A comparative study of wool fibre surface modified by physical and chemical methods

The wool scale present on the fibre surface gives rise to certain unwanted effects such as felting and poor wettability in textile wet processing. In general practice, the removal of scale was done either by surface modification through physical/chemical degradation of scale or by deposition of a polymer on the scale. In modern treatment, combination of both methods is usually carried out. Since the deposition of a polymer on the fibre surface depends much on the surface characteristic of the fibre, therefore, the surface property of modified fibre is an important factor for polymer application. On the other hand, the surface modification methods may also result in improved hydrophilicity of fibre. The present paper investigated the surface physico-chemical properties of wool fibre under the influence of different surface modification treatments: (i) low temperature plasma (LTP) treatment with nitrogen gas and (ii) chlorination. The surface physico-chemical properties of the LTP-treated and chlorinated wool fibres were studied which included contact angle measurement with different solvents, determination of critical surface tension and surface free energy. Experimental results showed that these selected properties were altered after the surface modification treatments. In addition, a polymer was deposited in the treated wool fabrics and scanning electron microscope was used for assessing the surface morphology.     

Effect of hollow polyester fibres on mechanical properties of knitted wool/polyester fabrics

The physical and mechanical characteristics of hollow polyester fibres were compared with solid polyester fibres in order to establish their processing behaviour and performance characteristics. The effects of hollow fibres on fabric properties were investigated by using microscopy and tests of tensile and bursting strength, pilling, abrasion resistance, water vapour permeability, and handle. The results show that tensile strength of hollow polyester fibres and yarns are negatively affected by the cavity inside the fibre. Hollow fibres also have higher stiffness and resistance to bending at relaxed state. Fabrics made from hollow polyester/wool blends and pure wool fabrics show three distinguishable steps in pilling. During pilling, hollow fibres break before being pulled fully out of the structure, leading to shorter protruding fibres. Microscopy studies showed that the breakdown of hollow fibres started during entanglement by splitting along the helical lines between fibrils. KES results showed that the friction between fibres and the fibre shape are the most important parameters that determine the fabric low stress mechanical properties. However, in some aspects, the hollow structure of the fibre does not have a significant effect.     

Surface Modification of Wool Fabric with POSS® Nanomaterial

Wool fabrics, without any surface treatment, can undergo undesirable and irreversible structural changes of wool fiber during washing under heat and mechanical agitation, leading to high shrinkage of wool garments. The traditional method based on polyamide resin can prevent felting and/or shrinkage of wool textiles, but adversely affect the surface hydrophobicity. In the present study, a treatment solution was developed based on TriSilanolIsooctyl POSS® and 3- mercaptopropyl trimethoxysilane, which created wool surface with increased hydrophobicity and highly resistant to shrinkage or felting, as measured after 3×5A wash cycles (equivalent to 24 domestic washes). After the treatment, the wool fabric appeared to be superhydrophobic with a water contact angle of above 150°, compared to the untreated fabric. The treatment has marginal effect on mechanical performance as observed in tensile properties. Scanning electron microscopic images revealed a coating of POSS® on the wool surface. The dyeing of untreated and treated fabrics appeared to be uniform to the naked eye, though spectrophotometric analysis indicated a difference in the extent of dyeing performance. This research showed that POSS®-based treatment is a potentially effective approach for developing shrink-resistant wool textiles with enhanced surface hydrophobicity, in contrast to traditional chlorine/polyamide resin treatment.     

Functional Antibacterial Finishing of Woolen Fabrics Using Ultrasound Technology

The growing concern for the personal health and hygiene has created the necessity of acquiring wool fabric antibacterial activity. Silicon dioxide nanoparticles (SiO₂ NPs) have appropriate features to enhance the functional properties of wool fabrics, especially with polymer application. In this study efficient coating using polyethylene glycol (PEG₂₀₀₀) and SiO₂ NPs were used for imparting antibacterial properties to treated fabrics. All the treatments were carried out using both conventional and ultrasound techniques. The physical and chemical properties were evaluated using FTIR, XRD, and SEM. The result indicated that treated wool fabrics by PEG/SiO₂ NPs improved the dyeability and antibacterial of the fabrics and also enhanced its mechanical properties. Furthermore, it is believed that the ultrasound radiation causes homogeneous distribution of cross-links and polymerization throughout the wool surface. This offers considerable advantages compared to conventional treatment.     

