Difference between revisions of "Bamboo textiles"

Latest revision as of 09:16, 20 September 2010

Bamboo textiles are cloth, yarn, and clothing made out of bamboo fibres. While historically used only for structural elements, such as bustles and the ribs of corsets, in recent years a range of technologies have been developed allowing bamboo fibre to be used in a wide range of textile and fashion applications. Modern bamboo clothing is clothing made from either 100% bamboo yarn or a blend of bamboo and cotton/organic cotton yarn. The bamboo yarn can also be blended with other textile fibres such as hemp or even spandex.

Traditional uses

In China and Japan, thin strips of bamboo were woven together into hats and shoes. One particular design of bamboo hats was stereotypically connected with rural life, being worn almost universally by farmers and fishermen in order to protect their heads from the sun.^[1]

In the West, bamboo, alongside other components such as whalebone and steel wire, was sometimes used as a structural component in corsets, bustles and other types of structural elements used in fashionable women's dresses.^[2]

Modern uses

Manufacture of bamboo viscose

Recent technologies have allowed cellulose processed from bamboo to be spun into viscose yarn ^[3]. Modern bamboo yarn is therefore a regenerated cellulose fibre. One such technology was filed in 2003 as US patent 7313906 by inventors Xiangqi Zhou, Zheng Liu, Liming Liu, and Hao Geng developed one such method of turning bamboo into yarn, creating new uses for bamboo in clothing.

The steps in the manufacturing of bamboo viscose are as follows:

1) Bamboo leaves and the soft, inner pith from the hard bamboo trunk are extracted using a steaming process and then mechanically crushed

2) The crushed bamboo is soaked in sodium hydroxide to produce cellulose. A common misconception is that sodium hydroxide is a harmful chemical^{[citation needed]}. If used in a responsible manner sodium hydroxide has absolutely no effect on the environment and health of workers. It is routinely used in the processing of organic cotton into fibre and is approved by the Global Organic Textile Standards (GOTS) and the Soil Association ^[4] Sodium hydroxide does not remain as a residue on clothing as it easily washes away and can be neutralised to harmless and non-toxic sodium sulphate salt. A chemical used in this step that can cause nervous system damage with chronic exposure is carbon disulfide ^[5].

3) The bamboo cellulose is forced through spinneret nozzles (like a sieve) into an acid bath that hardens the solution into bamboo fibre threads and neutralizes the caustic sodium hydroxide.

4) The fibre threads are spun into bamboo yarn and rolled onto spools.

The processing of the cellulose pulp into fibre can be cleaner than the processing used for conventional viscose if a closed loop process captures and reclaims all the solvents used in the manufacturing, though this is not standard practice ^[5]. The resulting bamboo viscose fibre is very soft to the touch.

Alternative manufacturing processes

The Swiss company Litrax ^[6] is one company involved in the manufacturing of bamboo fibre. Litrax claims to use a more natural way of processing the bamboo into fibre. In this the woody part of the bamboo is crushed mechanically before a natural enzyme retting and washing process is used to break down the walls and extract the bamboo fibre. This bast fibre is then spun into yarn ^[7]. In fine counts the yarn has a silky touch^{[citation needed]}. The same manufacturing process is used to produce linen fabric from flax or hemp. Bamboo fabric made from this process is sometimes called bamboo linen. The natural processing of litrax bamboo allows the fibre to remain strong to produce an extremely high quality product. This process gives a material that is very durable.

Source of raw material

Most of the bamboo used to make bamboo fibre and bamboo clothing is grown in China by Hebei Jigao Chemical Fiber Company ^[8] They hold the patent on the process for turning bamboo into fibre. This facility produces all of the bamboo viscose on the market. The bamboo is certified organic by OCIA (The Organic Crop Improvement Association) ^[9] To strictly control the quality of raw material, Hebei Jigao Chemical Fiber Company has built its own bamboo plantation in Sichuan Province, China, and keeps strict control over it. The bamboo is grown in accordance to the international organic standard of OCIA/IFOAM and the USDA National Organic Program, so as to ensure each bamboo stalk is of 100% natural growth and without any chemical pesticides. The proof of the ecologically sound methods behind bamboo production is the fact that all of the fibre produced at the facility in China is Oeko-Tex 100 certified ^[10] This certifies that the finished fibre has been tested for any chemicals that may be harmful to a person’s health and has been found to contain no trace chemicals that pose any health threat whatsoever. This means that every company working with bamboo starts with the same raw material and that this material is not contaminated.

Benefits of using bamboo for clothing

Numerous claims have been made for the superiority of bamboo yarn over other textiles. These include the following:

Organic Quality more accessible - bamboo is often grown without pesticides or fertilisers.

Soft - bamboo is soft.

Sustainable - Moso bamboo is one of the world’s fastest growing plants, growing up to a metre in a day. Bamboo is a grass, so once cut it can regenerate quickly without the need for replanting. It grows very densely and so the yield per acre is high in comparison to cotton.

