Hello all! I've been a little distant these last couple of months. As someone has said in another post, having a private life sometimes seems to slow your research down to a standstill. I have been helping my girlfriend with her apartment down the coast, and I must admit that spending my weekends over there has been a constant temptation that i am not strong enough to resist :) But this is not the only issue that has kept me away from reprapping tasks! I have been batteling for the last 2 months to get my purchase order delivered!! Spain is just a bitch to get deliveries to... Today I finally got the base materials that will allow me to research into 3D serigraphy and heat activated hardening. Nevertheless, I'm a little concerned about the difficulties of people getting these very basic products at home. Someday we will have to think about basic products acquisition. This will lower the purchase prices drastically and improve reliability and accessibility. Anyway, I missed you people and I'm happy to be busy with reprap again! :) https://reprap.org/forum/read.php?180,5730,5730#msg-5730 Fri, 07 Aug 2026 20:26:07 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?180,5730,38671#msg-38671 https://reprap.org/forum/read.php?180,5730,38671#msg-38671
Wonderful to see that you have kept after this side of things.

Since the Furfuryl reaction is a dehydration reaction one of the easiest ways to slow things down is to add a little water or even a mild base since when the blocking agent comes off of the catayst the resultant acid will be bufffered. That allows you to not starve the individual areas of the build while still controling the reaction rate.

I have been thinking that maybe the best way to do this would to inject small amount of unblocked catayst onto a just extruded paste containing furfuryl, the blocked catayst and a filler. You might be able to use the reaction heat from the furfuryl and the unblocked catayst to activate the rest of other catayst(s). The sustained heat would also dry out the furfuryl and push the reaction towards completion.

I had also been thinking that blocked catalysts with different unblocking temps could be dripped over a just extruded paste of Furfuryl and filler would allow for the very slow heat up and dehydration. There is a commerical system that uses a bed of filler(sand usally) that is coated in unblocked catayst and then the liquid furfuryl resin is sprayed over-top of it. The filler bed indexes down slightly and a fresh layer of filler is added on top to allow the process to continue. It's used to produce foundry sand cores and works wonderfully.

Mike]]> ohiomike Paste Extrusion Working Group Tue, 09 Mar 2010 19:06:04 -0500 https://reprap.org/forum/read.php?180,5730,7247#msg-7247 https://reprap.org/forum/read.php?180,5730,7247#msg-7247
I will continue my this thread under the Gooey Extrusion sub-forum as it seems a more appropriate place to talk about... well, gooey stuff

[forums.reprap.org]

See you over there!]]> spota Paste Extrusion Working Group Tue, 11 Dec 2007 16:38:04 -0500 https://reprap.org/forum/read.php?180,5730,6960#msg-6960 https://reprap.org/forum/read.php?180,5730,6960#msg-6960 ohiomike Paste Extrusion Working Group Wed, 05 Dec 2007 15:28:27 -0500 https://reprap.org/forum/read.php?180,5730,6750#msg-6750 https://reprap.org/forum/read.php?180,5730,6750#msg-6750 I made a batch 2 days ago and left it to polymerize with straight catalyzer, no blocker.

here are the figures:
4 grams of flour
4 grams of Furfuryl Alcohol
1 gram of catalyzer solution (40% pTSA in a common alcohol sovent)

The result, as I saw them today are a flexible yet tough black polymer. Comparable to, say, shoe sole material! That's an unexpected result for me as I thought that flour containing only 11% gluten would not be good enough to add these features to the mix. But it did!! I was a foo not to believe! :)
And it also had the effect of chemically stabilising the FA, making it safe to mix with non-blocked catalyzer.

I think that varying the load of flour and adding a mineral dust, like Kaolin, Titanium Oxide will yiel a series of polymers from hard and brittle to soft and pasty.

