Neutral dyeing of wool and wool/polyester blend fabrics using sulphatoethylsulphone reactive‐disperse dyes

Two models of temporarily anionic sulphatoethylsulphone reactive disperse dyes were applied to wool, polyester and wool/polyester blend fabrics at different dyeing pH. Maximum exhaustion values and colour yield were observed at pH 7. The results showed that reactive disperse dyes containing bis‐sulphatoethylsulphone reactive groups were more convenient for neutral dyeing of wool and wool/polyester blend fabrics if compared with a dye containing a mono‐sulphatoethylsulphone group. Excellent to very good wet fastness properties on all dyed fabrics were achieved.     

Dyeing of nylon 6 fabric with a bifunctional sulphatoethylsulphone reactive disperse dye

A bifunctional reactive disperse dye containing two temporarily anionic sulphatoethylsulphone groups was synthesised and applied to nylon 6 fabric by exhaust dyeing at a variety of pH levels and temperatures. A monofunctional reactive disperse dye containing one temporarily anionic sulphatoethylsulphone group was also synthesised, and its dyeing behaviour was compared with the bifunctional dye. The bifunctional reactive disperse dye exhibited high exhaustion and total fixation yield under alkaline conditions. The results also indicate that the introduction of two temporarily anionic sulphatoethylsulphone groups of the bifunctional dye gave an enhancement in dyeing performance compared with that of the monofunctional dye. The dyes also showed very good levelling and fastness properties on nylon 6 fabric.     

PLA/棉混纺织物一浴一步法染色

本文通过研究聚乳酸纤维的染色工艺特点,探讨国内外涤/棉、PLA/棉混纺织物染色工艺技术进展,分析分散/活性染料一浴一步法染PLA/棉混纺织物存在的技术问题,提出了适合PLA/棉一浴一步法染色的染料及染色方法,并对一浴一步法染色的前景做了展望.     

Improving the dyeability of polyimide by pretreatment with alkali

Polyimide fabric, as a high‐performance fabric, possesses advantageous properties, such as outstanding thermal stability and chemical resistance, but has poor dyeability. In this paper, polyimide fabric was dyed successfully with disperse dyes by high‐temperature and high‐pressure dyeing in the presence of a swelling agent and auxiliaries. Under optimal dyeing conditions, it is pretreated with NaOH 6 g l^?1 and dyed with disperse dyes 5% o.w.f., NaCl 1 m , benzyl alcohol 60 ml l^?1 at 135 °C for 45 min to obtain a satisfactory colour yield with good washing fastness and dry rubbing fastness with 93.3% strength retention. The experimental results demonstrate that the Nernst adsorption isotherm is a favourable model for polyimide fabric dyeing with disperse dyes.     

Levelling properties of some reactive dyes on cellulose

The levelling properties of nine reactive dyes containing one or two sulphatoethylsulphone reactive groups or one sulphatoethylsulphone and one monochlorotriazine reactive groups have been investigated. A novel test method specifically applicable to reactive dyes has been used in order to evaluate levelling. Undyed and dyed cotton samples were simultaneously dyed in the same bath and the fractions of the additional dye fixed on each of the cotton samples were determined afterwards. A dye distribution index has been proposed that predicts reactive dye levelling according to whether the index exceeds 50% or not. The index was found to depend not only on the nature of the dyes, but also on the concentration of the dye fixed on cotton, the dyeing temperature and the salt concentration in the dye liquor. In redyeing tests the degrees of primary and secondary exhaustion and of dye fixation were measured as a function of concentration of the dye fixed on cotton. Finally a satisfactory correlation was found between the index and the classical inorganicity/organicity value of the dyes. The results also suggest that the levelling properties depend on the degree of dye aggregation.     

Dyeing of nylon 6 fabric with a new bifunctional vinyl sulphone reactive disperse dye

A new bifunctional reactive disperse dye containing a temporarily anionic sulphatoethylsulphone and a nonionic disulphide bis(ethylsulphone) groups was synthesised and applied to nylon 6 fabric by the exhaust dyeing at a variety of pH and temperature conditions. A monofunctional reactive disperse dye containing only nonionic disulphide bis(ethylsulphone) group was also synthesised and its dyeing behaviour was compared with the bifunctional dye. The bifunctional reactive disperse dye exhibited high exhaustion and fixation values at pH 6 and 120 °C. The results also indicate that the combination of temporarily anionic and nonionic reactive groups of the bifunctional dye provided great enhancement in dyeing performance compared to that of the monofunctional dye. The dyes also showed very good levelling and fastness properties on nylon 6 fabric.     

