Evaluating antistatic performance of plasma-treated polyester

Use of low temperature plasma treatment has been attempted in the textile industry and there the has been some success in the dyeing and finishing processes. In this paper, an attempt was made to apply low temperature plasma treatment to improve the antistatic property of polyester fabric. The polyester fabrics were treated under different conditions with low temperature plasma. An orthogonal array testing strategy was employed for obtaining the optimum treatment condition. After low temperature plasma treatment, the polyester fabrics were evaluated with different characterization methods. Under the observation of scanning electron microscope, the surface structure of the polyester fabric treated by low temperature plasma was found to be seriously altered which provided more capacity for polyester to capture moisture and hence increased the static charges dissipation. The relationship between moisture content and half-life decay time for static charges was studied and the results showed that the increase in moisture content would result in shortening of the time for static charges dissipation. Moreover, the antistatic property of the low temperature plasma treated polyester fabric was greatly improved. In addition, the antistatic property of the polyester fabric treated by low temperature plasma was compared with that of the polyester fabric treated with a commercial antistatic finishing agent.     

Transport properties of layered fabric systems based on electrospun nanofibers

Layered fabric systems with electrospun polyurethane fiber web layered on spunbonded nonwoven were developed to examine the feasibility of developing protective textile materials as barriers to liquid penetration using electrospinning. Barrier performance was evaluated for layered fabric systems, using pesticide mixtures that represent a range of surface tension and viscosity. Air permeability and water vapor transmission were assessed as indications of thermal comfort performance. Protection performance and air/moisture vapor transport properties were compared for layered fabric systems and existing materials for personal protective equipment (PPE). Layered fabric systems with electrospun nanofiber web showed barrier performance in the range between microporous materials and nonwovens used for protective clothing. Layered fabric structures with the web area density of 1.0 and 2.0 g/m² exhibited air permeability higher than most PPE materials currently in use; moisture vapor transport was in a range comparable to nonwovens and typical woven work clothing fabrics. Comparisons of layered fabric systems and currently available PPE materials indicate that barrier/transport properties that may not be attainable with existing PPE materials could be achieved from layered fabric systems with electrospun nanofibrous web.     

Improvement of hydrophilicity of polylactic acid (PLA) fabrics by means of a proteolytic enzyme from <Emphasis Type="Italic">Bacillus licheniformis</Emphasis>

Polylactic acid (PLA) has received considerable attention as a biomass material for the textile industry. To use a PLA fabric in the textile industry, suitable postprocessing that can promote hydrophilicity of such fabrics is required. Here, hydrolytic action of a proteolytic enzyme (alcalase from Bacillus licheniformis) on PLA fibers was evaluated. In addition, the effects of an additive on the enzymatic hydrolysis were analyzed. The results revealed that the optimal enzymatic-hydrolysis conditions for this alcalase are pH 9.5, temperature 60 °C, enzyme concentration 50 % on weight of fabric (owf), and Lcysteine concentration of 3 mM. PLA fabrics were hydrolyzed effectively, however; there was no damage to these fabrics judging by tensile strength and surface observations. X-ray diffractometry identified a new peak (at 2θ=18.5 °), implying a morphological change caused by the treatment. Moreover, hydrophilic properties such as moisture regain and dyeing properties were enhanced by this proteolytic enzymatic hydrolysis. Therefore, according to this study, enzymatic hydrolysis is a suitable finishing method for improvement of hydrophilicity of PLA fabrics.     

Evaluation of the Electromagnetic Shielding Effectiveness of Carbon-Based Screen Printed Polyester Fabrics

Electromagnetic shielding has a very emerging role in the textile applications. Screen-printing is a well-known, easy and cost effective process for textile printing. In this study, carbon black and graphite particles were used to impart electromagnetic shielding property to polyester fabric by screen printing technique. To this aim, printing pastes containing carbon materials were prepared with different binder concentrations. The electrical resistance, surface morphology, color coordinates and washing fastness properties of screen printed polyester fabrics were investigated. The washing durability of electromagnetic shielding effectiveness of carbon based printed fabrics as a function of binder concentration have also been studied. Electromagnetic shielding effectiveness was evaluated in the frequency ranges between 15-3000 MHz. The results showed that the electromagnetic shielding properties of fabric were affected by increased binder concentration. The most durable electromagnetic shielding effectiveness after washing process was obtained at highest binder concentration. The surface morphologies and color difference values of printed fabrics after washing process also provided a positive contribution.     

