Bamboo Fiber: The Manufacturing Process and Fabric Care
Bamboo is the fastest-growing plant on earth. Some types can grow up to 1 meter per day. Bamboo is a grass belonging to the Gramineae family. Bamboo grass grows from one foot (30 cm) to huge bamboo plants of wood that can grow to more than 100 feet (30 meters). Bamboo plants exist in all regions around the world and play an important economic and cultural role.
Bamboo is classified according to its root types. Some of them, called runners, are widely spread, while others are classified as sympodial, meaning they slowly expand from the original cultivation. There are also different types of root systems that are a mixture of these types. Generally, there are about 1,200 bamboo species in about 90 genera. Taxonomists are still debating the total number of bamboo and ethnic species due to the long cycles of flowering plants.
Bamboo is not only used for furniture, construction, and musical instruments, but also in the textile industry. Bamboo fiber is obtained from bamboo pulp, which extracted from the bamboo stem through the process of hydrolysis-alkalization and multiphase bleaching. Due to the soft silky fabric and environmental benefits of bamboo fiber, bamboo clothing has become popular in some modern luxury fashions.
China and India are the world’s bamboo distribution center. The region has concentrated 80 percent of the world’s bamboo species, and 90 percent of the total area of bamboo forest.
Britain, France, Germany, the Netherlands, and other countries in Europe have begun to cultivate bamboo. The plant is also quickly spreading to Africa and America.
A Brief History of Bamboo Fiber
Bamboo has deep roots in the cultures of China and Southeast Asia. The Chinese planted and used bamboo 7,000 years ago. It was used for food, clothing, transportation, housing, musical instruments, and weapons. Bamboo strips were used as the most important writing medium for other widely used materials, such as silk, animal fur, and rocks. The first books of China were made from bamboo strips on the string.
The oldest record of U.S patents regarding bamboo fibers date back to 1864 by Philipp Lichtenstadt. His idea was to introduce a new and useful process for breaking up bamboo fibers to be used in making ropes, fabric, mats or paper pulp.
In 1881, another patent included blending bamboo fibers with wool, but it did not go into mass production for reasons that might include ineffective or expensive processing methods.
In the early 2000s, Beijing University released the results of converting bamboo fibers into usable fabric.
In 2002, renewed cellulosic bamboo fiber was first manufactured by Hebei Jigao Chemical Fiber Co.
Macroscopic Structure of Bamboo Fiber
Chemical Structure of Bamboo Fiber
The cross-section of the single bamboo fiber is round with a small lumen. Bamboo fibers have a high breaking strength as well as good absorbability properties, but they have low elongation.
The main components of bamboo are cellulose, heme-cellulose, and lignin. The secondary components of bamboo are resins, wax, and inorganic salts. Bamboo contains other organic components in addition to cellulose and lignin. It contains about 2% oxidant polysaccharide, 2-4% fat, 2-6% starch and 0.8-6% protein.
The bamboo carbohydrate content plays an important role in its durability. The strength of bamboo against the attack of mold and fungi is closely related to their chemical composition.
Characteristics of Bamboo Fiber
- Softness: The fibers of bamboo are regenerated cellulose fibers, so they are soft and healthy for the skin like cotton.
- Luster: Bamboo fibers have a bright color and a special luster like silk.
- Anti-bacterial: Bamboo is rarely eaten by pests or infections from pathogens because bamboo possesses antibacterial substance and a biological agent called Bamboo Kun. This substance binds with the bamboo cellulose molecule tightly throughout the bamboo fiber production process.
Did You Know?
The Japanese Textile Inspection Association has proven that even after 50 rounds of washing, the bamboo fiber fabric still has excellent anti-bacterial function.
- Moisture absorption: Bamboo fibers have excellent absorption and ventilation because the cross-section of bamboo fibers is filled with fine gaps and various tiny holes. This gives a feeling of relief, especially on hot summer days.
