The bast of hemp crops contains many celluloses and some glue impurities. Because the glue impurities make the fibers together, hemp fibers cannot be directly used for spinning. In addition, the presence of various defects on the bast during the growth, harvesting, and stripping of hemp crops is not conducive to the spinning process, so degumming must be done before spinning. Degumming is an important process in the preliminary processing of hemp fiber, which removes the gum in the bast and separates the hemp fiber from each other. The degumming methods of various hemp are also different for different hemp fibers due to different physical and mechanical properties and different uses. Now there are mainly two kinds of chemical degumming and biological degumming because chemical degumming has the disadvantages of poor quality of hemp fiber, high cost, and environmental pollution. Therefore, with the development of biology, the application and research of biological enzymatic degumming in the processing of hemp spinning raw materials Gradually attracting attention, this article will focus on the preliminary discussion of enzymatic degumming.
1. The application of biotechnology in textile
After the 1940s, biotechnology achieved rapid development in both theory and practice, laying a solid foundation for the application of biotechnology in the future. Now biotechnology has been widely used in agriculture, forestry, medicine, food, textiles, and other industries. The application of biotechnology in textiles has a long history in China. As far back as the Tang and Song Dynasties, the technology of extracting enzymes from animals and plants has been mastered, and the enzymes have been used to degumming and refining silk fabrics. Around 1857, Europe, America, and Japan began to use maltose extraction enzymes to remove the starch size of the fabric to facilitate printing. Now biotechnology has been widely used in textiles, using enzymes for the biological degumming of hemp fibers, softening treatment of hemp fibers, scouring of silk, desizing of gray cloth, and wastewater treatment of textile finishing by using enzymes, etc. Enzymes can also be used in the finishing of fabrics. For example, using cellulase can successfully remove defects such as pilling and fluffing, reduce hairiness and improve the smoothness of the hand, or achieve the effect of fading and refilling (stone-grinding and water washing), which improves the quality of the fabric. , but does not damage the fabric. This is a relatively young technology, but it has been widely used in industry. The application of biotechnology in the textile industry has improved production efficiency and product quality, reduced costs, reduced environmental pollution, and produced obvious economic benefits.
2. Research status of hemp fiber biological degumming
2.1 Research status of hemp fiber degumming
For a long time, the primary processing of raw materials for hemp spinning mainly refers to chemical degumming mainly based on ramie, and biological retting degumming mainly based on flax. Pot and Ribbon Dried Hemp Production Line. The traditional degumming method that has been used for a long time cannot be effectively solved due to the long processing time, the consumption of a large amount of water, the large amount of harmful chemical components in the treated sewage, and the recycling is not easy to pollute the environment. Therefore, scientists Start looking for new degumming methods. with biological
With the development of technology, the application of biological enzyme preparations in the processing of hemp-spinning raw materials has attracted people’s attention, and textile workers are strengthening research in this area.
The fibers of fiber plants are all in the phloem of the plant stem. The purpose of degumming is to use the action of microorganisms to decompose the pectin between the phloem and the xylem, between the phloem and the skin and the membrane tissue, so as to obtain the raw material fiber of the textile industry. Enzymatic degumming is a large amount of crude enzyme solution produced after the degumming bacteria are cultivated to the senescence stage of the bacteria, and the crude enzyme solution is used to impregnate hemp bast, or the crude enzyme solution is purified and concentrated into a liquid, or the crude enzyme solution is Dried into a powder, then dissolve the concentrated solution or the powder in water, and then impregnate the hemp bast to decompose the high-molecular pectin and hemicellulose and other colloids into low-molecular-weight components under the action of enzymes and dissolve in water or become easily removable substances.
Applying biological enzymes to degumming raw hemp can reduce the cost of degumming, reduce environmental pollution, and increase the production rate of dry hemp and the rate of combing and carding. The fibers after enzyme degumming, are fluffy and curled, and the average length of fibers increases. The hairiness is obviously reduced, and the spun yarn quality index is significantly improved.
2.3 Various factors affecting enzyme degumming
2.3.1 Effect of temperature on enzyme degumming
Whether the temperature is appropriate or not has a direct impact on the degumming speed. Appropriate temperature can enhance the action of the enzyme, and speed up the degumming speed, and the degumming effect is good. When the temperature is low, the activity of the enzyme decreases, and even makes it stops life activities and becomes dormant. Excessive temperature will kill the enzyme, both of which are extremely unfavorable to the degumming process.
2.3.2 Effect of water quality on enzyme degumming
Water quality is very important for maceration. The fermentation of organic matter in the water will lengthen the maceration degumming time. The water should not contain acids because it has a great influence on the pectin fermentation during the maceration process. Pectinase produces several acids, which will inevitably increase the acidity of the maceration solution and affect the growth conditions of the enzyme.
2.3.3 Effect of water velocity
If a natural water pool is used for dipping and degumming, the water speed should not be too fast. If the water speed is too fast, the degumming time will increase because the water will take away a large number of bacteria and nutrients needed for bacterial reproduction, and the enzyme activity will decrease.
2.3.4 Effect of ventilation on enzyme degumming
In the process of impregnation, we should give the most suitable living conditions and supply sufficient nutrients when the enzyme cells are active alone in order to speed up the degumming speed and improve the degumming effect.
3. Conclusion
Hemp fiber is one of the important textile fibers in my country. Hemp degumming continues to develop in the direction of high quality, continuous, energy-saving, and less pollution. Enzymatic degumming has broad prospects. We should actively research and promote this technology.