Bamboo: Spinning and dyeing with bamboo

Bamboo is one of the many newer fiber choices available to spinning aficionados everywhere.  Hailed as a “green fiber” it is technically a form of viscose and you can read more about that at the end of this article.  That aside, let’s get down to what we spinners want to know about bamboo:
Bamboo is silky, soft, lustrous, as gorgeous as silk and easy to dye.  It is readily available both as pure bamboo  top and in blends with wool—most notably merino and superwash merino.
Viscose from bamboo: purple is blended superwash merino, gold is pure bamboo and green is with merino
The picture nearby at left shows the items in the packets available at my workshop.  The violet is a blend of 60% merino, 30% superwash wool and 10% nylon.  The green is a 60% blend of merino and a 40% blend of bamboo. Both the green and the violet were immersion dyed using Pro-Chem kiton acid dyes that dyed only the wool.  The gold is pure bamboo and was dyed using Pro MX Reactive dyes using the room temperature method for cellulose fiber.  For more on this, read down to the section on dyeing.
Spinning the pure stuff
I started spinning plain white bamboo roving straight from one of my favorite suppliers of interesting things, the Coppermoose,  I found the fresh white stuff to be a bit slippery and daunting.  A picture of early efforts is shown.
Pure bamboo fresh from the bag.
 I recommend the “inchworm” method to start before getting fancy.  Allow yourself to become accustomed to the fiber and learn to get the feel of it.  Once you’ve done this, then feel free to explore using longer draws including the two handed double drafting technique I demonstrate in the picture below.
I found double drafting to be a good way to spin bamboo.
Double drafting is essentially a two handed approach to spinning where you draw back your fiber supply some distance with one hand letting a bit of twist in but pinch off the rest of the twist going in with your other hand and then “feed” twist in while you attenuate (pull to lengthen) the thread.  This produces a lovely almost elastic feel as you spin and is said to introduce air into the spinning to create a lighter yarn.  I cannot verify this claim, but since bamboo yarn likes to be smooth and dense, a little air is a boon. 
For my workshop, I provide a dye version of pure bamboo, in this case my golden glow colorway.  Interestingly, the dyed bamboo is easier to spin—possibly the stirring in my dyepot to distribute the color helped it behave a bit more, but in preparing for the workshop I found the dyed fiber a total delight to spin and I hope all of you do too!
Woolen mixtures and preparing the rovings
Bamboo rovings blended with wool are readily available to spinners and it was these I used in my workshops.  Besides the Coppermoose, I found others at ParadiseFibers.   Though I am not a fan of superwash wool, I did come across a blend of bamboo, superwash merino and nylon which I think is ideal for socks.

Ready, set

Before starting to spin any roving, including the pure bamboo, you need to gently snap it along its length something I show you in the two pictures above using my favorite purple roving.  Why snap? Roving has come a long way from the factory, dyepot, etc. and tends to become compacted.  The gentle snapping loosens the roving and gets it ready to spin.  I liken a properly snapped roving to a batt fresh off the drum carder.  
Baxter wanted to help.
 Many people like to predraft their rovings, however, I don’t recommend this.  I simply fold my fiber over and start to spin from the clump. 
You can fold over to spin from the clump or just start from one end and let the clump form itself, whichever works.  I personally find spinning from the clump superior to all the stripping and pre-drafting taught nowadays because I feel it gives me much more control over the spinning triangle—that magical place between  the twist and the fiber where your ultimate control of yarn thickness lies.  In this nearby photo, I am attempting to demonstrate spinning from the clump—Baxter, my dog decided to lend a paw.
Handspun dyed bamboo and superwash merino with completed sock.
When it came to spinning, I absolutely loved spinning my bamboo/superwash merino/nylon blend using the double drafting technique I described earlier.  I ended out with a really nice three ply fingering weight wool (defined by me as 14 wraps per inch) and I am using it knit the socks shown below.  Next to them is a demo skein of the yarn.  The sock shown used 1.7 ounces of the yarn and I have plenty left for a second sock.