Gotta go!
Cheers!]]> spota Paste Extrusion Working Group Sat, 01 Dec 2007 04:37:40 -0500 https://reprap.org/forum/read.php?180,5730,6667#msg-6667 https://reprap.org/forum/read.php?180,5730,6667#msg-6667
I think, it's simply ceramic-dust wuth waterglass too!

We used this paste for embedding and covering high-temp-sensors for 500]]> VDX Paste Extrusion Working Group Wed, 28 Nov 2007 01:48:20 -0500 https://reprap.org/forum/read.php?180,5730,6648#msg-6648 https://reprap.org/forum/read.php?180,5730,6648#msg-6648 Roach_S Paste Extrusion Working Group Tue, 27 Nov 2007 18:13:00 -0500 https://reprap.org/forum/read.php?180,5730,6645#msg-6645 https://reprap.org/forum/read.php?180,5730,6645#msg-6645
Maybe these Alkali silicates will help you lower down the fusion temperatures of your ceramics? this is what in German would be called "Fliess Mittel".

I know that for this purpose Postassium Carbonate, Sodium Carbonate, Lead Carbonate are being used in the glass industry. My chemists gut feeling tells me that Alkali silicates should lower the melting temperatures down to more sensible values.

Keep me posted, I'm very curious about ceramic sintering as a promising repprap process!]]> spota Paste Extrusion Working Group Tue, 27 Nov 2007 17:14:17 -0500 https://reprap.org/forum/read.php?180,5730,6610#msg-6610 https://reprap.org/forum/read.php?180,5730,6610#msg-6610
I found that dexpanthenol is reacting with my soldering glass-powder, so it can't stay longer time or it changes chemically, in consistency and in end-colour.

For this i searched for another solvent and found waterglass (water-soluble Alkali-Silicate).

It seems to be a perfect solvent for ceramic and some powders, it's used in paper-industry as glue/solvent, in mineral-paints for better fixing and in soap-powders as antioxidant shielding for the metallic machine-parts ...

As the fumes are weak toxic and korrosive, they should be ventilated and/or filtered away.

For me it's the next experiment-basis for glass- and ceramic-pastes (some tests with metall-powders too) for the SLS-fabbing ...

Viktor]]> VDX Paste Extrusion Working Group Tue, 27 Nov 2007 04:20:28 -0500 https://reprap.org/forum/read.php?180,5730,6466#msg-6466 https://reprap.org/forum/read.php?180,5730,6466#msg-6466
... for the polymer-muscles i used voltages until 2kV, much safer is the range until 60Volts, of course ;)

I think it's the balancing between current and voltage to support power-consumpting devices - with higher resistance you have to rise the voltage to get the same amount of energy through the lines without heating them ...

Maybe the idea of high-frequency-AC (>50kHz) with shielded line-pairs is a way too?

I have multilayer-PZT-actuators, which need a voltage of 48 Volts, but this can be adressed with a cascade, so 12 Volts and 100 mA current should work too.

For the material: in this special work we use so small droplets of the precious materials, that a bottle with 5 gramms ultrafine gold-powder (1 micron sized particles, nearly 300 Euros) is a one-year-dosis ...

For printing electronics it's much to expensive, so i would prefer to use copper or another common metall too.

Maybe it's interesting to try graphite or better a reducing receip, where the metall is chemically solved and with an added component will fallout and reduce to solid, so i can paint fluid lines, which converts to thin metallized films?

Viktor]]> VDX Paste Extrusion Working Group Thu, 22 Nov 2007 06:20:30 -0500 https://reprap.org/forum/read.php?180,5730,6465#msg-6465 https://reprap.org/forum/read.php?180,5730,6465#msg-6465
Thanx Zach! I also think this could be usefull. I will try and put together a recipy that people could easely work with.
I guess that building a simple circuit board would be th enext step... but I'm not very much of an electronics guy, so maybe somebody has a simple diagram that I can build. Nothing crazy. Just stuff to test resistors, transistors, condensators etc with this type of tracks.