Effect of wool surface modification on fluorocarbon chain re-orientation

There is an increasing demand for air-dry performance of fluorocarbon finished materials. Thus, surface modifications of wool fabrics were evaluated. Untreated, gaseous fluorinated, Chlorine/Hercosett processed 100 % wool fabrics were treated with different fluorochemicals and their liquid repellency after washing, and dry cleaning were evaluated. The results indicated that Chlorine-Hercosett treated samples, wool with a positive charge, after few washing cycles, showed better air dry performance with higher level of repellent properties. In addition, the comparison of the wool surface modifications treatment with different applied fluorochemicals, with different commercial formulations, illustrated that the fluorocarbon chain re-orientation and fastness properties are more affected by the nature of the wool surface while the used fluorocarbons showed more or less similar behaviours. In general, the fluorination increases fabric stiffness with lower fabric formability. The surface interface was effectively probed by X-ray Photoelectron Spectroscopy, XPS, which enabled the characterisation of the loss of surface lipids, the nature of the fibre oxidation and the deposition of fluoropolymers.     

Dimensional properties of low temperature plasma and silicone treated wool fabric

Three different silicone polymer systems, such as aminofunctional, epoxyfunctional, and hydrophilic epoxyfunctional silicone polymers, were applied onto plasma pretreated wool fabric to improve the dimensional properties. The results showed that the plasma pretreatment modified the cuticle surface of the wool fiber and increased the reactivity of wool fabric toward silicone polymers. Felting shrinkage of plasma and silicone treated wool fabric was decreased with different level depending on the applied polymer system. Fabric tear strength and hand were adversely affected by plasma treatment, but these properties were favorably restored on polymer application. Therefore, it has been concluded that the combination of plasma and silicone treatments can achieve the improved dimensional stability, and better performance properties of wool fabric. The surface smoothness appearances of treated fabrics were measured using a new evaluation system, which showed good correspondence with the results of KES-FB4 surface tester.     

The effect of temperature and water on the mechanical properties of wool fibres investigated with different experimental methods

The tensile and durability properties of single wool fibres were investigated with tensile testing method and lever equipment giving the results examined by Zhurkov’s kinetic equation under the effects of temperatures and water. Moreover, Differential Scanning Calorimetry (DSC) method was applied to determine denaturation and degradation peaks and corresponding enthalpies of wool fibre. It was shown that with increasing temperature, tensile properties and durability of the wool fibres decreased considerably. A great decrease on tensile properties was seen at temperatures higher than ∼200 °C after which a denaturation doublet of α-keratin and a wide thermal degradation peak were observed in DSC diagrams. Moreover, the wet fibres obtained lower tensile characteristics except breaking extension which increased by 9 % and 20 % for the fibres kept in water for one h and one month, respectively. However, the breaking extension of the fibre tested in water increased greatly by 73 % which indicates the important role of water molecules on the intermolecular interactions during stretching. The weakening effect of water molecules on the structure was also shown by DSC result of wet wool fibres at which the thermal degradation enthalpy of α-keratin and other histological components decreased by 22 %. The changes of the tensile and durability characteristics of wool fibres were compared and discussed in detail based on Zhurkov’s equation and intermolecular interactions.     

Improvement of shape stability and thermal properties of PCM using polyethylene glycol (PEG)/sisal fiber cellulose (SFC)/graphene oxide (GO)

This study prepared a polyethylene glycol (PEG)/sisal fiber cellulose (SFC)/graphene oxide (GO) composite using a novel dynamic impregnating method to obtain a high-performance shape-stabilized phase change materials (PCMs). In this material, the ternary system PEG served as the latent heat storage material and SFC and GO served as the supporting materials. The structure, morphology, thermal conductivity, phase change temperature, and latent heat of the composite PCMs were characterized by fourier transform infrared spectroscopy, wide-angle X-ray diffraction, polarizing microscope, digital camera, scanning electron microscopy, differential scanning calorimetry, and thermal conductivity analysis. Results show that the composite PCMs exhibit a fine impregnation morphology and excellent shape-stabilized feature during the phase change process, the shape of the PEG/SFC/GO composite PCMs are unchanged even after being placed on a 85 °C hot plate. Thermal behavior tests indicate that the composite PCM (PEG weight percentage of 80 wt.%) shows a high latent heat storage capacity of approximate 140 J/g after more than 100 thermal cycling, and exhibits good heat-conducting performance.     

