| Kapok fiber is a type of natural cellulosic fiber. Because of the unique structure, it is extensively applied to many fields. Traditionally, it was utilized as packing materials, sorbent materials and non-woven fabrics in Southeast Asian countries. Recently, kapok fibers have been blended with cotton fibers to apply as clothing fabrics, but little study on this field. The research on finishing technology and wearing comfort of kapok fabric could improve the wearability and enhance added value of product, further expand its application. Therefore, based on the structures and properties of kapok fiber, this paper studies the finishing technology and wearing comfort of product in order to enlarge the applied scope of kapok fibers.1.Compared with cotton fiber, the microstructure and surface wetting ability of the kapok fiber had been investigated.The kapok fiber shows a unique morphology with hollow lumen, thin cell walls, and two closed ends in nature. The kapok fiber and cotton fiber have complex pores distributed in range,from broad mesoporous to less macroporous. Compared with cotton fiber, kapok fiber has more variation in dimensions range of porosity. The specific surface area of kapok fiber (13.124m2/g) is more than that of cotton fiber (0.6581m2/g), and its porosity is about 102.2030% which is also more than that of cotton fiber (91.5715%), therefore interior structure of kapok fiber is looser than that of cotton fiber. kapok fiber has the same characteristics of the absorption spectrum band with cotton fiber, except lignin characteristic spectra. Compared with cotton fiber, kapok fiber has lower crystallinity and thermal stability. Untreated Kapok fiber and cotton fiber belong to low surface energy materials, but kapok fiber is more hydrophobic than that of cotton fiber, its polarity component (-4.16 mN/m) is smaller than that of cotton fiber (-3.78 mN/m).2?Based on the structures and properties of kapok fiber, this paper had been studied influence of alkali on micro-structure and properties of kapok blended yarns for the first time. To investigate the influence of alkali treatment with different mass concentrations of NaOH on structure and properties of blended yams with various kapok fiber content, FTIR spectra, x-ray diffraction(XRD), weight loss analysis, capillary rise height, exhaustion and mechanical properties of yarns were observed before and after alkali treatment.The results show that after scouring process, the weight loss and capillary effect of fabric significantly increase but breaking strength less increased with increasing kapok fiber content,treated fabrics have good wettability, meanwhile, compared with cotton fabric, wetting property of kapok/cotton blended fabric more improved and polarity component of surface free energy more increased.After alkali mercerization process, without any apparent change of cellulosic chemical compositions, indicating that alkali treatment had little influence on the chemical composition of the cellulose. Meanwhile, lignin characteristics of the backbone benzene rings corresponding to main peaks significantly reduce and almost disappear in original positions, indicating that alkali solution could dissolve lignin in kapok fiber and generate alkali-lignin. In the meantime,mercerization treatment lead to lower degree of crystallinity for blended yarms by destroying crystalline structure and finally parts of cellulose ? were transformed into cellulose ?. Meanwhile,as the content of kapok fiber increased, the hygroscopicity of yarns significantly improves while the increased value of breaking strength is less. However, the higher kapok fiber content, the lower dye exhaustion and light color together with negative chromatism. In contrast to different alkali treatment processes, it could be found that kapok fiber has rather poor alkali resistance than cotton fiber. Therefore, relatively mild alkali treatment conditions for kapok fiber must be necessary in dyeing and finishing processes.3. For the first time, the adsorption mechanism of kapok blended fabric and cotton fabric on flame-retardant finishing had been studied.Through static and dynamic experiments of adsorption phosphorus, model of adsorption and the attractive factor were obtained by dynamics model and thermodynamic model, effect of fiber structure on adsorption in solid-liquid system was analyzed. The results show that the adsorption process of fabric to phosphorus presents rapid speed in earlier stage, and then gradually decreased.While adsorbed amount of kapok blended fabric to phosphorus is higher than that of cotton fabric.By means of the data of adsorption kinetics experiments, the result shows dynamics model of kapok blended fabric belongs to second order reaction, as well as that of cotton fabric, and its second order reaction kinetic equation is dqt/dt=0.0202(4.63-qt)2,that of cotton fabric is dqt/dt=0.0169(3.67-qt)2.The static absorption experiment results indicated that the adsorption performance of kapok blended and cotton fabrics to phosphorus obeyed the Langmuir-Nemst equation. Adsorbed amount of kapok blended fabric to phosphorus is higher than that of cotton fabric, which obtains the same conclusion as adsorption kinetics experiments. Langmuir-Nemst equation of kapok blended fabric is qe=O.0324ce+0.328ce/1+0.3794ce , that of cotton fabric is qt=0.0244ce+0.03776ce/1+0.4353ce. Mechanism of fabric adsorption to phosphorus in two componentadsorption behavior is primarily due to physical association. There exists no difference on adsorption amount of Langmuir adsorption between kapok blended fabric and cotton fabric, but the Nemst adsorption amount of kapok blended fabric to phosphorus is higher than that of cotton