Problem with print on some materials(weak stickiness)

Hi all
I have UV printer with Epson L805 from China.

I have problem with print on stainless or (some types)plastic material.
I have 4 types of plastic 3 types of cases and one cover from CD(on test)
1.: I have problem with 2 types of cases on mobile



Image which I print is easy to sratch or When I bend a cover Image start unstick.
2: I have problem with stainless print.
First I tried print without coating fluid and image is possible to scratch off.
When I try spray surface of stainless with coating fluid, image is possible to scratch off easier then first.

When I print on cover of CD, printing is not possible to scratch, but material is plastic too.
Covers difference is in flex.


Have You some solutions,tips or advices about(choosing material, printing practise,...)?

I wrote to seller, but his advice does not work.

Thank You

 

Hi,
I think a have pretty the same Printer but there is always an error. I cant even print Sometimes ist a paper load, paper jam oder just error and all three lights are blinking.
Maybe you have an idea because i am pretty disappointed and helpless
Thanks for your help