Heated tank to mitigate surface tension?

[Deadbot1]

Has there been any thought of using a heated tank/heated water to help lower viscosity and thus surface tension of the resin?

[/dev/null]

It may be interesting idea, but I think it will be of no use to most people who ordered Peachy Printer Kit. It's way too complicated. However, if it turns out to really improve results, it may be an idea/option for Peachy Pro.

However, when I have Peachy Printer, I will definitely try this, among other things, in order to try improve printing quality and widen range of resins I can use. If it turns out to be useful, I'm sure many other people who do not mind adding temperature sensor, heater and microcontroller will try it too.

P.S. In future, please do not cross-post basically the same thing in multiple topics; it would be enough to just create new topic.

[/dev/null]

I did some quick research/googling, and I do not think that heating resin will help much. It may reduce viscosity greatly, but surface tension will remain mostly unchanged. At least this is what I think at the moment; I did not find general study of many types of resins, but all studies I have found so far do not mention big change of surface tension. For example, some resin has slightly more than 41 dyn/cm surface tension at 25°C, after heating to 60°C it is reduced, but very slightly, by 6-7% (to 38.5 dyn/cm). I guess this is why some manufactures who provided surface tension in datasheet do not even bother to specify temperature. I could be wrong about all of this, if so, feel free to provide example of a resin which can reduce its surface tension greatly (relatively to its state at room temperature). But at the moment I have an impression that heating resin is mostly useful to reduce its viscosity. This does not mean that you idea is not useful - it's still possible that heated resin could produce higher quality prints, it is hard to tell without experimenting. Heating also may help with some thick or old resins.

[Deadbot1]

Sorry about the cross posting. It may not help reduce surface tension, but I think that a thinner resin that can flow easier should be able to fill in faster and more uniformly. this should make for a better finish, more uniform layers, and any reduction in surface tension is a good thing.

As far as complicated, a simple aquarium heater should suffice. A more complicated system using PID controllers is not a requirement. It's just a better system to have steady temps.


I think you aren't giving those who ordered the kits enough credit. When ordering the kit we already need to supply our own reservoir and build tank. How hard is it to add a heater to the mix? This is childs play for most anyone who will be using the kit. I think that if it gives a better result, then many will be willing to go that little extra bit to achieve it.



I'd love to do the experiment myself, but I have 2 problems...

1. I don't have a peachy yet. I plan on putting my preorder in after this next pay period(yay overtime).

2. I don't have a peachy yet.....

edit: After further research on the subject, it seems that there is little to no correlation between viscosity and surface tension. The only way I have determined to lower surface tension will be with an additive, which may adversely affect the bonding during curing of the resin.

That said, it is still my firm belief that raising the temp to lower the viscosity would be beneficial and at the least would result in an ability to print at faster speeds with better results.

and I found yet a third reason why I can't complete the experiment on my own...

3. I still don't have a peachy yet....

[mike_biddell]

Sorry about the cross posting. It may not help reduce surface tension, but I think that a thinner resin that can flow easier should be able to fill in faster and more uniformly. this should make for a better finish, more uniform layers, and any reduction in surface tension is a good thing.

As far as complicated, a simple aquarium heater should suffice. A more complicated system using PID controllers is not a requirement. It's just a better system to have steady temps.


I think you aren't giving those who ordered the kits enough credit. When ordering the kit we already need to supply our own reservoir and build tank. How hard is it to add a heater to the mix? This is childs play for most anyone who will be using the kit. I think that if it gives a better result, then many will be willing to go that little extra bit to achieve it.



I'd love to do the experiment myself, but I have 2 problems...

1. I don't have a peachy yet. I plan on putting my preorder in after this next pay period(yay overtime).

2. I don't have a peachy yet.....

edit: After further research on the subject, it seems that there is little to no correlation between viscosity and surface tension. The only way I have determined to lower surface tension will be with an additive, which may adversely affect the bonding during curing of the resin.

That said, it is still my firm belief that raising the temp to lower the viscosity would be beneficial and at the least would result in an ability to print at faster speeds with better results.

and I found yet a third reason why I can't complete the experiment on my own...

3. I still don't have a peachy yet....

I think you will find that surface tension decreases significantly with temperature

[Deadbot1]

No, /dev/null is correct from what I have been reading. Surface tension doesn't seem to be affected by anything other than additive(surfactants). Heat will lower the viscosity(how easily a fluid flows). However the lower the viscosity the less that surface tension should be a factor, I believe. If the resin can flow easier, it shouldn't be held back as much by its surface tension. It's the difference between trying to push an object into a bubble of tar and a bubble of water. the water actually has higher surface tension, but lower viscosity so is easier to push into. the difference is that the tar will coat and adhere more quickly, where the water may actually form a film above the part until the surface tension breaks.

edit: Think of it this way, we use soap to make the surface tension of water lower, this helps the water to reach the dirt on our hands. We use heat to make the water dissolve more of the dirt. In our application we will be using heat to make the resin better flow into the void left by the raising of the z axis.

