Prototyping with Powdered Plastic...Need Info

Found this youtube video of a rapid prototyper:

[www.youtube.com]

Machine made by Engineering & Manufacturing Services uses powdered polymer. The powder bonds when a chemical agent is sprayed on it by an ink-jet print head. With each new layer, more powder is applied, and a dull scraping blade levels the surface. the unbonded powder holds up any overhanging parts, which is one worry that is eliminated. This thing is fast, and looks like it has pretty high resolution. You might be able to build one of these with parts salvaged from an ink-jet printer.

Small disadvantage: hollow parts need to have an opening to release the unbonded powder.

What kind of plastic are they using?

the one shown? Starch.

Not kidding. The Z-Corp printer (not E&MS) uses a starch based fill. The inkjets provide adhesion and coloring. These things are HIGHLY hydroscopic and need a laquer coating. If you bring an unlaquered part outside on a high humidity day, it gets kinda... squishy. They have decent strength but are very brittle.

[www.zcorp.com]

Their newer, higher end units handle what appears to be a powder with a two part epoxy coating and the activator in the print head, but don't quote me on that.

That may explain why the company's web site doesn't say anything about the plastic used.

...but the brittleness and solubility could be useful. The machine could be used to make a mold for an epoxy resin object. The starch structure could then be broken, with any residue to be washed away.

... in particular you can use any powder ...

In the basic model the inc is water-stretched super-glue and eventualy some coluring.

I found the analog idea with sugar an an hot-air-nozzle for molding very funny and usefull

Maybe i test this in the next months with a modified Pen-plotter ...

Ciao, VDX