Graphics Reference
In-Depth Information
Today's 3D printers work mostly in plastic. Although the word plastic has
become a synonym for low-cost materials, 3D printing plastic isn't cheap. In
fact, the cost of plastic printing material quickly adds up to become a signii-
cant part of the cost of running a 3D printer.
Most 3D printer manufacturers provide their own proprietary material. At
ABC Imaging when John showed me buckets full of commercial-grade printing
powder, he likened the cost of 3D printing plastic to the infamous “razor and
blades” business model. “It's like Gillette,” he said. “They give away the razor
but you can only get the cartridges that it from Gillette.”
The fact that industrial 3D printing technology is optimized to print propri-
etary vendor-speciic 3D printing materials either dampens or drives innova-
tion, depending on who you ask. The downside is that users are discouraged
from experimenting with cheaper materials because they risk voiding their
manufacturer's warranty. The upside of proprietary materials is that 3D print-
ing manufacturers are eager to invest in developing high-performance and
proitable raw materials that will move the technology forward.
Someday print materials will contain living tissue or tiny bits of comput-
ing power or will be able to behave in ways that defy understanding. Today,
however, most companies and printing hobbyists must content themselves
with plastic, metals, ceramics, edible semi-solid foodstuffs, and to a lesser
extent concrete or glass.
Plastic is the most commonly used printing material. Plastics engineers
divide plastics into two major categories: thermoplastics and thermosetting
polymers. The difference between them can be easily remembered by thinking
of eggs and cheese. Like cheese, thermoplastics melt when heated. Like cheese,
thermoplastics do not change their internal composition when heated, so they
can be melted and re-melted many times. Like eggs, thermosetting polymers
solidify when heated. Like eggs, they can be used only once; because their
internal composition changes when heated, thermosetting polymers can't be
melted back down into a reusable liquid form.
Most consumer printers (the kind that deposit raw material through a print
head) use a type of thermoplastic called ABS, the same kind used in LEGO
bricks. Most stereolithography (SL) 3D printers use light-sensitive thermo-
setting polymers (the egg-style plastic). Printers that use laser sintering use
powdered thermoplastic (the cheese-style plastic).
