Pla General
PLA is preferred by some 3D printing enthusiasts. A few other companies have switched over to PLA exclusively. PLA is generally considered to be a more environmentally friendly Solution.
Rep Rap enthusiasts have covered a great deal here.
http://en.wikipedia.org/wiki/Polylactic_acid also has some great information.
Relative Advantages
PLA is preferred over ABS in some cases for the following reasons
- Environmentally friendly: PLA is preferred over ABS in this category because is it biodegradable. Under optimal conditions, exposed to moisture and bacteria the plastic can biodegrade in as little as 90 days. This does not happen under normal circumstances, and prints made with PLA should last for months, if not longer with proper care.
- Food/body safe: While ABS is often used in children's toys, and food related products, PLA is considered to be far safer around food and the body. PLA is often used in medical implants, and degrades into safer materials than ABS does. However, it should be noted that PLA doesn't survive prolonged exposure to water as well as ABS does. In practice, the actual difference is quite minimal to all but the most demanding of users.
- PLA does not require a heated bed. PLA is known to be dimensionally stable, this means that it doesn't need to be heated for it to adhere to the bed, and for layers to adhere to each other.
- Clear Filament: There is a greater variety of colors available in PLA at the moment, and clear filament tends to work better with PLA than ABS.
Potential Issues
- Adhesion: PLA tends to stick to Acrylic, in a very hard to remove, semi permanent way. If you decide to use PLA on your Acrylic bed, we suggest that you put down some blue painter's tape first. Some users have tried other surfaces including glass, and polycarbonate. The Reprap article mentioned above gives excellent specifics on this.
- Moisture: Just like ABS, PLA has a habit of absorbing ambient moisture from the air. This can foul the PLA over time, and create tough to track printing issues. Make sure that you store your PLA in an area where it will not be able to absorb moisture.
