Polyamide Fabrics Research Articles

Effect of paste properties as inkjet printing film and Mathematical Model to Follow the Kinetic of Wetting Phenomenon

Inkjet printing is a type of non-impact printing with the ability to produce high quality color images. The application of this procedure is very delicate in term of the paste composition and the operative conditions. In this field, firstly the present paper investigates the drying morphologies for the coating film. Then, the effect of film compounds which are widely as functional coatings in textile was studied. Results show that the drying condition and the system thickener – urea compounds affect deeply the film coating morphology. Furthermore, the wetting and the impregnation behaviors are directly related to the studied system compounds and the experiment applications. Finally, these obtained results are confirmed by the wetting behavior on the knitted polyamide fabrics

Functionalization of polypropylene, polyamide and cellulose acetate materials with pyrethrum extract as a natural repellent in supercritical carbon dioxide

This study discusses the possibility of supercritical solvent impregnation of polypropylene and polyamide fabrics as well as cellulose acetate in the form of beads and films with pyrethrum extract in order to fabricate functionalized materials with repellent properties. Impregnation experiments were performed at temperature of 40 °C and pressures of 10 and 20 MPa in supercritical carbon dioxide. The time of impregnation was varied from 0.5 to 18 h. Loadings of pyrethrum extract into polypropylene fabrics and cellulose acetate films higher than 30% were attainable at 10 MPa. In the case of polyamide fabrics and cellulose acetate beads, the pressure of 20 MPa was needed for obtaining the loadings higher than 11%. Pyrethrum extract release study revealed different capabilities of the tested materials for the repellent release, implying a variety of their possible applications. The impregnated solids were characterized by SEM, DSC, FTIR, Mercury intrusion porosimetry analyses and HPLC analyses.

Application of Prunus amygdalus By-products in Eco-friendly Dyeing of Textile Fabrics

Natural dyes have become an interesting subject of study because of their better ecological properties in comparison to their synthetic counterparts. This article concerns the dyeing of wool, silk, and polyamide fabrics with natural dyes extracted from almond shells and stems. The developed method of dyeing by these extracts is interesting and very attractive for several reasons: firstly, the extracts used are the black liquor discharged from the industries of delignification, which is a chemical process for removing lignin from agricultural wastes to produce a cellulosic fiber; (ii) these natural dyes are renewable and available in large quantities; (iii) this method is economical; and (iv) lastly, the dyeing performances of the obtained dyed textiles are very promising. The color of each dyed material was investigated in terms of the CIELAB coordinates and their fastness properties measured by washing, rubbing, and light.

The Effect of Catalyst in the Process of Nano-Silica Particle Formation as a Hydrophobic Material

<p>Nano Silica is known as a hydrophobic material used to coat the material that further modifies the surface properties of the material. In this study the process of making nano silica material is using sol-gel method. The sol gel process is defined as the process of forming an inorganic compound through chemical reaction in solution at a low temperature wherein the process a phase changes from the colloidal suspension (sol) to a continuous liquid phase (gel). The types of catalyst were studied. The result was then applied to cotton, polyamide and silk fabrics. Acid catalyst showed the greatest moisture reduction based on Moisture Content and Moisture Regain evaluation in cotton and polyamide fabrics, whereas base catalysts showed a significantly less moisture reduction on the three fabrics. The use of these types of catalyst will also affect the value of the tensile strength of each fiber. Tensile test results showed that the use of acid catalysts decreased the maximum tensile strength in cotton fabrics by 88.57%, compared to polyamide and silk fabrics and the use of base catalyst showed less significant decreased on tensile strength for all fabrics.</p>

Study on Surface Properties of Polyamide 66 Using Atmospheric Glow-Like Discharge Plasma Treatment

