涤/棉针织物染色新工艺与染料助剂的筛选

本文重点讨论了涤/棉针织物一浴法染色新工艺,包括精炼染涤一浴法、练漂染涤一浴一步法、先染涤后棉氧漂一浴两步法、分散/活性一浴一步法、分散/活性一浴两步法。对分散/活性两浴法染色节能工艺也进行了考察。实验结果表明：合理的染色工艺和适当的染化料能很好的保障染色质量,而且对提高生产效率、降低染色成本、减小环境污染都有很大帮助。     

改进涤/棉染色工艺处方克服黄斑初探

本文叙述了克服涤/棉织物用分散/活性染料染色所产生的黄斑。将黄色染色工艺处方用单分散黄代替分散/活性黄;色色用分散/还原红代替分散/活性红;鲜艳的翠蓝等色分散/活性一浴两步法代替分散/活性焙固法,收到了好的效果,满足了内外贸生产的需要。     

锦/棉交织物活性染料一浴法染色工艺的研究

锦纶和棉的染色性能不同，所以锦/棉交织物的同色性染色工艺较为复杂。传统的染色方法是采用分散/活性，分散/直接，酸性/活性等两浴法染色。本文用活性染料对锦/棉织物进行一浴两步法染色。选择pH值4.5-5可以对锦纶染色，在碱性条件下对锦纶不上色或轻微上色的活性染料，首先在酸性条件下对锦纶纤维染色，然后调节pH值到碱性对棉纤维染色，得到了优异的同色性。     

分散/活性一浴一步法染色工艺稳定性研究

涤纶与纤维素纤维染色过去通常采用分散/活性二浴法染色工艺,工艺流程长,设备费用及操作成本高,但染色比较稳定,色光好,牢度高。目前许多厂家采用了一浴一步热熔焙固工艺,此法既简单又经济,效果很好,但常常因分散染料与活料染料在高温条件下与分散剂、碱剂及尿素的互相作用而使染色工艺缺乏稳定性,为此,有必要分析原因并找出相应的措施。     

涤/棉针织物的一浴练染效果探讨

为了分析涤/棉混纺织物一浴练染工艺的可行性,对一浴练染工艺的染色效果进行了探讨。结果表明:涤/棉混纺织物一浴练染工艺中,分散/活性染料二步染色法比分散/活性染料一步染色法更有利于染料的上染、得色量及提升性的提高,有利于色牢度和匀染性能的提高。一浴练染工艺中分散/活性染料二步法的染色K/S值、耐洗牢度、摩擦牢度均与涤/棉传统染色工艺相接近,提升性比传统工艺稍有差距;一浴练染工艺分散/活性染料二步染色法与传统染色工艺比较对色调没有影响;操作误差对一浴练染的重现性影响较小。     

释酸剂在分散/活性高温高压同浴染色中的应用

在T/C混纺织物高温高压同浴染色工艺中,选择有机酰胺、有机酯和有机卤代物为释酸剂与碱剂组成固色盐,使染浴pH在染色过程中随温度升高而降低,提供满足分散/活性染料固色的条件,完成分散活性高温高压的同浴染色。     

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.     

大豆/PTT微胶囊分散染料/活性染料一浴一步法染色

探讨了纯碱和氯化钠用量、染料浓度对微胶囊分散蓝2BLN/活性染料(活性蓝KN-R、活性深蓝B-2GLN和活性蓝K-3RL)一浴法染色大豆/PTT混纺织物表观色深K/S值的影响,测定了不同染色工艺对染色织物牢度的影响.结果表明:当染料总用量为2％(o.w.f.),纯碱用量1g/L,氯化钠用量20 g/L,95℃条件下保温30分钟时,可使大豆/PTT混纺织物获得较高的表观色深.     

涤/棉混纺织物的一浴染色

涤/棉混纺织物的应用愈来愈广泛。但涤/棉混纺织物的染色一般是用两浴染色法,工艺流程长,能耗大,成本高。若把传统的两浴染色改为一俗染色法,可节省时间、能量和降低成本。目前采用两浴法染色的原因,主要是染涤和染棉用的两种染料的性质相差甚远,不适     

涤/棉深墨绿用分散/活性一浴法轧染的工艺探讨

多年来,涤/棉织物深墨绿在染色工艺上一般采用分散/还原一浴法或二浴法轧染及分散/还原二浴法竭染。由于棉上用染料Solanthrene绿F2F(国产还原艳绿FFB)及还原灰BG价格昂贵,因此染料成本高达40～45元/百米。后来,我们选用了还原橄榄绿B、还原蓝RSN及少量还原黄G拼色代替Solanthrene绿F2F及还原灰BG,染料成本降到23元/百米,但色光灰暗且不浓艳,尤其在一浴法轧染中,因高温焙烘使还原橄榄绿B色光变萎,还原蓝RSN常因过氧化或过还原而导致色光萎暗,工艺难以控制,前后色差大,因此我们开始寻找一种既     

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.     

