Hi everyone,
In a quest to find the best sorting methods I made multiple post on different ways of separating plastics.
In this post I will explain separation by spectrometry.
A more industrial way of sorting plastic is with infrared spectrometry. This works by shining infrared light at a sample and observing the reflection of the infrared light. The way the sample breaks the light gives a distinctive reflection. Machines that can do this are very expensive and cheaper ones (Public Lab made one) don’t have the required range.
+ precise
– expensive
Hi @Sadbeaver
Thanks so much for your input, it was just a quick research that i did, in the comming weeks im going to look into this! sound really interesting!!
Hey there. I was wondering: if a spectrometer could be built that does this effectively, what would be the ideal price range of such a tool to make it viable? Of course, cheaper is always good, but it would be good to know a ballpark for the price range.
Also, from what I take in your post, you are looking at ATR spectroscopy, which is not ideal for applications with hydrocarbons since it usually results in poor sensitivity. Add to the problem the issue of painted plastics or plastics with protecting layers of other stuff, and you have a real mess in the IR region. I would instead look at either Raman spectroscopy or Transmission spectroscopy for this kind of application. There are a bunch of YouTubers that made DIY Raman spectrometers using DSLR cameras, grating lenses and lasers. FTIR transmission could also be done using similar systems.