Evolution of moisture management behavior of high-wicking 3D warp knitted spacer fabrics

Moisture management behavior is a vital factor in evaluating thermal and physiological comfort of functional textiles. This research work studies functional 3 dimensional (3D) warp knitted spacer fabrics containing high-wicking materials characterized by their profiled cross section. These spacer fabrics can be used for protective vest to absorb a user’s sweat, to reduce the humidity and improve user’s thermal comfort. For this reason, different 3D warp knitted spacer fabrics were produced with functional fiber yarns in the back layer of the fabric (close to the body) and polyester in the front and middle layers (outer surface). Comfort properties such as air and water vapor permeability and wicking and other moisture management properties (MMP) of different fabric samples were measured. It is demonstrated that by using profiled fibers such as Coolmax fiber, moisture management properties of spacer fabrics can be improved, enabling them to be use as a snug-fitting shirt worn under protective vests with improved comfort.     

Optimization of enzymatic treatment of polyester fabrics by lipase from <Emphasis Type="Italic">Porcine Pancreas</Emphasis>

The aim of this study was to provide the optimum condition for improving the hydrophilicity of PET fabrics by lipase treatment. The lipase hydrolytic activity, moisture regain, and wettability of PET fabrics were measured at different pH, temperature, reaction time, and concentration. The hydrolytic activity of lipase was evaluated by the number of carboxylic groups, using the titration method. Each treatment condition was controlled by measuring the hydrolytic activity, moisture regain, and wettability. The lipase treatment condition was controlled at pH 7.5, temperature 40 °C, treatment time 90 min, and concentration 6.25 g/l. Lipase treatment was an effective method to improve the moisture regain and wettability of PET fabrics because lipase hydrolysis formed hydrophilic groups on the surface of PET fabrics. The surface of the lipase-treated PET fabrics showed cracks and voids, largely responsible for the increase in the PET’s water-related properties. The nitrogen contents of the lipase-treated PET fabrics were measured at only 0.072 %. Thus, the improvement of the surface wettability of the lipase-treated PET surface was associated with the hydrolytic action of lipase rather than with protein absorption.     

Functional modification of sanitary nonwoven fabric by chitosan/nanosilver colloid solution and evaluation of applicability

For their functional enhancement, sanitary nonwoven fabrics with a relatively smooth surface were treated using chitosan, a natural polymer with excellent biocompatibility, and nanosilver colloid solution, which has strong antibacterial effects even when used in small amounts. The treatment effect was examined at various mixing ratios. When the mixing ratio of the nanosilver solution was higher, antibacterial and deodorization activity was increased. For CH3/NS1 treated fabric, when the mixing ratio of chitosan and nanosilver solution was 3:1, the air permeability was most excellent, and worked as a positive in improving the pleasantness of the sanitary nonwoven fabric. In all samples, the electrostatic propensity was reduced, regardless of the mixing ratio. In terms of the moisture characteristics of chitosan/nanosilver treated nonwoven fabrics, the moisture uptake was found to be superior in the CH3/NS1 treated fabric. When the mixing ratio of the nanosilver solution was higher, moisture permeability decreased, showing a similar tendency to that of air permeability. The vertical water permeability coefficient increased in all treated fabrics. The dynamic water absorption rate was good in CH4 and CH3/NS1 treated fabrics. This means that the absorption of water in the liquid state became easier, thus improving applicability as sanitary nonwoven fabrics.     

Cotton fabric mechanical properties affected by post-finishing processes

Following the work done previously [1]. In this paper, the effect of various post-finishing agents on the low stress mechanical and surface properties of dyed cotton fabrics, as well as their handle value have been studied. The mechanical properties of the treated cotton fabrics were measured by the famous KES-FB system. It has been found that cotton fabric mechanical properties and fabric handle can be modified by not only the external finishing agents but also the internal finishing agents which are used for correcting the inherent defect of the fabrics. The results in this report will inform the textile industry in engineering required fabric properties with appropriate finishing processes.     

