Untreated Wool Research Articles

Effect of polydopamine-modified protease on shrink-resist properties of wool fiber

Dopamine is considered to have great potential in the field of immobilized enzymes due to its excellent biocompatibility and simple immobilization process. Herein, we propose a new shrink-resist treatment strategy for wool. The catechin in the dopamine structure is chemically cross-linked with the amino group in the enzyme molecule to control the hydrolysis reaction on the fiber surface. At the same time, using the characteristics of dopamine self-polymerization, excessive polydopamine is polymerized on the surface of wool fibers, forming multiple interactions between dopamine, protease, and wool. The structure and morphology of protease and polydopamine-protease-treated wool fibers were characterized by FTIR and scanning electron microscopy, and the effect of dopamine on protease activity was studied. Compared with untreated wool, this effective method can significantly improve the dimensional stability (2.34%) and wettability of wool fabric to felt, and can also make up for the strength loss caused by protease. However, affected by the color of dopamine itself, the treated wool is light gray, and the K/S value reaches 2.988. This study provides a new way for enzymatic modification of keratin-containing fibers such as wool using dopamine and other natural biopolymers with similar structures.

Hierarchically fibrillated spunlaced nonwovens from waste wool supported ionic liquid as solid amine adsorbents for CO2 capture

The environmental crisis caused by excessive emissions of carbon dioxide-based greenhouse gases has garnered widespread public concern. Solid amine is considered to be one of the most effective carbon dioxide (CO2) adsorbents. However, traditional solid amine carriers have problems such as structural collapse, low efficiency and poor regeneration. In this study, waste wool having hierarchical fibrous structure was spunlaced, fibrillated and later compounded with amino acid ionic liquids (AAIL) leading to the formation of the AAIL@feather-like wool nonwoven absorbents. A synergistic co-amine effect was observed after primary and secondary fibrillation without any sacrifice in the mechanical property of wool nonwovens. Also, the fibrillated nonwovens had high specific area which provided high loading rate (13.53 %) on AAIL. Compared with untreated wool nonwovens, the CO2 adsorption capacity of feather-like wool nonwovens was higher by 65 % (11.75 mmol/g) after loading AAIL. Furthermore, the CO2 adsorption capacity was retained (95.2 %) even after 12 cycles at 80 ℃, indicating that the AAIL@ feather-like wool nonwovens possess good long-term stability. This work paves the way for large scale manufacturing of biobased solid adsorbents with a hierarchical nonwoven structure for efficient CO2 capture.

Antibacterial and mothproofing wool fabrics modified by M-Arg/PHMG and ZnO

The increasing focus on sustainable and eco-friendly materials has sparked a growing interest in wool as a natural fiber for sustainable fashion, thanks to its skin-friendly properties, warmth, breathability, renewability and biodegradability. The advancement of wool fabrics with durable antimicrobial and moth-resistant qualities could significantly enhance the utilization of wool in the production of high-quality textiles. This study investigates the synthesis of M−Arg and polyhexamethylene guanidine hydrochloride (PHMG) and their application in the surface modification of wool fibers, with an evaluation of the antimicrobial properties of the treated fabrics. Initially, plasma was used to pre-treat the wool fibers, followed by the adsorption of M−Arg and PHMG and ZnO in situ on the fibers’ surface. The antibacterial effectiveness against gram-positive (Staphylococcus aureus, S. aureus) and gram-negative (Escherichia coli, E. coli) microorganisms was assessed through antibacterial testing of the M−Arg/PHMG/ZnO-Fiber (MPN-Fiber). Results showed that the MPN-Fiber exhibited a significantly higher antimicrobial rate compared to untreated wool fiber. The prepared MPN-Fiber inhibited E. coli and S. aureus by 99.64 ± 1.04 % and 96.47 ± 2.14 %, respectively. Additionally, the MPN-fiber has good washing resistance (20 times, lose only 10 %). The experimental results clearly demonstrated that the MPN-Fiber exhibited exemplary antibacterial and moth-proof properties, confirming the success of the innovative surface modification approach.

