The problem: you want to produce varying line thicknesses when 3D printing. The solution, if you are the Liqtra company, appears to be to put seven print heads together and enable one for thin lines, all of them for thick lines, and something in between for everything else. The technical details are scant, but from the video below and some pictures, you can get a general idea.
There are some obvious benefits and drawbacks. You’d expect that for the right kind of part, this would be fast since you are essentially laying down seven tracks at once. The downside is your track width varies in pretty course steps, assuming you have to use the maximum width of each nozzle to prevent gaps. New slicing software is a must, too.
The demos and pictures show multiple filament colors because it photographs well, but you’d assume in practice that you would use seven spools of the same material. The good thing is that you could print with a single nozzle where that’s important. We assume all the nozzles are the same size, and that will control the practical layer height, but that’s a small price to pay.
The company claims a much faster print, but as we mentioned, this will depend on the specific printed part. They also claim inter-layer strength increases as well, although we found that surprising. This is probably overkill for home users, but we imagine this would be an interesting technology for people trying to run production quantities through a printer.
We don’t remember seeing this approach with a homebrew printer, although having multiple extruders into one or multiple nozzles isn’t unusual anymore. It seems like you could experiment with this kind of technology pretty readily. Of course, there’s more than one way to speed up production.