Enzyme and silicone treatments on jute fibre. Part II: Effect on process performance during yarn making and yarn properties

Characterization of modified jute fibres treated with selective mixed enzyme and aminosilicone compound has been reported earlier. This part of the study relates to assessment of the effectiveness of such chemical (aminosilicone) and biochemical (mixture of cellulase, xylanase, and pectinase enzymes) modifications of raw jute fibres (with or without selective pretreatments using dilute NaOH, H₂O₂, and a combination of H₂O₂ and K₂S₂O₈) on process performance during yarn making and property parameters of such yarns. Usually, jute fibres are spun into yarns applying 1.5% to 3% mineral oil-in-water emulsion prior to carding. 0.5% aminosilicone treatment of jute fibres under specified condition makes them suitable for yarn making without the use of mineral oil, and produces a softer yarn having substantially lower yarn mass irregularity and yarn imperfection values, though with some lowering in tenacity values. Some advantages accrued in regard to process performance (energy efficiency and less fibre droppage during carding) during yarn making for 4% mixed-enzyme-treated jute fibres at 55°C for 2 h over raw and bleached jute fibres are outweighed by the increase of spinning end breakage rate, much lowering of yarn tenacity, and specific work of rupture. However, 1% mixed enzyme treatment of jute fibres shows some advantages in process performance associated with much lower extent of reduction in yarn tenacity and specific work of rupture with acceptable end breakage rate during spinning, rendering an overall gain from this treatment.     

不同生物酶处理对黄麻纤维的影响

分别用漆酶、纤维素酶、木聚糖酶及果胶酶对黄麻纤维进行脱胶处理,简要分析了各种酶对黄麻纤维脱胶效果的影响,得出了各种酶处理工艺的相对最优工艺参数。各种酶的最优化工艺比较分析结果显示漆酶处理是最有效的脱胶方式。     

染整加工对喷气涡流纺棉纱强力的影响

为提高喷气涡流纺棉纱的强力,增加其在色织工艺中可织造性,研究了染整加工对其强力的影响。结果表明：对喷气涡流纺棉纱分别进行碱氧练漂一浴法与酶氧练漂一浴法前处理,当烧碱和酶质量浓度分别为5、10 g/L 时纱线强力提高率最大,分别为9.0%与13.7%;选择X型、KN型、K型与B型4种活性染料分别对练漂后纱线进行染色,染色纱线强力比练漂纱线有不同程度的提高,其中B型活性染料对纱线强力的提高率最大;B型活性染料质量分数为2%（o.w.f）时,分别对碱氧练漂纱与酶氧练漂纱进行染色,原纱的强力提高率分别为15.9%和24.5%。从数据分析,适当的染整加工能够提高纱线的强力。     

生物酶对半乳糖醛酸的降解作用

用GC-MS总离子流色谱图来比较半乳糖醛酸在分别经漆酶、果胶酶和木聚糖酶处理前后量的变化,结果发现,用漆酶、果胶酶或木聚糖酶处理后的试样,半乳糖醛酸峰完全消失。用颗粒电荷测定仪测定阳离子需求量,来确定3种不同酶对半乳糖醛酸的作用,结果表明,漆酶或果胶酶处理后的半乳糖醛酸试样阳离子需求量分别下降了91.9%和96.9%,木聚糖酶处理样的阳离子需求量较半乳糖醛酸空白样有所升高,若将木聚糖酶的阳离子需求量扣除,半乳糖醛酸的去除率仍达到84.2%。     

生物酶处理对亚麻/棉织物杂质的去除作用

研究了果胶酶、纤维素酶、木聚糖酶和漆酶单一及混合处理对亚麻/棉织物上果胶和木质素的去除作用及前处理效果,并与传统工艺进行了比较。结果表明,虽然生物酶前处理对织物的强力损失远低于传统的前处理工艺,但对木质素的去除率与传统前处理工艺相比还有很大差距,而且,对果胶的去除率也没有传统前处理工艺好。在前处理效果上,生物酶前处理的润湿性和麻皮去除情况与传统前处理工艺相比有一定差距。     

不同预处理方法对漂白针叶木硫酸盐浆制备溶解浆性能的影响

以漂白针叶木硫酸盐化学浆为原料,分别采用9%NaOH,6%NaOH+3%H2O2,1%H2SO4,9%H2O2等化学法和木聚糖酶、漆酶及混合酶等生物法进行处理,探讨不同处理方式对漂白针叶木纸浆改性制备黏胶纤维用溶解浆的影响。试验结果表明:采用9%NaOH,1%H2SO4能有效提高α-纤维素含量和纤维素反应性能,而木聚糖酶或漆酶的处理效果不明显。     