Enhanced coloration and functionality of wool fabric by Hydroxypropyl-β-cyclodextrin coated magnetic nanoparticles

The functionality and excellent low temperature dyeability of wool fabrics play a crucial role in expanding their potential applications in the fields of healthcare and technical textiles. The study proposes a highly effective modification method to impart coloration enhancement and functionality for wool fibers using lipoic acid (LA) as a coupling agent to bind hydroxypropyl-β-cyclodextrin (HP-β-CD) capped magnetic nanoparticles (Fe3O4). The structure and morphology of the modified wool fabrics (MWF) were characterized by various measure techniques including FT-ATR, FE-SEM/EDS, XRD, X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TG). The results demonstrated the successful immobilization of HP-β-CD capped Fe3O4 nanoparticles on the surface of wool fibers through LA. The MWF exhibited enhanced wettability, anti-wrinkle performance, improved UV resistance, effective antioxidation, and good antibacterial effect against Gram-positive (Staphylococcus aureus). These properties were found to be dosage-dependent on LA. In addition, the dyed MWF with Curcumin and Acid red 1 demonstrated higher color strength compared to untreated wool, and the color strength (K/S value) reached to 17.1 and 23.4 respectively when using 4% (o.w.f) dye concentration at 80℃ without any pH adjustment. Furthermore, the dyed MWF with both dyes exhibited the improved rubbing and washing colorfastness. This study presents a potential effective approach for enhancement in the bio-functionality and dyeability of wool fabrics.

Marine Biodegradation Behavior of Wool and Other Textile Fibers

Microplastic pollution is a growing concern for the earth’s terrestrial and marine environments. Synthetic fibers from textiles are one source of microplastic pollution as fibers may be released from garments during use and especially during laundering, whereby they may enter the aquatic environment via wastewater systems. Wool is a natural fiber, but it is often given treatments to enhance its performance, such as to make it resistant to shrinkage caused by machine washing. Treatments of this type might influence the fiber’s inherent biodegradability. We sought to understand the aquatic biodegradation behavior of wool (in its unmodified form, and chlorine-Hercosett shrink-resist treated) and a range of synthetic fibers that are used in similar clothing applications. The biodegradation test was carried out in a simulated marine environment using a natural seawater inoculant according to the ASTM D6691 method with some modifications. Biodegraded wool residues were characterized by Fourier transform infrared and energy dispersive X-ray spectroscopies. The extent of fiber damage was observed by scanning electron microscopy. Both types of wool biodegraded readily under these conditions and machine-washable wool biodegraded to a greater extent than untreated wool. Regenerated cellulosic fiber (viscose rayon) also degraded readily, but all three synthetic fibers (polyester, nylon and polypropylene) showed virtually no biodegradation. Analysis of solid and liquid residues generated by the biodegraded wool showed no evidence that the chlorine-Hercosett-treated wool generated any non-degraded residues. Based on these findings we believe that, unlike synthetics, wool fibers are very unlikely to lead to microplastic pollution in the aquatic environment.

Viability Study of Serra da Estrela Dog Wool to Produce Green Composites.

The environmental emergency has alerted consumers and industries to choose products derived from renewable sources over petroleum derivatives. Natural fibers of plant origin for reinforcing composite materials dominate the field of research aiming to replace synthetic fibers. The field of application of green dog wool composite materials needs to be reinforced and proven, as the industry is looking for more sustainable solutions and on the other hand this type of raw material (pet grooming waste) tends to grow. Hence, in the present work, the feasibility of applying natural fibers of dog origin (mainly composed by keratin) in green composites was studied. The green composites were developed using chemically treated dog wool of the breed Serra da Estrela (with NaOH and PVA) as reinforcement and a green epoxy resin as a matrix. The chemical treatments aimed to improve adhesion between fibers and matrix. The fibers' composition was determined using X-ray Diffraction (X-RD). Their morphology was determined using a scanning electron microscope (SEM). The wettability of the fiber was also evaluated qualitatively by analyzing drops of resin placed on the fibers treated with the different treatments. The mechanical properties of the composites were also studied through mechanical tensile, flexural, and relaxation tests. Overall, the best results were obtained for the dog wool fibers without treatment. The tensile and flexural strength of this biocomposite were 11 MPa and 26.8 MPa, respectively, while the tensile and flexural elastic modulus were 555 MPa and 1100 MPa, respectively. It was also possible to verify that the PVA treatment caused degradation of the fiber, resulting in a decrease in mechanical tensile strength of approximately 42.7%, 59.7% in flexural strength and approximately 59% of the stress after 120 min of relaxation when compared to fiber made from untreated dog wool. On the other hand, the NaOH treatment worked as a fiber wash process, removing waxes and fats naturally present on the fiber surface.

