Applications of micro-scale combustion calorimetry to the studies of cotton and nylon fabrics treated with organophosphorus flame retardants

Effective testing methods are critical for developing new flame retardant textiles by the industry. However, the current testing methods all have limitations. In this research, we applied micro-scale combustion calorimetry (MCC) for evaluating the flammability of the cotton woven fabric treated with a traditional reactive organophosphorus flame retardant in combination with a synergistic nitrogen-containing additive and the nylon-6,6 woven fabric treated with a hydroxyl-functional organophosphorus oligomer and crosslinkers. We found that MCC is capable of differentiating small differences among the treated fabric samples with similar flammability. MCC is able to make quantitative measurement of the peak heat release rate, the most important parameter related to fire hazard of materials, of textile whereas such analysis is more difficult using cone calorimetry due to textile fabrics’ low thickness. By using the thermal combustion parameters measured by MCC, we were able to calculate the limiting oxygen index (LOI) of various treated cotton fabric samples with near-perfect agreement between the experimentally measured and the predicted LOI values of treated cotton fabrics. We also compared the capability of MCC and differential scanning calorimetry for analyzing flame retardant cotton textiles.     

Using chemometric methods and NIR spectrophotometry in the textile industry

A quantitative and qualitative technique for identification of textiles, moisture measurements, textile coatings and process control was developed, using near infra-red spectroscopy (NIR) in combination with chemometric methods. These applications demonstrate by the use of computer assisted data processing the possibility of identifying textile fibers, not only for quality control but also for online textile recycling processes. In this study, seven various textile fibers (cotton, polyester, viscose, silk, wool, polyacrylonitrile, acetate) were used and all combinations of two factor blends were qualitatively identified using NIR spectroscopy and the chemometric PLS2 method for the calibration.

A quantitative analysis of textile moisture can also be performed with this technique. Water content above 50% does not deliver good results for a calibration set to determine the dampness of fibers. But to measure residual moisture from ≈0.05 up to 50%, the NIR technique is particularly good. Furthermore, the examination shows that the NIR method and chemometric methods can be used in quality- and product-control during the industrial production of upholstery fabrics. With this technique it will be possible to identify nylon flocks and to measure the residual moisture of the flocks and fabric, too.     

Influence of knitted structures on heat transfer

In this paper we studied the influence of knitted structures on heat transfer. The structure of the knitted fabric was expressed by geometric properties such as thickness, surface mass and bulked mass, and knitted structure. Heat transfer was experimentally measured on three types of devices. It was found that the measured structural properties do not have a significant effect on heat transfer of knitted fabrics. From three types of devices, the selected device was Alambeta as the most objective method for measuring thermal parameters. It was determined to be the most suitable of knitted structure which provided the best thermal insulation properties.     

Measurement uncertainty in testing for antimicrobial activity on textile materials

Measurement uncertainty is widely recognized among physicists and chemists, but is a relatively new concept to many microbiologists. Generally, available documents about measurement uncertainty in microbiological testing are applicable to food and water microbiology. Two quantitative methods for evaluation of antimicrobial activity of textile materials are used commonly in textile laboratories. Methodology and expression of results for the two methods are similar; thus, calculation and expression of measurement uncertainty for results obtained by these test methods are also similar. This contribution describes the way in which measurement uncetainty for these methods can be evaluated and reported.     

Enhanced Self‐Cleaning Properties on Polyester Fabric Under Visible Light Through Single‐Step Synthesis of Cuprous Oxide Doped Nano‐TiO2

Nowadays, introducing self‐cleaning properties on various fabrics under daylight irradiation for automotive and upholstery application is in a central point of research. This can be achieved by application of metal‐doped TiO₂ nano particles on the textile fabrics. Here, alkali hydrolysis of polyester fabric has been carried out along with synthesis of Cu₂O/TiO₂ nanoparticles in a single‐step process by using sonochemical technique. CuSO₄.5H₂O was used as a source of copper in the presence of glucose as reducing and stabilizing agent. Moreover, central composite design based on response surface methodology (RSM) was used to determine the role of variables (CuSO₄.5H₂O, glucose and pH) and their effects on the self‐cleaning properties and weight of the fabric. The self‐cleaning property was investigated by degradation of Methylene blue on the surface of the treated fabrics under daylight. Further, the tensile properties, colorimetric measurement, and washing fastness of the treated fabric produced in the optimum conditions were investigated. The morphology of Cu₂O/TiO₂ nanoparticles was examined using X‐ray diffraction and field emission scanning electron microscopy (FESEM). The new polyester fabric obtained through in situ synthesis of Cu₂O/TiO₂ nanoparticles can be used as a desirable stable fabric with high tensile strength and visible‐light self‐cleaning properties.     