Encapsulation of phase change materials by complex coacervation to improve thermal performances and flame retardant properties of the cotton fabrics

This paper reports a study on the thermal stability and flame-retardant properties of microencapsulated phase change materials (PCMs) with clay nano-particles (Clay-NPs) doped gelatin/sodium alginate shell. The novel microcapsules were fabricated by the technique of complex coacervation using gelatin and sodium alginate as the shell and PCM n-eicosane as the core. Their flame retardant property as well as their practicable thermal performances when incorporated into woven cotton fabrics by pad-dry-cure were investigated. Thermal storage/release properties of the prepared microcapsules were analyzed using DSC instrument. Thermal gravimetry (TG) analysis was performed to measure the thermal stability and surface morphology of the microcapsules was observed by means of optical microscopy and SEM. The DSC results indicated that the latent heat storage capacity of prepared microcapsules changed in range of 97-114 J/g. The microcapsules had spherical shape with particle sizes between 1.37 μm and 1.6 μm. The PCM microcapsules (PCMMs) and nano-composite PCM microcapsules (NCPCMMs) with clay-NPs doped gelatin/sodium alginate shell were found to have good potential for developing thermal comfort in textiles. Comparing with conventional PCMMs, NCPCMMs have significantly better thermal stability. Nano-composite structure of the NCPCMMs, in which clay-NPs doped in the polymeric shell structure, attributed to increase the shell thermal stability. Improved flame retardant properties of the cotton fabrics treated with NCPCMs were declared as a result of flame retardant tests. Thermo-regulating properties of the fabrics were proved by thermal history (THistory) measurement results from releasing heat from microcapsules.     

Self-cleaning and handle properties of TiO2-modified textiles

Self-cleaning surfaces based on photocatalysis are an extremely promising nano-technological field of extensive research and development. Recently comprehensive research work has been performed to evaluate the optical, photocatalytic and antimicrobial properties of TiO₂ nano-particles and composites thereof. The aim of this study was to obtain self-cleaning properties for regenerate cellulose surfaces by nano-modification, using TiO₂ nano-coating and to define the impact of the modification on fabrics end-use properties. Two different modified fabrics with self-cleaning effect were prepared and analysed, i.e. the modification efficiency was determined. In addition, the influence of fibre modification on several textile properties was determined. However, a soft handle, good appearance and some other surface properties accompanied by appropriate mechanical properties represent the basis for a high quality fabric therefore the influence of the modification procedure on textiles handle was studied.     

Leveraging the Antibacterial Properties of Knitted Fabrics by Admixture of Polyester-Silver Nanocomposite Fibres

Leveraging the antibacterial properties of polyester-cotton knitted fabrics has been attempted in this research by admixture of small proportion of polyester-silver nanocomposite fibres. Polyester-cotton (50:50) yarns were spun by mixing 10, 20 and 30 % (wt.%) polyester-silver nanocomposite fibres with normal polyester fibres so that overall proportion of polyester fibre becomes 50 %. The proportion of cotton fibre was constant (50 %) in all the yarns. Three parameters, namely blend proportion (wt.%) of nanocomposite fibres, yarn count and knitting machine gauge were varied, each at three levels, for producing 27 knitted fabrics. Polyester-cotton knitted fabrics prepared from polyester-silver nanocomposite fibres showed equally good antibacterial activity (65-99 %) against both S. aureus and E. coli bacteria. Antibacterial properties were enhanced with the increase in the proportion of polyester-silver nanocomposite fibres, yarn coarseness and increased compactness of knitted fabrics. Yarn count and blend proportion of nanocomposite fibre were found to have very dominant influence in determining the antibacterial properties of knitted fabrics.     

Properties of cotton fabric after irradiation with infrared CO2 laser

Thermal effect of interaction between laser beam and fabrics presents a risk of material damage, because strong laser beam energy is applied to a very small area of fabric. At present infrared laser beam is widely applied to decolouration of denim fabrics, cutting of textiles. There were investigated the morphology, color change and mechanical properties of irradiated samples of cotton fabric. Chemical damage of cotton fibers was quantified by copper number and behaviour of dissolved polymer. Results was discussed in connection with practical applications.     

