Pretreated Cotton Fabric Research Articles

Objective measurement of hand properties of plasma pre-treated cotton fabrics subjected to flame-retardant finishing catalyzed by zinc oxide

In the present paper, flame resistance property is imparted to cotton fabrics by N-methylol dimethylphos-phonopropionamide (Pyrovatex CP New, FR), melamine resin (Knittex CHN, CL), phosphoric acid catalyst (PA), and ZnO/nano-ZnO co-catalyst. The study shows that effectiveness of the FR-CL-PA reaction to form a crosslinked structure is enhanced by the co-catalytic reaction, resulting in enhancement of fabric’s compressional recovering ability. However, the low pH reaction weakened the fabrics, resulting in poor tensile strength and toughness, stiffer hand feel, brittle and tendered polymer layers, a less spongy fabric structure, and a roughened fabric surface with fuzzy fibrils. In addition, atmospheric pressure plasma jet (APPJ) was used to enhance materials properties by sputtering or etching effect. The roughening effect of plasma treatment enhances tensile properties of treated specimens. Nevertheless, the positive effect is negligible after post-treatment with flame-retardant agents. Moreover, the increased inter-yarn friction enhances the subjective stiffness of fabric and the rigid effect is even worse for plasma pre-treated cotton specimens subjected to flame-retardant treatment. However, plasma pre-treated specimens have a compressible structure after post-treatment with flame-retardant agents. Moreover, neutralization of flame-retardant-treated specimens helps minimize side effects of acidic finishing, irrespective of tensile and compression properties. The process also minimizes shear and bending rigid effect by removing unattached metal oxides from the fabrics.

A study of metal oxide on antimicrobial effect of plasma pre-treated cotton fabric

Cotton, a natural fibre that consists of cellulose, is highly popular because it is sweat-absorbing and comfortable to wear. However, cotton fabrics provide an excellent environment for microorganisms to grow, owing to their ability to retain moisture. Therefore, numerous chemicals have been used to enhance anti-microbial activity of cotton textiles. This paper reports results of use of silver oxide (Ag2O) or zinc oxide (ZnO) as a catalyst in the antimicrobial formulation (halogenated phenoxy compound (Microfresh, MF)) and a binder (Microban, MB) for improved treatment of cotton fabrics and minimisation of side effects of the treatment. In addition, from the morphological study, plasma technology was employed to roughen the surface of the materials to improve loading of metal oxides on the surface. Moreover, the characteristic infra-red bands related to plasma-treated cotton produced results different from untreated fabric, implying plasma treatment can improve hydrophilicity of the fabric. Mechanical strength of the specimens was also increased by plasma treatment. Meanwhile, the research showed that the control fabric slightly inhibited the growth of S. aureus because of the bleach residues on fabric surface. On the other hand, anti-bacterial activity of MF-MB-treated specimen, especially in the presence of metal oxide catalyst, was enhanced, providing a slightly larger zone of inhibition. Moreover, plasma gas contains reactive oxygen species that can enter the cell, eventually causing its death. The hydrophilic nature of carbonyl groups present in oxygen plasma pre-treated specimens also increased the anti-microbial activity after treatment with MF-MB.

Modification of enzyme pretreated cotton fabric using acrylonitrile, acrylonitrile/solvent mixture and its characterization

The presented research deals with modifying the chemical structure of the bioscoured cotton fabric by acrylonitrile, acrylonitrile/acetone, and acrylonitrile/ethanol mixture. The modified cellulose was tested for weight gain, shrinkage, and wicking height and characterized by X-ray diffraction (XRD), thermal analysis (TG/DTA), elemental analysis, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and atomic force microscopy (AFM). The weight gain and shrinkage % show increased value for modified fabrics. The wicking height increases with addition of solvent. The crystallinity and thermal studies show a significant change. FTIR analysis confirms the modification by the occurrence of -C≡N stretching and -CONH2 stretching. The SEM morphology of modified fabric shows uniform swelling of fibers with better smoothness. The AFM topography reveals that the addition of solvent affects the particle size. Clear surface morphology of modified fabric reveals that this processing method can be used for preparation of medical textiles with more swelling.