Impregnation of a porous material with a PCM on a cotton fabric and the effect of vacuum on thermo-regulating textiles

The purpose of this study was the preparation of a form-stable composite phase change material (PCM) by incorporation of n-nonadecane within the expanded dolomite (ED). In this investigation, two approaches called impregnation treatment with vacuuming and impregnation by magnetic stirrer were used. This method was first proposed for textile thermal protection. In this method, n-nonadecane was applied as the phase change material and ED as the supporting in order to prepare and construct the composite PCM. Composite properties were determined by Fourier transformation infrared spectroscope and scanning electronic microscope (SEM) techniques and the heat transfer measurement and differential scanning calorimeter (DSC) were used to determine the thermal properties of composite on fabrics. Also, moisture transfer properties were measured. The SEM results showed that the n-nonadecane was well absorbed in the porous network of the ED. DSC analysis and heat transfer also indicated that fabric temperature range for the amount of coated PCM depends on its area; further, by adding composite to the fabric surface, thermal transfer could be reduced. The maximum percentages of n-nonadecane within ED in the composite PCM1 and PCM2 were measured to be about 90 and 70 mass%, respectively. Thus, the composite PCM1 can be considered as a form-stable composite change phase materials.     

Near-infrared chemical imaging used for in-line analysis of inside adhesive layers in textile laminates

This paper demonstrates for the first time that near-infrared (NIR) chemical imaging can be used for in-line analysis of textile lamination processes. In particular, it was applied for the quantitative determination of the applied coating weight and for monitoring of the spatial distribution of hot melt adhesive layers using chemometric approaches for spectra evaluation. Layers with coating weights between about 25 and 130 g m⁻² were used for the lamination of polyester fabrics and nonwovens as well as for polyurethane foam. It was shown that quantitative data with adequate precision can be actually obtained for layers applied to materials with significantly heterogeneous surface structure such as foam or for hidden layers inside fabric laminates. Even the coating weight and the homogeneity of adhesive layers in composites consisting of black textiles only could be quantitatively analyzed. The prediction errors (RMSEP) determined in an external validation of each calibration model were found to range from about 2 g m⁻² to 6 g m⁻² depending on the specific system under investigation. All calibration models were applied for chemical imaging in order to prove their performance for monitoring the thickness and the homogeneity of adhesive layers in the various textile systems. Moreover, they were used for the detection of irregularities and coating defects. Investigations were carried out with a large hyperspectral camera mounted above a conveyor. Therefore, this method allows large-area monitoring of the properties of laminar materials. Consequently, it is potentially suited for process and quality control during the lamination of fabrics, foams and other materials in field-scale.     

Synthetic fabrics coated with zinc oxide nanoparticles by electroless deposition: Structural characterization and wetting properties

Electroless deposition was successfully applied in developing crystalline particles of zinc oxide onto polyester textile materials; this deposition is here presented in comparison with other materials made from poly(lactic acid), polyamide or hemp. Structural and spectroscopic characterization of the raw and deposited samples has been performed. The structure of zinc oxide particles was that of wurtzite type as indicated by X‐ray diffraction (XRD) and scanning electron microscopy (SEM). Crystallites were 20–500 nm in diameter and up to 1 µm in length. The grown particles cover the fibers not only on the fabric surface but in the textile depth. Contact angle measurement by the sessile drop method was used to study the wettability behavior of the investigated composite systems. The hierarchical roughness structure generates superhydrophobic properties onto polyester fabrics, for which water contact angles exceed 150°. The other functionalized samples also become more hydrophobic after deposition. Cassie‐Baxter model was found suitable to describe the behavior, though the fraction of surface occupied by the water–solid interface is high enough. The electroless deposition technique applied previously for cotton fabrics was once more proven to be highly reproducible, easy scalable, and cheap, allowing a wide range of applications. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2013, 51, 1427–1437     

