One of the latest developments in the textile sector, where the need for new raw materials and products is rapidly increasing, is the use of bamboo plant, which has been used in building materials, furniture, decoration, accessory products and high performance composite materials for a long time, in various textile products.
Bamboo is a plant that grows in tropical climates, reaches maturity in a short period of 3-4 years and is used in many fields such as paper, furniture, construction, food, chemical industry. Bamboo fiber used in textile is of Asian origin in terms of development and production, and Moso bamboo (Phyllostachys heterocycla pubescens) is obtained from the type of bamboo called . Bamboo fiber finds a wide area of use in textiles and creates an alternative to other cellulosic fibers, thanks to its natural antibacterial properties, biodegradability, high moisture holding capacity, softness and brightness, and UV rays refraction.
PRODUCTION METHOD OF BAMBOO FIBER
Bamboo fiber is of two different types: bast fiber obtained by separating from the bark parts of the plant when the plant matures, and regenerated cellulosic fiber obtained from bamboo pulp, which is formed by thinning and purifying the stem and leaves of the bamboo plant as a result of hydrolyzalcalization and multi-phase bleaching processes. Bamboo fiber obtained as bast fiber is also defined as natural bamboo fiber.
Based on the principle of hydrolysis alkalization and multi-phase bleaching The production of regenerated bamboo fiber consists of the following steps. It is formed.
1. Preparation: The soft and spongy tissues of the bamboo leaves and stem are extracted and broken down.
2. Soaking: The shredded bamboo cellulose is immersed in 20-25% sodium hydroxide solution for 1-3 hours at a temperature of 15-20°C to form alkaline cellulose.
3. Pressing: Bamboo alkali cellulose is pressed to remove the sodium hydroxide solution.
4. Shredding: Alkaline cellulose is broken down into small pieces to make the cellulose easier to process and to increase its surface area.
5. Drying: Alkaline cellulose, which is broken into small pieces, is left to dry for 24 hours to contact oxygen. During this process, alkali cellulose is partially oxidized and reaches a lower molecular weight due to its high alkalinity. This reduction must be controlled to form short chains in the spinning solution which are sufficient to obtain the appropriate viscosity.
6. Sulfurization: At this stage, carbon disulfide is added to the alkali cellulose solution and sulphidization is achieved.
7. Xanthate: The carbon disulfide remaining from the sulphurization step is removed by evaporation, resulting in cellulose sodium xanthate.
8. Dissolution: At this stage, dilute sodium hydroxide solution is added to the cellulose sodium xanthate solution and a viscose solution containing 5% sodium hydroxide and 7-15% bamboo fiber cellulose is obtained.
9. Fiber pulling: After successive aging, filtration, and degassing, viscose bamboo cellulose is sent through the nozzles into a dilute sulfuric acid solution to cure cellulose sodium cantate and convert it into cellulosic bamboo fibers. Regenerated bamboo fiber can also be called bamboo viscose, since the chemical production method of regenerated bamboo fiber is largely similar to the production of viscose rayon.
Bamboo fiber can also be produced by mechanical method. In the mechanical method, the woody parts of the bamboo plant are broken down and become soft with natural enzymes. Thus, the fibers are mechanically separated from the structure and used in yarn production. This method is less preferred because it requires more labor and is costly. The cross-section and longitudinal appearance of the regenerated bamboo fiber are largely similar to the conventional viscose rayon fiber.
Regenerated bamboo fiber has a high level of moisture retention and air permeability due to the large amount of micro-voids and pits when its cross-section is examined. The cross-section of the bamboo fiber is elliptical and due to this structure of the natural bamboo fiber, which has a hollow structure in the middle, it is concluded that water absorption and moisture conductivity are high as in the regenerated bamboo fiber. In addition, there are horizontal lines and knots that are irregularly distributed along the length of the natural bamboo fiber. Compared to conventional viscose and Tencel, regenerated bamboo fiber has lower crystallinity. Therefore, moisture absorption and drying properties of regenerated bamboo and conventional viscose fibers are better than Tencel, due to the higher ratio of amorphous regions in their structures. On the other hand, the thermal stability of regenerated bamboo fiber is not as high as conventional viscose and especially Tencel. The types of regenerated bamboo fiber according to their fineness and length are shown below.
