| 摘要 |
A rapid prototyping system (10) has a liquifier (59) carried by an extrusion head. The liquifier (59) is formed of a thin-wall tube (212) preferably made of metal, encased in a heating block (214). The thin-wall tube (212) has an inlet end (224) for receiving a filament of molding material and an outlet end (226) for delivering the material in liquid form. A first section of the tube (212) adjacent the inlet end (224) and exterior to the heating block (214) functions as the entrance or cap zone. A second section of the tube (212) passes through the heating block (214) forming a heating zone. A nozzle (226) for dispensing the material in a molten state is formed by swaging the outlet end of the tube to a nozzle geometry, or a nozzle may be brazed or welded to the outlet end of the tube. The heating block (214) contains a heating element (220) in heat exchange relation to the second section of the tube (212), and the heating block (214) preferably has two detachable sections, which allow removal of the thin-wall tube (212). In an alternate embodiment, the extrusion head (32) carries two liquifiers that share a common nozzle (262), for receiving and dispensing two different materials. |
