Oh no, you didn’t account for leap days. I believe there’s been 30 since 1907, so you’ll need to add to your total, and maybe a few extra buffer days to make sure everyone knows why you’ve done this so that no one else invents completely artificial plastic either.
How many rounds around earth til un-inventing plastic?

1 turn = 1 day
Completely artificial plastic was invented in 1907 - 118 years ago.
1 year = 365 days
118 years x 365 days = 43,070 days
So 43,071 rounds should do it, and then just clonk Leo Baekeland over the head or something.
Oh no, you didn’t account for leap days. I believe there’s been 30 since 1907, so you’ll need to add to your total, and maybe a few extra buffer days to make sure everyone knows why you’ve done this so that no one else invents completely artificial plastic either.