Here's the machinery doing it.[1] It's just using RGB and IR cameras; they're not using lasers to vaporize samples and analyze the spectrum. That would be both overkill and a fire hazard.
Overview of modern waste handling.[2] Most of the separation is entirely mechanical, with screens, vibrators, rotating drums, and air blasts. But HDPE and PET plastics are separated using infrared sensing.
Here's the machinery doing it.[1] It's just using RGB and IR cameras; they're not using lasers to vaporize samples and analyze the spectrum. That would be both overkill and a fire hazard.
Overview of modern waste handling.[2] Most of the separation is entirely mechanical, with screens, vibrators, rotating drums, and air blasts. But HDPE and PET plastics are separated using infrared sensing.
[1] https://www.youtube.com/watch?v=51S3ET7M138
[2] https://www.youtube.com/watch?v=6rkHt34AztY