Bamboo yarn is a type of yarn made from the fibers of bamboo, which is a type of woody grass. To make bamboo yarn, the stalks of the bamboo plant must be broken down so that cellulose fibers can be extracted from them. Yarns made from pure bamboo tend to have a soft, silky texture, a subtle shine, and a good amount of drape. They are also usually popular with fiber artists who are concerned about the sustainability of fiber sources, as bamboo is a resource that is easily renewed. Bamboo yarns are usually available at craft stores in a variety of colors and yarn weights, or strand thicknesses.
There are two common processes for making bamboo yarn from bamboo stalks, both developed in China, where large crops of bamboo are cultivated for many different uses. One of these processes involves physically crushing the bamboo stalks and then allowing natural enzymes to continue the process of breaking down the plant. Cellulose fibers are then combed out of the stalk in a process that is similar to the extraction of flax fibers from the flax plant. The second process produces a yarn that is more similar to rayon, and involves the application of chemicals such as lye and carbon disulfide, a type of chemical solvent. After the bamboo stalks have been broken down by this chemical bath, the cellulose fibers are mechanically extruded from them using spinnerets.
Bamboo yarn is similar to silk in shine and softness, but generally costs less, making it a cheaper alternative to yarns made from silk. It is also breathable like cotton and naturally cool to the touch, making bamboo yarn a good choice for crafting garments meant for warm weather wear. Bamboo also has antibacterial and antimicrobial properties, although these properties are not present in bamboo yarns that have been treated with chemicals.
The bamboo plant is a renewable resource, making bamboo yarn a popular choice amongst fiber artists who are concerned with sustainability issues. Bamboo stalks are hardy plants that usually survive the process of harvesting. Instead of planting new bamboo crops after every harvest, cultivators merely need to wait for the bamboo to grow back. Bamboo grows relatively quickly, with stalks reaching their full height of 60 to 75 feet (18 to 23 meters) in just over a year. Another environmentally friendly property of bamboo yarn is that it is biodegradable as long as the yarn has not been blended with acrylics or other synthetic fibers.