CLIP: UV-resin based 3D printing
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When is the best time to buy a 3D printer? If you are really enthusiastic, even serious about the whole arena, then perhaps the best time, paradoxically, is 'never' - or at least 'not yet'! The field is changing so fast that multi-thousand dollar/pound extrusion-based units the size of refrigerators are being increasingly edged out by high quality desktop variants costing somewhere in the hundreds, or perhaps nudging into the low thousands. The early adopter's life is rarely a happy one.
Extrusion-based 3D printers, currently seen happily whirring away en masse at every 3D print show, could be heading for Ebay in the very near future. Expect some major deals on filament based printers very soon when “it” hits the fan.
The “it” in question is CLIP technology, or Continuous Liquid Interface Production. It's a resin based 3D printing method that creates monolithic objects at very high speeds and resolutions, at least relative to current standards. Carbon3D, who are championing the technology, claim (and show) some very impressive results in comparison to other extant printing methods.
Mechanically, the CLIP system is centred around a shallow, glass-bottomed reservoir that holds the resin print-medium. A UV light projects an image of the current print cross-section, up through the glass and against the base of the build platform, which in turn draws the forming object out of the resin. As the table increments upwards, more micro-slices are hardened by the UV light, each directly against the previous one until the printed shape is fully formed.
A particularly cunning aspect of the device is in the glass window itself; while it permits UV transmission, it is also permeable to oxygen. This allows for a layer of oxygen several “tens of microns thick” to be maintained just above the glass. Well, so what? This is crucial to the process as oxygen inhibits the UV hardening, therefore a “dead zone” exists between the hardening resin and the glass reservoir base. Above this, the reaction is uninhibited, allowing the print to harden initially against the platform, then against subsequent object layers as the print is drawn out, so that the forming object is prevented from sticking to the floor.
in comparison to SLA (the older relative of optical/resin based tech), a target object's print-time drops from 11.5 hours to an unimaginable 6.5 minutes, but this is just the beginning. CEO Joseph DeSimone can envision print speeds reaching a thousand times faster than we are currently used to, like for like, with liquid cooling employed to keep the mechanism operable.
For the nerds among us, we're talking Star-Trek Replicator speeds at last! The serious and sobering aspect of ‘nerd-speed’, of course, is that the confines of the rapid-prototyping niche (whilst still important) are no longer a limitation. We're going full-scale-manufacture here with 1000-speed printers delivering finished modules/units, or even finished goods. One of the main criticisms of 3DP (speed) is set to abruptly disappear.
Yes, but what about 'finishing'? Well the nature of the process - it's tempting to use the word 'organic' - effectively removes the layering that is so inherently irritating about the filament extrusion method. This currently requires extra hands-on time to remove, and is a skilled process, lest the integrity, intention and structure of the object be compromised. To all intents and purposes, CLIP produces monolithic results. Arguably it's still a “layering” process (if one frame of projected UV light equates to one layer), but it's so fine that the output under relatively high levels of magnification resembles that of substances formed (grown?) from a single material rather than stepped sections. Perhaps an analogy would be that of adding glue that is curing to glue that is already semi-cured?
At any rate, the process delivers other distinct payoffs: layering imposes limitations on how an object is printed and it also has a bearing on the final structural integrity. CLIP allows objects to be pulled free-form from a tank of resin with less restriction on orientation, with greater structural cohesion and therefore: greater strength. Impressive stuff.
Tagged with: Carbon3D, UV resin