- Anti-ultraviolet radiation: This property has differences around it; At the 235th national meeting of the American Chemical Society, Appidi and Sarkar of Colorado State University stated that the raw bamboo fabric allows nearly all harmful UV rays to pass through, and reach the skin, on the other hand, the viscose bamboo industry in China found that 100% bamboo fabric did not allow UV rays through when the UV fabric test was completed using the test method GB/T 18830-2002 (Bambro Tex 2008).
- Resistant to static electricity: Bamboo fibers do not contain a free electron, so they are resistant to static electricity and do not cling to the skin.
- Durability: Bamboo fibers are as durable as jute fibers.
- Dyeing ability: Fibers of bamboo have good dyeing properties and colorfastness.
Eco-friendliness: Textiles made from bamboo fiber is biodegradable. It can be 100% decomposed in the soil by microorganisms and sunlight.
Manufacturing Process of Bamboo Fiber
Regenerated bamboo fibers can be manufactured by mechanical or chemical processing:
The Mechanical Process
In mechanical processing, harvested and crushed bamboo wood is initially treated with natural enzymes that break down bamboo into a soft material. Next, natural fibers can be mechanically combed to obtain individual fibers, followed by yarn spinning. The fabric manufactured through this process is often called bamboo linen, and this process is considered environmentally friendly because no harmful chemicals are used.
The Chemical Process
In the chemical process, Bamboo leaves and inner core are extracted from bamboo and crushed together to make bamboo cellulose. The crushed bamboo cellulose is soaked in a solution of 18% sodium hydroxide (NaOH) at 20 °C to 25 °C for 1-3 hours to form alkali cellulose. The alkali cellulose is pressed to remove any excess sodium hydroxide. Alkali cellulose is then broken down by a grinder and left for 24 hours to dry. After that, carbon disulfide (CS2) is added to the mixture of alkali cellulose.
Bamboo cellulose, sodium hydroxide, and carbon disulfide mixture are decompressed to remove carbon disulfide resulting in cellulose sodium xanthogenate. A diluted solution of sodium hydroxide is added to the cellulose sodium xanthogenate which dissolves it into a viscose solution. The viscose bamboo cellulose is forced through spinneret nozzles into a large container of dilute sulphuric acid solution that works to harden viscose bamboo cellulose sodium xanthogenate and reconverts it into bamboo cellulose fiber threads that are spun into the yarns to be woven into a fabric.
Chemical treatment requires the use of chemicals such as carbon disulfide and sodium hydroxide, which can pollute the environment through side reactions in the treatment. These are not considered environmentally friendly. Also, some pollutant chemicals are used, such as zinc, which makes the process environmentally harmful. Consequently, research is on-going to find more sustainable ways to get better-regenerated bamboo fibers.
It is better to use active dyes during the dyeing process of bamboo fiber, the alkalis should not be more than 20g/liter, and the temperature should not exceed 100 °C. During the drying process, low temperature and slight tension are applied.
Uses of Bamboo Fabric
Bamboo fibers can be used in making bathrobes, towels, bedclothes, underwear, T-shirts, socks, sweaters, summer clothing, mats, and curtains.
Also, non-woven bamboo fabric can be used in the manufacture of the sanitary, napkin, masks, mattress, food-packing bag, and surgical clothes.
How to Care for Bamboo Fabric
- Use a gentle wash cycle or hand wash and use a good brand of gentle soap liquid.
- You can use oxygen bleach because chlorine bleaches yellowing the fabrics.
- It is preferable to dry the Bamboo fabrics in the sun. You can use a low-temperature drying cycle because over-drying can damage the fabrics.
- Ironing the bamboo fabric is easier when somewhat wet. Use a dry iron at a low temperature because high temperatures can burn bamboo fibers.
- http://www.fao.org/3/a-a1243e.pdf. World bamboo resources: A thematic study prepared in the framework of the Global Forest Resources Assessment 2005.
- EcoPlanet Bamboo aims to make alternative timber big business | GreenBiz. As anti-deforestation efforts ramp up, one bamboo supplier aims to take the industry from a "hippie business" to a serious, industrialized option for Fortune 500 companies.
© 2020 Eman Abdallah Kamel