Plastics

From CandyFabWiki

While the primary target has been sugar, the SHASAM fabrication process is in fact suitable for any granular media with a low melting point. It is a long term goal of the CandyFab project to fabricate not only edible media, but also plastics and metals.

Thus far, only some limited experimentation with plastic has been performed-- a few larger crude-resolution objects have been made. The plastic used in the first CandyFab team trials was Dow HDPE 30460M Injection Pellets see article. The pellets were rather large reducing possible resolution. Finely powdered plastic should be more suitable. HDPE in particular may be one of the less suitable materials because of its very large coefficient of thermal expansion-- this can lead to fusion failures between layers, and potentially severe deformation of the finished model. However, it might be possible to recycle HDPE plastic from plastic bottles and other plastic products by putting them in a blender, so it is a potentially inexpensive material. Easily available polypropylene pellets have also been tried, with similar results.

One interesting feature of printing plastic is that it can be supported during the build by layers of sugar (or other suitable materials), meaning that a volume of plastic large enough to fill up the entire bed is not needed. After the build, excess sugar can be washed off of the plastic.

• Advantages:
  • Wont be sticky at room temperature the way sugar is.
  • Can be less brittle that sugar depending on the plastic used.
  • Waterproof
  • Durable
• Disadvantages:
  • Higher cost ($1 a pound)
  • Produces fumes; requires ventilation and/or filtration
  • Inedible