As a knitter, I see lots of Bamboo yarns appearing on store shelves. Some of them looks attractive; to show you, I selected an ad from Amazon showing a yarn that could be used to knit a nice sweater, vest or possibly a cozy looking hat.
These bamboo yarns are frequently marketed as ecofriendly. I was always a bit skeptical of this claim.
After all, bamboo, like wood, makes splendid knitting needles; I suspected that, like wood, turning it into a spinnable fiber would involve quite a bit of chemical processing. Turns out it does. In fact, according to an article appearing in The Wall Street Journal
To create fabric, it’s chopped up and dissolved in toxic solvents—the same process that recycles wood scraps into viscose or rayon. Indeed, bamboo fabric technically is rayon.
So, making bamboo fiber not only involves just as much processing as making rayon from wood, bamboo yarn actually is rayon.
Now, I like many things about rayon. But no one markets rayon as eco-friendly. You can read a bit about the process to make rayon here.
The WSJ article says many interesting things. But, this paragraph highlights issues that always struck me as a bit odd I odd with respect to marketing of bamboo:
Bamboo’s story sounds clear and appealing: like hemp, the plant grows quickly without the irrigation, pesticides or fertilizer often used to grow cotton. It’s often sold as “biodegradable,” and the plant’s antimicrobial properties have been used to market athletic clothes made from the fiber. “People are switching from cotton to bamboo,” says Aarti Doshi, regional manager for bamboo-fabric distributor Doshi Group, based in Mumbai, India.
When I looked below the surface, though, I found that bamboo fabric is less “eco” and “sustainable” than it seems. The bamboo used in textiles has to be heavily manipulated to go from stem to store. To create fabric, it’s chopped up and dissolved in toxic solvents—the same process that recycles wood scraps into viscose or rayon. Indeed, bamboo fabric technically is rayon.
Ok. For the odd things:
- Why would people consider bamboo a substitute for cotton? I’m pretty sure rayon was originally marketed as a substitute for silk! Rayon was never a particularly good substitute for cotton. Cotton tends to be durable and crisp. Rayon is not durable and is limp. Rayon’s limpness actually makes it nice for fluttery scarves; lack of durability means undershirts and socks will wear out. On the other hand, both rayon and cotton are cool; both wrinkle. Both fibers have little elasticity– that’s why cotton socks often have elastic woven into the ribbing. So, they both share each others bad features!
- Even if bamboo-rayon was anti-microbial (which it’s not) do athletic fabrics really need to be anti-microbial? If you are worried about microbes, doesn’t it make more sense to change clothes and wash them?
- Rayon production from either bamboo or wood is heavily processed. No matter what any marketer claims, the fiber is not eco-friendly. Given the intensity of the processing, I’m sort of wondering about the carbon foot print of bamboo relative to cotton, wool, silk or any man made fibers.
Ok, the marketing has always puzzled me. In addition, as a knitter, I’ve also been a bit perplexed at some of the bamboo yarn offerings. For those of you who remember I suggested the yarn above would make a cozy looking hat: That’s right: Cozy looking. The yarn is bulky meaning the hat will be thick. But insulating property of rayon is relatively low. So, expect a bulky knit rayon hat to be about as warm as a bulky cotton hat. Still, I have a friend who is allergic to wool, never feels particularly cold, but would like something pretty to match her parka. I may end up knitting her a bamboo hat.
Now, returning to the ecological claims: It turns out the FTC is sufficiently upset by ecological and anti-microbial claims that they have sued companies for deceptive practices. I suspect I’ll be seeing fewer displayed by the knitting yarn in future.
On the other hand, I think the needles may be eco-friendly. If you are looking for a nice gift for a sock-knitter who is eco-aware, bamboo needles really are nice. As for yarn– well, I’m not going to have to investigate whether soy yarn is eco-friendly!
Lucia: My wife only knits with wool. I bet it has a huge carbon hoofprint. Do you not use wool?
Ah! Finally a post a chemist can sink his teeth into! 😉
You are right, the viscose process is a mess in terms of energy and chemical inputs. There is a fair quantity of water involved as well, so unless the process is well designed for recovery/re-use, the volume of waste water could be pretty high. The worst thing about rayon is that the viscose process requires the very high molecular weight cellulose molecules (millions of Daltons) be hydrolyzed to much lower MW pieces, or the viscosity of the viscose solution would be too high to work with. This means that the physical strength of the finished fiber must be poor compared to cotton. All pain, no gain… unless you need a fabric with that limp look.
Yes, yes. . . all well and good but more importantly — what do the cats think of it?
Jack–
Wool is my favorite fiber to knit. But, naturally, I always look at what’s on the shelves. I’ve always just been puzzled by bamboo!
SteveF– Limp can be good for women’s imitation silk scarves and some clothing designs. But it’s not a positive for many clothing applications. This is why “rayon” is not a plus when marketing clothing. Consumers are familiar with rayon. Calling it bamboo means consumers don’t say “Oh. It’s that limp not very warm fiber that doesn’t wear well.” Instead, the marketers make ecofriendly claims.