Hey Vik!
It's very interesting to see pictures of your researches.
I prefer to go with cheaper materials than gold or silver as I'm trying to make it as available as possible to everybody. I'm trying to think big scale and affordable, and silver, gold or exotic alloys are better suited for specialty and super-accurate applications as yours.
I haven't come accross a DVD laser yet as I'm a little impaired with my broken arm, but that's very much on my list. I just want it! :)

When you speak of copper reacting inside the polymer at higher voltages, what voltages are you talking about? My multimeter does the usual 9V at the higest ohm-meter scale. I guess we don't need it to be stable much further of the 15V for the circuit-board application.
For higher power applications, I would have to test it further, but I guess 1 Ohm resistance is high enough to produce heat enough to cause trouble...

(I think I should create a separated thread with this conductive polymer issue)]]> spota Paste Extrusion Working Group Thu, 22 Nov 2007 05:01:12 -0500 https://reprap.org/forum/read.php?180,5730,6455#msg-6455 https://reprap.org/forum/read.php?180,5730,6455#msg-6455
The pads are 150 microns wide and nearly 300 microns long, the droplet of gold-paste was something between 100 and 200 microns in diameter, when wet.

With 'low-energy-curing' (diode-laser at 1 Watt, 100-micron-laserspot) i dried the dexpanthenol-solvent away and then melted the gold-powder with some 3 Watts laser-power to solid.

Some tests with melting gold- and glass-pastes on pure surfaces (without predefined pads) showed, that you often need a fixing-basis, or the gold (or metall in general) didn't connect to the surface.

With mixing of gold AND glass in a paste i hope to get better connecting on ceramic-surfaces without metallic coating, so i can 'paint' very stable and rigid conducting trays of pure metall and embed electronic components and wires in solidified glass or ceramic ...

Viktor]]> VDX Paste Extrusion Working Group Wed, 21 Nov 2007 16:25:18 -0500 https://reprap.org/forum/read.php?180,5730,6449#msg-6449 https://reprap.org/forum/read.php?180,5730,6449#msg-6449
... for risers or vias you can insert metall-pins or silvercoated copper-vias (as used in manually assembled double-layer-pcb's) in the wet paste.

Viktor]]> VDX Paste Extrusion Working Group Wed, 21 Nov 2007 02:05:22 -0500 https://reprap.org/forum/read.php?180,5730,6440#msg-6440 https://reprap.org/forum/read.php?180,5730,6440#msg-6440 As it is, you can lay traces in the X-Y plane, but it doesn't sound like you can build risers.

The conductivity of the bottom layer sounds good, though.]]> Roach_S Paste Extrusion Working Group Tue, 20 Nov 2007 17:41:50 -0500 https://reprap.org/forum/read.php?180,5730,6428#msg-6428 https://reprap.org/forum/read.php?180,5730,6428#msg-6428
... yes! that seems to be the ideal basis for electric circuits - touch-safe, but conducting :)

Can you try to apply a higher current to the trays and look, if they change in resistance?

Copper isn't so stable in some polymers, so after a while or with higher currents it oxidize and the conducting went poor or vanish completely ...

We use a heat-curing polyimid-silver-paste, which is very good conducting, stable in normal ambient conditions (break down with hot NOX or acids!) but didn't sedimentate ...

In the silver-paste the silver-particles are thin flakes, so the interconnecting is very good - if your copper-particles are more spheric, then you have to compact them for proper conducting (with the sedimentation, for example)

For some experiments with polymer-muscles i mixed a resin with graphite, it's a tricky play between conducting and shape-morphing, but works for lower currents and higher voltages too ...

