Fiber Finish Research Articles

Development of Environmentally Friendly Wool Shrink-Proof Finishing Technology Based on L-Cysteine/Protease Treatment Solution System.

The particular scale structure and mechanical properties of wool fiber make its associated fabrics prone to felting, seriously affecting the service life of wool products. Although the existing Chlorine-Hercosett treatment has a remarkable effect, it can lead to environmental pollution. Therefore, it is of great significance to develop an environmentally friendly and effective shrink-proof finishing technology. For this study, L-cysteine was mixed with protease to form a treatment solution system for shrink-proof finishing of wool fibers. The reduction performance of L-cysteine and its effect on wool were compared with those of other reagents, demonstrating that L-cysteine has an obvious reduction and destruction effect on the wool scale layer. Based on this, L-cysteine and protease 16L were mixed in a certain proportion to prepare an L-cysteine/protease treatment solution system (L/PTSS). The shrink-proof finishing of a wool top was carried out by the continuous multiple-padding method, and the processing parameters were optimized using the response surface method. The results indicated that when the concentrations of L-cysteine and protease 16L were 9 g/L and 1 g/L, respectively, the wool was padded five times at 50 °C, and each immersion time was 30 s, the felt ball density of the treated wool reduced from 135.86 kg/m3 to 48.65 kg/m3. The structure and properties of the treated wool were also characterized using SEM, TG, and tensile strength tests, which indicated that the fiber scale structure was stripped evenly. Meanwhile, the treated fibers still retained adequate thermal and mechanical properties, indicating suitable application value. XPS, FT-IR, Raman, UV absorbance, and other test results revealed the reaction mechanism of L/PTSS with the wool fibers. After L-cysteine rapidly reduced the disulfide bonds in wool, protease can hydrolyze peptide chains more effectively, causing the scale layer to gradually peel off. Compared with the chlorination method and other protease shrink-proof technologies, L/PTSS can achieve the finishing effect on wool rapidly and effectively, without causing excessive pollution to the environment. The conclusions of this study provide a foundation for the development and industrial application of biological enzyme shrink-proof finishing technology.

Influence of yarn structure and coating on the mechanical performance of continuous viscose fiber/epoxy composites

AbstractThe present study investigated the effect of selected structural parameters on the mechanical performance of regenerated cellulose composites. The experimental setup comprised continuous viscose (rayon) yarns embedded in a matrix of epoxy resin. Mechanical and microscopic characterizations involved comparing the following: yarns consisting of untwisted filaments and twisted warp and weft yarns taken from a plain weave fabric, yarns with and without avivage (fiber finish), as well as yarns with and without an acrylic coating. During the epoxy treatment, samples were either prestressed or laid horizontally to preserve the original yarn structure. Tensile tests revealed that yarn crimp had a significant impact on the strength properties of composite specimens, a higher crimp ratio leading to a decrease in performance. Applying prestress to crimped yarns has proven to be an effective way to enable straight alignment in the loading direction, which is essential for the design of stiffness‐ and strength‐optimized yarn composites. Unlike an avivage, which did not markedly affect the mechanical properties of composite yarns, the application of an acrylic coating prior to resin impregnation was found to provide significantly increased extensibility and more ductile fracture behavior.

PVC and POM gripping mechanisms for tension testing of FRP bars

The present study pertains to the introduction of two new types of grip adaptor for universal testing machines, namely Polyvinyl Chloride (PVC) and Polyoxymethylene (POM) grip adaptors, and their application to tension testing of FRP bars with different fiber and surface finish types. The tabs are connected to the FRP bar sample with the help of mechanical anchors, i.e. bolts. These new adaptors offer vital superiorities over the existing end tab designs (anchors with filling material or mechanical anchorage), including the reduction in the time and labor for production, reusability and the mild nature, i.e. low hardness of the tab material, which retards and even prevents peeling and crushing in the gripping regions of an FRP sample. The methods were successfully applied to FRP bars with different types of fiber (CFRP, GFRP and BFRP) and different types of surface texture (ribbed, wrapped, sand-coated and wound). The test results indicated that the both types of end caps prevented slip of the bar, crushing and peeling in the gripping zone. The mechanical properties from the material tests with the new caps were in perfect agreement with the ones from the material tests with steel tubular caps.