Adenosine Triphosphate/Chitin Whisker/Phenylboronic Acid-Modified Wool Fabrics with Enhanced Dyeability.

Promoting the uptake of dyes is an important part of the sustainable processing of wool products. This study presents an effective modification approach to enhance the dyeability of wool fabric with adenosine triphosphate as an activator, 3-carboxyphenyl boronic acid as a ligand-binding agent, and chitin whisker as a couple agent. The structure and surface morphology of the as-prepared wool fabric was characterized in detail. Natural luteolin and acid red 1 were used to dye the modified wool fabric, and the effect of different dyeing parameters on dyeing properties was discussed. The results indicated that the modified wool gained better surface color depth (K/S) and uptake without additional agents than the untreated wool fabric. When the modified wool fabric was dyed at 45 °C with luteolin and at 60 °C with acid red 1, the dyeing processes of the two dyes on the modified wool fabrics followed the Langmuir isotherm and the pseudo-second-order kinetic model. Furthermore, the dyed modified wool fabrics possessed improved color fastness. Overall, this work offers a facile, effective, and sustainable way to improve the low-temperature dyeability of wool products.

Evaluation of the Mechanical Performance and Structural Characterization of Hybrid Green Composites Based on Periploca laevigata Aiton and Wool Natural Fibers

The current research is focused on developing and evaluating new composite materials that are reinforced with natural fibers to enhance sustainability and create environmentally friendly composites. The use of both wool and Periploca laevigata Aiton fibers was chosen in the construction of the hybrid composite due to their similar organic composition, while also taking into account their different properties such as weight, density, and water absorption capabilities. This combination created a composite material that is not only lightweight but also has little water absorption. To further improve the quality of the wool, a treatment involving cold plasma has been carried out to enhance the bonding between individual fibers. Vacuum infusion technology is used during the manufacturing process to ensure the quality of the composite materials by eliminating trapped air, allowing for consistent purity in each repetition. The fibers used in this study include untreated wool fibers, NaOH‐treated wool fibers, and cold plasma–treated wool fibers. Wool fibers were treated with a 5% sodium hydroxide solution for 30 min, resulting in fiber degradation. The concentration of the solution was gradually reduced until it reached a practical level of 0.1%. The hybrid composite incorporates wool that has undergone plasma treatments, which are crucial for removing organic contaminants from surfaces, strengthening the surface layer, and altering the chemical structure. The electric field applied had a strength of 9 kV and a frequency of 60 Hz. Atmospheric air was employed as the gas, with a flow rate of 800 L/min, and the fiber treatment lasted for 60 min. An analysis of natural fibers using Fourier transform infrared (FTIR) and X‐ray diffraction (XRD) unveiled similarities in the organic structures and chemical bonds shared between Periploca laevigata Aiton fiber and wool fibers, despite their unique origins. While wool fibers are animal‐derived, Periploca laevigata Aiton fibers stem from plants. By identifying these parallels, a hybrid composite material was formulated by combining plasma‐treated wool fibers with Periploca laevigata fibers. This resulted in a significant improvement in the tensile, flexural, and compressive properties of the composite, establishing it as a promising avenue for enhancing mechanical performance. The PLAF‐WLF hybrid composite exhibited a remarkable tensile strength of 26.02 MPa and Young’s modulus of 2.35 GPa, surpassing all other composites. In comparison, the PLAF composite demonstrated an impressive tensile strength of 20.1 MPa and Young’s modulus of 2.34 GPa. The PLAF‐WLF hybrid composite exhibited the highest flexural load‐bearing capacity of 253.15 N and Young’s modulus of 1.21 GPa. PLAF‐WLF demonstrates a hybrid compressive strength of 59.56 MPa, while its Young’s modulus is 0.5 GPa. The mechanical analysis findings revealed that the hybrid composite incorporating cold plasma–treated wool fibers and Periploca laevigata Aiton fibers displayed superior mechanical characteristics. Additionally, the composite made of Periploca laevigata Aiton fibers, recognized for its lightweight nature, smooth surface, and high quality, showed notable mechanical properties as well.