Viktor]]> VDX Paste Extrusion Working Group Tue, 20 Nov 2007 14:51:01 -0500 https://reprap.org/forum/read.php?180,5730,6426#msg-6426 https://reprap.org/forum/read.php?180,5730,6426#msg-6426
that is awesome fernando. if that is the case, it should be very simple to lay down tracks of this mixture to create traces.

bravo sir, bravo.]]> ZachHoeken Paste Extrusion Working Group Tue, 20 Nov 2007 14:11:17 -0500 https://reprap.org/forum/read.php?180,5730,6421#msg-6421 https://reprap.org/forum/read.php?180,5730,6421#msg-6421
After 2 weeks spent with a broken ellbow, i'm back on the workbench.
Nothing, i say NOTHING will hold me back :)

I have had some interesting results while mixing copper powder with this resin.
I mixed around 70 weight% of copper vs the resin mix. The resin polimerzed slow enough so that the copper powder subsided towards the bottom of the polimer.
When braking off the sample, which is 2mm thick, i can clearly see the layering: on top the black polymerized plastic and below a dark brown mix of resin with a copper fraction far above the 70%.

When measuring the resistance of the lower layer, i get values below 1 Ohm. The top layer is completely insulating.
I think these are very promising results!]]> spota Paste Extrusion Working Group Tue, 20 Nov 2007 14:02:17 -0500 https://reprap.org/forum/read.php?180,5730,5945#msg-5945 https://reprap.org/forum/read.php?180,5730,5945#msg-5945
... sounds really good!

Actually i'm bound with other tasks, but that's a way, i want to go - keep us informed and be carefull, not to rocket your house in the sky ;)

To the diode-lasers: you should salvage lasers only from newer Drives, so 40x or faster - in older drives the diodes haven't enough power, in pointers it's the same - with a 5mW-Diode there isn't a sensable heat in the focus ...

The 54x-CD-Drives and 12x-DVD-writers have 150 to 220 milliwatts, when supplied with 80% max. current and good cooling, they didn't wear out, so with a 220mW-Diode you can have a stable power-output of 180 mW or so without much worry.

The focussing is another part - if it's possible, use the lenses of the drive in the same setup.

The diodes have a very poor output-quality, so the focussing to a small spot isn't so easy without to much power-loss.

I use fiber-coupled laserdiodes with 1,2 Watt at home or 8 Watts in the job - the 1,2-Watt-diode runs with max. 0,8W, the 8-Watt-diode runs actually at 5 Watts max, so i didn't bother with lifetime or so ...

The fibers have a diameter of 100 microns, so with two lenses i can focus the beam down to nearly 60 microns.

If you manage to fit the diode with a thinner fiber (i'm playing with the idea to taper the fiber gently with heating and pulling it, so it should expand and shrink down to 30 microns or so), so you can reduce the focus and rise the energy-density too ...

Viktor]]> VDX Paste Extrusion Working Group Thu, 01 Nov 2007 14:26:13 -0400 https://reprap.org/forum/read.php?180,5730,5943#msg-5943 https://reprap.org/forum/read.php?180,5730,5943#msg-5943
Hi all!

Today I made some progress on the blocked catalyzer.
As a reminder, the catalyzer is para-Toluene Sulfonic Acid (pTSA), wich is a strong organic acid, in solid form. I have dissolved it in Isopropanol alcohol (a solventquite similar to Ethanol).

This catalyzer, if added in this solved form to Furfuryl Alcohol (FAlc, the actual polymer resin) will cause it to polymerize extremely fast and under the release of heat. This should not be done, take my word! ;)

The trick here is to reversibly block the catalyzer just enough, so that you can mix it with the FAlc and the mix stays stable, for at least a day. The reversible word here means that with the application of heat, the catalyzer gets released again and the resin starts polymerizing on demand.

So this is what I have been testing today: I have tried different degrees of blocking and the temperatures necessary for unblocking the catalyzer.

The blocker I used is a strong organic amine base (N-Methyldiethanolamine, short MDEA).
This amine will react with the organic acid and form an organic salt, but that is reversibly bound. The fact that it's a base makes it possible to use the pH level (acidity level) to measure on how much it has been blocked.

