Has anyone received a “bad” PEI sheet?

[EL Cuajinais]

I have a PEI sheet installed in my RMAX V2 at home and it works lovely. However I installed another sheet in the printer at my workplace, (same vendor), and the prints will just not stick. I mean they stick, but eventually become loose and fail. Gluestick on glass works good on this printer so I know the issue is not the printer. Today I sanded the whole PEI sheet with 1500 grit paper and washed it with water and alcohol several times and now it appears to be worse. Has anyone failed to print with PEI? I have a friend whom I referred to PEI and the prints were actually sticking too much for his liking. Is it possible I got a bad sheet of PEI that does not stick?

[KAS]

What bed temp?

[teoman]

Differences in pei could be the case but i think that it is a matter of temperature tuning.

Which depends on the thermistor which is not exactly accurat plus the thermal path.

Thermal path affects the actual temp on the surface. For example when i installed a heat spreader plate under the glass i had to bump up the temperature. So try increasing / tuning the temperature.

Enclosure or wind stoppers also help a lot.

[mhackney]

It could also be "cleanliness". I suspect they use mold releases when making these sheets. Try cleaning with isopropyl alcohol with a little elbow grease.

Roughing up with 600 grit sandpaper followed by cleaning with IPA will also take care of it but will give you a matte finish on the bottom of the part. That's what I do and the matte appearance is exactly what I want.