fabric, and this results that the total adsorption amount of kapok blended fabric to phosphorus is higher than that of cotton fabric, the reason for the difference lies in fiber structure.4?For the first time, technology optimization of flame retardant finishing and product structure property of kapok blended fabric had been studied.Through analysis experiment of single factor affecting flame retardant property, the scales of the main procedure parameter are determined. Based on the analysis experiment of single factor,by means of the rotational composite design of quadratic regression, the mathematical model of kapok blended fabric between the parameter (Flame Retardant x1,linking agent x2, temperature x3,time x4) and the flame retardant property is Y1=11.53-0.5958X1-0.1958X2-0.1125X3-0.2875X4--0.1124X22-0.08735X32-0.1624X42+0.1313X3X4, the mathematical model between flame-retardant parameter and mechanical properties is Y2=1023-15.04X1-84.38X3-17.67X32+17.94X2X3.Based on optimization mathematical model, optimization technology was obtained, the best flame-retardant technology conditions are as follows: 380g/L CP, 81.8 g/L6MD, temperature 156?, time 4.7minutes.Through discussing the 3-D graphics contour line of factor and flame-retardant property, the results show that the relationship and influence between the concentration of flame-retardant and temperature are the most for flame-retardant quantity on damage charcoal length, the concentration of flame-retardant has more significant effects on damage charcoal length than that of temperature. When flame-retardant concentration is biggest and temperature is highest, damage charcoal length is smallest. While the influence of flame-retardant quantity on tensile strength is less, while temperature have greater influences on tensile strength, and effect is significantly especially interaction with linking agent.By measuring microstructure and thermal stability of kapok blended fabric and cotton fabric before and after flame-retardant finishing, it had been found that flame-retardant finishing on kapok blended fabric is more uniform than that of cotton fabric. There exists the characteristics of the absorption spectrum band of CP flame-retardant in IR spectrum of kapok fabric after flame-retardant finishing, and the absorption strength of -OH functional group lessens greatly too.After flame-retardant finishing, the amount of char residue of kapok blended fabric increase remarkably, thermal cracking temperature significantly decreases and the flame-retardant property increase clearly.5.For the first time, effect of structure and content of kapok fiber on moist conductivity had been studied, the moist conductivity gradient model of woven fabric was established based on plant structure effect, and then moist conductivity double fabric containing kapok fiber was built.The polynomial synthesis of moist conductivity of kapok blended fabric was calculated and analyzed, effect of weave structure and moist conductivity path on moist conductivity properties of double fabric containing kapok fiber was studied. And grey cluster analysis and evaluation system was used to make a comprehensive evaluation for thermal-moisture comfort of the kapok blended fabrics.The results show fabrics with high content kapok fiber have better moist conductivity than that of cotton fabric. Under the optimized conditions, kapok fiber content and wick high demonstrates good linear relationship, while kapok fiber content and diffusion areas demonstrate good linear relationship.Different moist conductivity of fibers, different density ratio, different weaves structure,different yarn thickness, when paired with among multilayer, create the moist conductivity gradient model of woven fabric. Based on the model, double fabric owing moist conductivity containing kapok fiber has been built, that which is kapok/cotton blended yarn interweave with coolmax in double layer, pore gradient structure is formed by loose and tight weave between double layer, weft yarn coolmax link double layer, and this model fabric has proved to own excellent moist conductivity by the polynomial synthesis calculation.Mechanism for the moist conductivity gradient model of woven fabric is based on the Fick law and differential capillary effect, liquid water transfer by diffusion transfer at a short distance,and liquid water transfer by differential capillary effect at a long distance.Though 8 samples polynomial synthesis analysis, and found that high content kapok fiber fabrics have better moist conductivity than that of cotton fabric with same specification and weave,fabric owing the moist conductivity gradient structure have better moist conductivity than that of conventional fabric with same specification and difference weave. Evaluation thermal-moisture comfort properties of kapok blended fabrics shows kapok/cotton blended fabrics have good warmth retention properties, the rate of warmth retention is significantly higher than that of cotton fabrics, the hot sense is little better than that of cotton fabric. Samples made of kapok fiber have better thermal-moisture properties under high or low humility conditions by grey cluster analysis and evaluation system.Kapok fiber has extraordinary void content, large specific surface area, loose structure,excellent moisture absorption and interface absorbability, therefore, good interface absorbability could improve absorption amount of fabric to finishing agent in process, and improve functionalism of finishing. Meanwhile, combining with fabric construction and design, using kapok fiber properties, good moist conductivity of fabric could be designed by using kapok fiber. |
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