Eco-friendly - bamboo absorbs 35% more carbon dioxide than equivalent stands of trees.

Absorbent - bamboo absorbs up to 60% more water than cotton. This makes it an excellent choice for towels and bathrobes.

Breathable - the porous nature of the fibre makes it breathable and extremely comfortable against the skin.

Thermo-regulating - Bamboo fibres expand when warm to let skin breathe, and contract when cool to trap heat close to the body.^[11]

Hypoallergenic - bamboo's organic and natural properties make it non-irritating so perfect for extra sensitive skin ^[12][13]

Ecological reasons for using bamboo as a raw material for textiles and clothing

Growth

Bamboo has many advantages over cotton as a raw material for textiles. Reaching up to 35 metres tall, bamboos are the largest members of the grass family ^[14] They are the fastest growing woody plants in the world. One Japanese species has been recorded as growing over 1 metre in a day ^[15] There are over 1600 species of bamboo ^[16] found in diverse climates from cold mountains to hot tropical regions. About 40 million hectares of the earth is covered with bamboo, mostly in Asia ^[17] The high growth rate of bamboo and the fact that bamboo can grow in such diverse climates makes the bamboo plant a sustainable and versatile resource. The bamboo species used for clothing is called Moso bamboo. Moso bamboo is the most important bamboo in China, where it covers about 3 million hectares (about 2% of the total Chinese forest area). It is the main species for bamboo timber and plays an important role for the ecological environment ^[18]

Harvesting

Once a new shoot emerges from the ground, the new cane will reach its full height in just 8–10 weeks. Each cane reaches maturity in 3–5 years. Bamboo can be continually re-harvested with no damage to the surrounding environment.^{[citation needed]} It is a grass and so regenerates after being cut just like a lawn without the need for replanting. This regular harvesting is actually of benefit to the health of the plant – studies have shown that felling of canes leads to vigorous re-growth and an increase in the amount of biomass the next year ^[19]

Yield and land use

Land use is of global importance as the world’s six billion people compete for water, food, fibre and shelter ^[20] Sustainable land use practices provide both economic and environmental advantages. Bamboo can be used as food, fibre and shelter and due to its ease of growth and extraordinary growth rate it is a cheap, sustainable and efficient crop. Bamboo grows very densely, its clumping nature enables a lot of it to be grown in a comparatively small area, easing pressure on land use. Yields of bamboo of up to 60 tonnes per hectare ^[21] greatly exceed the yield of 20 tonnes for most trees and only 1-2 tonnes per hectare for cotton ^[22] with a one-time planting for bamboo and little care and maintenance needed. In a time when land use is under enormous pressure, bamboo’s high yield per hectare becomes very significant.

Greenhouse gases and global warming

Human activity is not only producing more carbon dioxide, but it is also severely damaging the ability of the planet to absorb carbon via its carbon sinks — the forests. Growing forests absorb CO₂ but deforestation results in fewer trees to soak up rising levels of CO₂. Bamboo minimises CO₂ and generates up to 35% more oxygen than equivalent stands of trees ^[23] One hectare of bamboo sequesters 62 tonnes of carbon dioxide per year while one hectare of young forest only sequesters 15 tonnes of carbon dioxide per year ^[24]

Deforestation

Bamboo planting can slow deforestation, providing an alternative source of timber for the construction industry and cellulose fibre for the textile industry ^[25] It allows communities to turn away from the destruction of their native forests and to construct commercial bamboo plantations that can be selectively harvested annually without the destruction of the grove. Tree plantations have to be chopped down and terminated at harvest but bamboo keeps on growing ^[26] When a bamboo cane is cut down, it will produce another shoot and is ready for harvest again in as little as one year. Compare this to cotton – harvesting organic cotton requires the decimation of the entire crop causing bare soils to bake in the sun and release carbon dioxide into the atmosphere. Before replanting next years crop the cotton farmers till the fields which releases yet more CO₂.^[27]

Water use

Very little bamboo is irrigated and there is sound evidence that the water-use efficiency of bamboo is twice that of other trees ^[28] This makes bamboo more able to handle harsh weather conditions such as drought, flood and high temperatures. Compare bamboo to cotton which is a thirsty crop – it can take up to 20,000 litres of water to produce 1 kg of cotton and 73% of the global cotton harvest comes from irrigated land ^[29] ,^[30] Some estimates indicate that cotton is the largest user of water among all agricultural commodities.

Soil erosion

Yearly replanting of crops such as cotton leads to soil erosion. The extensive root system of bamboo and the fact that it is not uprooted during harvesting means bamboo actually helps preserve soil and prevent soil erosion. The bamboo plants root system creates an effective watershed, stitching the soil together along fragile river banks, deforested areas, and in places prone to mudslides. It also greatly reduces rain run-off ^[31] Conventional cotton-growing also causes a severe reduction in soil quality through the impact of constant use of pesticides on soil organisms.