This merino/bamboo blend also made nice socks.
The green yarn and roving shown is the regular merino and bamboo blend.  This is a lot fuzzier as it has the wooly characteristics of, well, wool since it is the real thing.  Superwash merino, as you may recall, has been heavily processed so it no longer does wooly things like felt.  Both of these preparations were very fun to spin, and I am planning to knit the green yarn into some nice hiking socks which I plan to test on the trail this summer and report back to everyone!
 Bamboo takes dye very well, and as claimed, uses relatively less dyestuff than the other cellulose fibers.  Please note that Bamboo is a cellulose fiber like cotton, ramie or linen and must be dyed with suitable dye materials.  I purchase my dyes from the Pro-Chem and Dye Company which not only carries a full line of dyeing supplies but also all the safety equipment, instructions, books and other materials you need for a safe and happy dye experience.
Dyeing bamboo roving was fun.  The pure stuff developed a lovely color using Pro MX Fiber reactive dyes and the instructions.  Even more fun were the bamboo and merino blends!
The wool was dyed green, the bamboo remained white.
I immersion dyed a pound or so of my 60% superwash merino, 30% bamboo and 10% nylon using the pro-chem  Kiton Acid Dyes in my favorite color violet.  This particular dye has the “annoying” habit of separating into its component fuschia and blue to a certain extent while dyeing.  I was not annoyed because I wanted the lovely variegation which you see in the roving. Also, the Kiton Acid Dyes only dye the protein fibers, leaving lustrous streaks of undyed bamboo to add even more interest.
The green merino/bamboo blend worked pretty much the same way using the Kiton Acid dye. Once again there was some separation of the color (sometimes gentle stirring of the dye pot can help minimize this, but don’t overdo it to prevent felting).  The separation is responsible for the golden yellow splotches among the green.  I’ve found yellow to often have a mind of its own in the dye pot.
Hybrid dyeing
What would happen if you dye first the wool in then the bamboo? Pictured here are the results.
Both the merino and the bamboo where dyed.
I did the wool first in Kiton Acid Dye color called Turkey Red.  After much rinsing, I redid the process using the Pro MX Reactive Dyes in a formula that would work on the bamboo only.  I added bright blue.
 Interestingly, the fiber subjected to both processes is not as soft as similar fiber subjected to only one, a drawback to this scheme.  I will need to ask a chemist why this might be so.  The protein process uses Citric Acid, whereas the cellulose uses Soda Ash.  At first I mistakenly thought Soda Ash was a base, but later looked it up to find out it is actually calcium carbonate, a water softener.  So who knows?  At the workshop, the consensus was this dual preparation wasn’t as soft.   In the future,  I think I’ll dye the fiber separately first and then put them through my drum carder to create a blend.

Is bamboo really green?

 Not being one to take any claims at face value, I wanted to investigate if the bamboo rovings now readily available to spinners can be classified as a green fiber. Technically, the fiber is viscose, made with the same industrial process that gave us Rayon, except that rather than wood pulp being processed into fiber, bamboo pulp is used. 
Growth rate 
The green part comes into play in growing bamboo—from what I’ve read, it grows like a weed. The variety (and there are many) used to make the fiber grows about three feet a year without needing fertilizer or insecticide. A field of this type of bamboo, grown generally in Southeast Asia, can be harvested every three to five years. Though this sounds sustainable, I suppose I’d have to consult a few agricultural journals to see if this is true. 

Industrial process
The greener among us might blanche at the industrial process. Viscose is a chemical process and uses sodium hydroxide, aka caustic soda, aka lye in the process. Since this is a fairly common chemical and can be used responsibly, lenient greenies could let that go. At least bamboo viscose is greener than say wood viscose based on the source of the pulp. I’ve recently seen yarn spun from sugar cane viscose.
Taking dye
One claim I was able to verify is the dye-ability of bamboo. I was able to dye my bamboo using a rich color with relatively less dyestuff than called for. Above is some in my golden glow colorway.
Odor free?
Some make bacteriostatic claims for bamboo, inferring it would be great for socks by keeping down bacteria derived odors. I will find out once I’ve worn a bamboo socks around on a hot summer day. It makes sense that if bamboo doesn’t need insecticide, it has evolved some pretty strong plant defenses, but doesn’t follow necessarily that these properties would survive processing or inhibit the bacteria that cause body odor. Also, one article referred to this as “bamboo kun” which doesn’t sound to me like the name of an anti-bacterial compound that’s been isolated from bamboo viscose.
Cool fiber
Bamboo garments have shown to remain a bit cooler on hot summer days than similar cotton garments. I'm interested in trying this out once I spin and knit up something in "golden glow."  It is believed to be a good performance fiber so I'd like to try out some bamboo blend socks on the hiking trail this summer.
However, it is a lovely silky lustrous fiber and is known to produce filmy cloth that feels cool and light.

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