Wednesday, August 19, 2009


I've been mentally debating about doing this post for a long time... last time I did an honest environmental post about ten percent of my readers left. But, darn it, I'm a treehugger and I can't shut up about it. (FYI, much of this is cribbed from "The Intentional Spinner" by Judith MacKenzie McCuin. Only honest discussion of synthetics I've ever seen in a fiberhead book. I hit Wikipedia for chemical info; *quotes are from there.)

Below, find discussion on how a lot of synthetic fibers are made. Decide for yourself if you consider them eco-friendly 'green' knitting, or not.

TRUE SYNTHETICS (nylon, acrylic, polyester):

All made from petrochemicals. If not oil, than coal, tar, or natural gas. To my knowledge, it does not rot under normal conditions. Researchers appear to have found a way to make it break down, using a fungus. Polyester appears to be made out of the same plastic (PET, polyethylene terephthalate) that uses antimony (a heavy metal, similar to arsenic) in its processing; the web sites are rather vague.

REGENERATED CELLULOSE (rayon, viscose, bamboo, Lyocell, Tencel, SeaCell):

These are produced two ways: The Viscose Process (nearly everything), and the Lyocell Process (Lyocell, Tencel, and SeaCell).

VISCOSE PROCESS: this accounts for all the bamboo, rayon, modal, 'art silk', and viscose used in knitting yarns, that I know of.

This one's kind of interesting. You get some cellulose fiber (trees, bamboo, leaves, anything plant-like, really), and you 'digest' it. That means dissolving it in lye. (No one talks too much about what they do with the lye, later.) Then it's dried, re-crumbled, 'aged' by exposing it to oxygen, re-dissolved in carbon disulphide (a chemical that's an emission of volcanic eruption, and may be " because it affects the nervous system. Significant safety data come from the viscose rayon industry..."*) left to 'ripen', filtered and degassed, then extruded through something that looks like a fancy shower head, to form the fibers. The newly extruded fibers go into a bath of sulfuric acid to harden (no one talks too much about what they do with the acid, later), then further processed by stretching and washing and sometimes cutting.

There may be some more chemicals in there, but after the lye and carbon disulphide it gets kind of blurry.

LYOCELL PROCESS: this produces Lyocell (duh), Tencel, SeaCell, and probably some other fibers I don't know about.

Supposedly, this process is just like the Viscose Process, but they substitute another chemical for the lye (N-methylmorpholine-N-oxide, if you MUST know), and the hardening bath is water and alcohol rather than sulfuric acid. They claim to use low-emission mills that recycle chemicals and even water, and won an award for environmental consciousness in the EU. They try to use farmed trees for the process. Apparently, due to the different manufacturing process, the fiber is harder to dye and needs more chemical additives to avoid pilling. No word on what those chemical additives are.

REGENERATED PROTEIN (corn/Inego, milk/Casein, soy, and even peanut/Ardil) dunno if this is the proper term for them - probably not - but that's how I think of them:

SOY: It was developed in 1937, so anybody thinking it's a new idea can scuttle that notion. It has been redeveloped in China, since, using more chemicals (dunno what, but I'm suspicious) to make the soy more workable. Sulfuric and hydrochloric acids are used.

CASEIN: It takes a hundred pounds of milk to produce three pounds of casein fiber. This strikes me as wasteful but that's another issue for another day. Otherwise, the process is a mystery. Having read the soy process, I'm suspicious.

CORN: Also probably wasteful (grinding up unused wood scrap to make fiber makes more sense than grinding up perfectly good food/ethanol/animal fodder). "For Super-Hero Zein, see AK Comics."* Teeheehee.

CHITIN: This is the cool stuff made out of shrimp and lobster shells and like that. It's put in sock yarn for anti-fungal and anti-stink properties, and used to be used to make bandages (and may be used again).

It was developed in the 1800s, can you believe it? Sounds so clever and space-aged when really it was cooked up at the beginning of industrial chemistry. Chitin isn't protein OR cellulose so it really does get its own category. How it's made is something of a mystery (no one will tell), but it's a polymer that's somehow close to cellulose - they say - so I'm betting the process is pretty cool (and maybe polluting; don't know).

There you go. Make up your own minds.


debsnm said...

Finally, some one making sense! Should have known it'd be you.

verify word: be a sight LOL

Sarah said...

I suppose things like bamboo yarn are labeled "eco-friendly" because it takes more land/resources to raise one pound of wool vs. one pound of bamboo, but really I'd have to look at the whole process from an industrial engineering standpoint to say which type of yarn is more "eco-friendly".

Now, "organic" is something completely different. I think that just means it was farmed without using certain presticides, or if we're talking wool or other animal fibers, that the animal was fed organic feed. At least that's what my biologist-who-studied-the-ethics-of-food-production tells me...

Emily said...

Why would your readers quit over information like this? I'm stumped.

Re tree-hugging, etc, and the strife between jobs & planet health: what nobody ever seems to mention is that there are simply too many people living on the planet. In my humble opinion.

Shoveling Ferret said...

