Analysis of Ethylene Glycol Degumming Process and Characterization of Hemp Fibers

To overcome the shortcomings of traditional degumming process,an efficient and environmentally friendly ethylene glycol(EG) degumming process was adopted to degum hemp fibers.The surface morphology,chemical composition,chemical structures,and mechanical properties of the fiber samples were analyzed to explore the mechanism of the degumming process.It was found that the EG degumming process could be divided into the main degumming stage(heating) and the supplementary degumming stage(insulation).The removal rates of hemicellulose and lignin in the main degumming stage were 70.56% and 60.17%,respectively.In the supplementary degumming stage,9.95% hemicellulose and 25.39% lignin were removed.It is confirmed that EG can separate hemp fibers effectively with less damage,which holds great potential for the biomass fiber separation technology.

Optimization for Microbial Degumming of Ramie with Bacillus subtilis DZ_(5) in Submerged Fermentation by Orthogonal Array Design and Response Surface Methodology

As a kind of natural fiber,ramie fiber has distinctive advantages in textile application,but the application is limited due to the traditional degumming mode.Compared with the traditional degumming process,the microbial degumming process has many advantages.To obtain the optimal conditions for degumming ramie with Bacillus subtilis DZ_(5)(BS DZ_(5)),a combined statistical approach of orthogonal array design(OAD)and response surface methodology(RSM)was used.The influences of initial pH of the bacteria medium,culture temperature,shaking speed,degumming time and inoculum size on submerged fermentation degumming were evaluated by using fractional factorial design.The main factors in the analysis were culture temperature,shaking speed and initial pH.The residual gum mass fraction was used as the optimization index,and the optimal conditions for degumming were determined by central composite design and RSM.Thus with only a limited number of experiments,an optimal ramie microbial degumming condition was found as the culture temperature of 40℃,the initial pH in the culture medium of 8.5,the shaking speed of 205 r/min,the degumming time of 96 h and the inoculum size of 5%.After microbial degumming of ramie under the optimal conditions,there was only 10.6%residual gum by mass in the fiber.In addition,the effective degumming of BS DZ_(5)was also confirmed by a scanning electron microscope(SEM).

Production of Pectinolytic Enzymes by Two Bacillus spp. Strains and Their Application in Flax Degumming

This study demonstrated that Bacillus licheniformis HDYM-03 and Bacillus megaterium HDYM-09, isolated from a liquid sample of fl ax retting pool, were able to produce pectinolytic enzymes using polysaccharides as substrates. Bacillus megaterium HDYM-09 produced pectin lyase that exhibited the highest activity of 2116.71 ± 11.55 U/mL. Bacillus licheniformis HDYM-03 produced pectate lyase that exhibited the highest activity of 611.21 ± 14.54 U/mL. Based on these fi ndings, we constructed four retting systems to degrade the pectin substance. The results showed that the content of galacturonic acid in the mixed system was 529.21 μg/mL, the content of reducing sugar was 98.14 mg/mL, and the weight loss ratio of cells reached 19.49%, which were signifi cantly higher than those in other systems. The mixed system has more advantages, and the utilization rate of degumming was higher, which further ensured that the degumming can be carried out effi ciently and quickly. The mixed system exhibits feasible applications in the fi ber and textile industry.

Degumming of Silk Fibers by CO₂Supercritical Fluid

This paper is to study a new method to remove sericin from raw silk fiber. This new process is done using an organic acid as a pretreatment and then using CO2 supercritical fluid to remove sericin from silk fiber. This method would be a huge break from the traditional environmentally unsustainable methods used today. This new processing method keeps the removed sericin in a clean state that can be used as a highly marketable silk protein in the medical and cosmetic industries.