Synthesis and Characterization of Aqueous Chitosan-polyurethanes Dispersion for Textile Applications with Multipurpose Performance Profile

As the use of high performance textiles has grown, the need for chemical finishes to provide the fabric properties required in the special applications has grown accordingly. In this project, a series of water dispersible polyurethanes dispersion (CS-PUs) with multipurpose performance profile was developed using isophorone diisocyanate (IPDI), polyethylene glycol (PEG), 2,2-dimethylol propionic acid (DMPA) and chitosan (CS) for textile applications. In two step synthesis process, NCO functional PU prepolymers prepared by reacting IPDI, PEG, and DMPA were extended with varying molar quantities of chitosan followed by structural characterization through FTIR. The prepared CS-PU dispersions were applied onto the dyed and printed poly-cotton blend fabrics. The performance behavior of the treated fabric in terms of crease recovery, tear strength, tensile strength, and antibacterial properties was evaluated by applying standard test methods. These investigations show that the CS-PU dispersions can be applied as antibacterial textile finishes with significant improvement in the physical and mechanical properties of poly-cotton fabrics.     

Application of PU-sealing into Cu/Ni electroless plated polyester fabrics for e-textiles

Electroless metal plated fabrics are favorable to be used as e-textiles due to the excellent conductivity and peculiar properties of textiles such as flexibility. But, the electrical durability is not enough to be used as e-textiles. Therefore, we applied polyurethane(PU)-sealing (single-sealing vs. double-sealing) onto the electroless metal plated polyester fabrics (Ripstop vs. Mesh) to reinforce the electrical durability. We investigated the changes of electrical properties of the PU-sealed metal plated fabrics after laundering by a multi-meter, examined the surface changes using scanning electron microscope, and checked the metal existence using energy dispersive X-ray spectroscopy. And, we finally proved the possibility of the fabric strips as transmission lines by alternating conventional earphone lines. PU double-sealing showed higher performance on Ripstop polyester fabrics even after being laundered 10 times, which was almost the same as Cu-based typical conductive lines did.     

Effect of ultrasonic laundering on thermophysiological properties of knitted fabrics

The paper focuses on the application of ultrasonic energy in textile laundering. In recent years, there has been an increasing interest in ultrasonic energy application in textile industry; however, the effect of ultrasonic laundering on the thermophysiological properties of knitted fabrics has not been studied yet. This study was conducted by using polylactic acid (PLA), cotton, polyethylene terephthalate (PET), and poly acrylic (PAC) fibres containing yarns and their blends. Knitted fabrics, single pique, were made from these yarns by using weft knitting machine. The fabrics were washed ten times for 15 and 60 minutes under 40 °C by using conventional and ultrasonic washing methods. The main aim was to determine the effect of washing methods on the thermophysiological properties of the fabrics. It is also aimed to analyse and evaluate the thermophysiological properties of the PLA fabrics. The incorporation of 100 % PLA and cotton/PLA yarns into single pique knitted fabrics has been attempted to produce for the first time and studied their thermal comfort properties. The results show that the washing processes have a critical importance for the tested fabrics in terms of thermal conductivity, thermal resistance, thermal absorbtivity, water vapour permeability, and heat loss. It has been also demonstrated that the fabric cleaning by using ultrasonic method enhanced the properties of tested fabrics such as thermal conductivity and % recovery. It was also noted that 15 minutes ultrasonically washed fabrics had significantly lower thermal resistance as compared to conventionally washed fabrics.     

Relations between the characteristics of Angora rabbit fibre

Angora rabbit fibre is one of the finest specialty animal fibres with its well-known reputation for fineness, lightness and softness. This study evaluated the Angora fibre shape and morphology in comparison with Cashmere fibre and wool as well as the relation between characteristics of Angora fibre. Unlike other keratinous textile fibres, single Angora fibre composes of two sections named as body and head, each of which has individual surface characteristics. Differences between the scale shapes, scale length and scale frequency of Angora hair types were explained in details. Medullation in Angora fibre was explained for different types of Angora hairs defined as down, awn and bristle. This classification was done according to the fibre fineness starting from the finer one. Relation between fibre shape and comfort factor was also analyzed. The relation between mean fibre diameter (MFD), fibre curvature (FC) and percentage of medullation by volume (MEDV) for Angora rabbit fibre was not as strong as wool and Cashmere fibre. Accordingly, when Angora hair types were analyzed individually, it was observed that relation between FC and MEDV for Angora fibre was stronger than wool and Cashmere fibre. Multiple regression analysis was also performed. Diameter distribution along the snippet length (about 200μm) of Angora fibre is uneven compared to Cashmere fibre and wool.     

