how do i get rid of passcodes completely?

Is there a way we can take the passcodes out of settings? We have a lot of ipads in the school library they are for the public/kids and sometimes they come back with passcodes, sometimes we will get the code and sometimes we don't so when we don't we have to reset the ipad and that is tedious having to do that then add the apps all over again.

Thank you it will help me alot if there's away.