不同脱胶方法对野生苎麻纤维性能的影响

分别采用化学脱胶、微生物脱胶和微生物-化学联合脱胶3种方法对野生苎麻进行脱胶,测试了脱胶纤维的性能,并与人工种植苎麻进行了比较.结果表明在一定条件下,经3种不同方法脱胶后的野生苎麻纤维,残胶率最低为4.08%,最小细度为5.89 dtex,最大强度为5.59 cN/dtex,最大断裂伸长率为4.71%.     

Effects of enzymatic treatments on the mechanical properties of corn husk fibers

Corn husk fibers were extracted by water retting, alkalization, and enzymatic processes at different concentration and duration levels. The effects of extraction process parameters on the mechanical and thermal properties and chemical characteristics of corn husk fibers were investigated. Chemical structures of the fibers were studied by IR measurements. The finest and the stiffest fibers were produced by water retting followed by an enzymatic treatment. The highest breaking strength and breaking tenacity were obtained by water-retted fibers. While resulting in loss of breaking tenacity and elongation in water-retted fibers, enzymatic treatment resulted in increase in initial moduli and breaking tenacity of alkalized fibers. No significant effect of enzymatic treatment duration was obtained on the mechanical properties of corn husk fibers. Alkalized fibers gave higher elongation and lower stiffness compared to water-retted ones. The IR spectra showed higher amount of lignin and hemicellulose in water-retted fibers compared to alkalized and enzyme-treated ones. Enzymatic treatment and alkalization enhanced the thermal durability of the fibers. The ranges for properties of the produced corn husk fibers can be summarized as a linear density 17.0–25.6?tex, initial modulus 150.9–401.8?cN/tex, breaking tenacity 6.8–21.7?cN/tex, and elongation 9.6–18.2%.     

Evaluation and Impact Factors of the Mechanical Properties of Phloem Bundle Fibers Obtained from Kenaf Germplasm

The mechanical properties of kenaf phloem bundle fibers are valuable for reinforced composites or boards, more so than similar materials also used in textile or papermaking applications. 55 kenaf germplasm studied here showed an average phloem bundle fiber tensile strength of 643.6 MPa and an average elastic modulus of 23.3 GPa after chemical retting treatment. 19 of these kenaf germplasm had fiber tensile strengths >700 MPa, which can be attributed to intensive breeding programs. The fiber tensile strength and elastic modulus of kenaf germplasm had a significant positive correlation, but there was no such correlation between a fiber’s mechanical properties and its diameter or agronomic characteristics. Among 56 hybridized combination F₁ generations, the highest tensile strength was 928.3 MPa from a combination of No.30 of Xinan Wuchi × Guatemala 4. Therefore, breeding and screening are both useful for improving the mechanical properties of kenaf phloem bundle fibers. However, the effects of the used bundle fiber preparation method or cultivation year on the fiber’s mechanical properties were more pronounced than those of the type of kenaf germplasm or breeding operation used. The mechanical properties of kenaf phloem bundle fibers treated by chemical retting were superior to those treated using natural retting.     

Effect of Inoculation of Pectinolytic Mixed Bacterial Culture on Improvement of Ribbon Retting of Jute and Kenaf

Abstract

Jute and kenaf are among the annually renewable fibre crops mainly grown over tropical and subtropical Asian countries. They are possibly the world's largest source of lignocellulosic bast fibre which is extracted from plants by a natural microbial process known as retting. But acute shortage of water for retting and the environmental pollution created from conventional system of retting has demanded for new method of retting.

The new method of retting launched has been recognized as ribbon retting. In ribbon retting barks are removed from jute and kenaf plants mechanically or manually in the form of ribbon. The ribbons are coiled and then allowed for retting in water with or without using a microbial inoculum. Ribbon retting has the following advantages over conventional retting: (1) It requires lesser volume of water, (2) it is faster, (3) it produces lesser environmental pollution, and (4) it produces improved quality fibre. Addition of efficient pectinolytic microbial inoculum may further boost up or improve the ribbon retting process.

