Your idea, "printed" in 3-D
A new layering process renders prototypes that pop.
In television’s “Star Trek,” the crew used “replicators” to instantly create anything from Earl Grey tea to engine parts. For modern science, that remains something of a frontier. But Z Corporation in Burlington, Mass., is working on a real-world variation that comes stunningly close.Skip to next paragraph
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The company stands among the early players in 3-D printing, in which engineers load up a schematic of what they want, feed in some plastic, and watch a machine print out a fully formed model – complete with moving parts.
At its heart, this style of “rapid prototyping” relies on a simple concept: building an object one cross section at a time, similar to laying down LEGO bricks to make a larger shape.
The field is still very young, says Scott Harmon, vice president of business development at Z Corporation. Several companies make these three-dimensional printers, the cheapest of which sells for about $10,000.
Despite a wide array of potential uses, interest and investment has been slow because “even designing a door hinge is pretty difficult,” says Mr. Harmon. What’s missing is the “killer app” – the thing that will give 3-D printing companies a reason to mass-produce. “You’d need to have some reason to want to make something you couldn’t get in a store.”
Z Corporations’ printers use a powder as the basis for the things it builds. The powder is laid down in a thin layer. When the printer head passes over it, the nozzle sprays out a glue-like substance instead of ink. The bed on which the powder is laid then moves down 4/10000ths of an inch, another layer of powder is put down and the process repeats. Making a small part can take a few hours – and the current generation of 3-D printers can produce parts up to about 640 cubic inches, somewhat bigger than a basketball.
The advantage to Z Corp.’s method – and other systems that use powder – is that hollow spaces can exist in the model, saving on material. The powder also acts as a support. The downside is that the model isn’t as strong, unless you dip it into a resin, which soaks into the tiny pores on the surface.
Harmon says that, besides industry, there is a market for making one-off models that Z Corp serves. One big application: wedding-cake toppers.
Other companies, notably Dimension in Eden Prairie, Minn., make machines that use plastic. The machine works in a similar fashion, laying down plastic layer by layer. The difference is that the print head alternates between the plastic used in the model and a support material, which helps keep the shape for overhangs and hollow forms. The supporting material can be chipped off the finished models.
An Israeli company, Objet, has a version that can make a wider variety of shapes and uses a resin. As each layer prints, the resin is dried and cured with an ultraviolet lamp.