I’m making a torsional spring using Silicone 40A and we’ve found that the stiffness when we don’t post-cure is ideal. Is there guidance on how the material properties change over time without post-curing?
They say the silicone isn’t safe to touch until its fully post cured, but I’d love to know if even a brief 5 minutes are enough to make it safe, or if it’s just that it hasn’t been tested without post curing.
Hi thanks for your response, where did you see that information?
It would probably be better to redesign to a thinner cross-section. Uncured parts aren’t skin safe, will likely leave residue, and you will also increase the durometer slowly as the part does cure from natural UV exposure.
How about if I post cured it for lets say 20 minutes instead of the recommended 45?
Post-curing for any amount of time will begin increasing the durometer of the material and you wont get the properties you want.
Hi @tj0805, to confirm the workflow from our side, we don’t recommend skipping the post-curing process, as skin-safety can only be ensured with post-curing.
Thanks Sophia, will definitely make sure I stick to post-curing. Is there any guidance on how different post-curing times affects skin safety and material properties? For instance if I post-cure for 10 minutes, will this be enough to ensure skin safety?
Skin-safety was only validated by us with the full post-curing time, so that’s the only condition in which we have data for skin safety testing.