From the present study it is understood that inoculation of a specific mixed bacterial culture in combination with 0.5% urea as N-supplement caused faster ribbon retting of jute and kenaf. Ribbon retting conducted in cement retting tank was faster than that in polythene tank. The mixed bacterial culture in combination with urea produced stronger, finer and brighter coloured jute and kenaf fibre in comparison to uninoculated control. One hundred twenty-day-old plant was found most suitable for ribbon retting. Ribbon retted fibre with pectinolytic mixed bacterial culture in combination with urea obtained higher grade in comparison to uninoculated control. Such ribbon retted fibres produced standard and regular quality yarn.     

Screening and identification of Acinetobacter junii for Apocynum vernetum L. fiber enzymatic retting

There are many kinds of ketones with antisepsis functions in the Apocynum vernetum L. fiber (ALF), but its enzymatic retting is difficult. In order to select the appropriate ALF enzymatic retting strain, wastewater from ALF retting was analyzed to screen a strain with high pectinase activity. Of the analyzed strains, the maximum pectinase activity measured was of the #2 strain: 103.2 IU/ml at a zymogenic time of 12 hrs at 37°C. The retting experiments verified that this strain was well suited for ALF; the residual gum rate of ALF was 15.26% and its fiber physicochemical properties were similar to those fibers which were chemically retted. The strain was determined to be a new retting strain, Acinetobacter junii, according to a 16S rDNA sequence analysis in combination with morphology, and biophysical and biochemical tests using fermentation, catalase, methyl red and gelatin liquefaction. As a new pectinase‐producing strain, Acinetobacter junii could be utilized in industrial enzymatic retting productions after further process optimization and can replace the conventional chemical retting process due to its improved fiber quality and reduced environmental pollution.     

天然竹纤维的再脱胶染色与织物性能

介绍了天然竹纤维的性能特点,以及天然竹纤维的再脱胶工艺,并对几种脱胶工艺的染色性能进行了对比分析.对几种天然竹纤维混纺织物的性能进行了比较,提出天然竹纤维在刚性、滑爽性、柔软度、尺寸稳定性等方面都适合开发穿着面料.     

Flax retting by degumming composite enzyme produced by Bacillus licheniformis HDYM-04 and effect on fiber properties

Flax enzymatic retting with composite enzyme produced by microbes with inexpensive substrates is widely researched due to less contamination and lower cost. Bacillus licheniformis HDYM-04, isolated from a liquid sample of flax retting pool, efficiently produced degumming enzymes after 48 h of fermentation with inexpensive konjaku flour, consisted of 587.5 U/mL pectinase, 365.2 U/mL mannanase, and 140.1 U/mL xylanase. Almost half the maximum activity of three above-mentioned degumming enzymes was maintained at pH 4.0–6.0 which demonstrated its stability in pH condition of flax retting. After 120 h of retting with this composite enzyme, scanning electronic microscopy showed more significant reduction in gummy components on the fiber surface than those of water retting. The fiber strength was 182.4 ± 9.3 N, 14.3% higher than water-retted samples. The long fiber rate and fiber yield also verified higher fiber productivity. The results permitted this degumming composite enzyme an applicable potential in flax retting.     

大麻快速脱胶菌株的选育与脱胶性能鉴定

 针对以烧碱蒸煮为中心的大麻化学脱胶工艺存在脱胶质量不稳定,纤维强度和出麻率低,环境污染严重等问题,进行了大麻脱胶菌株的选育与脱胶性能鉴定的研究。通过广泛采集菌样,初筛、复筛和诱变育种,获得了1株在16 h内完成大麻脱胶的快速脱胶菌株;在实验室条件下,该菌株进行大麻生物脱胶具有脱胶周期短,纤维产量高和品质好等特点;与传统水沤法相比,缩短脱胶周期90%以上,干茎出麻率提高2.1%,束纤维强力提高7.9%,且纤维颜色浅,质地均匀,光泽好。     

Comparison of the performance of kenaf fiber using different reagents presoak combined with steam explosion treatment