Effect on physical characteristics of jute fibres with cellulase and specific mixed enzyme systems

This research investigated the effect of using cellulase enzyme and a mixture of enzymes (cellulase, xylanase and pectinase), under specific treatment conditions, on the physical characteristics of jute fibres. The physical characteristics such as tenacity, elongation to break, flexural rigidity and structural analysis using scanning electron microscopy and colour measurements using colour spectroscopy were studied. Tensile characteristics of these enzyme-treated jute fibres in terms of tenacity (cN/tex) were found to decrease by approximately 9.05%, 14.76% and 19.83% for cellulase enzyme treatment and 11.96%, 13.47% and 23.81% for mixed enzymes at 2%, 3% and 4% concentration levels, respectively. Significant improvements in physical characteristics such as elongation, whiteness index, brightness index and reflectance of these enzyme-treated jute fibres were noticed when compared to those of raw jute fibres. The significant reduction in flexural rigidity and yellowness index of these enzyme-treated jute fibres was also noticed. Scanning electron microscopy reveals the degradation of the jute fibre at surface level and along with the removal of the gummy substances present on the surface; this degradation depends on the various concentrations of the enzyme.     

The optical properties of hand-woven carpet

Abstract

The reflectance spectra and color properties of yarn when used in carpet are different from its cross-sectional direction as the pile of hand-woven carpet. This paper presents a comprehensive study of reflectance spectra and color properties of the pile in longitudinal direction and hand-woven carpet. For this purpose, the wool yarns were dyed with madder as a natural dye in various concentrations from 10% to 100% on the weight of sample. In order to study of the optical properties of the pile of hand-woven carpet, the dyed yarns were used to weave the hand-woven carpet. The obtained results showed that the yarn in longitudinal direction is lighter than the pile of hand-woven carpet, and so, the color strength of hand-woven carpet is more than the color strength of yarn. The spectrophotometric properties of samples were also studied by Principal Component Analysis (PCA). The difference between reflectance spectra of yarn in longitudinal direction and reflectance spectra of the pile of hand-woven carpet was also shown by PCA results.     

Dyeing of Biotreated Jute Fabric

Abstract

Grey jute fabric has been scoured, then treated with a mixed commercial enzyme at a fixed concentration and thereafter bleached with hydrogen peroxide. Three sets of pretreated jute fabric, viz., grey-bleached, scour-bleached and scour-enzyme treated-bleached were dyed with five different class of dyesnamely, direct dye, reactive dye, 1:2 metal complex dye, acid dye and basic dye by conventional dyeing procedure. Analysis of the results reveals noticeable improvement of dye uptake in case of scour-enzyme treated-bleached jute fabric in comparison with only grey-bleached jute fabric. Enzyme treatment also results in improvement of handle property of jute fabric as evident from reduction in bending length values. Scour-enzyme treated-bleached-dyed jute fabric shows some reduction in tensile strength.     

黄麻/棉混纺纱线的柔软改性整理与性能研究

选用不同线密度和混纺比例的4种黄麻/棉混纺纱线,测试了黄麻/棉混纺纱线的拉伸性能、柔软性能和毛羽,探讨了碱处理工艺中NaOH浓度对混纺纱线拉伸断裂强力和毛效的影响,以及生物酶柔软处理对混纺纱线失重率、拉伸性能、柔软性和毛羽的影响规律。试验结果显示：黄麻/棉混纺纱线刚度大,柔软性较差,毛羽多;对黄麻/棉混纺纱线进行NaOH碱处理和生物酶柔软处理后,黄麻/棉混纺纱线的柔软性能得到改善。     

酶预处理对麦草NaOH-AQ制浆性能的影响

利用木聚糖酶、漆酶和纤维素酶在蒸煮前对麦草进行预处理,可降低化学浆的卡伯值,提高未漂浆的白度。和对照浆相比,酶预处理的化学浆尤其是木聚糖酶和漆酶化学浆具有更高的裂断长和撕裂指数。酶法化学浆具有良好的可漂性。漆酶和木聚糖酶的协同作用使纸浆的卡伯值进一步下降,并具有更高的强度性能。     

