Our Simple Answer:

It’s a bit like icing a cake, or making a 3D jigsaw…
The object* is made up of Layers, like Geography…
Each layer of material is put down as an outline and then filled in, for every layer ( there can be thousands of these layers :-O)

The Technical Answer:

There are many 3D Printing manufacturing processes, but we will look at the ones available at 3D Printing LEEDS.

*FDM 3D Printing

FDM (Fused Deposition Modeling) 3D printing is one of the most popular and widely used 3D printing technologies. Here’s an overview of how it works:

1. Preparation:
   • A digital 3D model is created or obtained using CAD software or downloaded from online libraries.
   • The model is then converted into a file format (typically STL or OBJ) that the 3D printer software can understand.
   • This file is imported into slicing software, which slices the model into thin horizontal layers. The software also sets parameters like layer height, print speed, and infill density.
2. Material Loading:
   • FDM printers use thermoplastic filaments (e.g., PLA, ABS, PETG). The filament spool is loaded into the printer and fed into a heated extruder.
3. Heating and Extrusion:
   • The extruder heats the filament to a semi-liquid state, typically between 180-260°C, depending on the material.
   • The printer’s nozzle, controlled by motors, moves across the print bed according to the sliced model’s instructions.
   • As the nozzle moves, it extrudes melted filament layer by layer onto the print bed, starting from the bottom and building up each layer until the model is complete.
4. Layer-by-Layer Building:
   • Each layer bonds to the layer below as the filament cools and solidifies. The print bed may move up or down between layers, depending on the printer’s design.
   • Supports or structures may be added if the design has overhangs or complex shapes to prevent collapsing during printing.
5. Cooling and Finishing:
   • Once printing is complete, the object is allowed to cool and solidify fully.
   • If supports were used, they are removed, and any rough areas or imperfections may be sanded, polished, or otherwise finished.

FDM printing is widely used due to its affordability, availability of materials, and ease of use. However, it does have some limitations in terms of print resolution and strength compared to other 3D printing methods.

SLA 3D Printing

SLA (Stereolithography) 3D printing is an additive manufacturing process that uses light to cure liquid resin into solid objects. Here’s a breakdown of how SLA 3D printing works:

1. Preparation:
   • Similar to FDM, a 3D digital model is created in CAD software or downloaded.
   • The model is sliced into thin horizontal layers using slicing software. The software also defines parameters such as layer height, exposure time, and supports.
   • The sliced file is then uploaded to the SLA 3D printer.
2. Resin Tank and Build Platform Setup:
   • SLA printers use a tank filled with liquid photopolymer resin that hardens (cures) when exposed to a specific wavelength of light.
   • The build platform is positioned just above the resin tank and can move up and down to build each layer.
3. Layer Curing with Light:
   • A UV laser (or a digital light projector, in some cases) is directed at the bottom or surface of the resin tank. The laser follows the pattern for each layer of the sliced model.
   • As the laser moves over the resin in precise patterns, it cures (solidifies) the resin in those areas to form a solid layer.
   • SLA printers typically build the object upside down, with the build platform lifting gradually out of the resin tank after each layer is cured.
4. Layer-by-Layer Building:
   • After each layer is cured, the build platform moves slightly upward or downward (depending on the SLA printer’s configuration) to allow a new layer of liquid resin to flow beneath or above the previous one.
   • The process repeats as each new layer is cured onto the previous one until the object is fully formed.
5. Post-Processing:
   • When printing is complete, the object is removed from the build platform.
   • The print typically requires a cleaning step, often involving an alcohol bath, to remove any uncured resin residue.
   • Some prints may need additional curing in a UV chamber to reach their final strength and stability.
   • Supports are then removed, and any surface finishing can be done as needed.

SLA printing is popular for its high level of detail, smooth surface finish, and suitability for intricate designs. It’s widely used in industries like dental, jewelry, and product prototyping. However, it has limitations such as needing specific resins and requiring post-processing to achieve the best results.