Effect of fibre diameter and cross-sectional shape on moisture transmission through fabrics

The current work incorporates an experimental study on the effect of fiber cross sectional shape and fibre diameter on moisture transmission properties of the fabric. Water vapour transmission of the fabrics was measured using the PERMETEST. In plane liquid flow through the fabric was measured using a gravimetric in-plane wicking tester and vertical movement of liquid along the fibres against gravity was also observed using a vertical wicking tester. With the change in shape factor and fibre diameter, it is seen that with increase in fibre specific surface area wicking rate through fabric increases, whereas water vapour permeability of the fabric reduces.     

Interaction of textile parameters,wash-ageing and fabric softener with mechanical properties of knitted fabrics and correlation with textile-hand. I. Interaction of textile parameters with laundry process

This is a study of the influence of repeated laundering and the use of fabric softener in the context of mechanical properties of fabrics with respect to textile parameters. In the large competitive market of fabric softener, the fabric softener producers claim benefits for fabric hand as well as the mechanical properties of textiles. The main aim of this study is to investigate the influence of ageing and the use of fabric softener on the mechanical properties of textiles during their cradle to grave life with respect to fibre type, fibre fineness, knitting construction and number of wash cycles. The low stress mechanical properties were evaluated by means of the Kawabata Evaluation system for fabric (KES-F) and Universal Surface Tester (UST). The tensile, shear, bending, compression and surface properties and changes in these parameters due to wash-ageing and the use of fabric softener during laundry were evaluated. These mechanical properties or combinations of them are the deciding factors for comfort aspects of apparel during wear. Hence, these mechanical properties need to be correlated with the sensory attributes. In Part I, we examine the change in mechanical parameters due to wash-ageing and the use of softener, while Part II deals with Fuzzy-Logic modelling to correlate these mechanical parameters with sensory attributes.     

Preparation and characterization of poly(methylmethacrylate-coglycidyl methacrylate)/n-hexadecane nanocapsules as a fiber additive for thermal energy storage

The interest to innovative products with high added values and processes in textile field has been rapidly increasing among the other industrial fields. One of innovations in this field is to produce of innovative textiles containing phase change material (PCMs) that have thermal storage and thermo-regulation properties. This study deals with preparation and characterization of poly(methylmethacrylate-co-glycidyl methacrylate)/n-hexadecane nanocapsules containing nhexadecane as phase change material for thermal energy storage. The chemical characterization of poly(methylmethacrylateco-glycidyl methacrylate)/n-hexadecane nanocapsules was made by fourier transform infrared (FT-IR) spectroscopy method as particle size and its distribution (PSD) were studied by scanning electron microscopy (SEM). Thermal properties of nanoencapsulated n-hexadecane were determined using differential scanning calorimetry (DSC). The melting and freezing temperatures of the nanoencapsulated n-hexadecane were 17.23 and 14.85 °C respectively as the latent heats of melting and crystallization were 148.05 and −147.63 J/g respectively. Produced nanocapsules were applied to polyacrylonitrile (PAN) by means of electrospinning and surface morphology of the fibers was investigated by SEM analysis. Based on the results, it can be considered that the nanoencapsulated n-hexadecane in poly(methylmethacrylate-co-glycidyl methacrylate) have good energy storage potential to be used in fibers.     

Development of durable shrink-resist coating of wool with sol-gel polymer processing

Knitted wool fabric was pre-treated with the serine type protease, Esperase 8.0L (EC3.4.21.62), and sodium sulphite followed by an immersion treatment with a sol-gel hybrid polymer. To enhance the durability of the sol-gel treatment on wool, one of two different alkoxysilanes containing coupling epoxy or mercapto groups were added to the sol-gel hybrid. The combination of protease treatment with an immersion sol-gel treatment achieved wool fabric that was lightweight with a soft handle and had combined shrink-resistance and hydrophobic properties without fibre discoloration. The addition of an alkoxysilane with a mercapto coupling group within the sol-gel hybrid gave better performance than using an alkoxysilane with an epoxy coupling group in terms of polymer uptake, fabric shrink resistance, whiteness and durability to washing.