Investigating the effects of draw ratio,hot-pin temperature,and overfeeding on the color values of air-jet textured polyester yarns

In this study, influence of draw ratio, hot-pin temperature, and overfeeding on the color values of air-jet textured yarns, which were produced from polyester partially oriented yarn, was investigated. Two different air-jet textured yarns were produced by setting the value of only one variable to its minimum and maximum, while the reference values selected for the production of the reference yarn were used for the rest of the variables. Six different air-jet textured yarns, which were produced by varying draw ratio, hot-pin temperature, and overfeeding, and the reference air-jet textured yarn were dyed with the same dyeing procedure. Some physical properties such as linear density, tenacity, and breaking extension of the air-jet textured yarns were measured and images of the cross-section of the yarns were taken. The color coordinates of the dyed yarn samples were also measured. The color differences of six yarn samples compared to reference air-jet textured yarn were calculated. Changing draw ratio, hot-pin temperature, and overfeeding affected the color values of the air-jet textured yarns according to the results. It was found that, overfeeding is the parameter that affects the color values of the air-jet textured yarn most.     

莲花蜂花粉酶解破壁工艺条件优化

为研究莲花蜂花粉的最佳酶解破壁条件,通过单因素试验确定纤维素酶-果胶酶-木聚糖酶-木瓜蛋白酶4种酶制剂的比例,在酶解破壁条件的单因素试验基础上,采用二次回归正交旋转组合设计试验方法对酶解条件进行优化,建立酶解pH值、复合酶加入量、酶解温度、料水比与破壁率之间的经验数学模型。复合酶中各种酶制剂的最适配比为4:2:1:3。莲花蜂花粉酶解破壁的最佳条件为酶解pH4.0、复合酶加入量12‰、酶解温度45℃、料水比1:14(g/mL),破壁率89.21%。     

黄麻混织针织物的设计与开发

本研究针对黄麻纱线粗硬、毛羽较多,弹性低等特点,对纱线毛羽、细度及强度进行测试并选择适合的棉及涤纶纱线进行混合。将黄麻与棉及涤纶纱线经过合股上蜡处理后,在针织横机上设计并编织罗纹、移圈、圆筒等不同组织和结构的黄麻混织织物及产品。通过对黄麻混织织物的耐磨性、透气性、抗起毛起球等性能进行测试与分析,结果表明麻涤1罗纹织物耐磨性、耐起毛起球性最好,而麻棉4为单面圆筒织物线圈密度最小,透气性能最优;麻棉2由于具有移圈及凹凸效果,透气性能次之,耐磨性稍差。所织织物适合制作具有田园风格的家居类装饰物,从而开发黄麻纤维更广泛的应用领域。     

Mixed Metal Mordant Dyeing of Wool using Root Extract of Rheum emodi (Indian Rhubarb/Dolu)

In the present study, the root extract of Rheum emodi (Indian Rhubarb/Dolu/Revandchini) has been used as a natural dye to develop a variety of harmonizing natural shades on woolen yarn using combination of ecofriendly mixed metal mordants. Dyeings were carried out in neutral acidic, and alkaline medium using 0.5%–5% dye concentrations pre-treated with (4.5% iron + 0.1% tin), (2.5% iron + 0.5% tin), and (0.5% iron + 0.9% tin) mordant combinations. A total of 54 shades have been developed by varying the amount of dye and percentage combination of mordants. The hue of color ranged from reddish-brown, greenish-yellow to dark yellow. The color of dyed woolen yarns was investigated in terms of color strength (K/S), CIELab, CIELch values. Fastness properties (light, washing, and rub/crocking) of dyed woolen yarn samples were also assessed.     

Changes in activities of cell wall degrading enzymes during fermentation of cassava (Manihot esculenta Crantz) with citrobacter freundii

The cell wall degrading enzymes polygalacturonase (EC 3.2.1.15),pectinase (EC 3.1.1.11), cellulose (EC 3.2.1.4) and xylanase (EC 3.2.1.8), as well as α-amylase (EC 3.2.1.1) and phosphorylase (EC 2.4.1.1), were monitored during fermentation of cassava (Manihot esculenta Crantz) with Citrobacter freundii. All the enzymes were detected in cassava at the start. During fermentation, initial decreases in polygalacturonase, cellulase and xylanase were followed by increases which peaked as the tissue softened. There were significant (P<0.05) increases in pectinase, xylanase, cellulase, polygalacturonase and phosphorylase in inoculated cassava and the fermentation medium relative to controls (uninoculated cassava and medium) during the softening period. The control cassava did not ferment, indicating that the textural changes in inoculated cassava were due to enzymes secreted by C freundii. Studies on the effect of enzyme inhibition on fermentation showed that the pectic enzymes and cellulase were of primary importance and that inhibition of α-amylase and phosphorylase had no effect on the process.     