Tentative Research of Short Process of Jute Degumming and Bleaching

The feasibility of combination process of jute degumming and bleaching with alkali-hydrogen peroxide in one-step-one-bath was discussed. The combination process basically has the similar function as the traditional two-step-two-bath method. The factors such as hydrogen peroxide concentration, CBI concentration, sodium hydroxide concentration, treatment time and temperature were studied respectively, and then an orthogonal experiment was designed to study the interactions among the hydrogen peroxide concentration, CBI concentration, sodium hydroxide concentration. After the designed experiments, the optimum treatment conditions were obtained as follows: hydrogen peroxide of 12g/L, sodium hydroxide of 4g/L, CBI of 4g/L, JFC of 1g/L, treatment time of 60min and temperature of 75℃.

Impact of Hydrogen Peroxide/Thiourea Redox Pretreatment on the Performances of Degummed Fibers for Apocynum Degumming

The degnmming pretreatment mechanism was investigated to improve degnmming performance and the spinnability of degummed fibers. Apocynum was treated with redox system in the degumming pretreatment process and the pretreatment parameters had been optimized, besides the effects of pretreatment on property index of degnmmed apocynum fiber were investigated. The results showed that the redox system degumming process reduced alkali boiling time and had good advantages over the traditional degumming process in extraction rate, single fiber length and strength. SEM was used to test the longitudinal morphology changes of fibers before and after pretreatment. At the same time, pretreatment solution was analyzed by UV spectra and electron paramagnetic resonance spectrometer （ESR）, and its pH value was also tested. The results showed that the pretreatment solution could release acid constantly to keep the stability of the pH which caused the swelling and dissolution of pectic substances in apocynum bast. Meanwhile, pretrcatment solution could activate the free radicals from apocynam bast and reduce the activation energy of non- cellulosic composition in apocynum bast.

Green Degumming of Silk by Enzyme Extracted from Natural Sources

The main objective of this work is to degum the silk with natural enzyme in lieu of conventional degumming to make it sustainable. Fibroin and sericin are the main composition of silk. Sericin provides a harsh and stiff effect of silk and decreases the valuable property like luster and whiteness and also leads to uneven dyeing. It is necessary to remove this sericin for the better post processing of silk. The removal process of sericin from silk is called degumming. Usually degumming process is done by using chemicals like soda (Na2CO3), detergent and other chemical staffs. But these chemicals are lethal to the environment. So, if such component found that can be substitute the fatal components and give the same required result or very close then that would be considered as an asset. This work deals with the different enzymes extracted from natural sources such as papaya skin, pineapple skin and guava leaf with variation of enzyme concentrations such as 10 (%), 15 (%) & 20 (%) as well as 35°C 45°C & 55°C temperatures that influence the degumming efficiency. By analyzing the various samples on the basis of degumming efficiency and other tests such as tensile strength, water vapor permeability, pilling and abrasion, crease recovery, whiteness test and spot test are done by standard method, it is found that the enzyme extracted from papaya skin shows the best degumming efficiency 15.9 (%) and other tests also show the good result at 15 (%) concentration and 45°C temperature whereas degumming efficiency 16.6 (%) for conventional process. From this work, it can be concluded that enzyme extracted from papaya skin can be substituted of conventional degumming which is also ecofriendly.

Research of Degumming Process, Microstructure and Properties of Mulberry Fiber

More and more novel nature fibers are used in textiles. The natural fibers include banana fiber, pineapple fiber and bamboo fiber etc. In this paper, as a kind of novel natural fiber, mulberry fiber is studied. The chemical component of mulberry bast is tested and analyzed. Meanwhile, the degumming method and process of mulberry bast are studied. Chemical degumming experiments to investigate the influence of alkali concentration, alkali boiling time and sodium phosphate tribasic ratio to material are conducted. Consequently, optimum parameters are obtained. The crystallinity of mulberry fiber is tested by using X-ray line, and the photos of scanning electron microscope （SEM） are observed. Testing results of the fiber properties （e. g. fineness, tenacity, length and elongation） show that mulberry fiber can be spun blend with cotton.

