FDM® Prototyping Overview:
FDM® is a process using molten plastics or wax extruded by a nozzle that traces the parts cross sectional geometry layer by layer. FDM® creates tough parts that are ideal for functional usage. FDM® works on an “additive” principle by laying down material in layers. A plastic filament or metal wire is unwound from a coil and supplies material to an extrusion nozzle which turns the flow on and off. The nozzle is heated to melt the material and can be moved in both horizontal and vertical directions by a numerically controlled mechanism which is directly controlled by a computer-aided design software package. The model or part is produced by extruding small beads of thermoplastic material to from layers as the material hardens immediately after extrusion from the nozzle.
Several materials are available with different trade-offs between strength and temperature properties, as well as acrylonitrile butadiene styrene (ABS) polymer. FDM® technology can also be used with polycarbonates, polycaprolactone, polyphenylsulfone and wax. A “water-soluble” material can be used for making temporary supports while manufacturing is in progress. FDM® systems build parts in thermoplastics. The main advantage to using FDM® is the very durable parts that can be made using waxes and various engineering plastics.
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