Comparison of different ultrasound support methods during colour and chemical oxygen demand removal of disperse and reactive dyebath solutions by ozonation

In this study, the effects of ozonation, ozonation with ultrasonic bath and ozonation with ultrasonic homogeniser processes on colour and chemical oxygen demand removal properties of disperse (CI Disperse Red 60, CI Disperse Blue 337) and reactive (CI Reactive Blue 171 and CI Reactive Blue 19) dyebath solutions with and without dyeing auxiliaries were investigated. Chemical oxygen demand (in mg/l) and colour (in Hazen) measurements of the studied dyebath solutions were determined. The ozonation process caused simultaneous chemical oxygen demand removal during decolorisation. However, the improvement in chemical oxygen demand reduction was less than of that on decolorisation. The application of the combination of ozonation with ultrasonic homogeniser is the most efficient process and creates a great time advantage over the other process types studied (ozonation alone and ozonation with ultrasonic bath) to reach the same colour and levels of chemical oxygen demand removal.     

Simultaneous afterclearing and decolorisation by ozonation after disperse dyeing of polyester

A set of trials have been conducted to examine the efficiency of ozonation on afterclearing of disperse dyed poly(ethylene terephthalate) fibres. Ozonation was performed in the cooled dyebath after the completion of the dyeing cycle. The ozone concentration used was 12.8 ± 0.3 mg/min at a gas flow rate of 400 ml/min. The results indicate that 3 min ozonation time is appropriate to achieve wash fastness results comparable to conventional reduction clearing. These results were obtained with simultaneous dyebath decolorisation ratios up to 67% and without significant colour yield ( K/S value) losses of the dyed fabric. Ozonation periods exceeding 3 min caused significant colour yield ( K/S value) losses, although dyebath decolorisation ratios increased up to 82% and wash fastness properties further improved. The chemical oxygen demand of the dyeing process decreased up to 62% by the ozonation afterclearing. The advantages of the ozonation afterclearing process are savings in terms of water, energy and time and reduction in environmental load.     

Adsorption of a spent reactive dyebath by a chitosan bed: study of water reuse,bed regeneration,and UV/Fenton oxidation

In the present paper, a facile process combining chitosan bed adsorption and the UV/Fenton advanced oxidation process for treatment and reuse of spent reactive dyebath waste has been developed. The chitosan bed was very effective in decolouring spent reactive dyebath waste by adsorption enrichment of CI Reactive Red 195, and the water and sodium sulphate therein could easily permeate through the chitosan bed and then be recycled. Although the resulting recycled dyebaths were used 10 times as reconstituted dyebaths for dyeing with CI Reactive Red 195, the colour difference and the relative unlevelness index changes of the dyed samples still remained within acceptable levels. That was also true for CI Reactive Blue 19 in the 11th recycling cycle. As a result, an average saving of 60.4% and 93.4% for water and sodium sulphate, respectively, was achieved with the reuse process for the 11 dyebaths. The exhausted chitosan bed can be regenerated three times by dilute alkali without any significant sacrifice of adsorbability or mass. Emissions of the elution concentrates generated from three regeneration runs of the chitosan bed and then treated by UV/Fenton oxidation were found to meet the most stringent emission standards for both chemical oxygen demand and colour in China. Results reveal that the process combining chitosan bed adsorption and UV/Fenton advanced oxidation is promising for treatment and reuse of spent reactive dyebath waste, which can potentially benefit the environment and reduce operating costs.     

Diffusion of disperse dyes into super-microfibres

The disperse dyeing process for polyester fibres is complex. It is characterised by the diffusion-controlled sorption of dyes and depends on dye concentration, dyebath temperature, dye liquor flow rate and fibre count. Moreover, the dyeing properties of super-microfibres are also quite different from those of microfibres or conventional polyester fibres. In this paper the influence of dyebath temperature, initial dye concentration and fibre count on the diffusion coefficient and the sorption isotherms has been studied. The analysis of kinetic properties has been restricted to infinite dyebath conditions. All experimental results have been compared terms of fibre count and dyebath temperature.     