To enhance the degumming effect of steam explosion on kenaf fiber, different chemical reagents including hydrogen peroxide (H₂O₂), sulfuric acid (H₂SO₄), and sodium hydroxide (NaOH) presoak combined with steam explosion were used and compared in this article. Distilled water coupled with steam explosion treatment and kenaf raw samples were used as control. The fiber morphology, chemical composition, crystalline structure, degree of fineness, and breaking tenacity of kenaf fibers after treatment were studied. The results showed that hydrogen peroxide (H₂O₂) performs better on removing lignin. It not only splits fibers, but also keeps the fiber’s tenacity during steam explosion treatment. Dilute sulfuric acid (H₂SO₄) performs better on hemicellulose removal, but it damages the fiber cellulose during steam explosion treatment and cause the fiber strength decrease a lot. Sodium hydroxide (NaOH) performs the best on removing hemicellulose and lignin, and splits fiber well. However, the breaking tenacity of the fiber is lower than the fiber pretreated by H₂O₂. Besides, NaOH is a pollutant to the environment. In conclusion, H₂O₂ could be considered as the most promising reagent to be used in combined presoak-steam explosion system.     

Diversity and Characteristics of Kenaf Bast Degumming Microbial Resources

Kenaf is one of the most important natural fiber crops. Traditional degumming with water retting causes serious environmental pollution and reduces the quality of fiber products. The development of kenaf industry is hindered by high production cost. Microbial degumming is suitable for kenaf bast degumming because of its high efficiency, energy conservation, low pollution, and high quality, among others. Through enrichment and screening from water sample, soil sample, and humus sample, we concentrated and identified 92 bacterial strains that could degrade kenaf bast colloid. The strains belonged to 11 genera and 16 species. Five of these strains did not produce cellulase and the weight loss rate of the kenaf bast fiber raw material was more than 20%. These strains belonged to Bacillus subtilis, Paenibacillus polymyxa, Clostridium acetobutylicum, Bacillus alcalophilus, and Erwinia chrysanthemi and were assigned with serial numbers from K1–K5, respectively. This study is the first to report the function of Bacillus pumilus, B. alcalophilus, Clostridium tertium, Brevibacillus brevis, Pectobacterium carotovora, E. chrysanthemi, and Tyromyces subcaesius in kenaf bast degumming. Pectinase and mannanase were the key enzymes in the degumming of kenaf bast.     

Extraction of Unconventional Bast Fibers from Kydia calycina Plant and their Characterisation

The Kydia calycina fibers were screened out from various plant sources through the water retting method and then the time duration for extraction of fibers was optimized. After optimization, the extracted Kydia calycina fibers were compared with cotton, flax, and jute fibers on the basis of physical and mechanical properties. The morphology of extracted fibers was also studied through SEM. The results showed that the Kydia calycina plant produces better quality bast fibers with respect to plants like jute and flax.     

Study on Reuse of Coconut Fiber Chemical Retting Bath. Part II---Recovery and Characterization of Lignin

Study aimed at recovery of lignin from the reused residual liquor of chemical retting bath of coconut fiber caused by partial delignification to make it soft. The lignin of 8.9% was obtained after recovery (maintaining pH 2.0 for 1 h at ambient temperature) and further purification. Extracted lignin is characterized through FTIR, TGA and particle size analysis. FTIR showed absence of polysaccharides in purified lignin. TGA indicates presence of higher methyl-aryl ether groups than aromatic groups in lignin of coconut fibre. Analysis reveals about 91% of particles in the rage of 1–500 µm, which shows its good dispersiblity in fluid. Recovery of lignin associated with two benefits i.e., diversified use of extracted pure lignin and reduction of organic load of the waste liquor to make it suitable for discharge.     

Review of Some Factors Influencing Jute Fiber Quality

Different factors that influence the production of quality jute fibers are presented. These include the soil, retting, and jute genotype. Several soil quality parameters influence fiber quality. Different aspects of retting, right from quality and quantity of retting water, microorganisms with balanced pectinolytic and xylanase activities with minimal or low cellulase activities, largely determine fiber quality. Efficient pectinolytic bacteria as well as fungi could be used in retting process. Future research needed in this respect has been expressed.     

