Microsoft Word - CET--006.docx CHEMICAL ENGINEERING TRANSACTIONS VOL. 59, 2017 A publication of The Italian Association of Chemical Engineering Online at www.aidic.it/cet Guest Editors: Zhuo Yang, Junjie Ba, Jing Pan Copyright © 2017, AIDIC Servizi S.r.l. ISBN 978-88-95608- 49-5; ISSN 2283-9216 The Optimized Analysis of the Dyeing Property of Coptis Chinensis towards Natural Bamboo Fiber Hong Chena, Mohan Zhanga, Hong Liub* aClothing and Design Faculty, Minjiang University, Fuzhou 350108, China bSchool of Fashion, Henan University of Engineering, Zhengzhou 451191, China liuhong329@163.com The paper researches the dyeing property of coptis chinensis and bamboo fiber through orthogonal experimental analysis and single factor comparative analysis, gets the optimized process of direct dyeing, pre- mordant dyeing, one-bath dyeing and post-mordant dyeing, as well as tests and compares the dyeing fastness and fracture tensile property of the optimized process of the four dyeing methods. 1. Introduction Coptic Chinensis is a Chinese medicinal herb, with the functions of clearing heat and purging fire, removing dampness, relieving internal fever, fighting a wide range of bacteria, and reducing blood sugar. The main active ingredients in coptis chinensis, such as berberine, coptisine, methyl berberrubine, alkaloids, belong to alkaloids natural pigments. Therefore, coptis chinensis is also a natural dyestuff. Dyeing the natural bamboo fiber with coptis chinensis extract, not only ensures the quality of pure natural bamboo fiber, but also improves the added value of the products, bring bamboo fiber the function of health care, as well as comfortable and safeness for wearing. 2. Experimental Results and Analysis 2.1 Orthogonal Experiment of Coptis Chinensis Dyeing Each factor that affects the coptis chinensis dyeing has been designed into an orthogonal test table consisting of 3 levels and 4 factors to do the orthogonal experiments. The bath ratio is 1:40, the mass of fiber is 0.4g, the design and results of the orthogonal experiment are as follows: 2.1.1 Direct Dyeing Take the dyeing temperature, dyeing extract dosage, pH value and Nacl dosage as the main factors influencing the dyeing process to design the orthogonal test table. Carry out orthogonal tests according to the table with the bath rate of 1:50 and the dyeing extract dosage of 20ml, the results are as shown in Table 1. From the R range analysis of Table 1, it is found that the order of the influences the factors have in direct dyeing on the dye-uptake is A>B>C>D respectively, while the order of the influences on the degree of fixation is A>C>D>B respectively, which means that, the dyeing temperature has the most significant influence on the dyeing effect in direct dyeing, followed by the pH value of the dye liquor and dosage of Nacl, while dyeing time has the least influence on dyeing effect. According to the value of K of each factor and judging by the dye- uptake of the fiber, the best technique is: A3 B1 C3 D1; judging by the degree of fixation of the fiber, the best technique is: A3 BC1 D3 B3. Combing both the two factors, the best technique is: A3 B2 C3 D1, which is, the dyeing temperature being 70°C, the pH value being 6, the dosage of Nail being 2.5g/L, and the dyeing time being 30min. (Kalla et al., 2015) DOI: 10.3303/CET1759123 Please cite this article as: Hong Chen, Mohan Zhang, Hong Liu, 2017, The optimized analysis of the dyeing property of coptis chinensis towards natural bamboo fiber, Chemical Engineering Transactions, 59, 733-738 DOI:10.3303/CET1759123 733 Table 1: The Orthogonal Experimental Results of Direct Dyeing EXPNO A B C D Dye-uptake Fixation rate Dyeing temperature (°C) Dyeing time (min) PH range Mordant dosage (%) 1 50 6 1.5 30 13.91 2.75 2 50 8 2.0 45 10.86 3.25 3 50 11 2.5 60 11.45 3.75 4 60 11 2.0 30 16.69 11.00 5 60 8 1.5 45 18.64 2.50 6 60 6 2.5 60 16.38 13.00 7 70 11 2.5 30 17.33 8.50 8 70 6 1.5 45 17.65 17.75 9 70 8 2.0 60 17.36 13.75 Dye-uptake K1 12.073 17.310 16.640 16.637 K2 17.563 16.050 14.970 16.517 K3 19.113 15.390 17.140 15.597 R 7.040 1.920 2.170 1.040 Fixation rate K 3.250 7.417 11.167 6.333 K 8.833 7.833 9.333 8.250 K 13.333 10.167 4.197 10.833 R 10.083 2.750 6.250 4.500 2.1.2 Mordant Dyeing Take the dyeing temperature, dyeing time, pH value and mordant dosage as the influencing factors to design a L9(34 ) orthogonal