By Frank Rovella
If you’ve been holding your breath waiting for 3D printing
to change manufacturing as we know it then your face is probably blue, or
you’ve already passed out. For years a
succession of technological breakthroughs has emerged but, each time falling
short of the ultimate goal. I’ve even heard proponents say that someday we’ll
all have 3D printers in the home so we can manufacture our own products on
demand. Manufacture what, plastic
silverware, Legos?
The plain truth is that for 3D printing to make any kind of
an impact, it will have to displace existing technology and do it
economically.
For the most part, 3D printing has been relegated to the
world of prototypes, short runs, and hobbyists. These days when I hear about the latest in 3D printing
technology I get a little skeptical. However, this time around it includes some
big names such as HP and Voxeljet, using phrases like “high-speed, low-cost
manufacturing” and the Holy Grail “cheaper than injection molding”.
Today the new savior of manufacturing futurists is called
“High-Speed Sintering” which has been in development for over a decade. One of
the people behind high-speed sintering technology is mechanical engineering
professor Neil Hopkinson, of the University of Sheffield in England. He
believes that this really is the way forward for 3D printing. Hopkinson’s entry is based on the layering principals of
laser sintering. As its name implies in laser sintering, a laser is used to
melt material in thin layers. Though the results can be very precise, the
technology is expensive and slow. In Hopkinson’s high-speed sintering approach,
the laser is replaced by an infrared lamp and what is basically an ink-jet
print head. In this process, the print head moves at high speed layering a
polymer powder that is blended with light/radiation absorbing material. As each
layer is laid down on the print bed, an infrared light fuses the powder.
Hopkinson claims that given a large enough build area high-speed sintering can
be 100 times faster than laser sintering, and deliver the same level of
dimensional precision. This seems to be where injection molding may finally be
impacted. High-speed sintering has no expensive tooling, design changes can be
made on the fly, and there is little or no setup, essentially providing manufacturing
on demand.
At this point, the technology has proven viable but there
are still some hurdles to overcome. The biggest is that because the polymer
must be mixed with a radiation absorbing material, it will only work with a
limited number of polymers. Although this may be in the early stages, there is
a lot of R&D money backing up this technology.
Hewlett-Packard has been working on a similar technology
called “Multi Jet Fusion.” In HP’s product, the radiation absorbing powder is
called a detailing agent. HP’s Multi Jet Fusion system is already available but
is still being advertised for short-run and prototype work. Hopkinson’s
high-speed sintering technology is now owned by the German 3D printer
manufacturer Voxeljet. Voxeljet certainly has the know-how and resources to make
this work, and German engineering can’t hurt either.
So to put it all into perspective, we have an obvious market
need and two competing manufactures developing very similar technology. Both
have a lot of capital, in HP’s case revenues of over $112 billion a year.
Voxeljet, on the other hand, is quite modest in size, but totally focused on
the industrialization of 3D printing and proving it with a pretty impressive
product line. They are heavy into innovation and manufacture one of the largest
commercially available 3D printers. Their VX4000 has a workpiece envelope of
157” x 79” x 40”. HP is certainly the 800-ton gorilla, but I’d put my money on
Voxeljet to get this to market first. Their concentration on developing large
scale volume manufacturing based 3D print systems is right in line with what
this technology is meant for.