The Preliminary Study on the Small-scale Test of the Microbial Quick-degumming Ramie

During the experiments with low temperature plasma treating the ramie degumming microbe,the authors found some kinds of microbe which can degum ramie in 5-6L fluid very quickly.In comparison with some standards of microbiological experiments,5L or 6L-scale can be called the small-scale.Therefore,the authors believe that the experiments of the microbial quick-degumming ramie can be enlarged from the laboratory-scale test to be applied in the future.

亚麻催化氧化与碱煮一浴脱胶工艺及其性能

使用棉纺系统进行亚麻纺纱前需经过脱胶处理,为解决传统碱脱胶工艺得到的亚麻纤维白度低和氧化脱胶时纤维易氧化受损、木质素残留造成纤维断裂伸长率低的问题,采用N-羟基-3,4,5,6-四苯基邻苯二甲酰亚胺(NHTPPI)催化氧化与碱煮一浴的方法对亚麻落麻进行脱胶,研究了pH值,反应温度以及催化剂NHTPPI、助催化剂9,10-蒽醌、双氧水、氢氧化钠质量浓度等因素对脱胶后亚麻纤维断裂强度以及白度的影响,得到了NHTPPI催化氧化与碱煮一浴亚麻脱胶的最佳工艺:pH值为10.5,反应温度为83.6℃,NHTPPI、9,10-蒽醌、双氧水、氢氧化钠质量浓度分别为0.6、0.5、10.35、5.67 g/L,此优化条件下得到的亚麻纤维断裂强度为4.39 cN/dtex,白度为70.53%。将催化氧化与碱煮一浴脱胶、高碘酸钠氧化脱胶以及传统碱脱胶与双氧水漂白3种工艺进行对比,发现3种工艺得到的纤维主体长度在28 mm左右,白度均在70%以上,但催化氧化与碱煮一浴脱胶得到的亚麻纤维断裂强度最高,处理时间最短。

亚麻生物脱胶的研究进展

脱胶是制备亚麻纤维的必经工序,为降低脱胶工序的污染和能耗,生物脱胶成为近年来的研究热点。生物脱胶主要包括生物酶法脱胶、微生物法脱胶以及生物法与其他方法联合脱胶。文章在介绍亚麻纤维结构和分类的基础上,概述生物法在亚麻脱胶上的研究进展和作用机理,以期为亚麻的生物脱胶提供一定的借鉴与参考。

菠萝纤维的超声波辅助低共熔溶剂脱胶工艺

采用氯化胆碱-尿素为低共熔溶剂,应用正交试验法优化超声波辅助低共熔溶剂对菠萝纤维的脱胶工艺。以菠萝纤维的残胶率、断裂强度、白度为评价指标,选取含水量、超声功率、超声温度为自变量设计正交试验,得到最佳的脱胶工艺为:氯化胆碱和尿素物质的量比1∶2.0,含水量20%,超声功率80 W,超声温度60℃,超声时间40 min。在此条件下测得纤维残胶率3.54%,断裂强度4.23 cN/dtex,白度85.2。

可纺性竹原纤维的脱胶工艺及其性能

针对传统竹原纤维制备过程能耗大、污染环境、时间长,且获得的纤维表面粗糙、长度低等问题,构建了氯化胆碱-乳酸低共熔溶剂(DES)脱胶、过氧乙酸(PAA)脱胶、DES协同PAA脱胶3种绿色脱胶方法。通过傅里叶变换红外光谱、扫描电子显微镜和X射线衍射仪等测试手段,对采用传统方法和3种不同绿色脱胶工艺所得纤维的理化性能进行了测试和表征。研究结果表明:制备竹原纤维的4种方法均可去除胶质部分,经DES溶剂脱胶可有效脱除竹原纤维的半纤维素,但木质素残余量高,PAA脱除木质素的效率最高,DES协同PAA脱胶制备的纤维素含量最高;随着竹原纤维无定形区域胶质部分的脱除,4种脱胶方式均可提高纤维的相对结晶度,但传统脱胶制备的纤维结晶度变化最小;DES协同PAA脱胶制备的纤维线密度最低(50.07 tex),断裂强度最高(2.98 cN/dtex),具有最佳的可纺性能。