Characteristics of double-layer coated fabrics with and without phase change materials and nano-particles

Stability in a low temperature environment is needed for a textile to be used as winter wear. This research was presented the characteristics of fabrics by double-thin-layered coating with and without phase change materials (PCM) and several nano-sized inorganic particles (N-particles). Silica, Ag, Zr, and carbon types of N-particles were used for investigating the N-particles effect. For the experimental method, the PCM and N-particles were coated consecutively in the wet and dry coating process, respectively. The N-particles on the surface of the coated fabrics were confirmed by energy dispersive spectroscopy (EDS), and after double-layer composite coating, the adhesion durability, water vapor permeability, water penetration resistance, DSC, thermographic photography, far infrared (FIR) emission effect, and the thermal insulation of the coated fabrics were tested for investigating the performances. Their compatibility and adhesion were superior when the add-on of N-particles was 10 %. From the DSC reproducibility results, we verified that the N-particles coated fabric preserved its thermal stability by absorbing latent heat. On the other hand, the FIR emission rate and energy of the Ag N-particle based sample were not better than the control sample.     

Development of moisture transition ability on porous complex structured woven fabric with convergence of pattern,porosity, and plasma technology

A porous complex structured woven fabric was manufactured to maximize the moisture transition ability of the prepared fabric by increasing the absorptive property of the fabric through surface modification using plasma, which is a dry modification method. Porous single and complex structured woven fabrics were produced by applying pattern, porosity, and plasma technology, including fabric patterning based on the sheath/core complex structure, the formation of porosity by removing the weft thread or warp thread, and hydrophilic surface treatment using plasma and the improvement in water absorption of different fabrics by the porous and plasma treatment was investigated. Therefore, two different types of fabrics were prepared. One is the porous single structured FAB-SINGLE fabric which was taken out in the direction of the Polyester (PET) warp thread of a general single structure to form a porous. Another is FAB-COMPLEX fabrics that the water-soluble polylactic acid (PLA) yarns with a 1.7 to 2.0 times longer absorption distance than that of PET yarns were inserted into the weft threads, and the PLA yarns were dissolved in a solvent to form the porous complex fabric. And then the physical properties and water absorption of the two types of fabric were compared after the plasma treatment. The results showed that when the FAB-SINGLE fabric, which has porosity induced by the removal of the warp threads in a certain gap, was plasma treated for 5 min, the contact angle was decreased to the extent that a measurement of the contact angle was impossible, whereas the fabric that had not undergone a plasma treatment had a contact angle of 123.6 o. The contact angle of the FABCOMPLEX with porosity caused by the dissolution of the PLA yarns was reduced from 76.8 o to 0 o after 3 minutes of a lowtemperature plasma treatment, indicating that the hydrophilic property was increased. In addition, the water absorption measurements showed that the absorption height was increased from 2.3 cm of the fabric sample that had not been treated with plasma to the highest absorption height of 8.3 cm, suggesting that the water absorption also increased with the improvements in moisture transition ability by the plasma treatment. The physical tensile strength of the fabrics was not changed by the plasma treatment, despite the changes on the fabric surface, suggesting that the combination of double complex structures and the plasma treatment helped improve the water absorption.     

A study of abrasion and frictional behaviour of nonwoven interlining produced with different coating methods

Interlinings are produced recently not only natural and synthetics fibers but also fiber sheet form in nonwoven production methods. During usage, the fabric wears out and because of this problem fabric surface structure deteriorates. As a result of, investigation of fabrics surface and frictional properties has been important before usage of garments. For this reason, a patented laboratory instrument was designed which is based on horizontal working principle of accessing friction coefficient of fibrous textile surfaces. The tested materials were nonwoven interlining materials produced by spunbond methods. Abrasion resistance of paste dot-CoPES nonwoven interlining material is lower than others because of softness handle. On the contrary, friction coefficients have been obtained higher values.     