Compostability of wool textiles by soil burial

Chemical processing has the potential to impact the composting of wool fabrics, influencing potential end of life options. The aim of this study was to investigate the comparative composting behaviors of a range of knitted and woven merino apparel fabrics. The range included scoured only control fabrics and variants which had undergone different chemical processes during manufacturing, including dyeing, bleaching, stain-repellence and various shrink-resist treatments. Biodegradation by composting was elicited by a soil-burial process incorporating three sets of randomized samples buried to a depth of 10 cm. Replicates were removed at regular intervals up to a maximum of 15 weeks burial. The dyes present in the fabric showed the greatest impact on composting. Chrome dyed samples exhibited only 60% mass loss over the trial period, whereas the other 10 fabrics all lost on average over 95%. When assessing easy care treatments, chlorine–Hercosett provided consistent initial resistance to decomposition. Soil burial test results suggested that chemical processing does impact the composting of wool fabrics, under the conditions of soil burial. Statistically significant longer-term effects were only observed for the chrome dyed sample. • Chemical processing of wool fabrics influences the onset of composting as a result of soil burial. • Dyeing fabrics had the greatest impact on the onset of composting as a result of soil burial. • Machine-washable wool has initial resistance to decomposition, compared with untreated wool, as a result of soil burial.

Effects of fiber electrostatic cling and moisture regain on timothy grass pollen attraction

The purposes of this study are to determine if there is a relationship between fabric parameters such as electrostatic charge and moisture regain on the attraction of Timothy grass pollen, and to determine the effects of various fabric treatments on their pollen attraction. Half of the fabrics were treated with acidic acid (vinegar), basic (ammonia), and fabric softener. Both untreated and treated fabrics were exposed to Timothy grass pollen. The pollen counts of both untreated and treated fabrics were then determined. The results showed that untreated wool was found to be the least attraction to Timothy grass pollen while nylon was the most attracted to this pollen. The relationship between electrostatic cling time and pollen attraction was not established in the fibers studied except nylon, which had the highest cling time and the highest pollen count. When examining the relationship between fiber moisture regain and their pollen attraction, the results showed that other than wool, which had the highest MR and the lowest pollen count, no consistency was found between the MR and pollen count for the rest of the fibers tested. For fabric treatments, the results showed that dilute acidic acid was found to be most effective in reducing the pollen counts in all fiber fabrics except made no change in wool. Fabric softener was found to be the least effective treatment in lowering the fabric pollen attraction on all fiber fabrics except nylon.

Eco‐friendly approach on wool pretreatment and effect on the wool structure and dyeability

AbstractThis research investigated the effect of various proteolytic enzymatic pretreatment on morphological and chemical features and the dyeability properties of wool fibres. Scoured merino wool fibres are treated with protease, papain, trypsin, and pepsin in specified conditions. Each enzyme activity measurement was provided by appropriate methods such as Bradford, BAPNA (N‐benzoyl‐1‐arginine‐p‐nitroanilide), and BSA (Bovine Serum Albumin). Enzymatic processes were carried out for 24 h in the incubator set at 40°C, 100 rpm, and specified pH with 1 mg/ml enzyme concentration. Whiteness index (Stensby) and yellowness index (ASTM D 1925) were examined after enzymatic pretreatment. Pepsin and trypsin‐treated wool fibres showed the highest whiteness index as 61.3 and 61.1, respectively whilst untreated wool fibres had 52.2. Fourier‐transform infrared (FTIR) analysis revealed the increase in the intensity of amide‐related bands and hydroxyl bands after enzymatic treatment. Scanning electron microscopy (SEM) photomicrographs manifested the cuticle layer is partially removed in enzyme‐treated fibres. Elemental identification was provided by SEM–energy‐dispersive X‐ray spectroscopy (EDX). It appears that the sulphur bonds decreased after the treatment and the pepsin‐treated fibres have fewer bonds of all. To examine the damage to the structure, photomicrographs were taken using fluorescence and light microscopes. The alkali solubility test (ASTM D1283) was also conducted to compare different enzyme types. Wool fibres were dyed in 2.0% concentration with reactive dyestuff. Dyeability and colorimetric features of fibres were measured by a spectrophotometer. The washing fastness test showed that all the samples have good results and the colour change after washing was better in enzyme‐treated samples (grade 5) compared to untreated wool fibres (grade 4–5).

