If it's PLA:
Get rid of the kaptone tape and use hairspray. I'be printed similar parts and curling/adhesion is no longer a problem!
Here's a post I put up in maker gear's forum, hope it helps:
I've been having success with hairspray (as others have mentioned in the forum). I haven't had any PLA parts warp (haven't tried ABS yet) and parts are held down really well. To remove parts I've been popping them off using a heavy kitchen knife, sliding the blade between the part and the glass, with a little momentum the part should pop off cleanly.
I've printed the same part in the same spot 4 times now (calibration) and there have been no adhesion problems.
I grabbed Loreal Elnett Satin from Walgreens. I basically looked for anything that was matte/satin and chose whatever said it had the strongest hold. Not the cheapest stuff but it's changed my perception on how easy printing can get with this approach.
- Remove the glass bed from the printer and ensure that it is clean
Lay it in a kitchen sink
Spray an even coat making sure to cover the entire bed
Wait about 30 sec for the coat to set
Repeat 2 more times for a total of 3 coats.
Let the bed dry and re-install it into he M2
When it's time to lay a fresh coat, take the glass off and clean under water, dry and re-apply.