One‐bath union dyeing of a modified wool/acrylic blend with acid and reactive dyes

Pretreated wool/acrylic fibre was obtained by a facile amidoximation process. Fibre characterisation (nitrogen content, tensile strength, shrinkage, infrared spectra and X‐ray diffraction) proved the success of the pretreatment. Union dyeing of wool/acrylic fabrics with acid and reactive dyes, namely CI Acid Red 40, CI Acid Blue 25, CI Reactive Red 194 and CI Reactive Blue 25, was obtained using a one‐bath dyeing process. Different factors that may affect the dyeability of the blend fibre, such as dyebath pH, liquor ratio, temperature, time and dye concentration, were evaluated with respect to the dye exhaustion, fixation, colour strength, levelling and fastness properties. Excellent to good fastness was obtained for all samples, irrespective of the dye used. The result of the investigation offers a new viable method for union dyeing of wool/acrylic fibres in a one‐dyebath process.     

One–bath dyeing of polyester/wool blend with disperse dyes

The present work aims to investigate and develop a one–bath dyeing process for most common blend fibres to replace the conventional two–step process usually applied to dye each fibre constituent separately. The main objectives of the proposed process is the conservation of energy, raw materials, dyes, auxiliaries and labour.     

One‐step dyeing of polyethylene terephthalate fabric,combining pretreatment and dyeing using alkali‐stable disperse dyes

In the conventional dyeing process, polyester and its blended fabrics are usually dyed in a weak acidic medium. In order to reduce cost and improve production efficiency, a new dyeing method – one‐step dyeing of polyethylene terephthalate fabrics, combining pretreatment and dyeing in alkali conditions – was investigated. The alkali‐stable disperse dyes Red 900, Red 902, Yellow BROB and Blue 825 were used to dye polyethylene terephthalate fabrics. The dyeing properties of polyethylene terephthalate fabrics in the case of one‐step dyeing at various pH values or sodium hydroxide concentrations were discussed in terms of colour yield, colour parameters and fastness. The performance of one‐step dyeing using alkali‐stable disperse dyes was excellent. The dyed fabric had good fastness. Wet processing could be combined and shortened. One‐step dyeing of polyethylene terephthalate fabrics could reduce the consumption of water and energy and improve production efficiency. One‐step dyeing of polyethylene terephthalate has potential application in cleaner textile production.     

Preparation of PTT/clay nanocomposites with solid‐state polymerized polytrimethylene terephthalate

To enhance the effectiveness of polytrimethylene terephthalate (PTT) for the preparation of clay‐based nanocomposites by melt intercalation and to upgrade the mechanical performance of these materials, solid‐state‐polymerization (SSP) experiments with neat PTT were carried out at 190, 200, and 210°C prior compounding to increase the average molecular weight and, based on this, the melt viscosity of this polymer. The progress of SSP was registered by time dependent sampling of intrinsic viscosity data. From this, activation energy of 180.6 kJ mol^?1 was calculated. A characteristic sublimate formed during these SSP‐reactions was identified by mass‐spectroscopy to be a mixture of cyclic oligomers containing 2, 3, 4, and 5 monomeric units. The melt viscosity of neat PTT(SSP) could be increased from ～ 460 to 15,000 Pa s^?1. Therefore, tensile strength and Young's modulus were improved by 3.5 and 9%, respectively. Manufacturing of PTT(SSP) and the modified nanoclay was carried out with a corotating twin‐screw‐extruder at 230°C. A concentration of 3% of the inorganic filler component in the composites was aimed at. Compared with the data of virgin PTT, tensile strength, and modulus of the PTT(SSP)‐based nanocomposites could be enhanced by ～ 9 and 40%, respectively. Additionally, a SSP‐reaction of the nanocomposite prepared with non‐pretreated PTT and nanoclay was performed at 210°C to test the robustness of the matrix polymer PTT against the influences of the nanofiller. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

PTT预取向丝的生产工艺

结合聚对苯二甲酸丙二醇酯(PTT)的特性,综述了PTT预取向丝的生产工艺及其后加工技术。PTT的POY纺丝完全可以适应PET和PA的高速纺丝设备,经过认真细致的工艺调试,并对纺丝装备作一些适当的改造,可以实现PTT预取向丝的工业化生产,制得成形良好、性能优异的PTT预取向丝,以便后加工的顺利进行。     

Improved reactive dyeing of wool with novel trifunctional reactive dyes†

The synthesis of a new trifunctional reactive dye is described in this paper by reaction of a di‐chloro‐s‐triazine dye with the specially synthesised amine, N,N’‐bis{2[(2‐chloroethyl)sulphonyl]ethyl}amine. When applied to wool from boiling dyebaths at pH 5, fixation efficiency values of 96% were recorded even at heavy depths (3% owf). In the case of the β‐chloroethyl sulphone group, there is good evidence that elimination to vinyl sulphone occurs readily in mildly acidic dyebaths at the boil. Since elimination is gradual, the reactive species does not form rapidly allowing migration and level dyeing to be achieved.     

