How to Identify Unmarked Plastic

This video has been a LONG time coming, but we finally got round to showing you guys a load of different ways in which you can work out what a piece of plastic even if it doesn't have a marking on. Unfortunately, it seems as though plastic manufacturing companies are still getting away with not marking their plastic, which makes it very difficult to work out what it is and whether or not you can recycle it.

In the video we cover the different between elastomers, thermosetting plastics and thermoplastics. We also show you what the Resin ID codes (recycling symbols) look like on plastic when they are there. Our favourite way to separate plastic is using float separation. You can use a number of commonly-available liquids (water, oil, sat water, alcohol etc) and see if plastic sinks or floats. Depending on what they do will give you an idea of the density of the plastic and therefore, what type it is.

If you are identifying and separating lots of plastic regularly, then the PlasTell by Matoha might be the perfect solution for you. This can tell you what plastic is using infrared light.

To find out more about plastic, the Precious Plastic website is a great place to start. They have lots of downloadable information within their starter kits that can help with plastic identification.

#BrothersMake #HDPE #PlasticRecycling #HDPERecycling #RecycledPlastic #RecycledPlasticBottles #PreciousPlastic #PlasTell #Matoha

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Music by Epidemic Sound

[orange-micro-fiber]

Pet is used a bunch in 3d printing. Cnc kitchen did a video on turning pet bottles into filament which can then be extruded. It's neat!

[TheStigma]

Tips for float test:
a very tiny amount of dish detergent (less than a drop, assuming your plastic is relatively clean already) will help break the surface tension of the water in the float test and create less false identifications when dealing with plastic that are very close to the water density.

If you get real geeky, you can actually separate out by density much more specifically then this by using other mixtures than pure water. If you add some common table salt for example, the water will start to weigh more. If you accurately measure the water density then you can determine exactly the density of the material, which can often uniquely identify what it is, or at least narrow down the options to just a few. (I see this is sort of covered later in the video)

Another useful thing to know is that all plastics that float in this test can not be easily painted (or glued). They either need a special plastic primer (which honestly is not guaranteed to work well either), or ideally they should be flame-treated on the surface. You can look up how to do that in another video.
Not all the plastics that sink are guaranteed to accept paint well, but most of the common ones are workable, at least with a light scuff sanding and/or primer.

[ericeinsmann]

Very informative! While I think the Plas-tell device is cost prohibitive for most people, the various water/oil/alcohol tests are much more useful! I have a garage full of kitty litter containers where the container itself is clearly hdpe, but the nice red lid is not labeled. If I test one and it too is hdpe, great! The next step is for me to build my plastic shredder (and for it to actually work😮)

[Sobou]

Excellent video! This is the kind of informative, easy-to-understand, instructional video I've been looking for that seems to be completely missing from the internet. The float/sink liquid tests are bloody brilliant! Thank you Brothers! Now I need some chips...

[Kargoneth]

Informative. Very useful. The alcohol and water mixture was interesting because you were reducing the density of the mixture. A hydrometer would allow you to determine the density of the liquid.

[meiloslyther]

Oh my god, thank you! I've been collecting milk jugs at home, but the caps aren't marked. Just by the feel I'm pretty sure they're HDPE, but now I can make sure. They're red, so they'll certainly add some interest to whatever I decide to make out of the boring white/translucent jugs.

[Mark_Agamotto_Smith]

For those plastics that can't be recycled, or safely recycled, there is always upcycling. Like, using a jug to make a scoop or holster.
Oops, I put can when I meant can't. Sorry. Edited to correct.

[aleksandrakim]

Hey! Good to see you doing this with such enthusiasm, it's riveting and contagious! Also, haven't seen a project of yours made of plastic other than hdpe (or am I missing something)? All the best to you two!

[EidolonandOnly]

The "thoroughness poke" is crucial.

[DevinJuularValentine]

Please could you go through your washing process? Some new coke lids have the most obnoxious white print on them and it takes me ages to remove it! Plus it seems no matter how much I wash white plastic lids, I always miss something and get caramelized whatever embedded into my sheets

[s.s.]

Really appreciate the content you guys make! I'm going to start up my own upcycling channel where I'll work with recycling plastic bags at home (among other things) and once I do I'm def linking a bunch of your guys's vids for further watching!

[KinneKitsune]

Wow, so all and only the plastics safe to home recycle float!

[ГеннадийБублик]

Your lessons provide a lot of useful information. Thank you. Tell me, is it possible to mix numbers 2, 4 and 5 with each other?

[leandrogaldeano]

I really liked this video! It almost felt like your first videos when you were more shy in front of the camera. This informative format is great. Well done bros!

[IvanWizard-Karl]

fantastic video lads, super helpful info

[beccalee]

Really nice work, you two put so much effort into the things you do. 👏
Just a question. When you did the water test, some of the plastics were sinking, is it the same in the oceans, or are more plastic types floating because the seawater has a higher density? 🤔

[tenchi]

Did you forget the link to the Plastell?

[rayanelsolh]

How do you deal with recycling plastics like HDPE, when the companies do not publish the additives (could be toxic) and dyes used when creating them? Thanks :D Great videos!

[volkhen]

To remove problem with water surface tension you should add a bit of detergent to water which will decrease surface tension. Some of them are really potent and there are one which do not create bubbles.

[danielworley]

So I'm trying to figure out what type of plastic kids toys are made of. I see them in dumpsters a lot and can get my hands on quite a bit to recycle if I can. Problem is they rarely have resin codes, and I've heard they're pvc and that would make it difficult to recycle.