Liquid-Ammonia-Mediated Dyeing Process of Wool at a Lower Temperature

Liquid ammonia as a non-aqueous medium has many physical properties close to water, such as small molecular weight and strong permeability. It has been widely used for the ecological processing of cellulosic fibers to improve their luster, softness and dyeing properties. However, there are few reports on the dyeing of wool treated with liquid ammonia, especially at a lower temperature. Herein, a continuous liquid ammonia finishing machine was used to batch process wool followed by dyeing in a commonly-used wool dyeing machine. The results showed that many scale flakes and some cuticle cracking were seen on the fiber surface, and the disulfide bonds of cystine were broken down after liquid ammonia treatment, which promoted the diffusion of dyestuff into the fiber. Moreover, the uptakes and K/S value of wool dyed with Lanaset and Lanasol CE dyes were higher than the untreated wool, and the dyeing temperature could decrease to 85 °C, while the degree of fiber strength reduction merely decreased by 3–5%. Furthermore, for the reactive dyes, the dyeing temperature can reduce to 70 °C with the chemical auxiliaries Miralan LTD, while the degree of strength reduction decrease by 8–10%. Liquid ammonia treatment can be used for dyeing at a lower temperature than boiling temperature (100 °C), reduce energy consumption and reduce the degree of fiber strength reduction of wool. The method shows considerable to great value and is significant in providing a feasible approach for the industrial application of low-temperature dyeing technology.

The enhancement of wool reactive dyes ink-jet printing through air plasma pretreatment

Ink-jet printing is a clean and high-definition printing method for wool fabrics. However, due to the existence of scale layers, the dyes were hardly absorbed into the wool fibers, resulting in poor printing quality. In this work, a green and efficient air plasma pretreatment method was proposed to improve ink-jet printing performance of wool fabrics using reactive dye inks. The results showed that the wool surface was etched after plasma treatment, which led to the increased contact area between wool fiber and dyes. Meanwhile, due to the introduction of more oxygen-containing functional groups on the fiber surface, and part of the –SH and –S-S- were oxidized into –S-O-, the wettability of wool was obviously enhanced with the contact angle decreasing from 135° to 27.5°. The breaks of C–C and C–N bonds resulted in the increase of binding sites between reactive dyes and wool fibers. Because of the above changes, the inks were easily absorbed into the fiber, which promoted the covalent binding of dyes and fibers. As a result, compared with the untreated wool fabric (K/S value of 14.64), the wool fabrics treated by air plasma for 3 min obtained a wonderful printing effect with a K/S value of 22.34. This pretreatment method provides an environmental and efficient approach for the improvement of wool fabrics ink-jet printing performance.

Antibacterial Properties of Non-Modified Wool, Determined and Discussed in Relation to ISO 20645:2004 Standard.

Wool is considered to possibly exhibit antibacterial properties due to the ability of wool clothing to reduce the build-up of odor, which arises from the microbial activity of skin microbiota. Indeed, when tested with a widely used agar diffusion plate test method, even wool or other textiles not treated with any antimicrobial agent can be interpreted to show certain antibacterial effects due to the lack of growth under the specimen, as instructed in ISO 20645:2004 standard. Therefore, we analyzed in detail what happens to bacterial cells in contact with untreated wool and cotton fabric placed on inoculated agar plates by counting viable cells attached to the specimens after 1 and 24 h of contact. All wool and several cotton samples showed no growth under the specimen. Nevertheless, it was shown without a doubt that neither textile material kills bacteria or inhibits cell multiplication. A reasonable explanation is that bacterial cells firmly attach to wool fibers forming a biofilm during multiplication. When the specimen was lifted off the nutrient agar surface, the cells in the form of biofilm remained attached to the wool fibers, removing the biomass and resulting in a clear, no growth zone underneath it. By imaging the textile specimens with X-ray microtomography, we concluded that the degree of attachment could be dependent on surface topography. The results indicate that certain textiles, in this case, wool, could exhibit antibacterial properties by removing excess bacteria that grow on the textile/skin interface when taken off the body.

