21 January 2011___Rapid Prototyping and Laser Cutting__ANNA MAGGI

21 January 2011

Rapid Prototyping and Laser Cutting/Engraving Etching
Ben Kenezevic

The second lecture of technical practice was about the Rapid Prototyping and Laser Cutting/Engraving Etching.

Rapid Prototyping
The rapid prototyping allows the user to build models from the 3dCAD file, it takes virtual designs from computer aided design (CAD) and transforms them into thin, virtual, horizontal cross-sections and then creates successive layers until the model is complete. The first techniques for rapid prototyping became available in the late 1980s and were used to produce models and prototype parts. The rapid prototyping use polymher to produce 3D models.
Today there are plenty of application of this technology, we can use it to produce concept models, fit and function models, master pattern for moulding and die casting, this way we can have the opportunity to obtain plastic moulds and then producing a certen number of copies of the object (around 100 copies) by moulding it. The rapid prototyping is also used to obtain wind tunnell models, clear model for fluid flow analysis, rapid tooling and rapid manufacturing.
This technique of rapid prototyping is called “stereolitography” and the cost and timing reduction in model process up to 50% are its best aspects. Especially, it has no geometrical limitations, this way every kind of shape can be processed and produced.
In the early 2000s another new technology called “Polyjet” appeared on the market, this new device cures the material by UV light immediately after it is jetted, producing fully cured models that can be handled and used immediately, without post-curing.
The rapid prototyping can only process 3D files, produced with 3D software like Rhinoceros, 3D studio max or Solid Works. There are many new opportunities of development in the future of rapid prototyping like new material development, the chance to produce Bio Material for medical needs, also its performance is expected to get better, it will have a faster producing time and it will become larger this way producing larger components.

Laser Cutting/Engraving Etching
Laser Cutting is a technology that uses a laser to cut materials, it works by directing the output of a high-power laser, by computer, at the material to be cut. The material then either melts, burns, vaporizes away, or is blown away by a jet of gas, leaving an edge with a high-quality surface finish.
This way the user can transfer every kind of pattern or drawings into a specific, selected material.
The best material for laser cutting is the acrylic but it also works very well with paper, card, wood, leather, fabrics, adesives and polyester.
The laser engraving etching is similar to laser cutting, it is the practice of using lasers to engrave or mark an object, the technique does not involve tool bits which contact the engraving surface and wear out.