Laundry process intensification by ultrasound

In domestic textile laundering processes, mass transfer and mass transport are often rate limiting. Therefore, these processes require a long processing time, large amounts of water and chemicals, and they are energy consuming. In most of these processes, diffusion and convection in the inter-yarn and intra-yarn pores of the fabric are limiting mass transport mechanisms. Intensification of mass transport, preferentially in the intra-yarn pores, is the key in the improvement of the efficiency of wet textile processes. Conventional methods of intensification of mass transport (e.g. operation at elevated temperatures) are not always feasible due to the undesired side effects such as fabric damage. Increasing the flow rate does not deliver the desired effect due to the multi-porous complex structure of textile materials. Van der Donck et al. [Tenside Surf. Det. 35 (1998) 119; 36 (1999) 222] reported that the deformation of yarns by placing a fabric in a pulsating flow or repeated mechanical elongation of the yarns improved mass transport. However, the additional mass transport caused by deformation is limited in practice. Power ultrasound is a promising technique to accelerate mass transport in textile materials. Several papers appeared in this field, which report an improvement in energy efficiency and processing time of the wet textile processes in the presence of ultrasound. In this paper, the different time and length scales are discussed in the intensification of the mass transport in laundry processes in the presence of ultrasound and compared with more conventional processes. It has been concluded that the characteristic mass transport rates in textiles can be increased by a factor of 6 applying ultrasound.     

Study of new protective clothing against SARS using semi-permeable PTFE/PU membrane

Chemicals which may pose a hazard to people upon contact may be in several forms, such as liquid, mist, vapor, etc. The damage caused can range from mild skin diseases to more serious chronic illnesses. Therefore, chemical protective clothing must be used to safe some personal who may be exposed to hazardous chemicals. The use of PTFE/PU membrane for chemical protective clothing is discussed in the article. By means of texturing with organic conductive fiber, and then treating with JAM-Y1 anti-bacteria agent, in the end, treating with the XL-550 waterproof agent, the PET fabric has permanent anti-static, anti-bacteria and waterproof and anti-oil properties. The PTFE/PU protective material is prepared by laminating with PET fabric by paste dot coating, and then coated by PU solution in a direct process. The PU coating agent, DMF and acetone, are used in testing through surface tension and peeling strength measurement. The penetration property of poliomyelitis virus in liquid and animalcule in air of PTFE membrane laminated textile, after being coated by PU solution are measured. The results show that it can separate SARS virus in air and liquid, and WVT is 11496 g/24 h m². Then it can provide a satisfactory wearing comfort.     

Durable Press Finishing of Cotton Fabric with 1,2,3,4-Butanetetracarboxylic Acid and TEOS/GPTMS

The sol-gel process is an excellent technology for coating various materials thus imparting new properties to the treated samples. 100% cotton fabric were treated in two steps with formulations containing BTCA (1,2,3,4-butanetetracarboxylic acid) and SHP (sodium hypophosphite) as catalyst and TEOS (tetraethoxysilane)/GPTMS (glycidylpropyloxytrimethoxysilane)-based solutions with different amounts of GPTMS. The samples were investigated by means of FT-IR/ATR spectroscopy, ²⁹Si-CP-MAS-NMR, XRD and HPLC. The textile physical properties were evaluated by means of DCRA (dry crease recovery angle), and the abrasion resistance was tested with a Martindale tester. The findings make evident that the DCRA values could be moderately improved applying a two step procedure (BTCA treatment, sol-gel treatment), while the abrasion resistance was significantly increased.     

