Forensic evaluation of clothing flammability

A set of 17 commercial garments were purchased, categorized based on their fabric composition and fire tested. Three fire exposures were used: (a) a simile of the United States regulatory test for apparel fabrics (16CFR1610), (b) a small vertical candle on a small swatch of fabric and (c) a candle applied to a full garment, placed on a mannequin. Comparisons were made between the results of the various tests and of the various fabrics tested. A general correlation was observed whereby increased fabric areal density [weight/unit fabric area] resulted in improved fire performance. Where outliers to this generalization were observed the improved fire performance was due to the superior inherent fire performance of specific fabric types such as silk. Overall, the quantitative behavior with regard to flame spread rate observed after ignition of cellulosic, thermoplastic and blended fabrics was more heavily dependent on fabric areal density than on their chemical composition. Two key conclusions are that very lightweight fabrics constitute a potential danger and that the United States regulatory value, set at 88.3g/m² (2.6oz/yd²), represents an essentially arbitrary cut‐off in this regard. Copyright © 2009 John Wiley & Sons, Ltd.     

Lipid distribution on cotton textiles in relation to washing with cellulase

Enzymes are used widely as effective additives to laundry detergents for improved detergency on soiled fabric. They have potential for cleaning of “dingy” soils in addition to the stain removal benefits. Cellulases contribute to the overall whiteness of cotton-containing textiles when worn and washed several times, meaning that their cleaning is not associated solely with the regions characterized by high amounts of fatty material, e.g., collars/cuffs. The focus of this research was to study further the performance of cellulases for whiteness maintenance of cotton textiles. Cotton garments soiled by multiple wearings and washed using a cellulase treatment were evaluated using scanning electron microscopy and X-ray microanalysis. Washing with cellulase significantly reduced residual soil concentrations at all morphological locations on the cotton fibers for each set of matched garments. The relative concentrations of residual soil on the fabrics agreed well with the color differences measured at 440 nm. Cellulase affected removal of oily soil from within the cotton fiber secondary wall, resulting in residual oil concentrations similar to those at morphological locations that were more accessible for detergency such as the fiber surface and crenulations. Since cellulase hydrolyzes cellulose, it was expected that the effect would be within the structure of the fiber, i.e., secondary wall. The cellulase effect on redeposition garments was similar to garments worn and washed. As with lipase, the enhanced removal of soil from the interior bulk structure of the cotton fiber with use of cellulase is unique, since most other detergent components have higher functionality at fabric, yarn, and fiber surfaces. We think that cellulase is functioning by hydrolyzing cellulose from the internal surfaces of fibrils within the secondary wall, opening up the pore structure for enhanced detergency and forming a new surface with each washing.     

Polymers for dye transfer inhibition in laundry applications

The deposition of dyes onto lightly colored garments, or onto lighter sections of multicolored garments, during laundry results in fabric discoloration. In particular, there is a requirement to restrict indigo dye transfer between garments. Polymers may be added to detergent formulations as dye transfer inhibitors to prevent dye transfer by blocking the deposition of fugitive dyes in aqueous solution. This article reports the generation of a range of dye transfer inhibitors produced by condensation reactions that are effective in preventing the transfer of unbound indigo dye to a variety of fiber types. Key design rules relating to polymer hydrophilicity and pendant polymer functionality were established for the creation of effective dye transfer inhibitors. Remarkably, polymers at concentrations as low as 0.1 mg/ml were found to be effective in inhibiting indigo deposition on a variety of fiber types, offering great promise for their inclusion within laundry detergent formulations as dye transfer inhibitors.     

Effect of solvent induced hydroxylation of cyanoethyl group on dye uptake of cotton fabrics

The present investigation deals with the dyeing behavior of solvent induced cyanoethylated cotton fabric. The modified cotton fabric was dyed by conventional method with commercial reactive dye (Drimarene Red). It is observed that acetone induced cyanoethylated samples exhibit higher color values than ethanol treated samples. The effect of nitrogen content on the dye uptake of modified fabric is assessed which shows a good correlation between them. It is obvious that crystallinity has a noticeable effect on the dye uptake of both solvent modified fabrics. For convenience and comparison, a set of samples are also dyed without addition of salt, alkali, and both. It is evident that even without addition of salt, alkali and both the samples exhibit a significant dye uptake. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci 2008     