Designing waterproof breathable materials based on electrospun nanofibers and assessing the performance characteristics

To develop waterproof breathable materials for diverse consumer applications, we used electrospinning to fabricate layered fabric systems with varying composite structures. Specifically, we developed layered fabric structures based on electrospun nanofiber webs with different levels of nanofiber web density, as well as different substrates and layer structures, and then examined the breathability and waterproofness of the material. The breathability and waterproofness of the layered fabric systems were compared with those of traditional waterproof breathable fabrics, including densely woven fabric, microporous membrane laminated fabric, and hydrophilic nonporous polyurethane coated fabric. Different breathability and barrier performance levels were achieved by varying the layer structure and substrates in the electrospun nanofiber web layered fabric systems. The uniformity of the nanofiber web and lamination process also affected the barrier and comfort performances. The comparison of waterproofness and breathability performances between the new materials and the traditional waterproof breathable materials revealed that the layered structures based on electrospun nanofiber webs provide a higher level of resistance to water penetration than densely woven fabrics and a higher degree of moisture vapor and air permeability than microporous membrane laminates and coated fabrics, with a proper selection of layer structure, substrate fabric, and lamination process.     

A method for mobility estimation of textile-polymeric systems

Laminated or coated fabrics are technical textile products and are defined as materials composed of two or more layers; at least one of them is a textile fabric and one or more polymer film. The presence of film layer changes all fabric’s properties and behaviour during its deformation. The goal of this research is to propose a new method for evaluation the influence of structural stability of coated fabrics and laminates on their shear stiffness. Seven commercial coated fabrics and laminates with woven or knitted base layer are used in this test. The shear behaviors of coated and laminated fabrics are analyzed during the uniaxial tension of parallelepiped shape specimens whose top and bottom edges are cut with pitch of 16 degrees. The extension test of such type specimens is carried out using a Zwick tension machine. The behaviour of the coated fabrics and laminates during shearing are evaluated from strain-stress curves and the results are presented.     

A new approach to evaluate the effect of body motion on heat transfer of thermal protective clothing during flash fire exposure

The effect of dynamic change of air gap between protective clothing and skin caused by continuous human body motion on thermal protective performance of protective fabric cannot be simulated in current bench-top test. In this study, a newly modified TPP test apparatus with a dynamic air gap manufacturing system was applied to investigate the effect of body motion on heat transfer of fabrics exposed to flash fires. Three different velocities of body motion were simulated respectively. The results indicated that the dynamic air gap with variation range of 0–25 mm significantly improved thermal protection of fabric comparing with no air gap, but approximated to static air gap of 6.4 mm width for different heat transfer modes. It was manifested that thermal protection had no linear relationship with the air gap width variation frequency due to convection heat in microclimate, and the TPP values was shown as 0.5 rps < 0.25 rps, 0.5 rps < 1 rps and uncertain for 0.25 rps with 1 rps. The amplitude of simulate epidermis surface temperature fluctuation had a negative correlation with air gap variation frequency. Most of the temperature curves rose smoothly along with periodical variation, only the temperature fluctuation of 0.25 rps could be observed in a variation cycle.     

Antibacterial finishing of cotton fabrics using biologically active natural compounds

The paper discusses a method to functionalize cotton fabrics using biologically active natural compounds to achieve the antibacterial characteristics required for medical application. The biologically active natural compounds include propolis, beeswax, and chitosan. Three 100 % cotton knitted fabrics with different degrees of compactness were impregnated in the emulsions containing the active ingredients and fabric variant G3 with the highest degree of impregnation was considered for the evaluation of the antibacterial properties and comfort characteristics. The results show that the treated cotton fabric had high antibacterial activity against both gram positive bacteria Staphylococcus aureus and Streptococcus β haemolytic, and gram negative bacteria Escherichia coli and Pseudomonas aeruginosa. The presence of the biologically active natural compounds on the cotton substrates modified the surface of the textile fibers as seen in the SEM images. The treatment also improved fabric comfort properties, the cotton substrates became less air permissive and more hygroscopic after the treatment. The experimental results indicated that propolis, beeswax and chitosan can be applied as an emulsion to functionalize cotton textile materials. The antibacterial performance of the functionalized fabrics suggested that the cotton fabrics treated with those biologically active natural compounds have the potentials to be used in medical fields.     