Combination of silica sol and dyes on textiles

The embedding in sol-gel coatings can improve the fastness properties of dyes on textiles. The aim of this study is to investigate, whether it is necessary to apply dye and sol together in one step or the application of dye and sol can be performed in separate steps. For practical applications, it can be of high interest to apply sol and dye separately, because by this the fastness properties of once coloured textiles can be improved by sol-gel coatings or an uncolored sol-gel treated fabric can be dyed afterwards with higher fastness properties. For this, modified silica sols and dye molecules were applied in combination on textiles. The investigations were performed with the two triphenylmethane dyes Malachite Green and Guinea Green. These dyes were applied using four different methods – without sol, applied before or after sol treatment and together with the sol. The silica sols were applied in different concentration. It was demonstrated that the application together with the silica sol or the aftertreatment of dyed textile with silica sol lead to significant improvement of leaching fastness. Also the low bleaching fastness of the triphenylmethane dyes can be enhanced significantly.     

Stability of poly(l‐lactic acid) in textile applications

The present paper is focused on the use of promising bio‐based thermoplastic—poly(l ‐lactic acid)—in textile applications and with possible limits related to its enhanced sensitivity to (bio)degradation. Linear and planar fabrics made of staple were exposed to standard washing cycles imitating the maintenance of textile materials. The effect of temperature and pH of the washing bath on the degradation rate of poly(l ‐lactic acid) was monitored by the abiotic hydrolysis test. The properties of the fabrics after carrying out the tests were evaluated from the changes of mass per areal weight, strength, and morphology of the fabrics. The changes of the structure of the polymer chains were assessed by differential scanning calorimetry, by the decrease of molar masses (determined using size exclusion chromatography) and of the viscosity of the polymer solutions, and by infrared spectroscopy. Poly(l ‐lactic acid) fabric finds application for various kinds of garments, and untreated fabric reliably tolerates 60 standard washing cycles. Copyright © 2014 John Wiley & Sons, Ltd.     

Electrokinetic properties of bare and particles containing textile

Functional, reactive and smart textiles are nowadays of great interest in the fields of both cosmetic and pharmaceutical industries. Textile functionalization according to demands of the consumers can only be achieved with better understanding of the properties of the textile surface as well as sound knowledge about the technique to be used to functionalize the textiles. The aim of this work was to investigate the zeta potential of polyamide textile and prepared sponge like particles as a function of pH and salinity of the electrolyte. Special attention has been dedicated to the electrokinetic properties of textile as a function of sponge like particles amount present during adsorption process. As a general tendency, streaming potential measurement showed the changes in surface charge density of textile because of the changes in pH, salinity and adsorbed particles amount. All presented results were discussed in terms of zeta potential. Copyright © 2016 John Wiley & Sons, Ltd.     

Biohydrolysis of nylon 6,6 fiber with different proteolytic enzymes

In recent years, the textile industry must go towards sustainable technologies and developing environmentally safer methods for textiles processing. One way is the processing with enzymatic system, rather than conventional chemical methods. The aim of this work was to investigate the changes induced on nylon 6,6 fiber by enzymatic system using different proteolytic enzymes. Technical measurements were studied including Fourier-transform infrared spectroscopy, scanning electron microscopy, thermal, dyeability, and fastness properties. For this purpose, nylon 6,6 fabrics were first treated separately with different concentrations of four protease enzymes. The dyeing process was then carried out on the treated fabrics with two reactive and acid dyes. The intensity of major peaks in FTIR spectra of the protease treated samples is in favor of chemical changes of the polypeptide functional groups in fabric. Thermal studies also show significant decrease in thermal degradation temperature of the treated polymer. Reactive and acid dyes showed higher dyebath exhaustion on the enzyme treated samples compared to raw material. The results of color measurements showed that the more concentration of enzyme used, the darker the color of dyed sample is. Interesting results were obtained in the studied topic.     

A novel method for the production of conductive ring spun yarn

To take the advantages of spun yarns such as porosity, softness, bending as well as usability as yarn/fabric forms, this study worked on an alternative conductive yarn production method. Different from widely used application methods, a conductive nanosuspension was applied to viscose, cotton and polyester open fibre bundles with different feeding amounts during the ring spinning with a specially developed apparatus. Reduced graphene oxide (rGO) synthesized with a single step process instead of two-step processes was used to impart conductivity. Following to yarn production, winding, knitting and washing processes were realized to evaluate the changes in yarn conductivity and the usability of the yarns in the post-spinning processes. In addition to tensile properties of the yarns and air permeability of the fabrics, electrical resistance and environmental impact of the method was compared with immersion and drying process. The results indicated that alternative method allows the production of conductive (lower resistance than 100 kΩ) but also strong, flexible, washable and breathable electronic textile products with an environmentally friendly process. There has been no effort, as yet, to get conductivity in this manner. Therefore, the developed method can be considered to be a new application in the functional yarn production field. The produced conductive yarns can be converted into fabric form by weaving, knitting and embroidery. Therefore, they can also be seen as an ideal as the platforms for future wearable electronics.