I have tried pH 7 (neutralized), 6, 5, 4, 2 and 1 (strong acid).
What I have discovered is that MDEA blocks pTSA quite a lot and that the pH 7 down to pH4 samples were only marginally active catalyzers, even at heats up to 100]]> spota Paste Extrusion Working Group Thu, 01 Nov 2007 13:47:30 -0400 https://reprap.org/forum/read.php?180,5730,5938#msg-5938 https://reprap.org/forum/read.php?180,5730,5938#msg-5938
... glass and ceramic melts much better then metall, but they have a higher thermal contraction, so i must mix materials with different TK-values for better stability, or it would brake apart, when cooling down ...

Another point: - i have to dry the paste with lower energy completely, befor i can melt the powder to solid, or the evaporating solvant would blast the powder away ...

For simple 3D-fabbing it's maybe better, only 'bake the paste a bit' to make it stiff enough to support the next slices - then put the object in an oven and heat it to end-temperature, for solidifying the body without melting it ...

I think, the 200mW-IR-diodelasers (and maybe the red ones too) from newer DVD-RW-drives should have enough energy, to heat plastic-powder-pastes and dry them, so a 3D-laser-fabber for plastics could be made 'cheap and dirty' ;)

With the UV-diodelasers from BluRay-drives there could be UV-laser-curing too!

But it's essential, to protect your eyes and the surrounding, so you have to find (or make with IR-blocking filters or Blue+UV for the BluRay-diode) laser-goggles for testing and make a light-tight housing for the reprap.

Viktor]]> VDX Paste Extrusion Working Group Wed, 31 Oct 2007 17:59:21 -0400 https://reprap.org/forum/read.php?180,5730,5937#msg-5937 https://reprap.org/forum/read.php?180,5730,5937#msg-5937
Good idea! I will try starch as it's pretty easy to get and it's also a standard product.
I don't know how much fiber it contains, but it's worth a try.

Its always great to hear about your sintering efforts. They really seem to be going well!
It seems that glass, having a big thermal inertia is easier to sinter than metal, is that correct?
This would be an interesting result and would aim you to wards ceramics as you say.
Did you consider ceramic glazing powders? They are standard and easily available, although I am not aware of the prices they come in. I do know you can buy them by the kilo and they come in different mixtures that seem to melt at lower temperatures than clay grains.
Dunno, just an idea.]]> spota Paste Extrusion Working Group Wed, 31 Oct 2007 17:07:17 -0400 https://reprap.org/forum/read.php?180,5730,5930#msg-5930 https://reprap.org/forum/read.php?180,5730,5930#msg-5930
... you can make tests with stark instead of cellulose, should work similar ...

My tests with laser-melting gold-dexpanthenol-paste went fine, the heavier part is now to adjust the output-power of the diode-laser, to liquidize the gold-powder, but stop melting, before the gold-pad under the paste is melted completely too ...

Tomorrow i'll try sintering or melt the iron-paste, which i mixed for the 'Artificial Muscles'-Thread.

Glass-powder-paste was fused/melted very good to solid glass, so i could make lines of solid glass on a surface - if the tension between stacked slices shouldn't be so strong that it brakes, this would be the proof-of-concept for 3D-printing with solidified glass.

The next step will be sintering/melting paste from ceramic-dust, when our supporter for the ceramic-sensor will give me some probes of their different print-pastes ...

Viktor]]> VDX Paste Extrusion Working Group Tue, 30 Oct 2007 16:30:21 -0400 https://reprap.org/forum/read.php?180,5730,5928#msg-5928 https://reprap.org/forum/read.php?180,5730,5928#msg-5928
Actually i started with Furfuryl Alcohol and not Furfur Aldehyde because it seemed to be less volatile as in less vapors. But I do have both and I want to complete the same tests on FAld as I'm doing on FAlc.