Surface modification of fiber fabric sometimes needs a large volume of cold plasma to improve its efficiency. This experimental study is based on the treatment of polyamide 66 (PA66) fabrics using large contact-area glow-like plasma, which are produced in the atmospheric air without any dielectric barriers. The atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) are adopted, respectively, to detect the surface changes in physical microstructure and the variations in the type and quantity of chemical functional groups. The results show that the PA66 fabric surface will be etched remarkably by the glow-like plasma, and the surface roughness and the surface energy are augmented. On the surface of the processed PA66 fabrics, the oxygen-containing functional groups’ content rises together with the decrease on the total primary C–C and C–N bonds. After 30 seconds of sterilization by the glow-like plasmas, most of the bacterial colonies on the fabric vanish. The effectiveness of this kind of plasma treatment could last for three days in a sealed environment.

Studies Regarding the Increase in Hydrophilicity of Some Textile Fabrics through Treatment by Cold Plasma and Grafting with Vinyl Monomers

The polyamide and polyester fabrics have been treated by glow discharge plasma and grafted with 2-hydroxyethylmethacrylate (HEMA) in order to increase the hydrophilicity and to improve the soil release properties. The plasma treatments were carried out at different exposure times. Grafting was obtained with gaseous HEMA and with alcohol or aqueous solution of HEMA at different concentrations. The physical and chemical surface changes were studied using scanning electron microscopy, infrared spectroscopy, colour measurements. The hydrophilicity was assessed through the absorption time of a water drop and the soil removal through washing by remission values.

Impregnation Behavior of Polyamide 6 in Carbon Fibers and the Properties of their Composites

Unidirectional carbon fiber (CF) / Polyamide 6 (PA6) composites were prepared by stacking fabrics method. Due to the effect of the textile structure and rough surface of PA6 fabrics, slipping of carbon fibers (CFs) during the stacking process was prevented and uniformity of impregnation was improved. Meanwhile, the usage of PA6 fabrics resulted in the minimum level of void content of composites, which improved the mechanical properties of composites. Additionally, the void content of materials was associated with the mechanical properties of composites. The flexural strength of composite reached 819.58 MPa when its void content was 3.49%. Moreover, a model based on Darcy’s law was developed to simulate the impregnation behavior of PA6 in CFs which was made by stacking fabrics method. The resin flow was observed by using optical microscopy. The evolution of void content in composites was related to the processing parameters (holding time, processing temperature and processing pressure).The comparison between the experimental and simulated data showed that the model was reliable to describe the impregnation process.

Physical, Chemical and Morphological Characterization of Polyamide Fabrics Treated with Plasma Discharge

Physical, Chemical and Morphological Characterization of Polyamide Fabrics Treated with Plasma Discharge

Environmentally benign 100% bio-based oligoamide microcapsules

Our aim was to investigate the synthesis of alternative bio-based microcapsules, offering similar thermal and mechanical properties as formaldehyde-based ones and being directly applicable to the textile field. In this prospect, oligoamide microcapsules were generated by interfacial polycondensation from two bio-based monomers: succinyl chloride and 1,4-butanediamine. Optimization of the process afforded the preparation of monodispersed microcapsules with a d(0.5) diameter of 3μm, exhibiting excellent stability over time. The expected amide groups in the microcapsules membrane were confirmed by FTIR, whereas SEC analysis suggested that microcapsules membrane was composed of oligoamide 4,4 chains with a DP¯n around 5. The chemical structure of model plane membranes prepared by interfacial polycondensation with jojoba oil as organic phase, was investigated by 13C NMR and MALDI-TOF. The plane membranes appeared composed of PA 4,4 oligomers, in accordance with the information provided by SEC. The microcapsules exhibited a thermal degradation occurring in the range 200–350°C, and a large melting endotherm peak centred on 200°C. Thanks to the accurate thermal and mechanical properties of oligoamide 4,4, those microcapsules loaded with jojoba oil were successfully applied on cotton and polyamide fabrics which were submitted to laundering and rubbing tests.

