- a process being replicated for hours before the finish of the model finally comes out.