experiment, and carry out pre-mordant dyeing, one-bath dyeing and post-mordant dyeing respectively. Considering the conflicts between the toxicity of some metal ions and the study on natural dyestuff, alum (KAL (SO2)2-12H2 O) is used as the mordant (Sivakumar A. et al., 2015). a) Pre-mordant Dyeing Pre-mordant dyeing method: after wetting the fabric, put it in the solution which contains alum mordant to process; after 20min, take it out and put it in the dye bath with natural plant dyestuff; use it for all kinds of index testing after the post-processing of dyeing. Technological process: mordant treatment—rinsing and dyeing. The experimental results are as shown in Table 2. Table 2: The Orthogonal Experimental Results of Adopting Mordant before Dyeing EXPNO A B C D Dye-uptake Fixation rateDyeing temperature (°C) Dyeing time (min) PH range Mordant dosage (%) 1 50 30 6 3 14.81 4.00 2 50 45 8 6 12.39 2.50 3 50 60 11 9 10.21 3.50 4 60 30 11 9 18.44 8.75 5 60 45 8 3 18.21 12.25 6 60 60 6 6 16.78 8.50 7 70 30 11 6 19.79 13.00 8 70 45 6 9 20.34 12.75 9 70 60 8 3 16.44 14.25 Dye-uptake K1 12.470 17.680 17.310 16.487 K2 17.810 16.980 15.757 16.320 K3 18.857 14.477 16.070 16.330 R 6.387 3.203 1.553 0.167 Fixation rate K1 3.333 8.583 8.417 10.167 K2 9.833 9.167 8.500 8.000 K3 13.333 8.750 9.583 8.333 R 10.000 0.584 1.166 2.167 734 Based on the analysis of range R of Table 2, under the pre-mordant condition, it is found that the order of the influences the factors have on the uptake rate in the orthogonal experiment is A>B>C>D respectively, and the order of the influences on the fixation rate is A>D>C>B respectively. Similar to direct dyeing, according to the K value of each factor and judging by the dye-uptake of fiber, the best process is: A3 B1 C1 D1 ; judging by the fixation rate of fiber, the best process is: A3 D1 C3 B2 . Combining the two factors, the best technique of pre-mordant dyeing is determined as: A3 B1 C1 D1, which is the dyeing temperature being 70 °C, the dyeing time being 30min, the pH value being 6, and the mordant dosage being 3%. (Rico-Ramirez et al., 2010) b) One-bath Mordant Dyeing The one-bath dyeing method: after wetting the natural bamboo fiber, put it into a dye bath containing mordant and natural plant dyestuff. After being dyed, the natural bamboo fiber is taken out for reprocessing, and all performance tests are carried out. The experimental results are as shown in Table 3. Table 3: The Orthogonal Experiment Results of One-bath Mordant Dyeing EXPNO A B C D Dye-uptake Fixation rateDyeing temperature (°C) Dyeing time (min) PH range Mordant dosage (%) 1 50 30 6 3 12.41 3.50 2 50 45 8 6 13.55 3.75 3 50 60 11 9 11.78 3.43 4 60 30 11 9 12.67 7.25 5 60 45 8 3 16.55 11.00 6 60 60 6 6 17.39 21.50 7 70 30 11 6 20.72 10.75 8 70 45 6 9 23.44 15.00 9 70 60 8 3 21.27 10.50 Dye-uptake K1 12.580 15.267 17.747 16.743 K2 15.537 17.847 15.830 17.220 K3 21.810 16.813 16.350 15.963 R 9.230 2.580 1.97 1.357 Fixation rate K1 3.567 7.167 13.333 8.333 K2 13.250 9.917 7.167 12.000 K3 12.083 11.817 8.400 8.567 R 9.683 4.650 6.166 3.667 According to the analysis of range R of Table 3, under the condition of one-bath mordant, the influence of all factors in the orthogonal experiment on dye-uptake in order is: A>B>C>D and on the fixation rate is A>C>B>D. Similar to the dyeing method above, according to the value of K of each factor, judged by the up- take rate, the best technique is: A3 B2 C1 D2 ; Judged by the degree of fixation, the best technique is:A3 B1 C3 D2 . Synthesizing the two factors, we concluded that the optimum techniques for the metachrome process are as follows: A3 B2 C1 D2, which indicates that the dyeing temperature is 70 °C and the dyeing time is 45 min. The pH value shall be 6 and mordant dosage 6%. c) Afterchromed dyeing The wetted bamboo fiber is put into a dye bath containing natural plant dyes. Dye after changing the orthogonal factors. The mordant will be added after finishing dyeing and 30 min later, the indicators can be tested after the mordant is treated. Technological process: dyeing, washing. Mordant treatment, washing. The experimental results are shown in Table 4. It is known from the range R analysis in Table 4, under the post-mordant condition, the influencing extent of all factors to the dyeing rate in the orthogonal experiment is A>B>C>D, the influencing extent of them to the