[Dragon.sh]

It may not help reduce surface tension, but I think that a thinner resin that can flow easier should be able to fill in faster and more uniformly. this should make for a better finish, more uniform layers, and any reduction in surface tension is a good thing.

According to rylangrayston, "all of the resins that maker juice sells will work well with the peachy printer, and also some of them work better", and MakerJuice resins can have viscosity as low as 25cP with 8% shrinkage and up to 90cP with 3.3% shrinkage. Is lower shrinkage more important than lower viscosity? We do not know that yet. It may be that viscosity is not that much important by itself, unless it's too high. But I think your idea is worth checking out regardless, just print first object normally and then the same object with heated resin and then it would be possible to compare them. With thicker resins difference maybe more apparent (if there will be noticeable difference).

As far as complicated, a simple aquarium heater should suffice.

I'm not sure if using simple aquarium heater for this purpose is a good idea. Surface temperature of the resin is what the most important in this case, and it will be lower than temperature of the water below, so the water needs to be hot enough. But I looked at some aquarium heaters at eBay and they are usually limited to 34C max. Perhaps there are better aquarium heaters or you know some easy hack for specific model. Also, there must appear no unwanted bubbles when heater works. I never used aquarium heaters, so I have no idea if this problem usually exists in practice or not.

[/dev/null]

Sorry about the cross posting. It may not help reduce surface tension, but I think that a thinner resin that can flow easier should be able to fill in faster and more uniformly. this should make for a better finish, more uniform layers, and any reduction in surface tension is a good thing.

That's exactly what I meant by "it's still possible that heated resin could produce higher quality prints".

As far as complicated, a simple aquarium heater should suffice.

That's one thing you can experiment with without Peachy (I would do it myself, but I do not have aquarium heater, and it seems like not every aquarium heater would be useful for this purpose). Put your aquarium heater in the tank you plan to use with Peachy and fill it with water just enough for aquarium heater to work. Increase power very slowly, small step at a time, until you start getting bubbles around it, then go back few steps to eliminate bubbles. Then after a while measure the temperature around water surface in different points. Then fill the tank as much as necessary to "cover" the tallest object you plan to print in it, wait for while, and take few measurements again. For all time monitor water to make sure there is no air bubbles because of heating. The higher the temperature the better, as long as there is no air bubbles (so if there are two heaters of same power but different surface area, heater with the most surface area is more likely to work better for this purpose). Keep in my mind that resin will be colder than water, so warm water is unlikely to noticeably improve result (assuming room temperature 25C).

I think you aren't giving those who ordered the kits enough credit. When ordering the kit we already need to supply our own reservoir and build tank. How hard is it to add a heater to the mix?

I think you are underestimating difficulty. Adding heater is not easy, and requires effort, spending time and money.

The only way I have determined to lower surface tension will be with an additive, which may adversely affect the bonding during curing of the resin.

You are right, modifying resin with additives may ruin it. And considering that manufacturer already worked a lot before releasing the resin to the market, finding a way to improve it would be difficult. This is why usually people experiment only with pigmentation.

That said, it is still my firm belief that raising the temp to lower the viscosity would be beneficial and at the least would result in an ability to print at faster speeds with better results.

It may give better results, but I do not see how it can increase printing speed.

[MemorianX]

This might make the whole build more complicated than it's worth but to avoid the bubbles around the heater to an effect on the resin you could construct a double walled containter where the outerwall has water with the heater and the inner tank is the build area.
You could even add some stirring or or similar effect in the heated water to improve heat transfer.

Another option to improve the heating and keeping the temperature steady to have the water reservoir heated aswell

[Deadbot1]

Bubbles??? How hot do you think we need to get? I would expect that we could stay reasonably below boiling temps. I am a Yank so I'm thinking in Fahrenheit, but I'll try to do metric conversions as well.

Boiling point of water at sea level...212 F /100 C
typical room temp.... 72 F / 22.2 C
expected heat of water for heating resin to comfortable 100 F.... 120 F / 48.9 C

There should be no bubbles. I don't think we need to get crazy hot. The resin I was thinking of when this thought struck me was Wahoo Int. ZeroVOC. They recommend heating to 100 F to thin the resin down. Most resins, even UV cure resins will go off if they are heated too far.

The way the Peachy is set up, I would heat the standby reservoir and have a well insulated build tank.

As far as how it could help to speed up prints, a thinner(lower viscosity fluid) can move into the next layer faster. Less time waiting for the resin to get into place before the next layer prints means faster overall print times.