ELI5: where I live in the UK, we're allowed to put glass in with our general recycling. How is it all sorted and separated? Is it done by hand or by a machine?

So all our plastic, paper, card, and glass is all in the same recycling bin. I have this image of underpaid folks sorting through chunks of broken glass and dirty unwashed food plastics in the recycling plant, but surely there's a better way to separate it all? Is it all just crunched up into small parts? How accurately can a person or machine separate paper, plastic, etc? What happens to the contaminated stuff? If food cartons etc aren't washed out at home do they just end up in a landfill or are they washed at the plant?Thanks in advance! This is my first reddit post and I'm incredibly sleep deprived, so apologies if I've done this wrong. via /r/explainlikeimfive http://ift.tt/2rcZVdW