Process of dyeability modification and bleaching of cotton in a single bath

Graft polymerisation of the cationic monomer, methacryloylaminopropyltrimethylammonium chloride (MAPTAC), onto scoured cellulose was carried out in the bleaching process, aiming at modifying the fibre using a single bath. The extent of MAPTAC fixation on cellulose was measured. The bleaching performance of hydrogen peroxide in the presence of the modifying agent was found to be slightly reduced. The modified bleached cotton fabric was then dyed with a commercial reactive dye in the absence of salt. The dye uptake and colour strength of the modified fabric was markedly increased with an increase in the concentration of MAPTAC. This was attributed to the presence of the cationic groups of the MAPTAC which played a crucial role in attracting the anionic dyes from the dyebath. The results suggest that the dyeing properties of the modified fabric are closely dependent on the efficiency of MAPTAC fixation on cellulose during concurrent modifying and bleaching of cotton.     

Study of the Influence of Gemini Cationic Surfactants on the Dyeing and Fastness Properties of Polyester Fabrics Using Naphthalimide Dyes

In this paper, the dyeing and fastness properties of three monoazo naphthalimide dyes including different imide groups (dye 1: ethyl amine, dye 2: ethyl glycinate and dye 3: glycine) on a polyester fabric were investigated in the presence of two gemini cationic surfactants (symbolized as 12‐4‐12 or 14‐4‐14) and a conventional single chain surfactant, dodecyltrimethylammonium bromide (DTAB). The color strength (K/S) of naphthalimide dyes on polyester fabric was measured through the reflectance spectrophotometric method, and the values obtained in the presence of different cationic surfactants increased in the order of dye 3 < dye 2 < dye 1. Although the K/S values indicated that the gemini cationic surfactants had almost no effect on the dyeing behavior of dye 1, but they were effective in dyeing ability of dye 2 and dye 3. The data for dye 2 demonstrated that build up of polyester fabrics in the presence of gemini surfactants are more than the conventional cationic surfactant, and also K/S values of dye 3 on polyester fabrics were in the order: DTAB > 12‐4‐12 > 14‐4‐14. It was found that the washing and rubbing fastness properties improved with increasing the concentration of surfactants. In addition, the sublimation fastness of dye 3 was more than the other dyes owing to the presence of a polar group in its chemical structure, and the light fastness of naphthalimide dyes on polyester fabrics was generally moderate.     

Optimization of a Fabric Softener Formulation with an Electrochemical Sensor and Streaming Potential Measurements

An electrochemical, cationic, surfactant-selective sensor based on multiwalled carbon nanotubes (MWCNT) functionalized with a sulfate group and the cetylpyridinium ion (MWCNT–OSO₃⁻CP⁺) as a sensing material was used for optimization of the formulation of a fabric softener. Potentiometric titrations were performed and response measurements were obtained using four cationic surfactants (CS) of technical grade and four CS of analytical grade. The slope closest to Nernstian was obtained for di-(tallow carboxyethyl) hydroxyethyl methylammonium methosulfate (MAS) (59.5 ± 1.1 mV/decade of activity in water and 57.5 ± 1.3 mV/decade of activity in CaCl₂). When using CS as analytes in potentiometric titrations, the best accuracy (99.8%) was obtained when using MAS; therefore, it was chosen as the CS for the fabric softener formulation. Due to the better properties of fabric softeners with silicone in their formulations, four silicones at several concentration levels were used as potential additives. Based on the stability and viscosity of the system, the diquaternary polydimethylsiloxane (DPS) (w = 0.19%) was chosen for the fabric softener formulation. The pH did not significantly influence the potential when in the range of 3–8 or the recovery of potentiometric titrations when in the range of 3–7. The application profile of the CS was assessed through streaming potential measurements of reference fabrics in an electrokinetic analyzer. The obtained electrokinetic parameters indicated on lag in adsorption of model fabric softener (MFS) based on MAS (w = 9%), with the addition of silicone DPS (MFS 3), on cotton and polyester fabrics, but advantage in stability when compared with other MFS investigated.     

