Modeling the deposition of fluorescent whitening agents on cotton fabrics

The adsorption of two widely used fluorescent whitening agents (FWAs) on unbrightened cotton fabrics has been investigated as a function of temperature, hardness of the wash liquor, initial concentration of FWA in solution, and fabric to wash liquor ratio. Sorption efficiencies of FWAs have been studied using a UV spectrophotometry technique. A mechanistic model has been developed to describe the dissolution process of FWAs, convective mass transport into the fabrics, diffusion in the stagnant layer to the fabrics' surface, and adsorption of FWAs on cotton fabrics. Dual porosity of the fabrics (inter‐yarn and intra‐yarn porosity) has been considered by allowing two different regions (outer and inner areas of the cotton fabrics) where FWAs molecules can diffuse and adsorb. Good agreement between experimental and predicted whiteness benefit by the proposed mathematical model has been observed for the range of variables considered. © The Authors AIChE Journal published by Wiley Periodicals, Inc. on behalf of 2017 American Institute of Chemical Engineers AIChE J, 64: 1305–1316, 2018     

Effect of fiber substrates on appearance and removal of aged oily soils

Aging of oily soils produces difficult-to-remove yellow stains on fabrics. This study examines the effect of different textile substrates on yellowing and removal of aged oily soils. Model oily, squalene and artificial sebum, were aged at 40°C on cotton, nylon, and polyester fabrics for 8 wk. Radiotracer and spectrophotometric analyses were used to quantify volatilization and color change of soiled fabrics upon aging as well as soil and color removal after laundering. Differences in volatility of oils from three substrates were insignificant, although cotton and nylon fabrics produced significantly more yellowness than polyester fabrics. Aging of oily soil enhanced detergency from all three fabrics. The largest increase in removal upon aging was found with cotton. Difference in removal from the three substrates became very small after aging. The effect of substrate was pronounced on yellowing due to aging with cotton and nylon having higher yellowness indices. Cotton visually appeared to be cleaner than indicated by the actual amount of residual oil present after washing, whereas nylon had less residual oil present even though it visually appeared more yellow than cotton. For polyester, the amount of residual oil correlated well with appearance after washing. We conclude that discoloration mechanisms differ among cotton, polyester, and nylon substrates. For polyester, discoloration is solely discoloration of oily soil that is physically bound in the fibrous structure, whereas for cotton, discoloration is a result of discoloration of oil as well as additional yellowing caused by retention of chromophores chemically bound to the cotton substrate. In the case of nylon, yellowing of nylon itself is an additional factor contributing to yellowness even though, most of the oil is removed upon washing. These results illustrate the importance of the method of detergency evaluation. Measuring color change in yellowness or reflectance is not the same as oil removal based on a quantitative measurement of soil mass. Thus, it may be necessary to measure both color and quantity of residual soil.     

Improvement of cotton cloth soil removal by inclusion of alkaline cellulase from Bacillus sp. KSM-635 in detergents

Alkaline cellulase from Bacillus sp. KSM-635 (EC 3.2.1.4) had reproducible detergent effects on cotton cloth that was artificially or naturally soiled with oily and/or particulate matter, under European washing conditions. The detergent effects of the cellulase, in combination with surfactants, apparently were the result of enzymatic action on amorphous regions of cotton fibers in which soil was trapped. The contribution of cellulase to soil removal increased as (i) the amount of soil in the amorphous regions of fibers in test fabrics was increased and (ii) the inhibition, by soil that adhered to the fibers' surfaces, of the action of the cellulase on fibers was reduced. Alkaline cellulase had the potential to replace, in part, both surfactants and zeolite in detergents, and it reduced washing time and allowed washing at lower temperatures under European washing conditions. The marked detergent effect of cellulase on naturally soiled cotton fabric was visually apparent, and it inhibited the accumulation of ash, calcium, and other inorganic components on cotton fibers during wash-and-wear cycles. These contributions of cellulase to the cleanliness of cotton fabrics were clearly increased by repeated wash-and-wear cycles. Cotton fabrics were not degraded by washing with the cellulase because effective hydrolysis by the cellulase occurred only in the amorphous regions of cotton fibers.     

Polyimide-coated fabrics with multifunctional properties: Flame retardant,UV protective,and water proof

Multifunctional technical textiles are of great interest both by industry and academia and these products are considered as high value-added products that contribute to the economies of countries. In this study, polyamic acid (PAA) was synthesized through polycondensation of pyromellitic dianhydride (PMDA) and 4,4′-oxydianiline (ODA) in dimethyl acetamide (DMAc) at low temperature. Then, PAA was coated onto woven cotton and polyester fabric by padding technique. Finally, polyimide (PI)-coated multifunctional cotton and polyester fabrics were obtained by an easy coating technique and low-temperature imidization. Thus, low cost, easily accessible and widely used cotton and polyester fabrics were converted to high-performance textile products, which are flame retardant, UV protective, acid resistant, and waterproof. The chemical, thermal, morphological, optical, mechanical, wettability, chemical resistance, and flame retardancy properties of developed fabrics were investigated. Optical results showed that both PI-coated cotton and polyester fabrics are UV-A protective compared to noncoated fabrics. Moreover, PI-coated samples have high contact angles which are 111.43° and 113.40° for PI-coated cotton (PI-c-C) and PI-coated polyester (PI-c-PET), respectively. Young's modulus of PI-c-PET fabrics increased four times more than noncoated polyester fabric. PI coating changed the burning behavior of both cotton and polyester fabrics in a positive way. All the test results showed that these developed multifunctional textile products might find an application in different industrial areas such as automotive, aerospace, protective clothing, and so on due to easy and inexpensive production techniques and also superior properties. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47616.     

