acrylic sublimation

[Kaviraj]

Hello all,
I am trying to make some key chains with acrylic by sublimation.I am using cast acrylic, the print comes out well, printing at 365 def F for 60 secs. But if we scratch it, some of the inks comes off the acrylic. I an cutting my own blanks from sheets.
Is there a way to protect the print from coming off.

Thanks