Quantitative structure–property relationship modelling for photoreduction‐fast azo dyes on a nylon substrate: a methodology for thermochemical analysis of the photocleavage of azo dyes using theRM1 semi‐empirical molecular orbital method

The rates of fading of 18 reactive azo dyes on polyamide fabrics and films upon exposure to a carbon arc in air have been determined from the initial slopes. The rates have been thermochemically analysed by calculating the heats of formation of the reactants, intermediates, and products by chemical equations describing (1) the second-order disproportionation (redox reaction) between the photoinduced hydrazinyl radicals and (2) the intramolecular H-transfer (self-decomposition) of the radicals, using the RM1 semi-empirical molecular orbital method. The rates of azo cleavage (or reductive fading) were studied to correlate the molecular structures with three molecular descriptors: (a) the heats of reaction for two reaction pathways, (b) the thermodynamic stability of the photoinduced hydrazinyl radicals, and (c) the quantum yields of generation. The possibility of structure optimisation of the examined azo dyes is discussed from the perspectives of (a) and (b). The light fastness of several previously reported substituted phenylazophenol (model) dyes on a polyamide substrate has been analysed by the same procedure. Two of the latter dyes exhibit typical photoreduction-fast properties, which determine the threshold ΔrH°(gas) value of the N11-hydrazinyl dye radical for (1), indicating that the chemical structures of azo dyes may, in principle, be modified to include reduction-fast azo groups. The current state of reactive azo dyes is considerably below the level required to achieve reduction-fast dye. The chemical structures of current reactive azo dyes appear not to have been optimised on the basis of the molecular descriptors (a) and (b), and only insufficiently on the basis of (c).

Electrochemical and mechanical stability of ion-exchange membranes in alkaline solution

This paper focuses on the transport and mechanical properties of ion-exchange membranes (IEMs) in an aqueous NaOH solution. Heterogeneous IEMs based on styrene–divinylbenzene and polyethylene reinforced with polyester (PES) or polyamide (PAD) fabric were studied. The IEMs were exposed to a 5% NaOH solution for 30 and 90 days and the changes in electrochemical resistance, transport number and permselectivity were evaluated. Moreover, the structure of the IEMs was observed after exposure and their mechanical properties were evaluated. The results show that NaOH solution has the most damaging effect, especially to PES cloth and the membrane as whole, mainly due to dimensional changes. Furthermore, changes in electrochemical resistance were observed.

Investigation of the adhesion properties of direct 3D printing of polymers and nanocomposites on textiles: Effect of FDM printing process parameters

In this paper, 3D printing as a novel printing process was considered for deposition of polymers on synthetic fabrics to introduce more flexible, resource-efficient and cost effective textile functionalization processes than conventional printing process like screen and inkjet printing. The aim is to develop an integrated or tailored production process for smart and functional textiles which avoid unnecessary use of water, energy, chemicals and minimize the waste to improve ecological footprint and productivity. Adhesion of polymer and nanocomposite layers which were 3D printed directly onto the textile fabrics using fused deposition modeling (FDM) technique was investigated. Different variables which may affect the adhesion properties including 3D printing process parameters, fabric type and filler type incorporated in polymer were considered. A rectangular shape according to the peeling standard was designed as 3D computer-aided design (CAD) to find out the effect of the different variables. The polymers were printed in different series of experimental design: nylon on polyamide 66 (PA66) fabrics, polylactic acid (PLA) on PA66 fabric, PLA on PLA fabric, and finally nanosize carbon black/PLA (CB/PLA) and multi-wall carbon nanotubes/PLA (CNT/PLA) nanocomposites on PLA fabrics. The adhesion forces were quantified using the innovative sample preparing method combining with the peeling standard method. Results showed that different variables of 3D printing process like extruder temperature, platform temperature and printing speed can have significant effect on adhesion force of polymers to fabrics while direct 3D printing. A model was proposed specifically for deposition of a commercial 3D printer Nylon filament on PA66 fabrics. In the following, among the printed polymers, PLA and its composites had high adhesion force to PLA fabrics.