Electrostatic self‐assembly dyeing of cotton fabrics

A new approach to the dyeing of cotton fabrics using an electrostatic self‐assembly method was evaluated. Cotton fabrics were pretreated with 2,3‐epoxypropyltrimethylammonuium chloride and cationic charges were produced on the fabric surfaces. For the dyeing of cotton fabric, reactive and acid dyes were used. Oppositely charged anionic reactive/acid dyes and cationic poly(diallyldimethylammonium chloride) were alternately deposited on the surface of cationised cotton fabrics. Ten multilayer films of dye/poly(diallyldimethylammonium chloride) were deposited on the cotton fabric surfaces using a padder. The build‐up of the multilayer films and the level of colour strength (K/S) achieved are discussed. Samples of cotton fabrics were also dyed with the same dyes, but using the exhaust method, and both types of dyed samples were compared. The washing, rubbing and light fastness properties were evaluated for the dyed fabrics.     

Reuse of spent dyebath following decolorisation with ozone

Spent reactive dyebaths were decolorised by treatment with ozone and reused in the bleaching, whitening and dyeing of two textile substrates. The study shows that the reuse of a spent dyebath is possible with little modification to the standard processes for dyeing cotton with reactive dyes, provided that the pH of the treated dyebath is adjusted. Moreover, the cycle of decolorisation and reuse was successfully repeated. Renovated reactive dyebaths were also reused for bleaching cotton fabric with hydrogen peroxide, whitening with optical brightener and dyeing polyester fabric with disperse dyes. The whiteness index of bleached and whitened cotton was comparable to that of the same fabric given a control treatment with fresh baths. Likewise, there was a negligible colour difference between polyester dyed using liquor from a spent reactive dyebath and the same fabric dyed in a new bath.     

Application of polycarboxylic acid sodium salt in the dyeing of cotton fabric with reactive dyes

In this study, the effects of polycarboxylic acid sodium salt on the dyeing of cotton with reactive dyes were evaluated by measuring and comparing the K/S values and dyeing fastnesses of the dyed cotton fabric samples. Results showed that the K/S value and dyeing fastness of cotton fabrics dyed with polycarboxylic acid sodium salt, substituting inorganic salts as exhausting agent were close to that of with sodium chloride when dip‐dyeing process was used. While, in pad‐dry dyeing, the K/S value of cotton fabric samples dyed with polyacid salts as exhausting agent was higher than that of with sodium sulfate, and the dyeing fastnesses of these samples were nearly the same. The dyeing mechanism of cotton fabric with reactive dye, using polycarboxylic acid sodium salt as exhausting agent was analyzed. The dyeing exhausting mechanism of reactive dye seems different when the inorganic salt and polycarboxylic acid sodium salt were used as exhausting agent in the dyeing of cotton fabric with reactive dye. The polycarboxylic acid sodium salt, as weak electrolyte, increased the dye‐uptake of reactive dye on cotton fabric not only by screening negative charges on cotton surface, but also by the effect of salting‐out or hydrophobic combination. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Dyeing properties of net‐modified cotton fabric with triazine derivative containing the multireactive and multicationic groups

Cotton fabric was modified with a 1,3,5‐triazine derivative containing the multireactive and multicationic groups, 2,4,6‐tri[(2‐hydroxy‐3‐trimethyl‐ammonium)propyl]‐1,3,5‐triazine chloride (Tri‐HTAC). Compared with unmodified cellulose, the net‐modified cotton cellulose has different dyeing properties. The modified cotton was dyed with reactive dyes without the addition of salt. The color yield was higher than that on unmodified cotton, despite the addition of large amounts of salt in the latter case. After dyeing, compared with unmodified cellulose with reactive dyes, the reflectance spectrums of modified cotton did not change. The modified cotton got better wash fastness than the unmodified cotton. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4388–4392, 2006     

Waterless dyeing of polylactic acid with disperse dyes using decamethylcyclopentasiloxane as medium

Polylactic acid (PLA) fibre as a new generation of eco-friendly polyester fibre is expected to substitute polyethylene terephthalate (PET) fibre to be an important textile fibre raw material. However, there exist severe strength loss and light dyeing colour by the traditional water bath dyeing method, which seriously affect the promotion and application of PLA fibre in the textile fields. Therefore, it is necessary to study waterless dyeing method for PLA. Decamethylcyclopentasiloxane (D5) possesses excellent physical and chemical properties with the characteristics of odourless, non-flammable, and stable to various chemicals, which has been studied to be used as a waterless dyeing medium for PET fabric. In this study, D5 was selected as the medium to study the waterless dyeing process and properties for PLA. The effects of disperse dye dosage, dyeing temperature, dyeing time and liquor ratio on the dyeing properties of PLA fabric were investigated. The results showed that the optimal dyeing process conditions were as follows: the dye dosage was 4%, dyeing temperature and time were 120°C and 40 min, respectively, and the liquor ratio was 1:10. Then PLA was dyed by three different colour disperse dyes using the optimal process which were compared with the traditional water bath. The results showed that the properties of dyed PLA fabrics with D5 could reach the dyeing effect of the traditional water bath method, while causing less influence on its mechanical property. Therefore, this research proved that D5 can be used as a dyeing medium for PLA fabric to substitute the traditional water bath dyeing.     