Flame retardant finishing of the polyester/cotton blend fabric using a cross‐linkable hydroxy‐functional organophosphorus oligomer

Blend fabrics of cotton and polyester are widely used in apparel, but high flammability becomes a major obstacle for applications of those fabrics in fire protective clothing. The objective of this research was to investigate the flame retardant finishing of a 50/50 polyester/cotton blend fabric. It was discovered previously that N,N′‐dimethyloldihydroxyethyleneurea (DMDHEU) was able to bond a hydroxy‐functional organophosphorus oligomer (HFPO) onto 50/50 nylon/cotton blend fabrics. In this research, the HFPO/DMDHEU system was applied to a 50/50 polyester/cotton twill fabric. The polyester/cotton fabric treated with 36% HFPO and 10% DMDHEU achieved char length of 165 mm after 20 laundering cycles. The laundering durability of the treated fabric was attributed to the formation of polymeric cross‐linked networks. The HFPO/DMDHEU system significantly reduced peak heat release rate (PHRR) of cotton on the treated polyester/cotton blend fabric, but its effects on polyester were marginal. HFPO/DMDHEU reduced PHRR of both nylon and cotton on the treated nylon/cotton fabric. It was also discovered that the nitrogen of DMDHEU was synergistic to enhance the flame retardant performance of HFPO on the polyester/cotton fabric.     

Mechanistic Studies of Particulate Soil Detergency: II: Hydrophilic Soil Removal

In this work, the removal mechanism of kaolinite and ferric oxide (model hydrophilic particulate soils) from hydrophilic (cotton) and hydrophobic (polyester) fabrics was studied using three surfactant types: sodium dodecyl sulfate (SDS), octylphenol ethoxylate (OP(EO)10), and cetyltrimethylammonium bromide (CTAB). This work investigated the relations between zeta potential, surfactant adsorption, contact angle, solid/liquid spreading pressure, and dispersion stability in washing solutions as compared to detergency performance and antiredeposition as a function of surfactant concentration and pH level. The SDS showed the best detergency for both particulate soils, followed by OP(EO)10, with CTAB being the least effective surfactant. For SDS, the electrostatic repulsion between fabric and soil was found to be the dominant force for hydrophilic particulate soil removal. For the nonionic surfactant OP(EO)10, electrostatics are also important and steric effects aid particulate soil detergency. Electrostatic forces and solid/liquid interfacial tension reduction aids CTAB detergency. These same detergency mechanisms have previously been found for the case of hydrophobic soil removal from fabrics. Dispersion stability did not prove to be a dominant mechanism governing particulate soil detergency. From the SEM photos of soiled fabric, ferric oxide attaches to the fabric surface with no entrapment between fabric yarns; moreover, ferric oxide tends to form larger aggregates on cotton compared to polyester fabric. The adhesion of larger particles is hypothesized to be weaker than the smaller ones. Therefore ferric oxide can be more easily removed from cotton fabric than polyester. The SEM photos for kaolinite show little visual difference in particle agglomeration on polyester compared to cotton. Removal of kaolinite from cotton was found to be higher than from polyester, but there is less difference than for ferric oxide.     

负载织物对纳米TiO2光催化剂净化氨气性能的影响

制备了纳米光催化剂悬浮液,借助后整理工艺对3种织物进行负载加工,并利用X射线衍射仪(XRD)和扫描电镜(SEM)等对其进行了表征. 通过自行设计的小型环境舱和光催化反应器重点考察了棉机织物、涤纶机织物和涤/棉混纺机织物对纳米光催化剂净化氨气性能的影响,并比较了在不同负载织物表面上纳米光催化剂的活性. 结果表明,负载纳米光催化剂的棉织物的氨气净化性能高于负载纳米光催化剂的涤纶织物和涤/棉混纺织物的氨气净化性能. 在负载Ag-TiO2光催化剂的条件下,负载涤纶织物和涤/棉混纺织物对氨气的净化性能有所加强.     

不同白度测试仪器在荧光增白剂增白性能评价上的差异

此文选用不同色谱纯度的荧光增白剂C.I.220（APC）,分别采用染纸和染布两种方法来评价其增白性能.采用分光测色仪、色差计和白度仪中的相应白度指标对被增白的纸张和棉布进行测试,通过对实验数据的分析,发现分光测色仪是评价荧光增白剂增白性能的适宜仪器,对纸张来说应用白度指标来衡量荧光增白剂的增白性能更适宜,对于棉布来说应用白度和增白强度来衡量荧光增白剂的增白性能均适宜,对于APC来说,染纸法更适宜于评价其产品应用性能.     