Telechelic PEG-polymers end-capped with chromophores: Using as cationic reactive dyes and salt-free dyeing properties on cotton fabrics

In this article, telechelic polymers containing polyethylene glycol (PEG) moieties as space groups were combined with chromophores to synthesize cationic reactive dyes (BCD-R, BCD-Y, and BCD-B). The salt-free dyeing performance of these telechelic polymeric cationic reactive dyes on cotton fabrics was evaluated. The exhaustion and fixation of the dyes in salt-free dyeing was above 89.33 and 77.22%, respectively. The color fastness of dry rubbing for the three dyes reached grade 4–5, and their color fastness to light reached grade 5–6. Their washing fastness also reached grade 4–5, except for that of BCD-Y (grade 3–4). The results showed that the dyes possessed good leveling and build-up properties and substantivity to cellulose fiber. The zeta potential (ξ-potential) of dyed fabric was estimated, and it was found that the ξ-potential of the fabrics increased after dying with telechelic polymeric cationic reactive dyes, and the more dye that was used, the greater ξ-potential increase. The exhaustion curves of dyes were also determined, and they were much different from those of anionic reactive dyes. The adsorption kinetics and isotherms of BCD-R were investigated. It was found that the pseudo-second-order kinetic model gave the best fit of the experimental data at all three tested dyeing temperatures (25, 45, and 65°C) with R² values over 0.998. Both the Langmuir and Freundlich models could be used to describe the adsorption of BCD-R onto cellulose fibers and the Langmuir model fit the experimental data better than the Freundlich model. The thermodynamic parameters (ΔG, ΔS, ΔH, and activation energy) of the dye adsorption process were researched further. The results indicated that the adsorption of BCD-R onto cotton fibers was spontaneous and exothermic and that after adsorption onto the cotton fibers, the degree of freedom of the dye decreased.     

Single‐phase ink‐jet printing onto cotton fabric

The current commercial application of ink‐jet reactive inks to cotton fabrics requires pretreating with pad liquor containing a thickener, urea and alkali prior to printing. In this study, attempts have been made to develop a reactive ink‐jet print in a single‐phase process by adding an organic salt to the ink formulation and hence removing the need to pretreat fabrics. This approach utilises inks containing both a reactive dye, in this case Procion Red H‐E3B, and an organic salt such as sodium formate, sodium acetate, sodium propionate or tri‐sodium citrate. The behaviour of a novel reactive ink formulation for ink‐jet printing on to cotton fabric was evaluated at different pH vlaues. The results at optimum pH indicated that printed non‐pretreated fabrics with ink containing organic salts exhibited a higher level of reactive dye fixation than printed pretreated fabric containing no organic salt ink. The yielded prints demonstrate excellent colour fastness to washing and dry/wet crocking properties. The light fastness of the printed fabrics was improved by adding an organic salt to the ink formulation.     

Dyeing and finishing of lyocell union fabrics: an industrial study

Lyocell union fabrics, namely lyocell/silk and lyocell/polyester fabrics, were woven in different fabric constructions and dyed with reactive dyes, acid dyes and a disperse dye. The resulting dyed fabrics were given a resin finishing treatment and their wash fastness was measured. With appropriate dye selection and control of dyeing conditions, some bright solid shades and effective cross‐dyed shades were obtained. The dyed and finished fabrics had a smooth, lustrous handle, ideal for lightweight garments.     

Novel delayed‐cure,durable press,shrink‐resist treatment of wool fabrics and garments

The relatively high heat stability of commercial easy‐care chemicals for cotton allows for greater flexibility in garment manufacturing, in particular the delayed curing of durable press, wrinkle‐resistant, shrink‐resist (SR) finishes on garments. Typically, the technology involves application of the wet chemical finish to the open width fabric, drying, storage, garment manufacture, heat pressing of the creases/pleats, and lastly garment baking to fully cure the durable press/crease‐resistant/SR finish. By contrast, for the wool industry, there is no comparable technology, and this presents an obvious commercial weakness. The reason for this technical deficiency is that the prepolymers used for imparting machine washability and potentially durable press to wool apparel polymerise on the fabric at room temperature in storage, thereby losing their reactivity. Subsequent manufacturing into the final garment still allows the fabric to offer stability to laundering, but the loss of prepolymer reactivity precludes any potential for introducing durable creases/pleats into the garment as an integrated late‐stage garment process. In this study, we present a simple solution to this technical deficiency through the use of cyclodextrin‐based technology and deliver a delayed‐cure, durable press, machine‐washable wool technology ready for market. In any commercial textile process, the effect of chemical finishing on the final fabric colour is important. It is demonstrated in this study that the addition of HP‐β‐cyclodextrin into the Synthappret BAP and EC 1354 formulations has an instrumentally detectable effect on the colour of the dyed wool fabric, but that this difference is less than one colour difference (ΔE_CMC) unit.     