Yeah, the sealed pot was a stupid idea, I know ;)
Afterwards I remembered you saying something about this in one of your previous posts. I think I will be very specific about safety measures on this one.

The pot life of the resin with the blocked mix, as long as you keep it safe from air and light is over 4 days (and running, i have it here next to me and it's still unchanged).
I will need to be very precise about the blocker additive, as it has a huge importance on the reactivity of the catalyzer. I have seen that a 0,5 to 0,5 mol mix of pTSA to MDEA is not enough reactive, so that I will go to th eroute of neutralyzing the pTSA with MDEA little by little untill I reach a pH of 6 or 7. This should happen at a ratio of 0,5 mol pTSA to 0,46 mol MDEA.

As a filler, I have noticed that Titanium Oxide is a LOT better than Kaolin. It's also more expensive but it really does the trick. it gives the resin a better stiffness, the end result is less brittle and more homogeneous. It also reduces the reactivity of the FAlc quite a bit, just the same as you described with silanes, making the whole thing mixed with catalyzer a lot more manageable.

For now, I make my tests of reactivity with waterbaths, as I can test a complete layer of resin mix in one go and can control the temperature very easely in steps of 10]]> spota Paste Extrusion Working Group Tue, 30 Oct 2007 15:15:38 -0400 https://reprap.org/forum/read.php?180,5730,5926#msg-5926 https://reprap.org/forum/read.php?180,5730,5926#msg-5926
I'm VERY, VERY glad you were only working with 10g at the time. Explosive polymerization is a very accurate term for what happens, isnt it. That you were working with a sealed jar is quite scary.

Whats the pot life like for the blocked catayst/resin mixture. Is the resin advancing due to the presence of small amounts of unblocked catayst? If you are using inorganic fillers you might consider added some silanes since they are mildly basic and in sufficient amounts they stablize the resin giving longer potlife, while also improving humidity resisance of the finished product. Ideally you want to be able to add the catayst to a large tub of the material and leave it there, without having to worry about resin advancement.

The other thing is, why Furfural Alcohol? Why not Furfural Aldehyde?

Even as I ask the question I suspect the answer, Furfural aldehyde is TOO stable the heat and acidity necessary to crosslink it are too high for high productivity. That is the reason that furfural alcohol became popular desite its dangers.

Please be safe and be careful.

Mike]]> ohiomike Paste Extrusion Working Group Tue, 30 Oct 2007 14:01:48 -0400 https://reprap.org/forum/read.php?180,5730,5838#msg-5838 https://reprap.org/forum/read.php?180,5730,5838#msg-5838
To bad i don't have such powerfull laser sources, it seems that a whole world of sintering possibilities lies there to be experimented...

Anyway, I will keep you indformed with the progresses I make with heat/light/UV activated polymer resins. Let's see if we can get some neat application working at low temperatures!

I'll inform you with mixture proportions soon. I'll also try to post more detailed exprerience procedures in the builders blog. I'm sure we will make several advances soon, as we seem to have a lot of knowledge to share.

OK, i'm signing out for tonight. I'll be back posting tomorrow!
Cheers!]]> spota Paste Extrusion Working Group Wed, 24 Oct 2007 18:11:47 -0400 https://reprap.org/forum/read.php?180,5730,5836#msg-5836 https://reprap.org/forum/read.php?180,5730,5836#msg-5836
... the gold is for a special problem: - we assemble a sensor, which is made from ceramic with gold-pads, on which we fix thin platinum-wires (10 microns and 1 micron diameter) as temp-sensing elements.

Until now the wires were fixed with a conducting silver-filled polyimid paste, which will be heat-cured at 175]]> VDX Paste Extrusion Working Group Wed, 24 Oct 2007 17:23:22 -0400 https://reprap.org/forum/read.php?180,5730,5833#msg-5833 https://reprap.org/forum/read.php?180,5730,5833#msg-5833
It sounds really amazing what you are doing.
One question: why are you concentratinmg on gold? Is that your trade? Are you a jeweler?