Bamboo fiber is also produced as a filament. As can be seen from the length and fineness values of the bamboo fibers available in the market, bamboo fiber can be used both in short fiber spinning systems and in long fiber spinning systems, both woolen and worsted. The physical parameters obtained under the test conditions of 20 oC temperature and 65% relative humidity to the regenerated bamboo fiber are shown below.
It is stated that bamboo fiber has many positive properties such as softness, natural antibacterial properties, air permeability, and UV protection, as well as its strength, especially its wet strength, which is a limiting factor in dyeing and finishing processes.
As mentioned before, bamboo fiber can be used as 100% bamboo or in various blends in both short fiber spinning systems and long fiber spinning systems, both straygarn and worsted. In the short fiber spinning system, ring, rotor and core yarns are produced.
USAGE AREAS OF BAMBOO FIBER
Men's and women's underwear and outerwear products: Bamboo fiber can be used in men's and women's outerwear products due to its properties such as absorbing sweat instantly, giving a feeling of coolness, shine, softness and texture. In addition to these, its natural anti-bacterial properties are used in underwear products and socks. Its ability to break down UV rays is especially suitable for summer clothes.
Hygienic products and medical textile products: Due to its natural antibacterial properties, bamboo fiber is considered suitable for use in many sanitary products such as bandages, masks, hospital clothes, food packaging, and medical textile products. Due to its natural anti-bacterial properties, it does not cause allergic formations on the skin since it does not require the addition of chemical antimicrobial substances in healthy products to be obtained from bamboo fiber.
Especially nonwoven products made of bamboo fiber are very similar to nonwoven products made of viscose fiber. In addition, thanks to the natural antibacterial properties of bamboo fiber, it is expected that it will find a wide range of applications in the field of healthy and medical products such as healthy cloths, protective pads and cloths, mouth masks and food packaging.
Home textiles: High moisture absorption, softness and anti-bacterial properties make bamboo fiber a suitable fiber for towels. Bamboo fiber, which is used in various home textile products such as bed sheets, duvet covers, blankets, is also suitable for curtains with its ability to refract UV rays.
In addition to bamboo fiber ready-made clothing and home textile products, geotextile products used for liquid filtration, soil stabilization and erosion prevention, filtration materials that clean air and water, special absorbent materials designed to separate oil from water and wetlands, industrial belts and filters, cord fabric production, It is used in automobiles, structures, medical textiles and aviation industry. Bamboo fiber is also used in today's high-tech composite materials, which are an alternative to metals in terms of lightness and high performance.
FINISHING PROCESSES APPLIED TO BAMBOO FABRICS
In finishing processes, the following sequence is generally followed: incineration, desizing, bleaching, enzymatic treatment with cellulose, dyeing, finishing processes.
Incineration: The purpose of the burning process is to remove the hairs on the fabric surface and to smooth the surface. Not using cooling cylinders increases the combustion quality.
Desizing: A desizing process is carried out according to the type and amount of sizing on the fabric.
Hydrophilization-Bleaching: Depending on the desired whiteness and hydrophilicity, the processes applied to other cellulosic fibers can be applied.
It can be dyed and printed with all dyestuffs that dye cellulose.
Enzymatic Treatment with Cellulose
After enzymatic treatment with cellulose natural bamboo fibers are finer, softer has a better handle and their clothing-use features is developed. Attention in the process The most important point is; material strength as possible is protection. used to achieve this enzyme concentration, time, Process parameters such as pH, temperature should be checked. made with cellulose fiber degradation occurs at the end of the process. is coming. This degradation The ratio of the fiber to the crystalline region depending on increases, the molecule in the crystalline region size is decreasing. Twisting of the fiber resistance decreases and usage characteristics is developing.