The roles of polymer relaxation phenomena,aqueous dye solubility and the physical properties of water in the mechanism of adsorption of a disperse dye on poly(ethylene terephthalate) fibres: part 5 analysis of polymer relaxation phenomena for different polymers

The temperature dependent uptake of a commercial disperse dye on cotton and polyamide 66 fabrics at dyeing temperatures between 30°C and 130°C adhered to the Williams–Landel–Ferry equation, insofar as, very good correspondence was observed between plots of experimentally determined colour strength data points (log1/f_k) and the respective structural relaxation times of the cellulose and nylon 66 polymers (loga_T data points), as a function of the parameter (T − T_g). Adsorption of the dye on both types of fibre therefore concurs with the fundamental precept of the free volume model of dye diffusion. Comparison of the adherence of the uptake of the commercial dye on cotton and polyamide 66 fabrics with that secured on polyester fabric revealed that despite the major chemical and physical differences between the three types of fibre, the same dyeing mechanism likely applies to each fibre type. The marked temperature dependent uptake of the commercial grade disperse dye each of the three types of substrate is the consequence of two, different, but inherently interconnected, thermally activated phenomena, namely the relaxation times of the molecular rearrangements occurring within the respective cellulose, nylon 66 or poly(ethylene terephthalate) macromolecule, in which polymer glass transition assumes the principal role, and the aqueous solubility of the commercial grade disperse dye.     

Synthesis of cationic binder through surfactant-free emulsion polymerization for textile pigment applications

The cationic P(DMDAAC-BA-MMA-HEA) copolymer latex was prepared with diallyldimethylammonium chloride, butyl acrylate, methylmethacrylate and hydroxyethyl acrylate as monomers via surfactant-free emulsion polymerization. The structures and morphologies of the latex were confirmed by Fourier transform infrared (FT-IR) spectroscopy and transmission electron microscopy (TEM). The utilization performance of the cationic latex as a binder for pigment dyeing of cotton fabrics was investigated. FT-IR showed that the polymer was prepared successfully. TEM micrograph revealed that the hybrid latex particles were uniform spheres with the diameter ranged from 500 to 600 nm. Cotton fabric dyed with the cationic binder demonstrated 3–4 grade dry and wet rubbing fastness and 4 grade soaping fastness, which were comparable with commercial binders. Moreover, the binder can be used safely in pigment dyeing to give the dyed fabric improved hand feel and excellent elongation at break. It could be said that an efficient way to produce a binder with good performance was developed by the use of cationic emulsifier-free emulsion polymerization.     

Union Dyeing of Easy Care-Finished Wool/Viscose and Cotton/Wool Blends

Wool/viscose (60/40) and cotton/wool (70/30) blended fabrics have been easy-care finished in the presence of certain nitrogenous additives to produce readily dyeable cationic cellulose for competitive dyeing with wool dyes. The enhancement of easy care properties and improvement in post-dyeing of the finished fabrics were determined by the nature of substrate (wool/viscose > cotton/wool), type of catalyst (ammonium persulfate > ammonium sulfate > ammonium chloride > none), the kind of nitrogenous additive, as well as the type of polyethylene glycol (PEG-400 > PEG-200 > NONE). Using triethanolamine hydrochloride as a reactive/nitrogenous additive (30 g/L) in the finishing formulation as well as curing at 150°C/3 min make it possible to attain higher fabric resiliency along with better dye receptivity, regardless of the used anionic dye. However, the change in dyeing and fastness properties of obtained dyeing is governed by the nature of the anionic dye.     

Acid dyeable and printable acrylic fabrics treated with cationic aqueous polyurethane

An acid dyeable acrylic fabric has been obtained by the pretreatment with cationic aqueous polyurethane, containing different amounts of quaternary nitrogen. Cationic polyurethane has the ability to interact with the carboxylic groups in the acrylic fabrics, as well as providing basic sites suitable for acid dyeing. The prepared polyurethane has been identified with FTIR, and the effect of the pretreatment conditions on the dyeability and printability of the fabrics has been investigated. The color strength values and the fastness properties of the dyed and printed samples, reveal the ionic interaction between the sulphonic groups in the acid dye molecules and the quaternary nitrogen on the fabrics. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Solubilisation of dyes by surfactant micelles. Part 4: Influence of dye fixatives

Dye loss from unfixed dyed fabrics has been found to be insensitive to change in surfactant type or concentration. There was accompanying dye transfer to white fabric but this was reduced by Synperonic A7 in the case of fabrics dyed with CI Direct Green 26, due to solubilisation of the dye in nonionic micelles. The anionic surfactant, SDS, selectively displaced dye from fixed dyed fabrics, paralleling its behaviour with water soluble polymers. Similarly, dye loss was related to concentration of surfactant monomer, the effect increasing with SDS concentration up to its critical micelle concentration. Other anionic surfactants have been found to exhibit a similar trend, the effect increasing with their increasing surface activity. The commercial polymeric fixatives, Tinofix ECO and Indosol E50, were the most effective of those studied and the single-chain cationic surfactant, CTAB, was the least effective.     

