Starting parameters on several resins

[Sebastien_Lani]

Dear all

My background applications: forming structures below 1mm (down to tens of micrometers) for micro engineering.

In addition of the solus printer, I have bought several resins to start with:
- Spot HT
- Spot E
- B9 cherry
- B9 r2 black
- MadeSolid Black Vorex Tough Resin (they said it works with DLP)

For the spot series, I bought them without pigment. I bought both black and blue pigment.

For the cherry, I will use the standard profile given with the solus.
For the spot HT, I have start using the standard profile (playing also a bit with the parameters), with black pigment for several compositions (mass percentage, 0.8%, 1.3%, 1.6%, 2.6%) it is already quite good (I measured lines of 50um +/1um which is excellent).

For the others resins, does anyone have experience on them?

I'm also looking some possible transparent resin for some medical applications.

Last question... does anyone know the resin from DSM somos?

If I found some of the answers myself, I will share them with you

Sebastien

[reify]

(I measured lines of 50um +/1um which is excellent)

Reading this makes me very, very happy.

I should be able to get the Spot E profile for you. There's a research group here that uses a Solus to print at similar resolutions and they discovered Spot E can be used to make molds for PDMS. All the other resins they tested inhibited the PDMS from curing (likely due to the forming of polymeric peroxides on the surface of the print).

[Archerm]

Very nice post up some profiles when you have them.

[Sebastien_Lani]

Small update to get your feedback

I did test with the spot HT with black pigment with 1.3% and now starting with 0.75%. I tried different z thickness (10 to 25um) and different exposure time

I used the testing structure below:

Below some printing results:

and with SEM microscope pictures

Regarding the dimension for these tests it is not too bad, I'm close to 10um resolution. One of my colleague had achieved previously better accuracy but he had not taken the parameters (resin+printing parameters).

The smallest structures size that I achieved was 80um with 0.75sec exposure time. I would like to reach lower structure size and I feel that the structures are over exposed. I did one with very low exposure (0.625sec) but there was cracks on the structure like not enough cured.

Do you have some idea to improve the printing resolution?

I will add some results later with the 0.75% pigment concentration.

[reify]

Hi,

Awesome stuff! Have you tried using a higher pigment ratio?

I'll try to see if I can get you a more specialized resin. From our tests, it offers an improved resolution.

[Sebastien_Lani]

I need to retry the higher pigment ratio with 5 or 10um thick layers.


For 0.75% pigment, I measured different thicknesses when changing the z layer thickness. By decreasing the z, the thickness of the printed component is increased and also is closed to the targeted value.

Is it due to the exposure dose regarding the z thickness?

I used 0.75 sec for 25um, 0.5 sec for 10um and also 0.5 for 5um

[Sebastien_Lani]

I'm currently testing the FTD black industrial blend...

First impression is that it is more hard to get high resolution. It is very sensitive to the exposure dose. The fabricated piece is much tough as planned which can be good to form mechanical components.
I'm using 25um thick z layers.

I was using a testing design made of lines (from 0.05 to 1mm width) and circles (from 0.25 to 2mm diameter).

Below an example of printing, there is always an extra layer polymerized making the structures larger and holes smaller (light bleeding I guess). This extra layer is also rounding all angles.

I know this is small features but I'm trying to get the small as possible.
As one as mention before to improve resolution, I tried to decrease brightness to minimum and increase contrast to maximum on both computer and projector but its looks worst.

Does someone as some idea to improve resolution?
I feel like it is a constant extra width polymerized layer so eventually I can reduce all the dimension as a back up plan.

The spot A was looking to be higher resolution but I would need a resin supporting 200°C.

Thanks.
Sebastien

[Sebastien_Lani]

I did some measurements in more than 10 printed batches of components with spot A HT with black pigment (0.75% and 1.5%).

I measured a shrinkage of 2-3% regarding the layout.

[Waever]

Hi
I want to try spot-ht
But i am curious with the result.
Do you have picture for the unpigment spot-ht print?

[Sebastien_Lani]

I made only few tests with spot-HT without pigment. On all tests I did the light was not blocked by polymerized resin so you are very limited in shape.

I have not tried to reduce to a very short exposure time.