Tim–
Based on experience, cats like all yarn. However, they seem to like goat yarns best. When “The general” (my orange cat) was still alive, I ran tests and he always picked mohair over wool and wool over acrylic.
(These tests were not double blind.)
Lucia: Why not knit with hemp? If it doesn’t work out you can smoke it..
Jack, I haven’t knit hemp. But people do!
Lucia — this is an interesting report as I have some bamboo fibre (maybe I should now say “fibre”) socks given to me by a hemp store as a sample after I bought some shirts and they have not lasted as well as cotton nor are they as nice to wear so now I understand my disappointment so thanks.
Andrew– Yeah. Rayon socks… not a great idea. Rayon shirts can be nice. they also don’t wear as well as cotton. That’s why you often see “hawaii” type shirts in rayon. These don’t have cuffs or neckbands, so you don’t need to worry about abrasion resistance quite as much.
Lucia,
There is a lot more to this story than meets the eye…
Ok…bamboo is rayon. Did you know that it is commonly accepted among textile experts…that rayon is a biodegradable textile? Ya, you will also find proof of this little nugget, hidden in scientific journals.
Are you familiar with the FTC’s criteria for the decomposition of bamboo fiber? well, suffice it to say…if you applied their definition to a head of lettuce, that lettuce would not be biodegradable. Things that make you go…hhhmmm.
There is a lot more, but I will just defer you to a blog that has about a dozen posts dedicated to this issue. This post is a good place to start:
FTC Bamboozles Public About Bamboo Fabric
Thanks,
Doug
Ahhh, again a posting I can reasonably comment on 😉
I’ve seen a bamboo sweaters some 2-3 years ago in a shop. Naturally I was curious as to what knitwear can be produced from that exotic stuff, so I tried one on. I would say it is a next best thing to a horsehair shirt – if one has a pressing need to wear one.
I perceived it as unpleasant on my skin, quite heavy and despite that not very warm.
And when I finally looked at the price tag for this “eco-bio-sustainable whatever”, I tossed it back – at that time it should have been cashmere for such money.
Doug–
Thanks for the link– I didn’t know the anti-microbial claim might be true. (I still prefer to wash my workout clothes rather than rely on anti-microbial. But it wouldn’t be a bad trait in a t-shirt or underwear.)
EW–
I’m surprised bamboo-rayon sweater was scratchy.
Rayon isn’t ordinarily scratchy– but it isn’t warm. (Some people actually do want ‘not warm’ sweaters. If they are always hot, but still want to ‘look’ like they are dressed for winter. I’m always cold, so I prefer wool sweaters.)
I usually look at price tags before trying on! Same with knitting yarn.
I’m surprised bamboo-rayon sweater was scratchy.
I like thin sweaters and T-shirts from the usual mix rayon-lycra, even rayon summer clothes, but I’m not much into thick cotton sweaters. But that bamboo sweater was different from both and very heavy. Since that time I’ve seen cheaper ones (probably also with less tags about eco and sustainability) but still it does not appeal to me.
And I’m with you about that anti-bacterial effect – I prefer changing and washing too.
Yes…I have to been viewed as biased…since I am a purveyor of bamboo fabric products. That said, we did a ton of research, and tried out many different bamboo garments and bedding, prior to making the decision to go into the “bamboo” business. I must say that the hand of any bamboo fabric that I have ever felt, has always been extremely soft, to me.
It seems more likely to me that the sweater had another material mixed in? Or, was of the mechanical bamboo variety. However, the latter is very unlikely, as I have yet to come across a U.S. vendor that actually carries the mechanical bamboo…including the online stores that claim to have clothing made from the linen-like material.
We offer our site visitors a free(-the 44 cents shipping) sample of the bamboo fabric directly from our 100% bamboo sheets. This affords them the opportunity to try before they buy, so to speak.
In actuality though…most of our customers purchase our products because a friend did so, and then communicated to them how soft the fabric is.
Also, in case anyone is interested – Based on our surveys, the vast majority of our customers purchase our products for the aforementioned reason, as oppose to “green” motivations.
Thanks,
Doug
doug–
Yes– my impression is that rayon is generally a fairly soft smooth fabric, so I would think sheets would be a good application for bamboo.
Lucia,
As for eco-marketing, I’ve recently changed my mind about companies that try to advertise for the econ-conscious consumer. For a long time, I would just roll my eyes and make my buying decisions based on my own factors. In other words, I basically ignored it, but I wouldn’t punish a company for trying to market to that segment of the consumer.
Lately, the threat of legislation that can do very real damage to the economy and my children’s future has made me change my attitude. When a company brags that it is combatting global warming, I immediately write it off as a company I will do business with. If they are going to use messages which reinforce alarmist propaganda (even a little), I’m not going to give them any more of my money.
Curious how many other skeptics or lukewarmers feel the same way.
stan–
I mostly ignore environmental claims. There is a lot of spin in advertising, and the marketers will pick a claim that might sound good, but which can hide something else.