100% recycled nylon powder

Since there is no unified category for FUSE printers, I write the question here in troubleshotting.

Has anyone tried printing from 100% used powder?

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Welcome to the forums Kostbone.

I have tried and failed several times experimenting with this.

Even the sift gives you a warning if you go below 50% refreshrate, so that should be a major red flag not to go below 50%.

That they market the nylon at 30-50% refreshrate is a complete lie as it will never work,
Nylon 12 nor Nylon 12GF can do that.

What i think alot of ppl is missing is that lets say you have a printer going with 100% new powder,

When that remaining powder goes into the sift, it is concidered recycled powder. You mix at 50% refreshrate and pour that into the hopper of the printer and 50% of that material is now concidered used and thus the quality has started declining. Cause as soon as the fresh powder has been heated up, it looses it integrity and becomes harder for the printer to sinter.

What this means is that after 5-10 prints with a refreshrate of 50% you can basically empty the sift cause the material is basically dead and not going to print good.

Have you sometimes noticed that the cake is stiffer to break apart when extracting the parts?

Well, my belief is that this occurs when the powder goes bad. As i have noticed this behaviour several times when the powders lifespan is coming to an end. Only way is to discard that powder and fill up with new powder, and pretend like it is raining when the cost of material is skyhigh at approx 110 dollar for a kg.

If someone else has opinions/thoughts on this matter, Feel free to jump in the discussion.

Edit: We have both Fuse 1 and Fuse1+ and especially the Fuse1+ the powder has a shorter lifespan than in the Fuse1. I have read some speculations that this is caused by heat leaking into the hopper on the Fuse1+. Not confirmed by Formlabs tho.

Then I will also join the discussion:
We use the normal PA12 and always print with a refresh rate of 30%. We have experimented with somewhat higher rates, 35% and 40%. However, these have not really produced different results than 30%.
Currently, our sift is set at 33% to somewhat compensate for the used powder portion when brushing the parts off a bit more thoroughly.
We actually push as much powder as possible from the printed build chamber into the sift. Among them is also a accordingly large amount of used powder. Therefore, we have set the specified minimum 30% to 33%.
At this refresh rate, the components are no longer as Tough as at higher refresh rates. Thin components are more brittle and can be broken through more quickly. In most cases, however, we can compensate for this by orienting the parts accordingly in the build space, by building up moving parts such as spring clips or clips along the Z-direction.
Our very first print on the Fuse1+ with PA12 had a 100% rate, of course. Here the parts were extremely resistant. The first test objects had a wall thickness of about 2mm and could hardly be broken with bare hands. Therefore, we want to experiment again with 50% and 55% in the future.

We occasionally have components that we have to dispose of because they have thermally distorted areas. Here, however, I am still undecided whether this is due to the refresh rate. We are currently trying to rule out other causes, such as the build chamber and humidity.

I would not have tried to print with 100% used powder myself, as this is not recommended by Formlabs and other manufacturers without reason. Nevertheless, it is interesting to hear that it has been tried. Many thanks at this point for the report.
The warning for below 50% refresh rate must be due to the PA12GF, as we do not get such a message here with PA12.
Unfortunately, the reports with PA12GF are still very mixed, which is why we will stay with PA12 for now.
Whether the material properties at 30% refresh rate are sufficient for the user, I think everyone must try out for themselves. However, I would call it printable in any case.

Unfortunately, it is very complex and difficult to achieve a higher fill rate. In order to be able to use 100% of the purchased nylon powder, it is necessary to fill the chamber with at least 30% of the parts, unfortunately, in reality I only manage to fill about 15%. If the parts are in good shape, I can sometimes get to 25%. But that’s the maximum. Once a year I managed even 31%. However, filling the chamber to, for example, 50% is nonsense. I tried it once - not actually printing, but just filling the chamber in the computer, and in order to reach 50%, the parts were in the shape of a cuboid, lying down and of a suitable size that they just fit in the chamber. However, in reality this is never achieved and so I have 85% unused powder that accumulates.

It is a great pity that it is not possible to use 100% of the used nylon powder, for example, on your own parts or test parts. I wouldn’t mind if the strength of the parts was lower, or if the part suffered in terms of surface quality. If I needed to print a part for myself and not for a customer, I wouldn’t mind worse features. When I tried to print 100% used nylon PA12, everything went well, the only problem was that the powder was more difficult to spread. He’s basically stuck. I’ve tried burying it while printing, unfortunately it has to be done every ten minutes or so, and since the prints last all day, it’s nonsense. If I didn’t, I only managed to print for about 2 hours straight.

So I am looking for an alternative to dispose of the used powder. It is also a great pity that the automatic packing is not ideal. It can’t compare to manually comparing parts in the chamber.

Hi everyone.
I’ve only received our Fuse 1 a few days ago and the first print was quite perfect.
but the second and third weren’t. we started to see some structural shift, bad surface finishes.
Not sure if it’s because of my model placement orientation.

On top of that. the first sift machine we received were faulty and leakes powder from the bottom and got replaced.
Some of the powder might be contaminated because a member accidently mix the powder on the floor back into the sift into the used powder.

Our environment is extremely humid and we are not sure how to solve it yet. We are extremely worried it will impact the quality (as it seems our second & third print have clear defects. )

We indeed are discussing with reseller here how to solve it. either we should store used powder and fresh powder in a low humidity box or he suggested for one add some IR lamp in the hopper to help keep it dry.
But as it seems from Andreasemilsson it is better not advised.

i mean my colleagues had a fuse 1 too.
And keeping the powder dry seems to be a big deal. we both agree the assembly tolerances/finishes and the anti-humidity design (if any) are quite poor on both fuse 1 and sift. makes me wonder if it’s really a USD$60000-worth machine (here for us)