Afterdecades of rapid development, the China’s denim industry has achieved gloriousachievements, and won an important place in the international market. Theexport of middle-end and high-end products of traditional denim garments mainlyfocuses on the markets of America, Europe, Japan and Korea. However, thesemarkets have gradually raised the requirements for environmental protection,functionality and fashion of the denim garments, and have increasingly-strictrequirements for the construction of social responsibility of processingenterprises. Obviously, the traditional denim garments cannot meet people’swearing demands, and the development of fashion-oriented, functional andhigh-end denim textiles has become an inevitable trend. To meet the sustainabledevelopment has become the theme of the modern textile industry, and conformsto recycling economy, being the mainstream of the future development.
 
1. Advantages of ‘Chinese denim’ in large quantity
 
Denimcloth and denim garments have always been popular with a vast number of consumersat home and abroad, and as the symbol of a free lifestyle, denim is daily wearof American consumers. According to a survey, the American consumers have 7jeans per capita, and jeans can be found in wardrobes of 96% of the Americanconsumers. China is the most important source for the import of American denimgarments. According to statistics of United States Customs, in 2019, jeansimports of America amounted to 5 billion dollars, and the import quantityreached 51.84 million, wherein the jeans from China accounted for 32.28% and37.23% of the two indicators separately. The average unit price of the Chinesejeans is lower than that of products of Mexico,Vietnam, Egypt and other majorsource countries, and is also lower than that of American global import jeans.This shows that the China’s export of denim garments to America has relativeadvantages in terms of the price and quantity.
 
2. Development trend of Chinese denim
 
Althoughthe domestic denim industry started decades later than the European andAmerican countries, after 40 years of development and innovation, denimtextiles at the present stage have witnessed brand-new changes in all theaspects involving the color, appearance, style, the use of raw materials, yarnstructure and linear density, finishing and processing, and wearing comfort,and two series of classic denim and patterned denim have been formed. Classicdenim continues to keep its roughness, conciseness, firm hand feeling, andoriginal nature and takes pure cotton 97~36.4tex (6s~16s) coarse yarn as mainraw materials. The patterned denim mainly features elaboration, lightweight,and weave diversity with the weave on the fabric surface developed from thetraditional 3/1 twill to the multi-twill weave, the raw materials developedfrom a single cotton fiber to a variety of fibers, the yarn density developedfrom the original coarse size to the medium and fine size, and the spinningtechnology developed from the original rotor spinning to a variety of spinningprocesses and multi-fiber blending. In terms of the application of fiber rawmaterials for denim yarn, more than 80% of the raw materials for denim fabricare cellulose fibers including cotton, viscose fibers, hemp, flax, tencel,etc., about 6% of the raw materials for the denim fabric are common chemicalfibers including spandex, polyester, high-elasticity nylon, etc., and about 14%are differential fibers including moisture absorption and sweat dischargefibers, high shrinkage fibers, hollow fibers, antistatic fibers, compositefibers, etc. Since the development and innovation of various kinds of denimtextiles need to rely on the innovation of denim yarn, the technologicalinnovation and quality improvement of denim yarn become an important prerequisitefor the development of new denim textiles. At present, the innovativetechnologies of denim yarn for the denim textiles in China mainly involve thetechnological innovation of elastic core spun yarn, and the technologicalinnovation of slub yarn, colorful dot yarn, linen yarn,multi-fiber combinationdenim yarn and the like.
 
3. Quality improvement and transformation of China’s denim industry
 
InChina’s market, about 90% of denim is used in the production of denim garments,of which 42.7% is used in the production of jeans, 29% is used in theproduction of jeans jackets, 10.5% is used in the production of children’sjeans wear, and 7.8% is used in the production of jeans skirts. At present, acomplete modern industrial chain has been formed for processing and productionof denim garments in China with rapid enhancement of capabilities of researchand development, design and marketing on the denim garments. Enterprisesgradually centralize their design and marketing centers on fashion metropolisessuch as Shanghai, Guangzhou, Shenzhen and Hong Kong, and even set up researchand development centers in fashion capitals of the United States, Europe andother international markets, so that the upgrading and structural adjustment ofthe domestic denim industry are promoted. According to the SWOT analysis on theChina’s denim industry, the development trend of the industry has entered adeep adjustment cycle at the current stage. The transformation and upgrading ofthe denim garment production enterprises are urgent so as to adjust the productstructure, reduce the low-end and low value-added products, and increasehigh-end and high value-added products. The further development of the denimtextile industry must rely on cooperation of various aspects including thedevelopment of raw materials, application of fashion colors, improvement inmechanical equipment, innovation on the design process technologies,particularly the improvement of the after-finishing process, updating ofclothing styles, exploration of the wearing field and the like. In this way,the denim textile industry can be constantly improved, the personal features offabric are furthermore highlighted, the fabric is endowed with novelty inahead, the development and innovation work of the denim textile industry makesprocess constantly, and an environmental protection idea of low waterconsumption, low energy consumption and low emission of the denim is accordedwith.
 