Dye demand/supply ratio as a predictor for the unlevelness of disperse‐dyed polyester

The ratio of the demand for dye by the fibre and the supply of dye by the dyebath is a useful indicator to predict unlevelness in the exhaust dyeing of polyester with disperse dyes, provided that dispersion breakage is small. The ratio can be calculated from the dye exhaustion curve, the dye solubility and the flow rate in the machine. The findings suggest that unlevelness can be successfully controlled by ensuring that dye demand never exceeds dye supply at any moment during the dyeing process.     

Fundamental studies on solvent dyeing with tetrachloroethylene. III. Effect of water added to the solvent dyebath on the diffusion of disperse dyes in poly(ethylene terephthalate)

The diffusion and adsorption of disperse dyes on poly(ethylene terephthalate) (PET) from the tetrachloroethylene (TCE) dyebath were investigated by the method of cylindrical film roll when water was added to the TCE dyebath. The diffusion coefficients of three disperse dyes were increased with an increase in the addition of water to the TCE dyebath, and that of C.I. Disperse Violet 8 showed a peak. The solubilities of water in TCE in the absence and presence of disperse dye were measured at 90°C by Karl Fischer titration. The solubilities in TCE were 0.040 in the absence of dye and 0.041–0.045 g H₂O/100 g TCE in the presence of disperse dye. In the presence of Violet 8, the solubilities showed a peak with increasing addition of water. The effect of water addition on the diffusion coefficients was attributed to the dissolution of water in the TCE dyebath. The water dissolved in TCE brought about an additional swelling of PET swollen previously by TCE. No marked influence on the surface concentration of dye was observed by the water addition to TCE.     

Study on analytical methods for quantifying the non‐adsorbed reactive dye forms in an exhausted dyebath

Reported herein are the results of an analysis of the compatibility of three methods for quantifying the non‐adsorbed forms of reactive dyes, in an exhausted dyebath, of the type monochlorotriazine/β‐sulphatoethylsulphone used in dyeing cellulosic fibres (cotton). The first method is based on spectrophotometric analysis and involves measuring the absorbance of the residual dyebath (after the dyeing process), the second is based on colorimetric analysis and involves measuring the reflectance of the dyed fabric and the third is based on high‐performance liquid chromatography. The purpose of the latter is to identify and quantify the non‐adsorbed dye forms in the residual dyebath. The calculated exhaustion values unequivocally prove the reliability and compatibility of these methods.     

VIS absorption spectrophotometry of disperse dyes

In the investigations of the dyeing processes, the low solubility of disperse dyes in water represents a practical problem for the determination of dye concentration in dyebaths and waste waters. Therefore the use of an organic solvent which, dissolves disperse dyes, is recommended in visible spectrophotometry of disperse dyes. Three organic solvents (ethanol, N,N-dimethylformamide, acetone) and two disperse dyes, the disazo dye C.I. Disperse Orange 29 and the anthraquinone dye C.I. Disperse Blue 56, were used for spectroscopic analysis in this present work. The absorbance of aqueous dye dispersions and various organic solvent dye solutions was measured to evaluate the effect of the solvent on the shape and intensity of the absorption spectra and on the wavelength shift of maximum absorption. The validity of Beer–Lambert’s law in each system was ascertained. A suggestion is made how VIS absorption spectrophotometry can be used to determine the dye concentration in disperse dyebaths. The addition of organic solvent to the dyebath leads to dye dissolution, and the Beer-Lambert’s law is then fulfilled. The optimum ratio between the dyebath dispersion and the organic solvents for the dyes investigated is also determined.     

Study of the removal of a disperse dye stain from a polyester/elastane blend

Polyethylene terephthalate and elastane fabrics were treated with azo disperse dyes in the same dyebath at 130 °C for 0, 30 and 60 min and then reduction cleared. The dyes adsorbed on each fabric were extracted using monochlorobenzene, in order to determine the amount of disperse dye in each of the polyethylene terephthalate and elastane fabrics, as the dyeing time was increased. It was observed that the amount of dye on the polyethylene terephthalate increased, while that on the elastane decreased, as the time at 130 °C increased from 0 to 60 min. After reduction clearing, the partition ratio of disperse dyes between the polyethylene terephthalate and the elastane increased. The dyed polyethylene terephthalate/elastane blend indicated that those dyes, which exhibited high partition ratios (polyethylene terephthalate:elastane), exhibited correspondingly higher wet fastness properties.