Solid State 13C NMR and Diffuse Reflectance Mid-Infrared Spectroscopic Analysis of the Effects of Retting on the Chemical Composition of KenafFibre

Bast ribbons from Tainung 1 (T₁) and Guatemala 45 (G₄₅) cultivars of kenaf ( Hibiscus cannabinus ) were subjected to a chemical retting process. The resulting changes at the base and tip regions of each cultivar were analysed using solid-state ¹³C NMR and diffuse reflectance mid-infrared spectroscopies. Chemical retting was performed by boiling the substrates in NaOH (70 g litre⁻¹) +NaHSO₃ (5 g litre⁻¹) for 1 h, after which they were neutralised, washed and air dried. This process produced large decreases in the non-cellulosic components, though 25% of the phenolic component was left undegraded, and cellulose crystallinity was increased by ∽5% over that in unretted samples.     

亚麻快速生物脱胶技术应用研究

 对亚麻快速生物脱胶技术进行了研究。结果表明,与常规温水沤麻方法相比,该技术具有脱胶周期短、纤维产量高、品质好、效益高和环境污染轻的特点,其中,脱胶时间缩短70%以上,长麻率提高3～4个百分点,纤维品质大幅度提高,生化需氧量BOD5和悬浮物SS排放总量分别减少33%和89%以上;每加工1t原茎产生直接经济效益270元以上,经济、社会和生态效益十分显著。     

蒽醌助剂对乙二醇溶剂脱胶苎麻纤维性能的影响

为解决苎麻在乙二醇有机溶剂脱胶中纤维易被氧化而导致性能下降的问题,在乙二醇溶剂中添加助剂蒽醌对苎麻进行脱胶,并对蒽醌不同添加量下制得的纤维进行结构和性能表征。结果表明:纤维中半纤维素含量随蒽醌添加量的增加而升高,纤维的聚合度、结晶度、物理力学性能先升高后降低,纤维的残胶率和线密度先降低后升高;当蒽醌质量分数为0.3% 时,这些性能均达到最佳值,此时纤维的聚合度、结晶度、制成率、断裂强度、断裂伸长率、断裂功比不加蒽醌时分别提高了7.32%、20.53%、1.46%、9.55%、6.89%、33.33%,纤维的残胶率、线密度比不加蒽醌时分别降低了17.91%、7.24%。     

温水沤麻废水再生的微生物种群研究

通过对温水沤麻废水微生物种群的分析与研究,对沤麻废水再生利用的方式和技术进行了归纳,并提出了应该注意的事项。     

脱胶方法对棉秆皮纤维成分及结构的影响

对原棉秆皮不同部位进行化学成分分析,利用常温水沤、常压脱胶及高压脱胶对棉秆皮进行处理,对脱胶后棉秆皮进行化学成分分析.实验结果表明:高压脱胶后棉秆皮纤维中的半纤维素和木质素含量下降最为明显,纤维素含量提高.对不同方法处理后的棉秆皮纤维的长度、线密度进行测量,用SEM、FT-IR、XRD对处理后的棉秆皮纤维表面形态结构、聚集态结构进行了表征,同时对脱胶后的棉秆皮纤维进行强伸性能等测试并得出断裂曲线.     

苎麻生物酶脱胶工艺研究

主要研究了苎麻的生物酶脱胶工艺。将生物酶脱胶后的精干麻与传统化学脱胶精干麻进行性能对比,得出生物酶脱胶精干麻的残胶率、断裂强力、柔软性均高于化学脱胶法,生物酶脱胶工艺煮液的COD值明显低于化学脱胶法的,对环境的污染小。通过正交试验得出苎麻生物酶脱胶的最佳工艺条件为SC0URZYME301用量15％,温度50℃,浸酶时间2h,堆置时间16h。     

韧皮纤维生物脱胶制浆的研究及发展

简单介绍了果胶的结构、化学组成及生物脱胶机理,详细总结了韧皮纤维酶法和发酵浸渍法脱胶制浆的研究、应用和发展情况,并对影响发酵浸渍法制浆原料和脱胶菌株的特性,特别是脱胶过程中主要外界因子进行了综述.