4. Sustainable innovation of China’s denim industry
 
Inorder to push forward the green sustainable process of China’s denim textileindustry, it is also necessary to develop some new technologies for thepreparation of green fibers from biomass or recyclable raw materials, so thatthe production process is low-carbon and environmentally friendly, and thefinished products are discarded without causing environmental pollution orrecyclable. At present, the green fibers mainly include biology-based chemicalfibers, recyclable chemical fibers, and original liquid colored chemicalfibers. In order to promote the construction of ecological civilization in thedenim textile industry, Smart Indigo technology, the global leadingelectrolytic reduction technology, has achieved clean production to a certainextent. By using a three-dimensional electrolytic reactor, liquid indigo can beproduced simply with indigo dye, water, caustic soda and electricity, and onlyoxygen is discharged. Compared with other indigo reduction technologies, SmartIndigo technology is efficient, environmentally friendly, small in volume, lowin cost, pure and stable in product content, and completely free of chemicaladditives or metal ions.
 
Thedenim dyeing process involves the four aspects of 1, innovation in the denimpulp yarn dyeing process, wherein composite reducing agents can be preferablyselected to replace sodium hydrosulfite and alkali sulfide in the traditionalpulp yarn dying production, the denim dyeing formula, production process andother technology applications are improved to achieve accurate proportioning,the production of sulfur-containing compounds and the total amount of waste gasand waste water produced in the dyeing process are directly reduced, cleanproduction of denim fabric dyeing is achieved fundamentally, and in this way,the consumption of indigo dye can be reduced by more than 20%, the consumptionof sulfide dye can be reduced by more than 10%, and the consumption of causticsoda can be reduced by 25%; 2, automatic innovation in dyeing equipment,wherein through the detection of image recognition equipment, infrared spectrumequipment, spectrophotometers and other equipment, color control in the dyeingprocess is achieved; 3, innovation in the dyeing process, wherein research and applicationof electrochemical dyeing, foam dyeing and other novel dyeing technologies areinvolved; 4, finished garment manufacturing after yarn dyeing or cotton dyeing,wherein in this way, excessive environmental pollution is lowered.
 
Theenvironment-friendly denim washing technology is an important link in the denimgarment manufacturing process, and also the embodiment of the core added valueof denim garments. As the traditional denim garments usually adopt stone grinding,sand blasting, rinsing, acid pickling, nostalgic washing, enzyme washing andthe like as major means for ‘old-washed color sense’ style finishing, theproduction process has the features of ‘three highs and one low’, which meanshigh pollution, high energy consumption, high labor density and low addedvalue. We can start from two aspects of intelligent equipment and innovativeprocess to realize the environmental friendliness of denim garment washing.Firstly, the intelligent equipment for denim garment washing needs to beresearched and developed including automatic and water-saving equipment for keyprocesses of washing production, comprehensive energy utilization systems andintelligent equipment for the drying process, and intelligent productionmanagement systems for denim garment washing. Secondly, the application of thelaser technology, ozone technology, bio-enzyme technology and digital printingtechnology in the denim garment washing process needs to be popularized. Inthis way, the water-free manufacturing technology which achieves the purposesthat less water is produced in the whole production process, no water isproduced in the key step, and the produced less part can be repeatedly used isput forward for the textile industry.
 
5. Opportunities and challenges of the industry
 
In2020, the European and American countries dominated by America will remain theglobal largest textile and clothing retail market. As the largest sourcecountry of the American clothing market, China’s relevant enterprises will alsobenefit. Faced with the difficulties brought by the outbreak of the novelcoronavirus pneumonia at the beginning of the year to factories and enterprisesacross China and the losses of the European and American markets, it is moreurgent to strengthen the application of new equipment and new technology,reduce carbon emissions, reduce water consumption and energy consumption,increase the energy utilization rate, reduce labor costs, improve productionefficiency and improve the recognition of denim product quality.