聚对苯二甲酸丙二醇酯合成研究

研究了以对苯二甲酸二甲酯(DMT)与1,3 丙二醇(PDO)为原料,采用酯交换、缩聚反应路线合成聚对苯二甲酸丙二醇酯(PTT)。动力学分析表明:酯交换反应在转化率为95%之前,符合二级反应动力学模型。实验结果指出,采用传统催化剂体系当原料配比n(PDO)/n(DMT)=2.2/1时,1gDMT的酯交换催化剂醋酸锌为400～600μg,反应温度为220℃时,酯交换反应速率较快;1gDMT的缩聚催化剂三氧化二锑为500μg,反应温度为265℃,在高真空下,可得较高摩尔质量的PTT。     

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.     

粘度法测定聚对苯二甲酸丙二酯分子质量的研究

采用外推法和一点法测定PTT特性粘度 ,结果表明采用一点法操作较简单 ,并拟合出重均分子质量与特性粘度之间关系式。     

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.     

Non-isothermal dyeing of wool

Kinetic models of the dyeing process are reviewed and diffusion of dye into the fibre is identified as the rate-determining step in most dyeing processes. A simpler approach to defining a linear exhaustion profile of acid dyes on wool fibres is proposed that takes into account non-isothermal kinetic models and analyses their possibilities of use. In this endeavour a novel dyeing rate constant is defined that appears to be characteristic of a particular dye class.     

Differential dyeing of wool fabric with metal‐complex dyes after ultraviolet irradiation

Experiments were conducted to investigate the ultraviolet irradiation of wool fabric as a pretreatment for differential dyeing. Wool fabric was irradiated using a medium‐pressure mercury lamp in order to obtain, on the irradiated area, increased dye uptake under the same dyeing conditions as untreated wool. The chemical modification of the fibre surface as a result of ultraviolet irradiation was confirmed by an increase in metal ion absorption and hydrophilicity, in agreement with Fourier Transform‐infrared–attenuated total reflectance spectra, although scanning electron microscopy showed that the fibre morphology was unaffected. A selection of 1:1 metal‐complex dyes was used to show the maximum colour difference between irradiated and untreated areas of the fabric. The experiments focused on two effects: a double face with the same shade but different depths (greater depth on the treated side), and a double face with different shades. The latter effect was achieved by dyeing the irradiated fabrics with mixtures of acid and metal‐complex dyes. Rubbing and washing fastness evaluations at 50 °C confirmed that the dyeings after irradiation with the selected 1:1 metal‐complex dyes scored identically to conventional dyeings.     

Mechanism involved in the dyeing of wool with an oil‐in‐water microemulsion system

This article investigates the influence of oil‐in‐water (o/w) microemulsions, used as media for both dye solubilization and dye baths, on the dye uptake on fiber surfaces. An acetic acid solution/Synperonic L7/benzyl alcohol microemulsion system was used to solubilize a water‐insoluble antimicrobial natural dye (C.I. Natural Orange 2) and to dye wool fabric at an acidic pH. The results clearly show that the dye exhaustion on the fabric took place mainly when the temperature of the dye bath promoted a change in the molecular organization of the microemulsions with the liberation of the dye solubilized in the oil droplets of the microemulsions. Although uniformly and evenly dyed fabrics were obtained, they showed very low wash fastness. To confirm the mechanism involved and to achieve dyed fabrics with good wash‐fastness properties, two different dyeing methods were also studied. The first method was dyeing at a constant low temperature, at which the o/w microemulsion remained a monophase system; the second one was dyeing at a high temperature, at which it was transformed into a multiphase system. Both the dye exhaustion and wash fastness improved considerably for the fabrics dyed at a high temperature. Moreover, uniform and even dyeing was achieved. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Right‐first‐time production in batch dyeing of wool†,‡

Powder dyes exhibit even more pronounced sorption behaviour than fibres. The moisture content and weight of the dyes and yarns change according to the ambient relative humidity. In this study, the variations determined in dyehouse stores caused weight changes and subsequent dyeings showed differences of Δ□E* and Δ□L* beyond permissible levels. The detrimental influence on the ability to reach right‐first‐time level of acceptance substantially diminishes the profit margin. The consequence for computer colour‐matching should be the integration of the moisture content of dyes and goods in the recipe calculation. From a technological viewpoint, however, it seems preferable to avoid any fluctuation in relative humidity where dyes and goods are stored. The costs incurred for investment in humidity control will pay in the long run and the factor of moisture content may be entirely negligible.     