Cold Plasma Treatment in Wet Chemical Textile Processing

Nowadays, cold plasma technology is highly involved in textile processing either to assist conventional wet-chemical processing and/or create innovative products. Plasma surface treatment is an ergonomically simple process, but the plasma process and its effect on the fibre surface are more complex due to the interplay of many concurrent processes at a time. The efficiency of plasma treatment mainly depends on the nature of textile material and the treatment operating parameters. The main objective of this review paper is to summarise and discuss the application of plasma treatment and its effect on the pre-treatment, dyeing, printing and finishing of natural and synthetic textile fibres. However, the application of plasma technology to different types of textile substrates has not been fully addressed.

Multifunctional finishing of cotton fibers using silver nanoparticles via microwave-assisted reduction of silver alkylcarbamate

Smart materials with multiple functions have been highly desirable. The in situ synthesis and integration of silver nanoparticles (AgNPs) into cellulosic fibers adds novel functions and extending their potential applications. Herein, we report a novel method toward green development of film containing AgNPs to introduce multifunctional cotton with antibacterial activity, electrical conductivity, superhydrophobicity, catalytic activity, ultraviolet blocking and coloration properties. The synthesis of AgNPs was performed using the facile pad-dry-cure adsorption methodology of silver N-(2-ethylhexyl)carbamate aqueous solution, followed by microwave-assisted reduction of silver ions (Ag+) on the fibrous cotton surface. The in situ generation of silver nanoparticles onto cotton fabrics were enhanced by plasma pretreatment. The morphologies of the developed multifunctional cotton were studied by Field-emission scanning electron microscopy (FE-SEM), X-ray powder diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX) and elemental mapping. Transmission electron microscope (TEM) was also utilized to investigate the morphology of the synthesized AgNPs. The colorfastness and coloration measurements of the AgNPs-coated fibers were investigated. The colored cellulose fibers demonstrated an improved antibacterial activity to S. aureus and E. coli pathogens. Furthermore, AgNPs/cellulose showed excellent electrically conductive and superhydrophobicity, as well as photocatalytic self-cleaning.

Bio-Inspired Coloring and Functionalization of Silk Fabric via Laccase-Catalyzed Graft Polymerization of Arylamines

Generally, dyeing and finishing of Bombyx mori silk fibers were proceeded at high temperature, which has the disadvantages of overmuch energy-consumptions. In the present work, bio-inspired in situ coloring and functionalization of silk fabric were carried out via laccase-catalyzed graft polymerization of arylamines, including aniline (ANI) and p-phenylenediamine (PPD). p-Hydroxyphenylacetamide (PHAD) as the model compound of tyrosine residues in silk fibroin (SF) was used to explore the mechanism of graft polymerization by means of MALDI-TOF MS. The actions of the dopants of sodium dodecyl benzene sulfonate (SDBS) and sodium p-aminobenzenesulfonate (ABSA) on the enzymatic treatment were also concerned. The results indicated that laccase might initiate the self-polymerizations of ANI and PPD, respectively, and formed the copolymers of arylamine and PHAD subsequently. High color depth and color fastness were obtained after incubation silk fabric with laccase and arylamines, companying with a noticeable pH-responsiveness. The laccase-mediated treatment endowed silk fabric with antibacterial and antioxidant abilities, meanwhile, the addition of dopants of SDBS and ABSA promoted the enzymatic finishing. Enzymatic graft polymerization of arylamine onto silk fibroin provides a novel approach for dyeing and functionalization of silk fabrics under mild treating conditions.

Eco-Friendly Dyeing and Finishing of Wool Fibers

Eco-Friendly Dyeing and Finishing of Wool Fibers

A review on the Development of Innovative Capabilities in the Textile Finishing of Natural Fibers

Here in focus on the nano technology and biotechnology as new technique knock for textile multifunctional finishing process with highly effective and recent research concentrate and restrict on using this promising technology concomitant also advanced highly effective tools namely sonication, plasma, microwave for finding out how to reduce conventional techniques utilities. Nanotechnology is revolutionizing the way in which the functional properties are imparted to the textile materials. Cotton, the king of natural fibers, requires nanotechnological interventions to achieve the functionalities like antibacterial, UV protecting, super hydrophobic and flame retardancy. Nano-finishing also helps to impart these properties without affecting the inherent comfort nature of cotton. In addition, the amount of material required to impart the functional property is relatively less due to its nano-size range. Enzymes have become an indispensable part of textile processing and are utilized for a wide variety of applications in the modern textile industry. Various established enzyme-based processes that are currently used in the textile industry demonstrate the potential of industrial biotechnology to successfully provide ‘greener’ alternatives

Use of pomegranate peels and walnut green husks as the green antimicrobial agents to reduce the consumption of inorganic nanoparticles on wool yarns