Nothing wrong with explaining the details behind types of fibers and garment tags. It's not like you're calling for everyone who uses certain things to all be hunted down and turned into eco-friendly yarn or something. :P
Soylent yarn is made from PEOPLE!!!!

Terby said...

Lye isn't a big deal. That can pretty easily be neutralized (NaOH + HCl = NaCl(salt) + H2O (water)). The carbon disulphide is more of a waste concern. It does sound like it could be recycled, but I'm guessing it goes to hazardous waste incineration.

Hydrochloric acid is a nuisance to work with, but it's easy to deal with as waste. Sulfuric acid is also relatively easy to deal with - it can be neutralized with sodium hydroxide (your lye from above) and dumped into the water.

Yeah, I know - it sounds bad hearing what goes into the water. What's much worse is what we DON'T put into the water, and instead incinerate or bury.

walterknitty said...

Organic and natural are two new buzz words. They dont necessarily mean anything, they just make people feel good (imho) Just because a fiber is made out of a "natural" substance (ie, corn, milk, soy, bamboo) doesnt mean it's environmentally friendly. With all the extra processing that goes into making yarn from these plants/animal protein it's hard to see how they are "green". Someone at SS09 had a booth selling yarn made from corn and from milk. The feel of it was not for me. I had no idea it took that much casein to make yarn. Makes sense though considering it's a protein in milk and it would take a lot of milk to boil down enough protein to make yarn. It's also made through an "extruding through a shower head" process.

Donna Lee said...

I have a problem with turning food products into yarn. I'd rather turn them into people by feeding some of those starving people in refugee camps. The chitin? That's ok, it's a waste product but milk and corn? Something wrong with that.

Leonie said...

Interesting to note some of the chemicals being used, as Terby said, the acids and lye are easily rendered safe, and disposal of the neutralised acids is no worse than what people put down their household sinks (cleaning agents, not saying they should, they just do), I'm more concerned with the safety of the manufacturing process in situ rather than the disposal in these cases. These strong acids and bases need careful handling or damage will indeed occur to the users.

A whole process eco-friendly assessment would indeed be useful and should be carried out by the appropriate people especially if they are going to claim their yarn is eco-friendly. Educated people make smart choices, you can't make educated decisions if you don't have the information available to you.

Nalamienea said...

Information is always good, no matter how you regard it. That being said, I always struggle with the process of learning more because to me it always leads to realizing that I know even less than I thought I did. lol Does that make sense?

I'm glad I know these things, so thank you for bringing them up and for at least beginning this conversation. It's important that we are talking about important issues.

Alwen said...

Yeah, the "green" and "eco-friendly" labels have no regulations whatsoever about what they are put on. They seem to be a "now you feel good about buying what you wanted to buy anyway" label.

If I dig hard enough, I can find guilt in pretty darn near everything I like!

Galad said...

Your posts are always interesting and make me look at things from a new perspective.

Thanks for the info - gives all something to think about in choosing yarns.

Bells said...

this is all good stuff. I ain't leaving!

Anonymous said...

I'm not going anywhere either!

It's all very interesting and educational. Thanks for an enlightening post!

Louiz said...

Interesting. I'd love to know about the additives in Himself's latest set of socks (speaking of chitin additives making it anti bactierial etc) - silver...

knitabulous said...

Right, that's it I'm off to delete you from bloglines.

I liked the post though.

knitabulous said...

OK I'm back. Lobster shell product sold in Australia under the label Chitosan (like chitin) stops the stomach from digesting fat. Fat slips through without entering the bloodstream. Slips through other places too they say, but still - chitin. Interesting those lobsters, aren't they? And delicious.

Roxie said...

And cotton depletes the soil, and linen uses caustic chemicals as do commercial wool producers. Oh, and reeled silk kills the caterpillar. Lessee, what does that leave us with?

Unraveling and re-knitting the same sweaters over and over is probably the most eco-friendly way to go.

Still, I appreciate the information. It's as important to know the cost of the things we buy as it is to know the price. You haven't lost me, kiddo. I'm addicted.

bobbins said...

This is a fascinating subject for me, so I would love to see you continue to write articles like these. I enjoy the way you make the subjects easy to understand.

In your research, did you find the recent article in the Fashion Incubator regarding the FTC labeling change for bamboo? I found the comparison of the claims about bamboo fabric/fiber vs reality answered some of the questions I had about the process.

Barbara said...

You're not getting rid of me that easily! I learn so much from you and you're so reasonable about things.

After a momentary spell of thinking wool was better than acrylic, I have come to feel that no yarn is better than any other. They all come from some "earthly" source and making/growing them all makes pollution.

Thanks for the info.

Amy Lane said...

All good information... and it comes down to the same thing: all human processes produce waste and use resources. The trick is to find a balance.

Maia said...

Hurrah! I love folks that look further than the surface claim! We need more discussion on what does green mean, organic vs. sustainable, and how we play a part in it all.

BTW, a bit of the bamboo fiber out there is bast (not that I can source it). Of course, you still have to wonder what process they used to get at those fibers.

Anonymous said...

V. interesting. I don't know if it leads me to any conclusions other than to avoid the petrochemical ones. But helpful, all the same. *ponders*