How to judge that it can be scanned without spraying (TiO₂)?

[[Pe...]]

With Atos Q, how to judge that it can be scanned without spraying (TiO₂)? Is there a guideline for reference?

[[Je...]]

Hello Peter,

I recommend to do a testscan with high quality and proper illumination. If there are no holes or noise in scan data, spraying is not needed. After doing this with a couple pf parts you will get a feeling for that recision very soon.

Most surfaces will work great, just translucent or shiny surfaces will be problematic, as every material is different there is no guideline,

the surface just has to be cooperative.

Best regards,

Jens Braun

[[Ji...]]

Our experience is that the data is ALWAYS better if the parts are dusted with a spray, regardless of the material.   We have had very good results for 12 years with our own formulation of very inexpensive materials.  Contact me if you would like more information.

[[Mi...]]

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 How I can contact you?

[[Vo...]]

Hello Jim, can you give further information please?

[[Sl...]]

Hi Jim,

I work on small parts and any extra layer added on to the surface will create a false results in the study. I use AE SUB spray (white) and on the label says that layer thickness is 0.007mm... I have done the study and randomly sprayed some parts, the results were between 0.020 - 0.050 mm layer thickness and my tolerances are sometimes smaller than this.

Please advice on what kind of spray do you use as we produce plastic parts and most of them are natural so they are translucent.

Regards.

[[Vo...]]

I can also confirm that coating thicknesses of 0.020 - 0.050 can be expected with AESUB from the can. For an initial overview, this is certainly ok for larger parts, but for small parts with high accuracy, of course, this does not work.

So, of course, we would all be interested in Jim's information.

Maybe someone else reading along here has a good tip.

[[Ji...]]

My email address is james.r.anderson@mahle.com

[[No...]]

We also scan plastic parts and from my experience using spray cans doesn't give acceptable results at all. You need at least a fine airbrush and a suitable spraying liquid. We still use TiO2 suspended in alcohol with very good results. Depending on the surface  finish I also often use a good (!) make-up brush and dust the parts with dry TiO2 while also using the brush to remove excess powder. Our parts have a ground or spark eroded finish most of the time, so with the brush there is enough surface structure for the TiO2 to settle in, resulting in an effective build-up of "next to nothing".

We did a lot of tests with common injection mold materials when GOM was new to us and we found that almost none of the materials we use gives good results without spraying. We spray 99.9% of our parts.

Edited June 14, 2023