Fundamental and practical aspects concerning the characterization of smart textiles

The research aims towards a novel methodology of ZnO impregnation onto polyamide supports, in order to attain a special inorganic-organic hybrid polymer material, with increased UV-barrier attributes and high hydrophobicity. The experimental approach employed ZnO micro particles powder. Solutions with different concentrations of ZnO powder dispersed in methanol are prepared as anti-UV finishing agent and applied onto polyamide fabric. The responsive behaviour of this complex polymer network to UV irradiation, the photo protective performance and its time stability, also the hydrophobic character are assessed by different characterization techniques. The proposed method has advantages, like: easy standardization, at lower production cost, resulting a high homogeneity and dispersion of ZnO micro particles into the textile polymeric network. The covered polymeric supports show better photo protective response, higher hydrophobicity and control on the surface charge induced by irradiation. This method granted enhanced quality, comfort and long term stability of the intelligent/smart garments.

Dyeability of Polyester and Polyamide Fabrics Employing Citric Acid

The employment of sustainable chemicals, such as citric acid, represents a possibility for the development of textile dyeing processes. This study aimed to analyze the possibility of replacement of acetic acid (commonly used in textile processing) by citric acid in polyester and polyamide 6 dyeing processes. The utilization of citric acid as leveling agent for disperse dyestuffs was also investigated. Dyeing processes in turquoise color for these fabrics were performed employing citric and acetic acid. Color differences between dyeing processes and color fastness to water were evaluated. All the color dyeing differences were not significant and there was no transference in color fastness tests (grade 5). Otherwise, the differences among polyamide dyeing processes could be related to the efficiency of citric acid solution as sequestering agent. Notwithstanding citric acid to be more expensive than acetic acid and the need of previous dissolution by stirring, it could be advantageous for some formulations.

Membrane Fouling Effect During Nanofiltration of Wastewater from Dyeing Cellulose and Polyamide Fabrics

Membrane Fouling Effect During Nanofiltration of Wastewater from Dyeing Cellulose and Polyamide Fabrics

An improved method for the durability of the flame retardant PA66 fabric

This paper describes an attempt in order to improve the durability of the flame retardant polyamide 66 (PA66) fabric prepared by the reaction of surface photografting with acrylamide (AM) under UV irradiation. In this study, N,N′-methylene bisacrylamide (MBAAm) combined with acrylamide has been used as a photosensitive monomer during flame retardant finishing of the PA66 fabric sample. “Durable efficiency” has been introduced to evaluate the durability of AM/MBAAm-g-PA66 fabric after 50 times washing with the 0.5 % commercial grade detergent solution. The result indicates that durable efficiency reaches its maximal value of 94.5 % when the MBAAm concentration is 5.0 mass%. The effect of MBAAm on the flame retardancy, thermal stability and tensile properties of the treated PA66 fabric has been investigated, respectively. And an interesting phenomenon shows that although MBAAm could improve the thermal stability of the treated fabric significantly at high temperature, it could have a negative effect on the flame retardancy and tensile properties of the fabric sample when its concentration is high. Its possible mechanism has been discussed here.

Antibacterial Efficiency of Mordant-Treated Cotton and Polyamide Fabrics, Before and After Dyeing

ABSTRACTDyeability of cotton and polyamide fabrics which were treated with some mordant (such as silver nitrate, copper chloride, and nickel nitrate) and antibacterial activity of them before and after dyeing were studied. The fabric samples were inoculated in mordant solution, then were dyed using acidic, basic and direct dyes. Color intensities of dyed fabrics were measured by using a UV VIS-NIR reflective spectrophotometer, over the range of 350–750 nm. The results show that, by using different mordant before dyeing, the relative color strength (K/S values) of dyed fabrics increase. This effect is more significant in case of using basic dyestuffs.Antibacterial efficiency of treated fabrics was tested against gram-positive bacteria Staphylococcus aureus. Treated cotton and polyamide fabrics show excellent antibacterial efficiency. The morphology of fibers treated with metallic salts before and after dyeing was assessed by SEM (Scanning Electron Microscopy). The main aim of this study was to examine the influence of dyeing on antibacterial efficiency of metallic salts–treated cotton and polyamide fabrics.