For reducing the cost of production and saving the environment, the utilization of chemicals, energy, and processing time should be minimized as much as possible. In this study, antimicrobial finishing of wool fibers was achieved by synthesizing Ag/Cu2O/ZnO nanoparticles (NPs) in-situ on the surface of wool fibers, and subsequently dyeing with two natural dyes extracted from Pomegranate peels and Walnut Green husks. The extracted natural dyes had also noticeable antimicrobial activities. This decreased the consumption of Ag/Cu2O/ZnO nanoparticles (NPs) for antimicrobial finishing of wool yarns. The wool samples were dyed at the initial dye concentration of 30% over weight of fiber (o.w.f.), at 100 °C, pH 5.0 for 60 min. The treated samples were characterized by Scanning Electron Microscope (SEM), X-ray diffraction (XRD) analysis, reflectance spectrophotometer, and electromechanical tensile tester. The presence of nanoparticles was confirmed on the surface of the samples by SEM micrographs and XRD profiles. The mechanical properties of the treated samples improved slightly (less than 2%). The antimicrobial activities of the samples treated only with Pomegranate peels and Walnut Green husks were 65% and 35%, respectively. The antimicrobial activity of the treated wool yarns with inorganic salts after the dyeing process was excellent (almost 100%). Moreover, the wash and light fastness properties of the treated samples were all very good to excellent. The dyed sample treated with Ag salt maintained its high antimicrobial activity (>91%) even after 10 repeated washing cycles. The light-fastness of the dyed samples was improved from moderate (5) to very good (7–8) after treatment with the inorganic salts. The proposed eco-friendly dyeing process can also improve the antimicrobial properties of wool yarns.

Directions of the Finishing of Fibres and Textile Development

The development of textile finishing techniques and technologies outside of reports in world-wide publications is also very visible at subsequent fairs. At international fairs, such as ITMA, ATMA and FESPA, machine, equipment and dye manufacturers present new techniques and technologies. The development of chemical fibre processing nowadays goes mainly towards the “ecological optimisation” of technological processes as well as the economics of processes. In this article, the main development directions of the chemical treatment of textiles in the field of the pre-treatment, bleaching, dyeing, printing and finishing of textile products are discussed.

Ambient Characterization of Synthetic Fibers by Laser Ablation Electrospray Ionization Mass Spectrometry.

Direct analysis of synthetic fibers under ambient conditions is highly desired to identify the polymer, the finishes applied and irregularities that may compromise its performance and value. In this paper, laser ablation electrospray ionization ion mobility time-of-flight mass spectrometry (LAESI-IMS-TOF-MS) was used for the analysis of synthetic polymers and fibers. The key to this analysis was the absorption of laser light by aliphatic and aromatic nitrogen functionalities in the polymers. Analysis of polyamide (PA) 6, 46, 66, and 12 pellets and PA 6, 66, polyaramid and M5 fibers yielded characteristic fragment ions without any sample pretreatment, enabling their unambiguous identification. Synthetic fibers are, in addition, commonly covered with a surface layer for improved adhesion and processing. The same setup, but operated in a transient infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) mode, allowed the detailed characterization of the fiber finish layer and the underlying polymer. Differences in finish layer distribution may cause variations in local properties of synthetic fibers. Here we also show the feasibility of mass spectrometry imaging (MSI) of the distribution of a finish layer on the synthetic fiber and the successful detection of local surface defects.

Value Addition Finishing of Protein Fibres used for Technical Textile

In the textile industry, there are some aspects for their growth and development i.e., 1. Value-added products with enhanced functionality, 2. Apparels, 3. Sustainable products. Antimicrobial textiles which improve functionality find a variety of applications in health and hygiene products, especially the garment worn close to the skin and several other medical applications for infection control and as barrier material. In the last few decades with the increase in newantimicrobial finishing technologies, there is an ever growing need of natural products for various finishing applications. With the steady improvement in technology and application standards, a gradual rise has been observed in consumer demands and to reach up to that mark, a manufacturer has to add something to their products to get some added value for their products. Protein fibers can be easily modified to form a specialist substrate by chemical modification. In this project we used raw wool and silk to increase their shelf-life by finishing with a novel anti-microbial finishing agent. Citizen along with Oxy-tetracycline was synthesized and successfully applied on dyed and undyed wool and silk, to obtain an excellent antimicrobial activity along with a bright colour. It also imparted better physical property like tensile strength. Such modification can be used in Agra textile, medical textiles and also in home tech.