Influence of different preparation and dyeing processes on the physical strength of the Ingeo† fibre component in an Ingeo fibre/cotton blend. Part 1; Scouring followed by dyeing with disperse and reactive dyes‡

A study has been conducted to examine the effect of different preparation and dyeing processes on the physical strength of the Ingeo fibre component of an Ingeo fibre/cotton blend. An alkaline scouring process (for the cotton), followed by a two‐bath, two‐stage dyeing process in which the Ingeo fibre underwent a simulated dyeing with disperse dyes, followed by the cotton being dyed with reactive dyes, caused minimal deterioration to the strength of the Ingeo fibre. However, it is considered that problems might arise if the Ingeo fibre was subjected to prolonged dyeing times, particularly at neutral or alkaline pH, e.g. if an excessive number of shading additions needed to be carried out.     

Deep‐coloured polyester/cotton blends with low concentrations of polymethylol dyes by a one‐pass continuous dyeing process

An obvious limitation of the one‐pass continuous dyeing process for polyester/cotton blends is its inability to achieve deep colour depth, which is caused by the low dye fixation yields of commercial reactive dyes. In this study, the performances of polyester/cotton blends dyed with high‐fixation polymethylol dyes and disperse dyes were compared with those of polyester/cotton blends dyed with a mixture of reactive dyes and disperse dyes. Polymethylol dyes were observed to be suitable for dyeing polyester/cotton blends when used in low concentrations; the required concentrations of polymethylol dyes were only 23–58% of the concentrations of commercial reactive dyes required to reach a given colour level on polyester/cotton blends. The wash and crocking fastness of polyester/cotton blends dyed with polymethylol dyes were similar to those of polyester/cotton blends dyed with reactive dyes.     

双一氟三嗪活性染料的染色方法与染色性能

合成了一支含双一氟三嗪活性基团的活性染料并应用于棉纤维的染色。详细考察了染色温度、固色温度、加碱量以及加盐量对其染色结果的影响。结果表明,在染色温度90℃,Na2SO4用量70g/L,固色温度40～60℃,碱量（Na2CO3）0～3 g/L时染料的固色率可以达到87%。与同结构的含双一氯均三嗪活性染料相比,含氟活性染料的固色率提高13.5%。该染料具有较好的各项牢度性能。     

Exhaust dyeing of polyester‐based textiles using high‐temperature–alkaline conditions

The factors affecting the dyeability of polyester‐based textiles with disperse dyes in an alkaline medium were studied. It was found, for a given set of dyeing conditions, that (a) the appropriate conditions for attaining a higher color yield were 45 min at 130°C with pH 9 using a material‐to‐liquor ratio of 1/10; (b) increasing the Diaserver® AD‐95 concentration to 2% ows (based on weight of substrate) as well as including triethanolamine to 2% ows in the dyeing formulations bring about a significant improvement in the dye uptake; (c) both a preheat setting from 160 to 200°C/30 s and an alkaline weight reduction have a positive impact on postdyeing with the used disperse dye; (d) the extent of dye uptake as well as the color strength are governed by the type of substrate, that is, knitted fabric > spun yarn > woven fabric, nature of the dye stabilizer, that is, EDTA > Diaserver® AD‐95 > Tinoclorite® CBB > citric acid > none, as well as kind of the disperse dye; (e) direct reuse of the disperse dyebaths, without reconstitution, in the dyeing of the used substrates was shown to be feasible in a single shade and in the reverse‐order dyeings (dark → light); (f) one‐bath, one‐step exhaust dyeing of polyester/cotton‐knitted fabric using selected disperse reactive dyes combinations under high‐temperature alkaline conditions is feasible; and (g) the color and fastness properties of the resultant dyeings depend on the type of the used auxiliaries, in addition to the nature of disperse/reactive dyes combinations as well as compatibility with other ingredients. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3563–3573, 2003     

One‐bath dyeing of polyester/cotton blends with disperse and bis‐3‐carboxypyridinium‐s‐triazine reactive dyes. Part 2: Application of substantive reactive dyes to cotton at 130 °C and neutral pH†

An earlier paper reported that the reactive dyes (not the disperse dyes) were responsible for the inability to achieve heavy depths of shade, when dyeing polyester/cotton blends by a one‐bath process at 130 °C and neutral pH using reactive dyes containing a 3‐carboxypyridinium‐s‐triazinyl group. It was shown that the poor colour yield of the bis‐3‐carboxypyridinium‐s‐triazine reactive dyes was because of their low exhaustion level at 130 °C and pH of 7.0–7.5. We now report the synthesis and evaluation of some bis‐3‐carboxypyridinium‐s‐triazine reactive dye structures, possessing highly substantive chromophores, as a means of obtaining high colour yield, on 100% unmercerised cotton, under the specified dyeing conditions. The technical performance of these dyes under such conditions was compared with that of selected Novacron (Cibacron) LS and Procion H‐E dyes, applied under their recommended (atmospheric) dyeing conditions.     