Sustainable dyeing and functionalization of wool fabrics with black rice extract

Traditional textile colorations and functionalization consume a lot of energy, take a long time, and use a lot of chemicals; hence, cost-effective and eco-friendly natural dyeing and finishing have become a prime concern. In this study, natural dyes of black rice extract was extracted and used for the coloration and functionalization of wool fabric without using any hazardous dyes. The dyeing conditions were monitored using a one-variable-at-a-time technique, and it was discovered that the optimal dyeing conditions were M: L = 1:100, pH = 3, time = 60 min, and temperature = 90 °C. The dyed wool fabric with Al 2 (SO 4 ) 3 mordant shows higher fastness ratings of 4–5 for wash, 6 for light, 4–5 for dry rubbing & 4 for wet rubbing. SEM photographs confirmed the successful deposition of black rice extract on wool fabrics. In addition, mechanical properties, UV protection, and antimicrobial tests also revealed that the treated wool fabric has excellent UV protection capability and good antimicrobial properties along with adequate strengths. The ultraviolet protection factor was more than 35 in optimized conditions, and the strength increased more than 10% comparing untreated wool fabric. The antibacterial performances shown more than 80% reduction rate after 20 washing cycles. Therefore, the black rice extract are very promising and can be considered as the potential candidate for the sustainable dyeing and functionalization of wool fabric in the textile industry. • Black rice extract was used as sustainable dyeing and functionalize of wool fabrics. • A one-variable-at-a-time technique was employed to optimize the dyeing conditions. • The dyed fabric with mordanting showed higher fastness to wash, light and rubbing. • The treated wool fabric shown excellent UV resistant, antimicrobial, and strength.

Extraction of keratin from sheep wool fibres using aqueous ionic liquids assisted probe sonication technology

Wool derived keratin is a potential biopolymer that can play a vital role as a cheap, sustainable, renewable source of material for designing various speciality products in the field of biomedicine. Unlike conventional methods for keratin extraction, the use of eco-friendly, a recyclable solvent like ionic liquids opens a new perspective for the processing of natural raw materials from livestock industries. In this research work, we develop a technique for rapid dissolution of keratin in ionic liquid assisted by probe sonication without any heating from an external source. The whole process of keratin extraction was optimized concerning the type of ionic liquid, sonication time, initial loading of the sample, and acoustic power of probe sonicator. The properties of regenerated keratin were studied further by using various analytical techniques such as Scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) analysis, thermogravimetric analysis (TGA), Nuclear magnetic resonance (NMR) spectroscopic analysis, Sodium dodecyl sulphate -polyacrylamide gel electrophoresis (SDS-PAGE). FTIR analysis showed the protein secondary structure and TGA analysis further revealed improved thermal properties of regenerated keratin when compared to raw untreated wool. The presence of intermediate filament derived low sulphur keratin along with some fraction of matrix protein in regenerated keratin was confirmed by SDS – PAGE analysis. Thus, further efforts are required to implement this technique at larger industrial scale to make this whole process of keratin extraction economical, quick, and environmentally friendly.

Surface modification of wool fabric using sodium lignosulfonate and subsequent improvement in the interfacial adhesion of natural rubber latex in the wool/rubber composites

In the present study, sodium lignosulfonate (SLS) was used to enhance the interfacial adhesion between the natural rubber latex and wool fabric. The coarse wool woven fabric was treated with various concentrations of SLS. After drying, the fabric was coated with natural rubber latex. The influence of SLS on the physico-mechanical properties of the composites was investigated. The SEM images showed that the SLS acted as a cementing material in between the wool fabric and the rubber latex. In comparison with the control composite sample, the SLS treatment causes up to a 32% increase in the areal density by enhancing the interaction between the wool fiber and latex. The SLS treatment at low concentrations significantly improved elongation of the composites in comparison with untreated wool composite, however, the water diffusion of the composites samples got considerably reduced after SLS treatment. After UV aging, 50% SLS treated sample showed better retention of tensile strength. Since the developed composite is flexible, it can be used for the development of bags, acoustics panels, and doormats.