Pesticides and fertilisers

Only 2.4% of the world’s arable land is planted with cotton, yet cotton accounts for nearly 25% of the world’s insecticide market and 11% of the sale of global pesticides. ^[32] Many of these pesticides are hazardous and toxic:

Aldicarb, a powerful nerve agent, is one of the most toxic pesticides applied to cotton worldwide and the second most used pesticide in global cotton production.

Endosulfan is widely used in cotton production and is the dominant pesticide in the cotton sector in 19 countries.

Monocrotophos, despite being withdrawn from the US market in 1989, is widely used in developing world countries. In 1997, Paraguay’s Ministry of Health and Welfare identified it as being responsible for causing paralysis in children living in cotton growing areas.

Deltamethrin, a nerve agent, is applied in over half of the cotton producing countries. Medical analysis in a community in a South African village located on the edge of a major cotton production area found traces of deltamethrin in human breast milk.

An estimated 1 million to 5 million cases of pesticide poisoning occur every year, resulting in 20,000 reported deaths among agricultural workers and at least 1 million requiring hospitalisation ^[33] Even organic cotton farming uses pesticides – copper and copper salts ^[34]

Fertilisers are also applied to cotton fields to increase growth rate and crop yields. A huge benefit of using bamboo as the organic base for textile fibres is that there is no need for pesticides or fertilisers when growing bamboo. Bamboo grows so rapidly there is no need for fertiliser. It also contains a substance called bamboo-kun – an antimicrobial agent that gives the plant a natural resistance to pest and fungi infestation ^[35] It is believed that the finished bamboo fabric retains this antibacterial property ^[36]

References

1. ↑ Yang Ye (1999),Vignettes from the Late Ming: A Hsiao-pʻin Anthology, University of Washington Press, pp. 17, 112
2. ↑ Akiko Fukai and Tamami Suoh (2002), Fashion: The Collection of the Kyoto Costume Institute, Taschen, pp. 154, 284
3. ↑ http://www.organic-babyclothing.co.uk/organic_bamboo_fabric.html
4. ↑ Soil Association Organic Standards January 2007 60 Textiles http://www.organicpurewool.co.uk/S-A.orgtextilestandards2007.pdf
5. ↑ ^{5.0 5.1} http://www.scientificamerican.com/article.cfm?id=bamboo-boom&page=3
6. ↑ http://www.litrax.com
7. ↑ 3. http://www.organic-babyclothing.co.uk/blog/index.php/2008/11/27/litrax-bamboo
8. ↑ http://www.jghx.cn
9. ↑ http://www.ocia.org
10. ↑ http://www.oeko-tex.com/oekotex100_public/index.asp?cls=02
11. ↑ http://www.rapanuiclothing.com/eco/bamboo-clothing.html
12. ↑ http://www.organic-babyclothing.co.uk/
13. ↑ http://www.greenflip.in/blog/greenflip-blog/
14. ↑ http://www.kew.org/plants/bamboos/index.html
15. ↑ http://www.kew.org/plants/bamboos/giantbamboo.html
16. ↑ http://www.mastergardenproducts.com/bamboo.htm
17. ↑ http://www.bbc.co.uk/dna/h2g2/A1275851
18. ↑ ‘Chinese Moso Bamboo: Its Importance’ Jinhe Fu, The Magazine of The American Bamboo Society, October 2001
19. ↑ http://www.indiaenvironmentportal.org.in/node/20202
20. ↑ http://www.sciencedaily.com: World Land Use Seen As Top Environmental Issue
21. ↑ http://www.geniaal.be/downloads/EBS4johangielis.doc
22. ↑ http://r0.unctad.org/infocomm/anglais/cotton/crop.htm
23. ↑ http://www.bamboocentral.org/shareinrepair/faq.htm
24. ↑ J. Janssen, Technical University Eindhoven, 2000
25. ↑ http://www.worldagroforestry.org/downloads/audio/VOA_Chin_Bamboo_Deforestation_Interview.mp3
26. ↑ http://www.bamboocentral.org/shareinrepair/whybamboo.htm
27. ↑ http://www.npr.org/templates/story/story.php?storyId=11951725
28. ↑ ‘Can Bamboo Replace Thirsty Trees?’ http://www.worldagroforestry.org May 2009
29. ↑ www.greencottonblog.com
30. ↑ http://events.earthhourcanada.org/what_we_do/footprint/agriculture/commodities/cotton/better_management_practices/water_use/
31. ↑ http://www.bs-bamboo.co.uk/bambooandtheenvironment.htm
32. ↑ http://events.earthhourcanada.org/what_we_do/footprint/agriculture/commodities/cotton/environmental_impacts/agrochemicals_use
33. ↑ 27. http://www.ejfoundation.org/page332.html
34. ↑ http://www.ifoam.org/growing_organic/1_arguments_for_oa/criticisms_misconceptions/misconceptions_no7.html
35. ↑ http://www.fashionandearth.com/index.php/faq.html
36. ↑ http://www.cahs.colostate.edu/news/item/?ID=550