fixation rate is A>D>B>C, that is to say, the influence of dyeing temperature to the dyeing result is the most significant, the second one is the bathing time, while the influence of pH value and mordant dosage to the dyeing effect is less. According to the K value of each factor, evaluated on the basis of dyeing rate of fiber, the best process is: A3 B2 C1 D2 ; Judged by the fixation rate of fiber, and the best process is: A3 D1 B2 C3 . Synthesizing two factors, the best one-bath mordant dyeing process is concluded: The best mordant dyeing 735 process is: A3 B2 C1 D2, which means the dyeing temperature is 70, the dyeing time is 45 minutes, the pH value is 6 and the dosage of mordant is 6%. Table 4: The orthogonal experiment results of post-mordant dyeing EXPNO A B C D Dye-uptake Fixation rateDyeing temperature(°C) Dyeing time (min) PH range Mordant dosage(%) 1 50 30 6 3 13.68 4.50 2 50 45 8 6 14.30 5.25 3 50 60 11 9 12.92 5.40 4 60 30 11 9 14.45 5.00 5 60 45 8 3 17.88 13.75 6 60 60 6 6 18.73 6.25 7 70 30 11 6 21.34 6.25 8 70 45 6 9 23.59 13.00 9 70 60 8 3 22.61 19.25 Dye-uptake K1 13.633 14.490 18.667 17.990 K2 17.020 18.590 17.053 18.123 K3 22.447 18.020 17.380 16.987 R 8.814 2.100 1.614 1.136 Fixation rate K1 5.050 7.500 8.000 12.500 K2 8.333 10.750 9.833 8.167 K3 15.167 10.300 10.717 7.883 R 10.117 3.250 2.717 4.617 2.2 Comparison of Staining Methods The bamboo fibers were dyed according to the best processes of dyeing methods above. The dyeing rate and fixation rate were measured and results are shown in Table 5. Table 5: Comparison of Dyeing Effects of Four Dyeing Methods Staining method Direct Dyeing Pre-mordant Dyeing One-bath dyeing Post-mordant Dyeing Dye-uptake rate/% 19.65 22.34 20.67 20.37 Degree of fixation/% 15.75 20.37 18.50 19.56 We can see from table 4 that there is great difference among the dyeing effects of the 4 different dyeing methods to the bamboo fiber, mordant dyeing has a larger dye-uptake and fixation rate than the direct dyeing, which demonstrates that mordant dyeing could make a deeper color of the fiber, the visual mordant dyeing method could make the color of bamboo fiber deeper and better contrasting with that of the direct dyeing method. This is because that the aluminum mordant can enter the fiber, form a reaction in the fiber, so as to improve the rate of dyeing, while among the mordant dyeing, the dyeing effect of the pre-mordant is better than that of one-bath dyeing and post-mordant dyeing, indicating that the natural vegetable dye, Coptis chinensis, it is suitable to adopt the pre-mordant dyeing method in staining bamboo fiber (Lee et al., 2017). 3. Test of colour fastness to dyeing fibre after coptis dyeing Colour fastness is one of the important indexes of judging dyeing product quality, which is extremely important for evaluating the dyeing of natural plant dyestuff. Color fastness to perspiration and soaping of four optimal dyeing methods are shown in Table 6: As seen from Table 6, after being dyed by the natural plant dyestuff Coptis, the bamboo fiber had a good color fastness to soaping, which reached grade 3 or above. Whether it is mordanted or soaped, its soaping fastness was greatly improved as compared with the direct dyeing. However after dyeing with natural vegetable dyestuff Coptis chinensis, the color fastness to perspiration of original bamboo fiber is relatively poor, which is completely below Grade 3. Whether it is through direct dyeing or mordant dyeing, the fastness to perspiration is poor. 736 Table 6: Comparison of the colour fastness of different dyeing methods Staining Method Degree/grade of soaping color fastness Degree/grade of color fastness to perspiration Alkaline perspiration Acidic perspiration Original sample discoloration Cotton staining Original sample discoloration Cotton Staining Original sample discoloration Cotton Staining Direct dyeing 3 3-4 2-3 2-3 2-3 2 Pre-mordant Dyeing 3 3-4 2-3 2-3 2-3 2-3 One-bath dyeing 3-4 4 2 2-3 2 2-3 Post-mordant dyeing 3-4 3-4 2 2-3 2 2-3 Note: Soaping after dyeing refers to the process in which the bamboo fiber first go through all kinds of dyeing and then be treated with soaping. 