Title: Additive Manufacturing
Course: ATEP - MMT: Module A: > Section: PHASE 7 REDESIGN THE SOLUTION

Newer technologies.

As the type and use of additive manufacturing (see table below) continues to become more mainstream, the costs of both the machines and the products they produce will continue to decrease. The chart shown below, shows the technology and the materials used to create the product.  (Animations of Tradition vs. Additive) MEDIA ASSETS

Additive technologies | Base materials
Selective laser sintering (SLS) | Thermoplastics, metals powders, ceramic powders
Direct metal laser sintering (DMLS) | Almost any alloy metal
Fused deposition modeling (FDM) | Thermoplastics, eutectic metals
Stereo lithography (SLA) | photopolymer
Laminated object manufacturing (LOM) | Paper, foil, plastic film
Electron beam melting (EBM) | Titanium alloys
Powder bed and inkjet head 3d printing Plaster-based 3D printing (PP) | Plaster, Colored Plaster

Fused Deposition Modeling (FDM) technology:

3D printers that build parts, layer-by-layer, from the bottom up,  by heating and extruding  a thermoplastic filament has become the most common for home and the classroom due to its low cost.  The process is much like using a hot glue gun but with Poly Lactic Acid (PLA) or ABS (Acrylonitrile Butadiene Styrene) filament materials.   Poly Lactic Acid  is a biodegradable polyester derived from renewable resources, such as corn starch tapioca roots, chips or starch, or sugarcane.  Acrylonitrile butadiene styrene (ABS) is derived from a petroleum hydrocarbon.  The process consists of:

1.  Pre-processing:  Build-preparation software slices and positions a 3D CAD file (STL: stereo lithography file format) and calculates a path to extrude thermoplastic and any necessary support material.  It also mathematically slices and orientates the model for the build process. If required, support structures can also be generated .

2.  Production:  The 3D printer heats the thermoplastic to a semi-liquid state and deposits it in ultra-fine beads along the extrusion path. Where support or buffering is needed, the 3D printer deposits a removable material that acts as scaffolding.

3.  Post-processing:  The user breaks away support material away or dissolves it in detergent and water, and the part is ready to use.   (Stratasys Ltd)

 Stereolithography (SLA) technology:

Similar to inkjet printing, but instead of jetting drops of ink onto paper, layers of curable liquid photopolymer are jetted onto a build tray  "printing" thin layers of an ultraviolet curable material one on top of the other.  By using multiple materials simultaneously, you can selectively position multiple materials in one printed prototype and even combine two or three materials to create composite digital materials with distinct, predictable properties.   The process is similar to FDM and consists of:

1.  Pre-processing: Build-preparation software automatically calculates the placement of photopolymers and support material from a 3D CAD file.

2.  Production: The 3D printer jets and instantly UV-cures tiny droplets of liquid photopolymer. Fine layers accumulate on the build tray to create a precise 3D model or prototype. Where overhangs or complex shapes require support, the 3D printer jets a removable gel-like support material.

3.  Support removal: The user easily removes the support materials by hand or with water. Models are ready to handle and use right out of the 3D printer, with no post-curing needed. (Stratasys Ltd)