PTT端羧基含量的影响因素研究

研究了催化剂种类 ,助催化剂用量 ,原料配比 ,稳定剂用量以及缩聚反应温度对聚对苯二甲酸丙二醇酯 (PTT)端羧基含量的影响规律。结果表明 ,端羧基含量随助催化剂用量的增加而降低 ,随着缩聚温度的增加而升高 ,随着原料配比的增加先降低后趋于平衡 ,随着稳定剂用量的增加先降低后升高 ,助催化剂用量宜小于 10 μg/g ;缩聚终温宜小于 2 75℃ ;稳定剂用量宜小于 12 μg/g。     

Microwave‐assisted dyeing of poly(butylene terephthalate) fabrics with disperse dyes

In this study, conventional heating and microwave dielectric heating in the exhaust dyeing of poly(butylene terephtalate) fabrics with disperse dyes were studied in order to determine whether microwave heating could be used to increase the dyeability of poly(butylene terephtalate) fibre in shorter processing times and enable dyeings of adequate wet fastness to be obtained. Accordingly, the samples of 100% poly(butylene terephtalate) single jersey knitted fabric were dyed with CI Disperse Yellow 160 and CI Disperse Yellow 42, CI Disperse Red 177 and CI Disperse Red 91, CI Disperse Blue 79:1 and CI Disperse Blue 54 at 98 °C with or without microwave dielectric heating. The colouristic properties, colour fastnesses and the tensile properties of the dyed fabrics were investigated and compared with each other. Microwave dielectric heating is regarded as a tool for ‘green chemistry’ and provides many advantages over conventional heating without any deterioration in the properties of the dyed materials. Microwave heat dyeing enhances the exhaustion and the fixation of dye, and good colour fastnesses and repeatability in dyeings are achieved in short heating times of the dyebath.     

The effect of liposome on dyeing mohair/wool blends

The aim of this study was to examine the use of liposome in the dyeing of wool and mohair fibres with acid dyestuffs. Soybean lecithin and cholesterol were used to form the liposome membrane utilised in the dyebath. Liposome production was performed according to the thin lipid layer method (Bangham Method) using a rotary evaporator. Two different forms of liposome were used for dyeing wool and mohair fibres. In its first form, liposome was utilised as an auxiliary agent, where it was added to a conventional dyebath at the beginning of the process. In its second form, dyes were encapsulated with liposome and then used in dyeing. The effects of these two different forms of liposome were compared with conventional dyeing. Dyeing was carried out at depths of shade of 0.5%, 1.0% and 2.0% using three different concentrations of liposome (0.33%, 0.66% and 1.33%). An analysis of K/S values, fastness to washing, and the alkali solubility of fibres was conducted. The fibre samples dyed in the presence of liposome exhibited very good fastness to light (grade 8). The wash fastness test results of the liposomal‐dyed samples were significantly better (grade 4‐5) than for those samples which were conventionally dyed. In the presence of liposome, the tensile strength of fibres was 20 gf, whereas it was 11 gf without liposomes.     

Studies on the ultrasonic‐assisted dyeing of poly(trimethylene terephthalate) fabric

Poly(trimethylene terephthalate) fabric was dyed with Disperse Red FB by using ultrasonic power. The effects of ultrasound on the K/S values of the fabric, the fibre structure and the disperse dye were investigated. The results show that the ultrasonic power increases the K/S values of the fabric, disintegrates the large particles of oligomer on the surface of poly(trimethylene terephthalate) fibre into smaller ones and reduces the particle size of the dye in solution. The K/S value of poly(trimethylene terephthalate) fabric dyed using ultrasound is much higher than that without ultrasound, especially when the temperature is over 60 °C. In addition, the adsorption isotherm study shows that the adsorption isotherm can be well fitted by the Langmuir model.     

Linear and nonlinear melt viscoelastic properties of fibrillated blend fiber based on polypropylene/polytrimethylene terephthalate

Polymer Bulletin - This work was aimed at understanding the influence of fibrillar morphology on melt viscoelastic properties of polymer blends containing various blend ratios...