Investigation of Ultraviolet Protection Properties of Cotton Fabric via Azoic Dyeing with Green Tea Extract

Green tea dyeing of cotton fabric via azoic combination method was investigated in order to improve ultraviolet protection properties without the application of polutting metal mordants. Three types of diazonium salts were prepared from three different primary aromatic amines (aniline, p-nitroaniline and 2,4 dichoroaniline) and subsequently, reacted with pretreated cotton fabric with coupling component or polyphenolic compounds found in green tea extract to form an azo dye inside the cellulose matrix. The result showed that as the strength of electron withdrawing groups of the substituents in the primary aromatic amines increase, both color strength and ultraviolet protection factor (UPF) of dyed fabrics dramically increased.

Dyeing and DP treatment of sol-gel pre-treated cotton fabrics

Cotton samples were pre-treated with various sol solutions containing different alkoxysilanes (TEOS, GPTMS, APTES, and TESP-SA). The as-prepared cotton samples were dyed with 2 % owf Red and 4 % owf Blue. Furthermore, dyed cotton samples were after-treated with the alkoxysilanes. The alkoxysilane were also incorporated into the dyeing bath. The as- prepared cotton samples were subjected to a treatment with the non-formaldehyde durable press finishing agent BTCA in conjunction with the catalyst SHP. The textile materials were evaluated with respect to the colorimetric data (L*, a*, b*, ΔE*) and the color strength expressed in terms of K/S values. Tensile strength and dry crease recovery angles of the durable pressfinished samples were measured. The findings indicate that APTES and TESP-SA exert a significant influence on the color properties.

Functionalization of cotton fabrics with corona/air RF plasma and colloidal TiO2 nanoparticles

This study discusses the possibility of using a corona discharge at atmospheric pressure and air RF plasma at low pressure for the cotton fibre activation prior to deposition of colloidal TiO2 nanoparticles in order to enhance antibacterial, UV protective and self-cleaning properties. X-ray photoelectron spectroscopy (XPS) analysis confirmed the presence of TiO2 nanoparticles on the surface of cotton fibres. XPS elemental mapping indicated that TiO2 nanoparticles were more evenly distributed across the surface of untreated and corona pre-treated cotton fabrics in comparison with RF plasma pre-treated fabric. Atomic absorption spectroscopy measurements revealed that the equivalent total content of TiO2 in the cotton fabrics pre-treated by corona and RF plasma was 31% higher than in the fabric that did not undergo any treatment prior to loading of TiO2 nanoparticles. In order to achieve maximum bacteria (Gram-negative bacteria Escherichia coli) reduction, untreated cotton fabric had to be loaded with colloidal TiO2 nanoparticles twice, but only once following corona or RF plasma pre-treatment. Deposition of TiO2 nanoparticles onto cotton fabrics provided maximum UV protective rating of 50+. Extraordinary photocatalytic activity of TiO2 nanoparticles deposited onto cotton fabrics was proved by self-cleaning of blueberry juice stains and photodegradation of methylene blue in aqueous solution under UV illumination.

Effect of zinc oxide on flame retardant finishing of plasma pre-treated cotton fabric

An organic phosphorus compound (flame retardant agent, FR) in combination with a melamine resin (crosslinking agent, CL), phosphoric acid (catalyst, PA) and zinc oxide (co-catalyst, ZnO/nano-ZnO) imparted effective and durable flame retardant properties. Also, atmospheric pressure plasma jet was applied as pre-treatment to improve post-finishing (flame retardant finishing) on cotton fabrics. In the present paper, surface morphology, chemical structure analysis, combustibility and mechanical properties of plasma pre-treated cotton fabrics subjected to flame-retardant treatment were investigated. Surface morphology of treated cotton specimens showed roughened and wrinkled fabric surface with high deposition of the flame retardant finishing agent, which was caused by the plasma etching effect and attack of acidic FR. The FTIR-ATR spectra for the treated cotton specimens showed some new characteristic peaks in chemical structure, interpreted as carbonyl bands, OH stretching vibration, COO− stretching vibration, CH2 rocking band and CH3 asymmetric and CH2 symmetric stretching. Moreover, FR-CL-PA-treated specimens showed remarkable flame-retardant property, which was further improved by the plasma pre-treatment and ZnO/nano-ZnO co-catalyst. However, flame-retardant-treated cotton specimens had poor mechanical strength when compared with control sample, resulting from side effects of the crosslinking agent used, while plasma pre-treatment and ZnO/nano-ZnO co-catalyst may compensate for the reduction in tensile and tearing strength caused by flame-retardant agents.

