Guest Author - Llyn Payne
One of the newer fibers available to hand spinners is bamboo. Billed as an eco- friendly renewable fiber, bamboo is found in many fiber blends available for spinners and clothing labels tout the fact that various items are made of bamboo fiber blends as more and more people “go green”. Bamboo fibers are lustrous, add softness and drape to blends and help keep prices low when compared to silk. So what’s not to love? Well, not all bamboo fibers are created equal and while some are eco-friendly, others are not.
A grass, bamboo is a renewable resource. It is fast growing, matures quickly, and is ready for harvest in four years. It does not need replanting as the network of roots it develops will sprout up again after harvesting. It needs no fertilizers and no pesticides. Sustainable agriculture, and eco-friendly. Sounds good but when it comes to producing fibers from bamboo things change.
First, there are two ways to obtain fibers from bamboo. One way is environmentally friendly while the other is not. Let’s briefly consider the two methods:
The first method is quite similar to the way in which flax is processed. The bamboo is crushed mechanically and is then soaked in an enzyme bath to break down the walls of the plant so that the fibers can be removed. The fibers, which are quite short compared to flax fibers, are then combed for spinning. Bamboo fibers are only as long as the stem segments between the nodes in the stem of the plant. Which means that only longer stem segments can be used for this method of extraction. Fabrics made from fibers extracted by this method are called “bamboo linen”. This is the eco-friendly method of obtaining bamboo fibers for spinning. Unfortunately, very few fibers are extracted this way as the process is labor intensive.
The second method of extraction is the chemical method. Most of the bamboo fibers available today are extracted by this method. Basically, the process used is the same one used to make rayon. The leaves and shoots of the plants are put into a chemical bath which reduces them to a viscous substance which is then forced through spinnerets (which resemble shower heads) to shape the liquid into fibers. These new fibers are then hardened by being treated with still more chemicals. Fast and easy - but not eco-friendly.
Those are, very basically, the two methods of extracting bamboo fibers from the plants. Carbon bamboo (called Black Diamond or Black Gold) is made somewhat differently and there are two processes for making this fiber. In the first process, the bamboo fibers are extruded and then baked at high temperatures to carbonize them. The high heat creates an exact carbon copy of the fiber. The second method involves burning the bamboo at a high temperature and under very exacting and controlled conditions, reducing the bamboo to charcoal. The charcoal is then reduced to nano-particles and the charcoal particles are then embedded into another fiber such as soy silk or cotton.
Spinning Bamboo Fibers
There are two forms of bamboo fibers available to spinners.
The first, bamboo linen, is hard to find and has a bit of a crisp feel, like a very fine flax. It is lustrous, long stapled, and slippery to spin. I found that a short forward draft worked well with this fiber. Controlling twist is important - too much twist and the yarn will snap; too little twist and the yarn will drift apart, especially when plying. Keep treadling even and keep the twist consistent to avoid problems with drift or breakage. Unlike freshly spun linen yarn, the bamboo yarn has a softer hand and nicer drape.
The second, the extruded fiber, which includes carbon bamboo, has a finer hand and has lost the crisp, linen feel. It feels much more like soy silk than like flax, which is not surprising as both are regenerated cellulose fibers. Short stapled, it can be spun either long or short draw without the drifting and breakage problems of the “bamboo linen” fibers. The yarn has a nice sheen and an excellent drape.