Surface modification of polyester fabrics by enzyme treatment

In this study, the effect of enzymatic hydrolysis using lipase and cutinase on poly(ethyleneterephthalate) (PET) fabrics was investigated in an attempt to improve the hydrophilicity of these fabrics. The hydrolytic activity of the enzymes was expressed for variations in pH levels, temperatures, enzyme concentrations, and treatment times. The effects of using a nonionic surfactant were examined by measuring moisture regain and surface wettability. Finally, the fabric characteristics that were affected by enzyme treatment were evaluated by tensile strength and scanning electron microscopy. The optimal treatment conditions for lipase were determined to be a pH of 4.2, a temperature of 50 °C, a lipase concentration of 100 %, and a treatment time of 90 min; those for cutinase were determined to be a pH of 9.0, a temperature of 50 °C, a cutinase concentration of 100 %, and a treatment time of 60 min. At optimal enzymatic treatment conditions, we got the significant results of increase on the moisture regain and the water contact angle (WCA) and water absorbency effectively decreased. Triton X-100 facilitated cutinase hydrolysis on PET fabrics; however, it was ineffective for lipase. With enzymatic treatment, the tensile strength did not decrease.     

Plasma-assisted surface modification of polyester fabric for developing halochromic properties

In the field of textiles, introducing pH-sensitive dyes onto fibrous materials is a promising approach for the development of flexible sensor. In this study, poly(ethylene terephthalate) (PET) textile surface with halochromic properties was fabricated by plasma-assisted sol-gel coating, followed by immobilization of two different azo pH-indicator dyes; namely Brilliant yellow and Congo red by conventional printing technique of fabrics. 3-aminopropyltriethoxysilane (APTES) was used as a coupling agent for attaching the pH-sensitive dyes through its terminal amines. The surface immobilization of APTES on PET fabric was conducted by the pad-dry-cure method. Moreover, the influence of oxygen plasma pre-treatment and the method of post-treatment either by oxygen plasma or by thermal treatment on the stability of sol-gel based matrix was investigated. The morphology and chemistry of 3-aminopropyltriethoxysilane coated PET surfaces were examined by using surface sensitive methods including electrokinetic and time-dependent contact angle measurements as well as X-ray photoelectron spectroscopy (XPS). In addition, fastness tests of the printed fabrics and color strength were carried out to assess the effectiveness of the fabric surface modification. Results indicate that sol-gel matrix exhibited a more stability by thermal post-treatment at 150 C for 5 min. Also, the results revealed that the printed fabrics with halochromic properties demonstrated sufficient stability against leaching by washing. The current work opens up a novel opportunity to develop flexible sensors based on fibrous materials, which have the potential to be employed in variable industrial applications.     

Changes in a knitted fabric’s surface properties due to enzyme treatments

Enzyme treatment technologies in textile processing have become commonly-applied techniques for the modification of fabric-handle appearance, and other surface and mechanical characteristics of fabrics. Most studies have focused on understanding the impact of enzyme treatments on the fabric preparation, dyeing, and finishing processes of woven fabrics, whilst only limited research has been reported regarding any enzymatic effects on the surface and handproperties of knitted fabrics. The aim of this study was to analyze the effects of two different enzymes Trichoderma reesei whole cellulase, and enriched (EGIII) endoglucanase cellulase, at three different enzyme dosages on 100 % cotton interlock knitted fabric. This was in order to evaluate certain surface properties such as pilling, friction. and geometrical roughness. Furthermore, the compression and tactile properties of knitted fabric were also analyzed. The results show that treatment conditions with enzyme Trichoderma reesei whole cellulase had the more pronounced effect on the surface properties compared to the enriched EGIII enzymes. In general, it can be concluded that both types of enzymes improved the surface properties and hand when compared with the silicone softener-treated reference sample of interlock knitted fabric, as is statistically confirmed by one-way analysis of variance.     

The effect of fabric balance and fabric cover on surface roughness of polyester fabrics

The effects of fabric balance and fabric cover on surface roughness values of textured polyester woven fabrics with different constructional parameters were investigated. The warp yarn properties (type, count and warp density) were kept constant while the effect of variation in weft yarn density and weave pattern were studied. Measurements were conducted on pre-treated white fabric samples and the results assessed in relation to their constructional properties. A general overview of the results showed that surface roughness values of polyester fabrics affected by fabric balance and fabric cover and the effects were related to fabric thickness, yarn densities, yarn crimp, positioning of yarns in fabric structure. A change in weave pattern from sateen to plain increased the fabric balance and fabric cover, but decreased the surface roughness. Similarly, an increase in weft density increased the fabric balance and fabric cover, but decreased surface roughness. In order to produce fabrics with smooth surface properties yarn density should be increased, yarn float lengths decreased, cover of fabrics increased and fabric balance improved.