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One of the hardest problems in plastics recycling is determining
what type of plastic a product is made of. Humans and
computers can fairly easily pick out milk jugs (LDPE) and soda
bottles (PET). Maybe even shampoo bottles (HDPE - usually).
The trick is *everything else*. If you spend the
time to look for
the little recycling number (if it's even readable) your recycling
will be really difficult and slow. But if you don't look for the
little number, it's almost impossible to tell the chemical
composition of the plastic you're looking at.
The solution is to simply make all plastics of a given type the
same color. Everything. Every single plastic thing can be made a
specific color. This would dramatically simplify manual or
computerized picking during the recycling process.
Fashion designers might not love this, but it's our world we're
talking about. Any non-recyclable mix of plastics would be
required to be baby puke green.
I darn you to heck
https://i.imgur.com/9r8D5Gf.gif
[Voice, Sep 23 2020]
Plastic Separation
https://plasticsrec...orting_Resource.pdf
[bs0u0155, Sep 23 2020]
Various Developing Techs For Sorting.
https://www.chemist...nge/4011434.article
[bs0u0155, Sep 23 2020]
[link]
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Good idea. I looked into how our local authority does
recycling and it's way more complicated. They ask us
to put everything (glass, metal, plastic, cardboard,
paper) in one bag. Then at the sorting plant, they
use eddy currents and magnets to extract non-ferrous
and ferrous metals, and a combination of fans,
spinning drums and flotation tanks with different
salinities of water to sort out the rest - I'm amazed it
works. |
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// designers might not love this // |
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Overspray the base colour with a paint soluble only in hot water. |
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Overprint or apply label as required. |
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At the recycling hub, hot-wash all incoming plastic, then sort by colour. |
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PRINT THE BLOODY RECYCLE NUMBERS/TRIANGLE-LOGO LARGE ENOUGH THAT PEOPLE CAN READ THEM. AND 'GARBAGE' PRINTED ON STUFF THAT CAN'T BE RECYCLED. |
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Like large enough that a recycle-droid can just glance then toss into the appropriate bin. The logo should be taking up an entire side of the container/other. |
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//at the sorting plant, they use eddy currents and
magnets to extract non-ferrous and ferrous metals, and a
combination of fans, spinning drums and flotation tanks
with different salinities of water to sort out the rest - I'm
amazed it works.// |
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That's insane. Nothing but a monstrous industrial process
that can probably be scaled at will with brutish
efficiency. Probably needs about 4 blokes to run and pays
for itself in aluminium alone. Will no one think of the
modest capital investment for this kind of thing? Shirley
there must be an alternative? Well, my old home town
has just that. |
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Why have some relentless industrial efficiency when you
can mobilize a small army of otherwise idle
surgeons /surveyors /solicitors /sommeliers to
amateurishly
hand-sort the trash? You can avoid that slight capital cost
of some silly machine and then use a selection of guilt
and fines to make sure the people that are forced to pay
you are also forced to work for you. And you'll still make
a killing on the aluminium. |
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This idea had a bun until the last three words. |
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Meh, last three words be danged. This should have been a thing some time ago. |
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[bs0u0155] - Exactly! It's complicated, but also the logical
and efficient thing to do. They're also so proud of the
engineering of their recycling machinery that (BC - Before
Covid19) they were offering tours of the recycling centre. |
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And by color, you mean bar-code encoded in particular absorption and
emission spectra? [+] |
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It would be possible to embed simple UV-fluorescent barcodes into the item at the time it's created. Then it can be any visible colour, but under UV it can be quickly identified. |
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Ach, Mk. 1 humans ... notoriously fault-prone, spares not available ... time for an upgrade ... |
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> Barcodes and UV inks don’t offer that |
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[kdf], I'm not talking about physical bar-codes, but making fun of color
spectrum. So, imagine each bar as a spike in Fourier frequency spectrum.