干法脱胶对亚麻籽植物乳稳定性和营养特性的影响

为探究亚麻籽胶对亚麻籽植物乳的稳定性、营养特性的影响,本研究对亚麻籽进行干法脱胶,并全面探究了不同脱胶率对亚麻籽植物乳营养素溶出和稳定性的影响,对不同样品的粒径、zeta电位、粘度、Turbiscan稳定性指数、流变性能、微观结构、总固形物含量、总酚含量和蛋白含量进行了测定和分析。结果表明,与未脱胶的亚麻籽所制亚麻籽乳相比,脱胶后亚麻籽乳的电位绝对值增大且粒径、稳定性指数和粘度均变小,其中脱胶率为4.0%的亚麻籽植物乳电位绝对值由26.72 mV增大至29.60 mV,D[4,3]由34.90μm减小至22.60μm,粘度降低了9.95%,且表现出剪切稀化行为,液滴分布均匀。脱胶率为6.30%的亚麻籽植物乳的总固形物含量提高了5.03%,达到7.73 g/100 mL,蛋白含量提高了18.78%,达到2.15 g/100 mL,表明亚麻籽经适度脱胶后能够提高亚麻籽植物乳的稳定性,促进蛋白质等营养素溶出,相关研究结果为亚麻籽高值化、全值化加工利用提供参考依据。

大麻纤维电化学联合生物酶脱胶工艺分析

为克服工业大麻脱胶过程中生物酶向麻内部渗透困难的问题,同时减少酶用量,降低生产成本,研究更加高效环保的前处理方法,采用高效低污染的电化学手段联合生物酶处理对大麻纤维进行脱胶处理。以大麻纤维的残胶率、白度、断裂强度、细度为评价指标,利用单因素分析法探究脱胶工艺参数对大麻纤维脱胶效果的影响。试验结果表明:电解水浸泡浴比为1∶60,亚硫酸氢钠质量浓度为50 g/L,浸泡时间为6 h,果胶酶、漆酶和木聚糖酶的质量比为1∶2∶1,过碳酸钠质量浓度为9 g/L条件下,大麻纤维的残胶率为12.7%,断裂强度为4.32 cN,线密度为2.8 dtex,白度为73.42%,脱胶效果最佳。

染整工艺对麻纤维抗菌性能的影响

从麻纤维自身形态结构、化学组成出发,分析了影响麻纤维自身抗菌性的因素。概述了染整加工工艺中脱胶、染料种类和染料助剂对麻纤维抗菌性能的影响,总结了麻织物的物理抗菌整理和化学抗菌整理方式。认为:在麻纤维自身具备抗菌性的基础上,采用添加天然抗菌剂、物理抗菌整理、植物染料染色等方法,可有效降低麻纤维生产加工过程中抗菌成分的流失,进一步提高麻织物的抗菌性能。

纺织精炼酶对蚕丝脱胶工艺条件优化及性能影响

为提高蚕茧脱胶率和蚕丝性能,实现绿色环保的蚕茧脱胶工艺,可对蚕茧进行酶法脱胶。文章采用碱性蛋白酶(NP-TEE)和纺织精炼酶(AP-TRE)对蚕茧进行脱胶处理,以脱胶率、单纤维拉伸断裂强力及白度作为考察蚕丝性能的指标,并通过正交试验确定蚕茧酶脱胶法的最佳工艺。试验结果表明:两种酶脱胶工艺对蚕茧脱胶效果均有影响,用纺织精炼酶法脱胶后的蚕丝性能与碱性蛋白酶法脱胶相比更好。纺织精炼酶对蚕茧的最佳脱胶工艺条件为酶解温度55℃、酶解时间60 min、酶体积浓度5 mL L,得到蚕茧脱胶率17.07%,单根蚕丝纤维平均断裂强力12.20 cN dtex,白度(66.04)高于原蚕茧(58.78);红外光谱表明,采用纺织精炼酶法脱胶后的蚕茧与原蚕茧结构无明显差异;扫描电镜下观察到与原蚕丝相比,纺织精炼酶脱胶后蚕丝表面更加光滑平整;热重分析显示,纺织精炼酶脱胶后蚕丝的热稳定性无明显变化。