Green technology for durable finishing of viscose fibers via self-formation of AuNPs

Sensitivity of dyes' colors to the surrounding environment causes lower durability and stability of color, which reflects the importance of durable finishing treatment. Current technique offered antimicrobial/durable finishing of viscose fibers through direct formation of AuNPs inside fibers macromolecules without using any external agents. By using the reducing properties of cellulose in viscose, Au+3 was reduced to AuNPs and CHO/OH of cellulose subsequently were oxidized to COOH. For comparison, two different media were used; aqueous and alkaline. Increasing the reactivity and accessibility of cellulose macromolecules in alkali leaded to enlargement of the reduction process and more incorporation of AuNPs. Size of AuNPs inside fiber was recorded to be in range of 22–112nm and 14–100nm, in case of using aqueous and alkaline medium, respectively. Structure and properties of fibers were not changed by treatment according to XRD and ATR-FTIR data. The treated fibers were acquired durable violet color by the action of LSPR for AuNPs and darker color obtained using higher Au+3 concentration. The treated fibers exhibited good inhibition against different pathogenic microbes including bacteria and fungi. One-pot, quite simple, inexpensive, green and industrial viable are the significant advantages of the current technique for viscose finishing (pigmentation and antimicrobial action).

Controlling fibrillation – experiences of the dyeing and finishing of lyocell fibres

This review centres on the development of dyeing and finishing technologies for lyocell (TENCEL®) fibres since they were introduced onto the market in 1992. Initially, it will look at the reason for starting manufacture of the fibre and its manufacturing technology. An overview of basic dyeing performance is followed by a critical assessment of the fibre's introduction into the commercial world and the problems that ensued from its fibrillation property. The review then outlines the pioneering process development efforts made in Japan. Dye machinery manufacturers also played an important role in developing processing routes, particularly, but not exclusively, Then, Thies, and Krantz. Courtaulds Tencel formed an alliance with Sir T & A Wardles of Courtaulds Textiles, setting up a project to demonstrate successful jet processing of lyocell fabrics. Investment in jet dyeing machines and personnel was critical: the review explains how it was done and results that were achieved. It also considers how to control fabric behaviour in relation to creasing and fibrillation. The latter phenomenon held the fibre back from knitted applications. Both Courtaulds and Lenzing developed non‐fibrillating versions of the fibres. This review covers these advances, as well as how new markets have been developed for the fibre, such as workwear and bed sheeting. It concludes by looking at the key market segments today and how Lenzing sees the lyocell market evolving.

Chemical Processing of Wool: Sustainability Considerations

Raw wool fibers contain fat, suint, plant material and minerals. It is necessary to remove these from wool by scouring with a combination of detergents, wetting agents and emulsifiers before further processing. Dyeing and finishing of wool fibers is necessary for their application in apparel and also in interior, automotive, smart and technical textiles. Some of the detergents and auxiliaries used in scouring are eco-toxic and some of them are endocrine disruptors. In many countries, wool scouring and dyeing effluents cannot be discharged to watercourses without further treatment by removing color and toxic components. Wool fibers can be given chemical treatments to make them stain-resistant, flame retardant, shrink-resistant, photo-stable and resistant to insect attack. Some of the chemicals under current practice to achieve these functionalities in wool are not eco-friendly and their discharge to water course is limited to the consent limit set by environment agencies. Environmental impact assessment of raw wool production is well studied but to our knowledge no comprehensive study has been carried out around the environmental impact of chemical processing of wool. Like those of other fiber types, the wool textile industries are under intense consumer as well as stakeholder scrutiny. Accreditation schemes now exist to provide reassurance to modern consumers, who want to see that not only are the marketed products safe but also that they are processed sustainably under ethically and environmentally acceptable conditions. Several alternatives to improve the environmental credentials of various chemical processes used for wool will be discussed.

Preparation and characterization of silicon nitride (SiN)-coated carbon fibers and their effects on thermal properties in composites

Abstract This study investigates the effect of silicon nitride (Si N)-coated carbon fibers on the thermal conductivity of carbon-fiber-reinforced epoxy composite. The surface properties of the Si N-coated carbon fibers (SiNCFs) were observe using Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive spectroscopy, and X-ray photoelectron spectroscopy, and the thermal stability was analyzed using thermogravimetric analysis. SiNCFs were fabricated through the wet thermal treatment of carbon fibers (Step 1: silane finishing of the carbon fibers; Step 2: high-temperature thermal treatment in a N2/NH3 environment). As a result, the Si N belt was exhibited by SEM. The average thickness of the belt were 450–500 nm. The composition of Si N was the mixture of Si N, Si O, and C Si N as confirmed by XPS. Thermal residue of the SiNCFs in air was enhanced from 3% to 50%. Thermal conductivity of the composites increased from 0.35 to 0.59 W/mK after Si N coating on carbon surfaces.