Evaluation of Dyeing Properties of Carpet Woolen Yarn with Natural and Wild Pomegranate Peel (Punica granatum)

Natural and wild pomegranate peel have been used as colorants for wool yarn because of their high tannin contents. The woolen yarns dyed with pomegranate peel showed different shades of yellow and brown. Wild pomegranate peel has been used traditionally for dyeing wool to obtain brown and darker shades. Both natural and wild pomegranate peel were applied on woolen yarn in presence of four different mordants. Good light fastness was observed in dyed yarns that is due to the formation of complex with the metal which protects the chromophore from photolytic degradation. The values of washing fastness of the dyed samples show very good grades but the rubbing fastness in dyed yarns with wild pomegranate rind are not so good. Therefore, the dyeing potential of wild pomegranate peel as a natural source for wool yarn dyeing is considerable.     

Dyeing Properties of Natural Dyes Extracted from the Junipers Leaves (J. excelsa Bieb. and J. oxycedrus L.)

In this paper, two natural dyes were extracted from Junipers leaves (Juniperus oxycedrus L. and Juniperus excelsa Bieb.). Wool yarn (for carpet) was dyed with the extract using ferrous (II) sulfate, potassium dichromate and sodium sulfate as mordant. Then, CIELab (L*, a*, b*, c,* and h) values, color differences (ΔE) and color strength (K/S) values of dyed wool yarns were examined and the fastness properties of dyed wool against dry and wet rubbing were evaluated. According to the experimental results, the use of mordant increased the color strength of dye goods. All mordant increased the rub fastness of dyed samples such as similar scientific studies previously. Compared to two junipers, dyeing samples of J. excelsa are dyed darker than that of J. oxycedrus.     

The effect of fibrolytic enzymes sprayed onto forages and fed in a total mixed ratio to lactating dairy cows

We investigated the effect of spraying different combinations of fibrolytic enzymes onto forages on their nutritive value for lactating cows. Holstein cows were fed a TMR consisting of 30% corn silage, 15% alfalfa hay, and 55% concentrate (dry matter basis). During a 12-wk treatment period, the forages were treated with no enzymes (control), cellulase D and sultanas B, or cellulase D and xylanase C. Enzymes were diluted in water and sprayed onto the forages while mixing. Both combinations of enzymes supplied similar amounts of fibrolytic activity based on classical enzyme assays conducted at 50 degrees C. Cows fed forages treated with cellulase D and xylanase B tended to produce more 3.5% FCM (+2.5 kg/d) than did cows fed the untreated forages. Dry matter intake, milk production, milk fat, and milk protein were unaffected by treatment. In vitro production of gas from forages treated with enzymes was greater than from untreated forage, but 96-h volatile fatty acid production was not different among treatments. With an alternative enzyme assay based on the depolymerization of dyed substrate at 40 degrees C, activity of xylanase C was greatest at a pH of 6.5 but was substantially reduced as the pH of the assay was decreased. In contrast, xylanase B showed highest activity at pH 5 and enzyme activity was twice that of xylanase B at pH 5.5 and 6. Overall, the results of this study provide more evidence that fibrolytic enzymes can be used to improve milk production in lactating cows.     

靛蓝染色体系的优化设计

采用染色增深渗透剂DP、保险粉、烧碱与靛蓝染料体系,利用 Minitab软件进行中心合成实验方案设计,改变各组分的用量,进行了20组染色实验。在25oC对纯棉半漂布进行染色,浸渍时间为20s,轧余率80%,氧化时间75s。通过对染色织物的上染率、K/S值、干湿耐摩擦色牢度和拉伸断裂强力进行测试,并对染色后纱线横切面上染料的分布情况进行观察。结果表明使用该染色体系,色纱切面染料分布均匀,无白芯,上染率和染色牢度显著提高。各组分的最佳用量：烧碱为6.63g/L,保险粉为5.65g/L,渗透剂为0.97g/L。