I would have guessed that using bronze or messing (brass) would be a cheaper and more obvious choice. Also, correct me if I'm wrong but gold melts around 800]]> spota Paste Extrusion Working Group Wed, 24 Oct 2007 16:47:28 -0400 https://reprap.org/forum/read.php?180,5730,5830#msg-5830 https://reprap.org/forum/read.php?180,5730,5830#msg-5830
... thanks!

Sounds to be a very interesting material, when dispensed and tracted with the laser ;)

With a heating spot of 50 microns i think the activation-zone should be around 80 microns, if the reaction doesn't expand on self?

If you find a mixture, which will stay stable and fluid at room-temp and harden in seconds when lasercured, then there should be some testing with partial hardening and use the fluid paste as a sort of support for the 'fine-structure' too ...

I'm actually testing baking and sintering/melting of different powders solved with dexpanthenol.

The mixed paste is stable for weeks and doesn't settle even with gold-powder, but when heated, the dexpanthenol vanish completely, so the powder can sinter to solid and with the right heating it melts to pure material.

I tried with soldering glass, which melts at 430]]> VDX Paste Extrusion Working Group Wed, 24 Oct 2007 16:02:38 -0400 https://reprap.org/forum/read.php?180,5730,5828#msg-5828 https://reprap.org/forum/read.php?180,5730,5828#msg-5828
The mix i'm testing now is made of Furfuryl Alcohol (FA, the actual resin [www.acros.com]) and p-Toluenesulfonate (pTS: [www.acros.com]), wich is a solid organic acid that you can solve in Isopropanol.

On the dissolved pTS you need to block the acid functional group. You do this by adding wether Vinyl-ether or N-Methydiethanolamine (http://www.acros.com/DesktopModules/Acros_Search_Results/Acros_Search_Results.aspx?search_type=CAS&SearchString=105-59-9)

The FA has to be mixed with some filler material. I'm trying Kaolin dust and TiO2 pigment, but a good solution would also be Cellulose or wood dust. Appart from stabilising the whole resin, wich otherwise can polimerise very fast and resleasing heat (caution!) I think the mineral dust will give the whole mix a greater thermic inertia, allowing the heat of the beam to be concentrated on smaller scales.

I have not thought yet what the best solution would be: a vat to be filled up one levelafter each hardening step or lowering the piece after each step... that remains to be seen.
Also, there is no definitive mix I have decided yet. There is still a lot of experimenting to be done as I have just started with this line of research.

Hope this helped a bit]]> spota Paste Extrusion Working Group Wed, 24 Oct 2007 14:57:39 -0400 https://reprap.org/forum/read.php?180,5730,5824#msg-5824 https://reprap.org/forum/read.php?180,5730,5824#msg-5824
I get it. I was thinking in terms of pools of fluid when the reality was much more refined. I understand the accuracy issue between thermal and UV curring. It doesn't seem like that much more trouble to UV cure than to heat cure.

Demented]]> Demented Chihuahua Paste Extrusion Working Group Wed, 24 Oct 2007 14:20:33 -0400 https://reprap.org/forum/read.php?180,5730,5822#msg-5822 https://reprap.org/forum/read.php?180,5730,5822#msg-5822
... my approach is a low-viscose paste, which i can dispense in diametres under 100 microns or single droplets down to 10 microns, which i heat-cure with the laser to harden directly after releasing ...

A second setup is to output a complete layer and bake the layer completely - then a big IR-heater, which activates the complete surface is better and faster, then a laser-spot ...

Heat-curing of fluid-surfaces, as in SLA-printers isn't so good, as heating makes a much bigger spot, then 'cold' UV-curing, so th eaccuracy isn't good.

Viktor]]> VDX Paste Extrusion Working Group Wed, 24 Oct 2007 14:16:45 -0400