By adding impurities to plastic, one could design unique arrangement of
spikes in the frequency spectrum. A "bar code" is also an arrangement of
"spikes" (vertical lines). Perhaps color-engineering could create equivlant
of a bar-code in the spectrum of color. |
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//[bs0u0155] - Exactly! It's complicated, but also the
logical and efficient thing to do.// |
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It's a surprisingly difficult concept to get across. The
general mindset seems to be "good people, like me,
recycle. You should do all you can to help, resistance to
this means you will be assigned as an Earth-hating
capitalist monster". |
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Maybe we should have recycling bins for other waste? One
for solid toilet waste, one for liquid. I'm sure it would
simplify things for the good people down at the sewage
plant. After that, I've got 25 minutes spare on thursday
that I'm happy to dedicate to national defense. I don't
know what I'm doing but I think I have a pointy stick
somewhere. |
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//one could design unique arrangement of spikes in the
frequency spectrum.// |
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Plastics (unless wrapped or black) are already pretty easy
to distinguish in the near infra-red <link>. |
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So rather than invest in educating people about
different grades of plastic and then consume people's
time laboriously sorting their recycling, the
investment should be in design of packaging
materials to make the automatic recycling sorting
machines at the recycling plant more efficient and
less likely to make errors. And composite materials
(e.g. a metal film, bonded to cardboard or plastic)
should be illegal. |
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That's Boeing and Airbus out of business for a start, then ... |
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... or find some technology that recycles
composite materials |
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Find a way to pry them out of the landscape first. Once the fire's out and the air crash investigators have taken the bits they want for evidence, there's not a lot left ... |
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Yep. A few tweaks to the some of the almost deliberately
tricky packaging designs and it's all solvable. |
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Conveniently about half of common plastics float, the other
half sink, in water so you can design a mechanism to
discriminate unknowns by shredding> settling tank. |
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That begs the question as to whether it's worthwhile making buoyant FDRs and CVRs, rather than going fishing for them in 1000m of water ... |
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//imagine each bar as a spike in Fourier frequency
spectrum//
While I'm not sure that is useful to the present concept, it IS
a brilliant idea in it's own right. The incident light would
have to be precisely defined (although I don't know much
about the UV->fluorescence process...). |
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//That begs the question as to whether it's worthwhile
making buoyant FDRs and CVRs, rather than going fishing
for them in 1000m of water ...// |
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Even if buoyant*, a CVR/FDR isn't going to be able to float
unless a precise minimum of damage occurs. Either
because it'll be physically attached or trapped. |
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//The incident light would have to be precisely defined
(although I don't know much about the UV->fluorescence
process...).// |
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We're very good at precisely defining light, and optics in
general as a species. Probably related to our particularly
nifty eyes. It's important to realize that fluorescence isn't
specific to UV. It's just handy that we can't see it, so you
can flood the place with UV and it's easy to pick out the
green thing on an otherwise dark background. But,
fluorescence occurs all over the optical spectrum, for
example, fluoroscein absorbs blue light (say 480nm) and
emits green (500-550nm ish). If you block blue light with
a long-pass filter that cuts light below 500nm, then you're
not blinded by the illumination light which can be an
order of magnitude or more brighter. There's really wuite
the selection, we have things that absorb and emit all
over the place, and the filters to discriminate are cheap. |
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*I'm going to start pronouncing that as "boo-ee-yant" until
the colonials realize they've been pronouncing "buoy" in a
frankly embarrassing way. |
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// unless a precise minimum of damage occurs. // |
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Not a problem, not a problem at all ... <Sniggering/> |
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// pronouncing "buoy" in a frankly embarrassing way. // |
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The spelling of "buoy" was created specifically to torment the welsh; since it contains two vowels and a semi-vowel ("y") and no double consonants, they are unable to pronounce it. It's rather like asking a German to pronounce "squirrel". |
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Love the idea but the title sounds like the name of a forlorn
blues song from the '60s. (Hi World, thanks for thinking of us,
signed; The World.) |
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"Ah woke up this mornin' ... an' all the milk bottles was blue ... " |
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The ugly thing is that recycling isn't all that we wish it was,
unfortunately. Most plastics used for commercial products
specify a minimum amount of virgin material to keep the
properties stable. |
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I really like [8th]'s overspray idea. Especially if you apply
the label over the water soluble spray, making removing
them for recycling easy. |
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Though I also like to imagine walking into a drug store and
seeing a whole aisle of orange shampoo bottles. Or some
overengineered product being a dozen different colors (each
easily separated back into their recyclable parts). |
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Of plastic ? That's the North Pacific Gyre, isn't it ? |
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