Investigation of fabric movement in a tumble dryer for the development of drying methods for wool fabrics to save energy

Tumble dryers are widely used for drying garments, but felting shrinkage can be caused to wool garments during the tumble drying process. To dry wool fabrics or garments in tumble dryers, the flat dry function has been introduced in the dryers; however, the energy efficiency is very low. The current study investigated fabric movement at different rotation speeds in the tumble dryer and their resultant performances in terms of specific moisture extraction rate, evenness of drying, fabric shrinkage, and fabric smoothness. For shrink-resist-treated wool fabrics, tumble drying at the rotation speed to keep fabric movement in projectile motion accompanied with occasional tumbling could achieve better energy efficiency, drying uniformity, and fabric smoothness. For untreated wool fabrics, introducing vertical movement to the flat dry in the tumble dryer can improve the heat exchange between the fabric and hot air, resulting in an increase in energy efficiency of approximately 30% compared with motionless flat drying. Wool fabric shrinkage can be controlled at less than 2% with the smooth appearance of fabric at grade 3.5 after drying under the recommended drying condition. This study could help tumble dryer manufacturers design optimal drying methods for wool fabrics with the potential for the reduction of energy consumption.

A Novel Approach towards Removal of Lipid Barrier from Wool Fibers’ Surface Using Thermophilic Lipase

ABSTRACT The hydrophobic nature of wool caused by the surface lipid barrier impedes any wet processes of wool fibers. The conventional methods that utilize alkaline solutions for removing this lipid layer are deteriorative for the fiber. The use of enzymes in textile industry is one of the most rapidly growing fields in industrial enzymology because of eco-friendly and nontoxic characteristics. Therefore, this work is aimed at isolation of thermophilic strains from a soil sample in a hot region. The bacterial strain Bacillus aerius strain 24 K showed the maximum extracellular lipase activity (150 ± 1.03 U/ml) among the seven investigated strains. The locally produced thermophilic lipase enzyme was utilized in scouring as well as one-bath scouring and dyeing of wool. The effect of enzyme concentration, treatment temperature, and time on the dyeability of wool fibers with acid, reactive, and basic dyes was investigated. The results of this investigation proved that the extracted thermophilic lipase enzyme is an appropriate candidate for enhancing the dyeability of wool prior to the dyeing process. One-bath scouring and dyeing of wool were successfully conducted to save energy and water. Unlike the conventionally scoured wool, bio-scoured wool exhibits similar chemical composition and solubility parameters to those of untreated wool.

Cellulose aerogel composites as oil sorbents and their regeneration.

BackgroundWith every oil tanker comes the risk of an accident and oil spill. Sorbents are the most suitable means to remove oil spills. Aerogels as sorbents have high porosity and can be made from cellulose from paper waste. The literature does not distinguish between paper and cardboard as sources of cellulose aerogels and little is known about composites of cellulose aerogels consisting of cellulose fibres and chemically untreated, unprocessed fibres or particles of straw, wool, macroalgae or cellulose acetate from cigarette butts. In this study, the sorption properties for marine diesel oil and biodiesel of such aerogels and their regenerative capacity with bioethanol were investigated.MethodsCellulose aerogels were prepared from office paper and cardboard waste without and with chemically untreated algae, straw, wool and cellulose acetate as a composite by freeze drying. All samples were hydrophobised with methylsilane. The density to calculate the porosity and the contact angle were determined. Then the sorption capacity was determined over five cycles of sorption of oil and regeneration with bioethanol.ResultsThe average contact angle of all samples was 125°, indicating hydrophobicity. Paper-based aerogels were found to consistently have higher sorption capacities for biodiesel, marine diesel oil and bioethanol than cardboard-based aerogels. In particular, the wool/cellulose aerogel composite was found to have better sorption capacity for biodiesel, marine diesel oil and bioethanol than all other samples. The cellulose acetate/cellulose aerogel composite showed significantly higher sorption capacities than the paper and cardboard control samples (highest value is 32.25 g g−1) only when first used as a sorbent for biodiesel, but with a rapid decrease in the following cycles.