FDM 3D tiskárna BCN3D Sigma R19

BCN3D Sigma R19

Jedná se o standardní 3D tiskárnu využívající k tisku strun. Tato konkrétní tiskárna tiskne ze strun o průměru 2,8 mm a je vybavena dvojicí nezávyslích trysek pro tisk typicky podpor z rozpustného materiálu. Ideální kombinací tedy je tisk pomocí PLA/PVA (vodou odplavitelný materiá) nebo ABS/HIPS (materiál odplavitelný v Lemonesol rozpouštědle). Další vhodné materiály jsou ASA, Pet-G, Flex, Nylon, Wood a dalších kovem plněných příměsí. Velikost tiskové plochy je 210 x 297 mm a maximální výška výtisku 210 mm.

Technologie FDM

During extrusion the thermoplastic filament is introduced by mechanical pressure from rollers, into the liquefier, where it melts and is then extruded. Flow geometry of the extruder, heating method and the melt flow behavior of a non-Newtonian fluid are of main consideration in the part. The rollers are the only drive mechanism in the material delivery system, therefore filament is under tensile stress upstream to the roller and under compression at the downstream side acting as a plunger. Therefore, compressive stress is the driving force behind the extrusion process. The force required to extrude the melt must be sufficient to overcome the pressure drop across the system, which strictly depends on the viscous properties of the melted material and the flow geometry of the liquefier and nozzle. The melted material is subjected to shear deformation during the flow. Shear thinning behavior is observed in most of the materials used in this type of 3-D printing. This is modeled using power law for generalized Newtonian fluids. The temperature is regulated by heat input from electrical coil heaters. The system continuously adjusts the power supplied to the coils according to the temperature difference between the desired value and the value detected by the thermocouple, forming a negative feedback loop. This is similar to heat flow rate in cylindrical pipe.