3D Printing Silicone

Any idea how they are doing this? I can see dual feeding the two part A/B components through a common nozzle to follow a .stl file...but liquid silicone has a pot life and takes time to solidify. Is there a quick curing process involved? Very interesting !!

3D Printing Silicone

CNC caulking gun .
Using a plunger, make your silicon mix and squeeze through nozzle tip.
expirementing with cures and hardener mixes may help.

Air flow may be the fix for fast curing, kinda like flashing with cold air.

its worth a thought.

Premixing the two components would limit the print time for larger parts, so I don't think that's how they do it. I think they have to be mixing at the nozzle as the material is deposited. But you may be on to something in the ratio of part B catalyst to part A. Normal ratios generate a certain pot life that allows for time to pour into a mold. Do you suppose they are using higher catalyst percentages to gel the mix almost immediately after the print head deposits it? I don't see how that would effectively blend the layers if the last layer has already gelled before the next layer is placed on top. My guess is they are not introducing heat into the printhead like we see in FDM printing. Still a mystery...any other ideas?

I thought
'UV Curing'

then google tells me
UV-curing silicone rubbers enable new applications.
[www.momentive.com]

Therfore, if you have a pre-mix, the shelf life is longer if it does not have UV light reaching it.

Thanks for the link. Seems reasonable until we get to the part where they say they can use any commercially available silicone mix components. This article says the UV curing is applicable to a new process silicone product. I guess we'll just have to wait to see how their printing process works to understand it.

Printable support structure from silicone + polymer
Original title (Material and method for three-dimensional modeling)
Patent number US7534386 B2
Publication type Grant
Application number US 11/985,387
Published 19. May 2009
Application 15. Nov. 2007
Priority 20. Apr. 1999
Fee status Paid
Also published as CN1666217A, 6 et al»
Inventors William R. Priedeman, Jr.
Original Assignee Stratasys , Inc.
Patent citations (90), Classifications (51), Legal Events (3)
External links: USPTO, USPTO assignment, Espacenet
Comment:
The inventor describes a method using a dual extractor with a
thermoplastic compound(A) and a silicon based material mix ( B ), where
( B ) does act as support structure material Several problems have to be
solved to achieve this. The support material for instance has to withstand
similar temperatures as the main material. The patents names the
compositions and the results from testing variation along with the
supplier of these chemicals..
Surprisingly the mix of thermoplastics such as Nylon, Peek, PEAK or
ABS and 10% silicone was able to prevent the nozzle from clogging.
Usually a nozzle has a maintenance free operation for around 3.5 Kg of
print material. With the addition of 10% silicone the inventors observed
up to 20 Kg operation without nozzle clogging. This effect was not the
goal of the invention (..).

From my book "3D printer-patents and innovations", Page 100


and another one that will supply helpful information:

3D print under water
Original title: “Device and method for the production of threedimensional
objects”
Patent number CN1450953 A
Publication type Application
Application number CN 00819378
Published 31. Oct. 2001
Application 17. Apr. 2000
Priority 17. Apr. 2000
Also published as CN1450953A, 6 et al»
Inventors Hendrik John, Ruediger Landers, Rolf
Muelhaupt
Applicant Envision Technologies Gmbh
Patent citations (1), Referenced by (8), Classifications (12),Legal
Events (2)
External links: DPMA, Espacenet
Comment:
The rather bulky patent text does reveal some interesting details at
second look.
The principle of this invention makes use of the effect, that certain
silicons cure immediately after the got in contact with water. Here the
inventor uses a syringe that deposits silicone below the water surface.
The silicone can be mixed with other ingredients in order to achieve
desired material properties. Since the curing goes so fast the inventor
claims that his methods makes the use of support structures obsolete.
It is also proposed to use living cells as component of the printing
material.
The author of this book raises the question, whether the syringe will not
clog due to cured silicone under these conditions.(..)

From my book "3D printer-patents and innovations", Page 137

Check out the patent number for full information.

Edited 2 time(s). Last edit at 09/26/2014 01:17PM by maboo.

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Books on 3D patents:
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[www.amazon.de] (deutsch)

Thanks maboo...interesting concepts. These patents are still in effect so it will be interesting to see if this new process is indeed something new or akin to prior art.

If they are platinum curing the silicone, they can just use heat to make it cure faster.

Quote
simspeed
Any idea how they are doing this? I can see dual feeding the two part A/B components through a common nozzle to follow a .stl file...but liquid silicone has a pot life and takes time to solidify. Is there a quick curing process involved? Very interesting !!

3D Printing Silicone

Maboo,
Your 1st patent re printing with silicone is completely different to whats being discussed here. Your suggestion (Printable support structure from silicone + polymer) is a method for coating the support structure with a release agent (silicone lubricant) so that it does not adhere to the main build material. That way at the end they can be easily seperated.
Your 2nd one is interesting though, I suppose that you could retract the silicone and introduce an air bubble into the nozzle via a tube to stop the resin from curing. Or use a resin that takes at least 30 seconds to cure and make sure that each layer is slowed down so that it has time to cure before the second layer is deposited. Then you could have the nozzle purge away from the build plate if it stalls for more than 25 seconds.

Re the topic under discussion, I think this is using SLA technology. It uses UV curing polymer resin.
Basically you have a pot of resin, you shoot it with UV light using either a laser or a projector. It cures in the shape that you shot it with the laser and you drop it into the resin by 0.1mm and shoot it again. Very slowly a part forms.
For a basic explanation see the Peachy printer on Kickstarter or search google.
Mike

Edited 1 time(s). Last edit at 09/29/2014 02:35PM by mikefiatx19.