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Sometimes green sucks

As I have mentioned before, I have a 3D printer.

This printer has turned out to be enormously useful, allowing me to knock up bespoke plastic items that solve a multitude of problems around the house, the office and the workshop.

When I my truck needed new tail-light lenses recently due to the effects that three decades of UV exposure had on the originals, I was even going to print some from transparent red, orange and clear PETG. Fortunately I managed to find a set of originals at a reasonable price but I'd started experimenting and found that printing would have been a viable alternative.

Of course in the 21st century, sustainability and recycling are big things and a lot of manufacturers want to crow about the way they're saving the planet. The suppliers of 3D printing consumables are no different -- but it sucks.

Most 3D printers use a spool of plastic filament to create their magic.

All sorts of claims are made in respect to evirnomental friendliness, one of the most oft-touted ones being that the PLA filament is bio-degradable and compostable.

Yeah-nah.

Sure, PLA (polylactic acid) plastics will biodegrade and can be composted under the right conditions but these are not conditions you'll find anywhere but in purpose-built commercial facilities. Throw your PLA scraps into the home compost bin and they'll still be almost as good as new even years later.

Why is that? Are we being lied to?

Well PLA requires quite high sustained temperatures, in fact the process only really starts at about 70 degrees C. Apparently there are composting standards (who knew?) and PLA will biodegrade when exposed to composting conditions that meet the AS4736 standard but not the certified home composting AS5810 standard.

Personally I don't care about composting my waste plastic -- I don't presently have a composting bin so my PLA goes in the rubbish.

The thing that has really begun to annoy me however, is the move from plastic spools to cardboard ones.

A few years ago, all filaments came on plastic spools.

These spools were tough, cheap to make and could be re-used many times if one had a desire to do so.

Today however, almost all the "name" manufacturers are using cardboard spools and claiming that they're saving the planet as a result.

I'm sorry but I *hate* cardboard spools for a multitude of reasons.

Firstly, almost all filament types are hygroscopic to the extent that they absorb moisture from the air and that can significantly affect (adversely) their printing characteristics.

"Wet" PLA becomes brittle and can break before it even reaches the printer's extruding head while plastics such as PETG become horribly stringy and can even pop and sizzle as absorbed water converts to steam as it is heated for printing. Other plastics such as nylon become almost impossible to use at all if they have more than the slightest amount of water in them -- to the extent that they're often printed in a totally sealed system with the spool itself in a dehumidifying hot-box.

As a matter of course, I dry all my filaments before use to ensure best results and have a commercially made filament dryer for this purpose.

If I throw in a full reel of something like PETG filament on a plastic spool it'll be dry enough to use within an hour or so. Throw the same filament into the same dryer on a cardboard spool and it can take two, three or even four times as long to dry.

Why is that?

Well the cardboard spool itself acts like a sponge for humidity, sucking moisture out of the air and creating a reservoir of the stuff that then transfers to the filament over time and which takes a lot more effort to get rid of.

How are cardboard spools saving the planet if I have to use three or four times as much electricity to dry a spool of filament wound onto them?

Right now I hear keyboards rattling away as readers say "store your filament in a plastic bag with dessicant and you won't have to dry it before use".

Well that works okay for plastics (such as PLA) that have a lower propensity to suck moisture out of the air but PETG, nylon and a few others still need drying before use if you want best results because plastic bags themselves can also absorb moisture and actually provide a very poor vapor barrier between their contents and the outside atmosphere. In fact, when I asked Google Gemini, it suggested that I do not draw a vacuum on bags I use to store hygroscopic filaments because the vaccum itself will increase the rate of vapor transfer from outside the bag to inside.

Another reason why I dislike cardboard is that it's nowhere near as durable as plastic when used to make a spool. Plastic can fray and wear -- which also represents a possible issue with small particles contaiminating the filament and clogging the print-head.

Some modern 3D printers also don't like cardboard spools because they don't turn as freely as the old plastic ones when mounted in them. This can be mitigated by 3D printing some plastic rings to slip over the cardboard edges -- but ugh!

Also, cardboard spools aren't really much good for re-using in the way plastic spools are. They get creases and fray; sometimes even the glued seams start coming apart.

So... please, 3D printer filament makers, please take note that it's not your job to save the planet -- it's your job to provide the best product on the most practical spool.

Bloody tree-huggers!

Carpe Diem folks!

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