The influence of chitosan and some of its depolymerized grades on natural color printing

AbstractChitosan samples with different molecular weights were prepared using sodium nitrite in acidic medium. These samples were practically confirmed by measuring nitrogen content and average molecular weight. The chitosan samples were applied to cotton fabric by the pad dry method. The pretreated cotton fabric was printed with natural coloring matter, curcumin. The color yield of the prints increased by increasing the molecular weight of chitosan. Both wet and dry rubbing fastness of the prints was good. The stiffness results of the printed cotton fabric pretreated with low molecular weight chitosan showed better performance. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 559–563, 2005

Fabric Pretreatment and Digital Textile Print Quality

Digital image analysis and optical microscopy are used to compare various print quality parameters of pretreated fabrics. In this work, woven and knitted cotton fabrics were treated with various chemical formulations containing ingredients like alginate, silicone based textile softeners and fine silica powder. A special print pattern was designed and printed on paper-supported pretreated fabric samples using a commercially available ink jet printer. Analysis of these print patterns was performed using an optical microscope and a digital image analysis program. The quality of these printed patterns were evaluated in terms of (1) color related metrics (L* a* b*) and (2) appearance related metrics (line width). Results show that digital textile printing quality on plain weave and knitted cotton fabrics is influenced by the fabric pretreatments, the most noticeable being the appearance related quality, i.e., the line width. The print quality on these pretreated cotton fabrics was not significantly affected by the fabric structure and the hydrophilicity of the fabric surfaces as long as the pretreatment can give cotton fabrics a balanced hydrophilic/hydrophobic character. From these studies it is concluded that digital textile printing quality can be optimized with appropriate pretreatments. For the plain cotton weave and knit fabrics studied, a pretreatment containing 2% alginate, 2% silicone softener and 1% silica shows good balance in colorant retention and line width control.

Direct Scouring of Greige Cotton Fabrics with Proteases

Our previous work demonstrated that proteases are effective scouring agents for boiling-water pretreated cotton fabrics. In this study, we investigate whether proteases are effective scouring agents when directly applied on raw greige cotton fabrics without the boiling water pretreatment. Direct reactions with three proteases, i.e., trypsin, chymotrypsin, and subtilisin, on greige cotton fabrics show that all three improve fabric wettability to a level similar to alkaline scouring under mild conditions (45-55°C, pH 7). The reaction conditions required to achieve optimal fabric wettability (cosθ > 0.6) are 5 g/L and 45°C for trypsin and 5 ml/L at 55°C for subtilisin. Chymotrypsin is effective under several reaction conditions, i.e., 1 g/L at 55°C, 2 g/L at 45°C, and 5 g/L at 35°C. Most reactions take 30 minutes, and room-temperature water rinses replace the post-reaction buffer rinses. Compared to protease scouring of boiling-water pretreated cotton, direct protease scouring of greige cotton fabrics requires increased concentration (subtilisin), higher temperature (subtilisin and chymotrypsin), or longer time (trypsin and chymotrypsin) to achieve similar water wettability and absorption properties. The most distinct outcome of direct protease scouring of greige cotton fabrics, in comparison to boiling-water pretreated and protease scoured and alkaline scoured cotton, are the resulting fabric characteristics, i.e., less lateral shrinkage, no change in surface friction, easier to shear, and more resilient to compression and bending.

Enzymatic Scouring to Improve Cotton Fabric Wettability

The ability of pectinase, cellulase, protease, and lipase enzymes to improve the surface wetting properties of raw and pre-treated cotton fabrics is studied. When applied alone to raw cotton fabrics, pectinase, lipase, and protease treatments provide very little improvement in water wetting and retention properties. A combination of pectinase and cellulase significantly improves water wetting and retention properties similar to those of commercially scoured cotton fabrics. A water pretreatment at 100°C enhances the effectiveness of subsequent pectinase and cellulase reactions. Pectinase following the 100°C water pretreatment produces improved wettability with the least weight loss and dimensional change. Cellulase treatments on scoured fabrics further enhance water wettability and whiteness, but with significant reductions in fabric weight, thickness, and strength.