Processing of Polymeric Materials - 3D FDM printing

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[...] Processing of Polymeric Materials - 3D FDM printing -3D printing is an additive manufacturing technique that proceeds by the addition of material in successive layers, dating back to the 1980s. This process contrasts with conventional subtractive manufacturing techniques such as machining. This technology enables the production of volumetric parts and was initially used primarily to facilitate low-cost prototyping. -3D printing has mainly developed in the industry and has opened up to numerous fields such as health, architecture, art and design, sports, fashion, biotechnologies, etc. [...]

[...] In terms of environmental impact, it is a polymer derived from petrochemicals and is not biodegradable. However, it is relatively easily recyclable. -The PETG (Polyethylene Terephthalate Glycol) is often used as a compromise between ABS and PLA as it exhibits mechanical resistances similar to both. It is less challenging to print, although it requires at least a heated bed. It melts at a higher temperature than PLA (≈230°C). Environmentally, it is derived from petroleum and is easily recyclable. -We can also find TPU, which allows the fabrication of flexible and elastic plastic parts, such as joints, for example. [...]

[...] The most popular one is the Cartesian printer, echoing its coordinate system. It consists of 3 translation axes and and depending on the model, the extruder or the bed will be responsible for the Z-axis (e.g., XY-core). The polar printer consists of 2 translation axes or Y and and 1 rotation axis This type of printer allows for large print volumes but may lack precision at the edges of the bed. The delta printer operates with 3 arms connected to the extruder, each having only a translation with Z and passive left-to-right movement. [...]

[...] There are a multitude of printable plastics via FDM printers. The most common ones are PLA, ABS, Nylon, TPU, and PETG. Other polymers include PP, PT, ASA, polycarbonate, etc. Two appreciated polymers for support structures are PVA and HIPS because they are respectively water-soluble and soluble in D-limonene. This reduces post-printing time for support removal. -In conclusion, we can say that FDM printing is a versatile and complex technology, considering its ecological impact. However, certain aspects require improvements. To enhance 3D printing, the idea of a 5-axis printer has long been a fantasy. [...]

[...] The 0.4mm nozzle diameter is generally the most commonly used to provide a better compromise between precision and speed. However, nozzle diameters can range from 0.1mm to the diameter of the inserted filament (requiring a powerful heating block). The use of a large diameter will result in a loss of precision and strength, but it increases speed, whether for shell thickness, where a 0.4mm nozzle will require 2 passes, one of 0.8mm will do only one, or with the reduction in the number of layers and thus passes, as the layer thickness should not exceed 80% of the nozzle diameter. [...]