     

Hydrophobization of polyester textile materials with telomeric tetrafluoroethylene solutions

Hydrophobic coatings formed on a polyester fabric by treatment with telomeric solutions prepared by a radiation-chemical procedure in acetone and butyl chloride were studied by IR spectroscopy (MATIR), energy-dispersive analysis, and atomic force microscopy. The hydrophobic properties of the textile material were evaluated by procedures traditional for textile chemistry. Conditions determining the formation of a thin, highly hydrophobic, uniform, and flawless coating resistant to the effect of operation factors were suggested.     

Investigation of the flammability of different textile fabrics using micro-scale combustion calorimetry

Evaluating and analyzing the performance of flame retardant (FR) textiles are a critical part of research and development of new FR textiles products by the industry. The testing methods currently used in the industry have significant limitations. Most analytical and testing techniques are not able to measure heat release rate (HRR), the single most important parameter in evaluating the fire hazard of materials. It is difficult to measure HRR of textile fabrics using cone calorimetry because textile fabrics are dimensionally thin samples. The recently developed micro-scale combustion calorimetry (MCC) is able to measure the following flammability parameters for textile using milligram sample sizes: heat release capacity, HRR, temperature at peak heat release rate (PHRR), total heat release and char yield. In this research, we applied MCC to evaluate the flammability of different textile fabrics including cotton, rayon, cellulose acetate, silk, nylon, polyester, polypropylene, acrylic fibers, Nomex and Kevlar. We also studied the cotton fabrics treated with different flame retardants. We found that MCC is able to differentiate small differences in flammability of textile materials treated with flame retardants. We were also be able to calculate the limiting oxygen index (LOI) using the thermal combustion properties of various textile samples measured by the MCC. The calculated LOI data have yielded good agreement with experimental LOI results. Thus, we conclude that MCC is an effective new analytical technique for measuring textile flammability and has great potentials in the research and development of new flame retardants for textiles.     

Current Technologies for Biological Treatment of Textile Wastewater–A Review

The release of colored wastewater represents a serious environmental problem and public health concern. Color removal from textile wastewater has become a big challenge over the last decades, and up to now, there is no single and economically attractive treatment method that can effectively decolorize the wastewater. Effluents from textile manufacturing, dyeing, and finishing processes contain high concentrations of biologically difficult-to-degrade or even inert auxiliaries, chemicals like acids, waxes, fats, salts, binders, thickeners, urea, surfactants, reducing agents, etc. The various chemicals such as biocides and stain repellents used for brightening, sequestering, anticreasing, sizing, softening, and wetting of the yarn or fabric are also present in wastewater. Therefore, the textile wastewater needs environmental friendly, effective treatment process. This paper provides a critical review on the current technology available for decolorization and degradation of textile wastewater and also suggests effective and economically attractive alternatives.     

Moisture permeation of clothing

The manner in which the wetting and drying behavior of a textile fabric depends upon the properties of the fibers comprising it is of both practical and theoretical significance. The consumer is justifiably interested in the relationship of fiber content to such serviceability criteria as wicking, solubility, wettability, and speed of drying. At the same time, the extent to which the drying of textiles conforms with or departs from theory is of scientific interest, particularly if noteworthy distinctions in behavior among fabrics can be related to intrinsic fiber properties or geometry of the textile structure. This work was undertaken to answer some practical questions about fiber-fabric-water relationships. Especially of interest was the extent to which rate of fabric drying might depend upon (a) fiber moisture regain, and (b) speed of capillary migration. These and other aspects of the general problem were examined in the light of pertinent theory in connection with appropriate practical findings. This revised version was published online in July 2006 with corrections to the Cover Date.