Durable Antistatic Finishes for Nylon Fabrics I—Coatings Incorporating Cationic Agents

In attempts to develop a satisfactory permanent antistatic finish for nylon fabrics, a durable but non-conducting coating of an acidic polymer on the nylon was made conducting by treatment with cationic surface-active agents. Certain cationic agents were found to be retained during rinsing. The antistatic activity, measured in terms of the surface electrical resistivity of the treated fabric, withstood several mild washes in an anionic detergent, and was completely regenerated when the fabric was re-treated with a cationic agent.     

Combination of a hydroxy‐functional organophosphorus oligomer and a multifunctional carboxylic acid as a flame retardant finishing system for cotton: Part I. The chemical reactions

Multifunctional carboxylic acids, such as 1,2,3,4‐butanetetracarboxylic acid (BTCA), have been used as crosslinking agents for cotton cellulose to produce wrinkle‐resistant cotton fabrics and garments. Polycarboxylic acids were used to bond hydroxy‐functional organophosphorus oligomer to cotton, thus imparting durable flame retarding properties to the cotton fabric. This research investigated the chemical reactions between the hydroxy‐functional organophosphorus compound and BTCA on cotton. BTCA crosslinks cotton cellulose through the formation of a 5‐membered cyclic anhydride intermediate and esterification of the anhydride with cellulose. In the presence of the organophosphorus compound, BTCA reacts with both the organophosphorus compound and cellulose, thus functioning as a binder between cotton cellulose and the organophosphorus compound and making the flame retarding system durable to laundering. The cotton fabric treated by the combination of the organophosphorus compound and BTCA demonstrated lower wrinkle resistance and less tensile strength loss than that treated by BTCA alone. The phosphorus retention on the cotton fabric after one home laundering cycle was approximately 70%. Copyright © 2003 John Wiley & Sons, Ltd.     

The roles of polymer relaxation phenomena,aqueous dye solubility and the physical properties of water in the mechanism of adsorption of a disperse dye on poly(ethylene terephthalate) fibres: Part 4 further aspects related to polymer relaxation phenomena

To further investigate the contribution of polymer relaxation times to the mechanism of disperse dye adsorption on poly(ethylene terephthalate) fibres, the temperature-dependent uptake of Teratop Yellow HL-G 150% on both cotton and polyamide 66 fabrics at temperatures between 30 and 130°C was compared with that on poly(ethylene terephthalate) fabric. Although uptake of the commercial grade dye on polyester fabric is governed by the thermally regulated, broad glass transition of the water-saturated poly(ethylene terephthalate) substrate, as this was not observed for either cotton or nylon 66 fabrics, the respective cellulose or polyamide 66 polymer glass transition does not present a major thermal impediment to dye uptake over the wide range of dyeing temperatures used. This is because the onset and end-set temperatures of the glass transition of the water-plasticised poly(ethylene terephthalate) material reside within the range of dyeing temperatures employed, whereas those of the water-plasticised cotton and polyamide materials occur below the lowest dyeing temperature examined (30°C). The thermal dependency of disperse dye solubility also likely makes a meaningful contribution to the temperature-dependent dye uptake observed for each type of fibre.     

Improving the properties of chemically damaged wool fabrics with carbohydrate polymers

Wool is a natural composite material consisting of keratin and keratin‐associated proteins as the key molecular components. During wool product processing, a variety of chemical and enzymatic reagents are used, the side‐effects of which can include the removal of the outside layers of the fiber (cuticle) and damage within the internal protein matrix of the fiber. This can reduce the mechanical strength and durability of wool fabrics. We report the use of neutral, cationic, and anionic carbohydrate polymers, namely 2‐hydroxyethyl cellulose, chitosan and alginate, as repair agents to improve the mechanical properties and morphology of wool fabrics damaged under harsh alkaline conditions. Tensile strength, peel adhesion, scanning electron micrographs, and fabric wettability evaluation reveal the cationic polymer, chitosan, to be most effective at remedying the effects of the alkaline treatment. The improved mechanical properties observed after chitosan treatment may offer viable remediation routes for adding value to processing‐damaged wool textiles. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3105–3111, 2013