Micro-roughening of polyamide fabric using protease enzyme for improving adhesion strength of rubber-polyamide composite

Abstract The adhesion between rubber and the reinforcing textile plays an important role in ensuring the serviceability of composites. The present study aims to develop an enzyme based surface roughening process for nylon 6,6 fabric to improve its adhesion strength to rubber. Polyamide (nylon 6,6) fabric was micro-roughened through catalysed hydrolytic degradation of the surface chains, using a protease enzyme treatment. The concentration of the enzyme was optimized in terms of surface roughness measured by a KES-FB4 surface tester. Scanning electron microscopy (SEM) images of the protease treated fabric showed a heterogeneous rough appearance with cracks and pits. Fourier transform infrared (FTIR) analysis confirmed the surface hydrolysis of polyamide-6,6 due to the enzymatic treatment. Protease enzyme treated fabrics were then subjected to resorcinol formaldehyde latex (RFL) treatment, followed by a rubber moulding. Micro-roughening of nylon 6,6 fibre with an optimum surface roughness (SMD) of 20.3 μm was obtained for 3% enzyme concentration. Physicochemical mechanisms of the optimum effect and enzyme assisted hydrolysis were proposed. In line with surface roughness, peel strength also increased up to an enzyme concentration of 3% and then it decreased, however, the enzyme treated fabric showed higher peel strength than the control fabric.

Trace elements in skin-contact clothes and migration to artificial sweat: Risk assessment of human dermal exposure

The concentrations of a considerable number of trace elements (Ag, Al, As, B, Ba, Be, Bi, Cd, Co, Cr, Cu, Fe, Hg, Mg, Mn, Mo, Ni, Pb, Sb, Sc, Se, Sm, Sn, Sr, Ti, Tl, V and Zn) were determined in various skin-contact clothes (T-shirts, blouses, socks, baby pajamas and bodies) from the Catalan (Spain) market. In addition, migration experiments with artificial acidic sweat were conducted in order to establish the migration rates of these elements. High levels of Zn (186–5749 mg/kg) were found in zinc pyrithione labeled T-shirts, while high concentrations of Sb and Cr were found in polyester and black polyamide fabrics, respectively. An environmental scanning electron microscope (ESEM) confirmed the presence of Ag and Ti particles and aggregates in several clothing items. The use of the ESEM complemented the results of the elemental analysis and migration experiments. Dermal exposure to trace elements was subsequently calculated, and the human health risks were assessed. Antimony showed the highest mean hazard quotient (HQ = 0.4) for male and female adults wearing polyester clothes; for one of the examined items (polyester T-shirt) the HQ was even above the safety limit (HQ > 1). Exposure to Sb from polyester textile could mean potential health risks in subpopulation groups who frequently wear these clothes, and for long time periods. The migration experiments with artificial sweat showed to be essential for establishing the exposure to trace elements through cloth with direct contact with skin.

Dynamic vapour sorption and thermoporometry of polyamide fabrics coated with chitosan hydrogels

In this work, chitosan hydrogels crosslinked with genipin have been incorporated onto the surface of polyamide fabrics and the porous structure of these modified textiles have been studied. The successful hydrogel incorporation was confirmed by weight gain and evidenced by cryo-SEM. By dynamic vapour sorption (TG-DVS) the water absorption ability of the treated fabrics was studied. The results show that fabrics coated with hydrogel have higher moisture content than uncoated fabric, and they are able to absorb more water at high relative humidity. Also, the pore distribution of fabrics was measured by thermoporometry, which allows the study of pore structures of materials in presence of water. These results show that the hydrogel coating provides new pores smaller than 100nm, which enhance the water retention.