Study of flame-retardant finishing of cellulose fibres: Organic–inorganic hybrid versus conventional organophosphonate

The aim of this study was to introduce a non-formaldehyde inorganic–organic hybrid sol–gel flame-retardant precursor (SiOP) containing phosphorous, nitrogen, and silicon and to compare its functional properties with those of the conventional formaldehyde-containing organic flame-retardant agent, organophosphonate (OP). SiOP was used at concentrations of 2%, 4%, and 8%, and OP was used at a concentration of 200 g/dm3. Both agents were applied to 100% cotton (CO) woven fabric by the pad-dry-cure method under the appropriate conditions. The presence of the SiOP and OP coatings on the CO fabric was confirmed by scanning electron microscopy, energy dispersive X-ray spectroscopy and Fourier-transform infrared spectroscopy. The results of the vertical tests of flammability and the thermogravimetric analyses showed that the presence of the SiOP coating changed the thermal degradation pathway of the CO fabric and resulted in an increase in the thermo-oxidative stability of the cellulose fibres. The thermo-oxidative stability was enhanced by the addition of higher amount of dry solids. At comparable dry solids contents, OP preserved significantly greater flame retardancy and thermo-oxidative stability than did SiOP. These results indicated that the SiOP precursor could not act as an effective alternative to the OP agent in the flame-retardant protection of CO fabric.

Poly (vinyl alcohol) fiber reinforced concrete: investigation of strain rate dependent interphase behavior with single fiber pullout test under quasi-static and high rate loading

A new single fiber pullout device was used to investigate interfacial debonding in the poly (vinyl alcohol) (PVA) fiber–cementitious matrix system under impact loading. For comparison, PVA fibers with two different surface states were used – as-received and after fiber finish removal by extraction in solvents. The indirect method was employed to determine the interfacial strength parameters, namely, the local interfacial shear strength, , and the critical energy release rate, G ic, from the peak load values reached in the pullout test. For both fiber surface states, the and G ic values for high loading rates appeared to be considerably greater than the corresponding parameters determined by means of a quasi-static pullout test. This can be explained using a model based on Zhurkov’s kinetic (thermal fluctuation) theory of the strength of solids, which also enabled to estimate the apparent activation energy for interfacial debonding. Its values (1.3 eV for both as-received and treated fibers) evidenced formation of strong bonds between PVA fiber and the concrete matrix and the identity of debonding mechanisms for both fiber types. Finish removal decreased interfacial adhesion due to smoothing the fiber surface and reducing interfacial mechanical bonding.

Eco-friendly Antibacterial Printing of Wool Using Natural Dyes

Natural dyes which are known to possess antibacterial properties can be safely used for the purpose of antibacterial finishing of natural fibres like wool. Chitosan is a functional biopolymer which can be utilized for various applications in textiles. In the present work bio-waste chitosan was utilized as a mordant in the printing of wool fabric with natural dyes making it eco-friendly. The efficacy of natural mordant chitosan was studied in comparison with alum as a standard mordant. Both the mordants gave prints of similar color values. The printed fabric showed excellent antibacterial properties against both S. aureus and E. coli. This method hence can be suitable for ecofriendly printing and antibacterial finishing of wool fabrics.

Modification of polylactic acid fabric by two lipolytic enzyme hydrolysis

Polylactic acid (PLA) has received considerable attention as a biomass material in the textile industry. To use PLA fiber in the textile industry, suitable post-processing is needed. To establish enzymatic finishing of PLA fibers, we evaluated the hydrolytic activities of two representative lipolytic enzymes; lipase and esterase. In addition, we established the optimal hydrolytic treatment conditions of each enzyme. Results showed that the optimal lipase and esterase treatment conditions are a pH of 8.0, a temperature of 40°C, a concentration of 10% owf, and a calcium chloride concentration of 10 mM. PLA fabrics experienced a weight loss of about 0.7% from enzyme treatment with no loss of tensile strength. Biodeterioration due to enzymatic hydrolysis were observed in scanning electron microscopy images. There was an approximately twofold improvement in moisture regain by enzymatic hydrolysis. Finally, X-ray diffractometry identified a new peak localized at 2θ = 18.5° after enzyme treatment. The degree of crystallinity was increased and the crystallite size was decreased.