4. Breaking property testing of the dyeing fiber dyed by coptis chinensis The breaking strength and elongation is also one of the important factors for measuring products dyeing quality. To test breaking strength and elongation of byeing bamboo fiber to prove that the dyeing effect on mechanical properties of dyeing fiber is particularly important for the evaluation of dyeing of natural plant dyes. 4 methods for dyeing bamboo fiber: pre-dyeing breaking strength, post-dyeing breaking strength, pre-dyeing breaking elongation and post-dyeing breaking elongation, see Table 7. Table 7: Breaking property of bamboo fiber before and after dyeing by coptis chinensis Dyeing method Direct dyeing Pre-mordant dyeing Apposition dyeing Post-mordant dyeing Before bleaching Breaking strength (context) 3.93 3.93 3.93 3.93 Elongation /% 12.38 12.38 12.38 12.38 After bleaching Breaking strength (context) 3.88 3.88 3.88 3.88 Elongation/% 11.86 11.86 11.86 11.86 After dyeing Breaking strength (context) 4.09 4.22 4.11 4.19 Elongation/% 3.5 4.3 3.9 2.3 Note: During the process of testing single fiber, it is discovered that the strength unevenness of bamboo fiber is on the high side. The key reason is that bamboo fiber has obviously uneven thickness. (Park et al., 2013) According to Table 7, the breaking strength of all bamboo fibers dyed by coptis chinensis increases, especially after mordanting, the breaking strength of bamboo fibers is relatively stronger than that after direct dyeing; But the breaking elongation of bamboo fiber after dyeing accordingly turns small, the reason may be that after dyeing, the mechanical property structure of bamboo fiber is broken, resulting in the decrease of breaking elongation. 5. Conclusion Coptis chinensis has best dyeing effect by using pre-mordant dyeing. Apposition dyeing can be used to dye bamboo fiber. Temperature and PH value have the biggest effect on the dyeing rate and the fixation rate. The dyeing temperature should not be too high, and the PH value should be controlled between 9 and 11. Through orthogonal test and extreme difference analyzing, the best pre-mordanting process of coptis chinensis to bamboo fiber is: A3 D1 C3 B2. Combining the two factors, the best process is: A3 D1 C3 B2. Combining the two factors, the best pre-mordanting process is: A3 B1 C1 D1, namely, the dyeing temperature is 70 °C, the dyeing time is 30min, PH value is 6, the mordant dosage is 3%. In direct dyeing and pre-mordanting, the dyeing temperature of the dye liquid has the greatest effect on the dyeing rate and fixation rate. In pre-mordanting and post-mordanting, the temperature and dosage of the mordant are both relatively important factors. The deepening effect of pre-mordanting is relatively remarkable. In all, after alum mordanting, the dyeing effect of bamboo fiber is better. The best dyeing temperature corresponding to alum is: 70 °C. 737 Soaping has certain effect on the dyeing fiber and makes the color of dyeing fiber shallow, while soaping color fastness of bamboo fiber is good and all reaches level 3 or above level 3. The soaping color fastness value can be increased through soaping after mordanting, but the improvement degree of mordant to soaping color fastness is not obvious. However, the color fastness to perspiration of dyeing fiber after dyeing is generally poor, which requires improvement. The mordant is not very helpful in improving the color fastness to perspiration. All the breaking strength of bamboo fiber increase after dyeing by coptis chinensis, especially the breaking strength of bamboo fiber after mordanting is stronger than that after direct dyeing. However, the breaking elongation of bamboo fiber after dyeing decreases accordingly, the reason may be that the mechanical property structure of bamboo fiber is destroyed after dyeing, resulting in the decrease of breaking elongation. Acknowledgments Supported by a project grant from Central Government Funds: “Clothing apparel industrial design center of Fujian Province” The Academician Workstation for Textile Research Institute of Minjiang University (No.3140420402). Reference Kalla S., Marcoux H., De Champlain A., 2015, CFD approach for modeling high and low combustion in a natural draft residential wood log stove, International Journal of Heat and Technology, 33(1), 33-38, DOI: 10.18280/ijht.330105 Lee Y.H., Lee S.G., Hwang E.K., Baek Y.M., Cho S., Kim H.D., 2017, Dyeing properties and deodorizing/antibacterial performance of cotton/silk/wool fabrics dyed with myrrh (Commiphora myrrha) extract. 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