Flexible 80A Sticky post UV Cure

Hello- we follow the postprocessing steps for 80A including UV Cure and the part is slightly stick. The function we are using the 80A part in requires a series of 30 second soaks in 70% ethanol as a requirement for the application for the overall assembly. Appreciate thoughts on reducing the sticky feel.

Hi Innovation,

70% ethanol does not have adequate solubility, we recommend 90%+. I’ve also found (from personal experience) that when printing Elastic 50A parts, rubbing the surface down with mineral oil or a light dusting of talc/baby powder helps, the same should apply with Flexible 80A. Hope this helps!

Henry

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Thanks Henry I appreciate the guidance. This 70% ethanol step is after we do the FormLabs defined wash in 95% IPA and Cure. The 80A flexible is being used in a part in a larger assembly.

Can you cure in a glass/jar of water? (water roughly same temp as cure temp) - this helps with Elastic 50A. Something to do with oxygen inhibiting cure apparently…

Stickiness is almost always due to dirty (less than 90%) Iso-OH. It is also helpful to let the excess resin drip back into the tank after your are done printing. I do this by resting the build platform at a 70-degree angle against the edge of the tank. That A0 removes a LOT of excess resin, and B) saves you some money on resin that will NOT end up in your wash solution.

I also run my parts through a simple sonicator in a 90+ % ISO-OH solution. (I know they say to only use flammable liquid approved sonicators but in 5 years i never, ever had an incident)