响应面法优化油莎豆油酸法脱胶工艺的研究

为了提高油莎豆油的品质,以溶剂法制取的油莎豆毛油为原料,对其酸法脱胶工艺进行了研究,以期为油莎豆油的深加工提供参考。首先确定了酸法脱胶时所需要添加的酸为柠檬酸,然后考察了柠檬酸溶液质量分数,以及柠檬酸添加量、水添加量、水化时间、酸化时间和反应温度等因素对油莎豆油磷含量和脱胶率的影响,并在单因素试验的基础上进行了响应面优化试验。结果表明:油莎豆油酸法脱胶优化的工艺条件为反应温度59℃、水添加量3.5%、水化时间49.5 min、柠檬酸添加量0.20%、酸化时间10 min,在此条件下,油莎豆毛油的脱胶率为95.9%±0.3%,磷含量可降至(4.4±0.3)mg/kg。利用柠檬酸对油莎豆油进行脱胶可显著提高脱胶效果,降低磷含量,提高油脂品质。

汉麻纤维脱胶技术研究进展

汉麻纤维是近年来备受关注的具有较高比刚度和强度的天然纤维,其韧皮纤维具有生物可降解性,且在汽车工业、结构复合材料、制浆和纺织等领域具有广阔的应用前景。文章对汉麻纤维的物理、化学、生物和综合脱胶工艺的优缺点,以及汉麻纤维脱胶工艺的最新研究进展进行了梳理和分析。研究认为:物理脱胶法适用于预处理及后处理;化学脱胶法需要与其他方法联合以减少环境污染及能源损耗,其是目前工业化脱胶最主要的手段;有机溶剂、电化学及微波法等新型脱胶方法尚处于探究阶段,很难应用于生产实践;生物脱胶法可有效降低能耗和环境污染,且对纤维的损伤小,具有广阔的发展前景。

脱胶处理对单向蚕丝/PCL复合材料性能的影响

针对聚己内酯(PCL)力学强度不足的问题,以单向蚕丝片为增强体,PCL为树脂基体,通过热压成型工艺制备了单向蚕丝/PCL复合材料。为了获得界面结合良好的单向蚕丝/PCL复合材料,采用Na_(2)CO_(3)溶液对单向蚕丝片进行脱胶处理。利用扫描电镜、接触角测定仪、万能强力仪、摆锤冲击试验机、热重分析仪等研究了不同质量分数的Na_(2)CO_(3)溶液脱胶处理对单向蚕丝片表面性质及蚕丝/PCL复合材料力学性能和热稳定性能的影响。结果表明:经过脱胶处理后,单向蚕丝片浸润性改善;在质量分数为1.5%Na_(2)CO_(3)溶液中脱胶1 h后,蚕丝表面丝胶基本除尽,树脂基体对单向蚕丝片浸润效果良好,复合材料中单向蚕丝片与PCL基体结合紧密,单向蚕丝/PCL复合材料的力学性能最好;与未脱胶单向蚕丝/PCL复合材料相比,脱胶后的弯曲强度和冲击强度提高了87.06%和56.25%;单向蚕丝片脱胶处理后,单向蚕丝/PCL复合材料的热稳定性能变好。脱胶处理后的单向蚕丝片作为增强体应用于可降解复合材料中,获得的单向蚕丝/PCL复合材料界面结合良好、力学性能优良,表明其在可降解天然纤维增强复合材料领域中应用潜力巨大。