Single-step dyeing and finishing treatment of cotton with 1,2,3,4-butanetetracarboxylic acid

A single-step dyeing and finishing (SDF) process was developed to eliminate dyeing problems associated with cotton crosslinked by polycarboxylic acid such as 1,2,3,4-butanetetracarboxylic acid (BTCA). This process consisted of several steps: (a) impregnation of the fabric by the bath containing BTCA, dye, and catalyst; (b) drying; and (c) curing at high temperature. Color strength (K/S) and dye fixation of cotton treated by the SDF process were excellent, especially with reactive dyes containing mono- or dichlorotriazinyl compounds and, in some cases, were higher than those of the sample dyed by a conventional batch process without finishing treatment. The presence of dye in the SDF process did not interfere with crosslinking of cotton. We believed that the reaction occurred between carboxyl groups of BTCA and s-triazinyl groups in reactive dyes in the presence of imidazole and other catalyst. FTIR, Raman, and X-ray fluorescence spectroscopies were used to confirm the mechanism of dye fixation. Elemental analysis also supported this mechanism. The SDF process can be an excellent way to dye fabric that also requires crosslinking treatment for smooth drying appearance. © 1994 John Wiley & Sons, Inc.     

Effect of Sandospace R on the dyeability of gamma-irradiated wool,wool/polyester and polyester fabrics with some disperse dyes containing amino groups

The effect of Sandospace R on the dyeability of gamma-irradiated wool, wool/polyester and polyester fabrics towards disperse dyes has been investigated. The effects of the different factors that may affect the colour yield of the dyed samples (such as radiation dose, Sandospace R concentration, pH strength of the dye bath, dye concentration, dyeing temperature and time were studied. In general, and regardless of the studied factor, the irradiated fabric showed a significant dye affinity for the disperse dyes employed compared/to the unirradiated fabrics. However, the different fabrics irradiated to a dose of 2Mrad showed the highest colour strength with a high level of dyeing. Also, it was observed that a concentration of Sandospace R as low as 0·5% effectively enhances the dye affinity for the disperse dyes used here. Moreover, it was found that the pH of the dyeing bath at which the highest colour strength obtained was 3. Increasing the dye concentration up to 4% based on fabric weight, caused a significant enhancement in the colour strength, whilst raising/the dyeing bath temperature from 60°C to 100°C appreciably accelerated the rate of dye uptake. Complete exhaustion absorption of the disperse dye occurred over a period of 2h. © 1998 Society of Chemical Industry     

Dyeing properties of novel electrolyte‐free reactive dyes on cotton fibre

A series of electrolyte‐free reactive dyes containing two quaternary ammonium salt groups as soluble moieties and one epoxy structure as the reactive group have been synthesised. The structures of the synthesised dyes were confirmed by Fourier Transform–infrared, proton nuclear magnetic resonance and elemental analysis, and their dyeing properties on cotton were studied using an electrolyte‐free dyeing process. The results indicate that electrolyte‐free reactive dyes with these structures give a high exhaustion rate, a high fixation rate and good build‐up properties on cotton. Fastness properties were, in general, also very good. The optimal dyeing process of these electrolyte‐free dyes for cotton fibre was 60 °C with 20 g/l sodium carbonate.     

One‐bath union dyeing of wool/polytrimethylene terephthalate blends†

The one‐bath dyeing of blends of polytrimethylene terephthalate (PTT) staple and wool has been investigated. The exhaustion of selected Terasil disperse dyes on PTT fibre and Lanasol reactive dyes on wool was measured as a function of temperature, together with the cross‐staining of the Terasil dyes on the wool component and the Lanasol dyes on PTT component. Most Terasil disperse dyes achieved satisfactory dye uptake on PTT at 110 °C, whereas on conventional polyester (polyethylene terephthalate) temperatures of up to 130 °C are required. An optimised union‐dyeing technique for wool/PTT blends was developed which minimised the staining of Terasil disperse dyes on wool and produced dyed goods with high levels of wet colour fastness. Carriers were not required to enhance the dyeability of PTT at low temperatures. The wool component appeared to be protected against damage at 110 °C by the reactive dyes. The results indicate the potential for blending PTT fibre and wool to produce fabrics that are easier to dye at lower temperatures than conventional wool/polyester blends.