涤棉织物化学回收工艺研究

以废旧涤棉织物为原料,乙二醇(EG)为醇解剂,通过改变醇解时间、醇解温度、EG/废旧涤棉织物中聚对苯二甲酸乙二醇酯(PET)质量比(mEG/mPET)、催化剂种类及用量等研究了蓬松态下废旧涤棉织物的醇解工艺,以及醇解过程对涤棉织物中棉纤维性能的影响。结果表明:随着醇解时间、醇解温度的提高,mEG/mPET的增大,涤棉织物的醇解程度增大,各参数达到一定程度后醇解程度基本不变;最佳醇解工艺为涤棉织物中mEG/mPET为2/1,催化剂用量为涤棉织物中PET质量的0.30%,醇解温度196℃,醇解时间1 h;在乙酸锌、碳酸钠、乙酸钾、氯化镁4种催化剂中,碳酸钠综合催化效果最佳;经醇解过程后涤棉织物中棉纤维表面变得粗糙,力学性能有较大下降。     

Untersuchung über die Wirkung enzymatischer Vorwaschmittel

Investigation on the Action of Enzymatic Prewashing Agents Sections of Krefeld standard cotton fabrics were uniformly soiled with blood, condensed milk, cocoa and egg yolk. After varying storage periods and denaturating treatments the soiled fabrics were soaked in or mechanically prewashed with enzyme-containing and enzyme-free solutions. Finally, a boiling and a peroxide bleach followed. The effect of enzyme-containing and enzyme-free washing agents on the soil removal was checked by measuring the degree of whiteness and protein content. The degree of whiteness provides information of limited use, whereas, extensive conclusions on the washing agent can be obtained from the protein determinations.     

Microbial detection,surface morphology,and thermal stability of cotton and cotton/polyester fabrics treated with antimicrobial formulations by a radiation method

Cotton and cotton/polyester fabrics were treated with a proposed antimicrobial formulation based on zinc oxide (ZnO), Impron MTP (binder), and Setamol WS (dispersing agent) under the effect of γ irradiation. The effect of this treatment on the growth of certain bacteria (Bacillus subtilis) and fungi (Aspergillus niger) was studied. In general, it has been confirmed that ZnO ratio is an inhibitory factor on the growth of both microbes. As a result of treatment of cotton fabrics, as an example, the B. subtilis counts were decreased by 4 log cycles whereas the A. niger count was decreased by 2 log cycles. This finding was illustrated by observing the surface microstructure of the fabrics after they had been buried in a moist soil for two weeks. The deterioration in the weaving structure of the nontreated was so strong that it could not distinguish the strings forming the fabric. On the basis of microbial detection, it was found that the treatment with ZnO formulation causes a net reduction in the bacterial cells amounts to 78 and 62% in the case of treated cotton and cotton/polyester fabrics while the net reduction in the fungi was calculated to be 80.7 and 32%, respectively. However, it was found that the treatment with ZnO formulation caused a reduction in the thermal stability of the fabrics as indicated by thermogravimetric analysis. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2604–2610, 2003     

Metal complexes of natural and synthetic fabrics grafted with vinyl monomers by gamma irradiation

Graft copolymers of natural and synthetic fabrics with acrylic acid (AAc) prepared by gamma irradiation were transformed into metal complexes of the divalent metal ions of cobalt, nickel, and copper. The factors that affect the grafting process without affecting the physical properties of fabrics and homogeneous grafting were studied. These factors involved inhibitor (FeCl₂) concentration, solvent composition, AAc concentration, and irradiation dose. The results showed that the appropriate irradiation dose in all cases was 20 kGy, whereas the inhibitor concentration was 0.1 wt% in the case of cotton and 0.2 wt% in the case of cotton/polyester blend and polyester fabrics. The suitable solvent composition was H₂O (90%)/MeOH(10%) in the case of cotton and H₂O (90%)/MeOH(10%) in the cotton/polyester blend and polyester fabrics. On the other hand, the suitable AAc concentration was 30% in the case of cotton and 50% in the cotton/polyester blend and polyester fabrics. The homogenous grafting and subsequent distribution of metal complexation was illustrated by a method based on the measurement of color parameters. Moreover, the effect of radiation grafting and metal complexation on the water absorption and mechanical properties of fabrics was investigated. POLYM. COMPOS., 2009. © 2009 Society of Plastics Engineers     

Property modifications of finished textiles by a cationic surfactant

Fabrics made of 100% cotton, 100% polyester and a 50/50 cotton/polyester blend with and without functional finishes were treated in aqueous solutions of the cationic surfactant distearyldimethylammonium bromide (DSDMAB). Finishes chosen were dimethyloldihydroxyethyleneurea (DMDHEU), a durable press finish, and poly(acrylic acid), a soil release finish. Selective sorption of the cationic surfactant by finished and unfinished fabrics was quantified. Cotton takes up much larger amounts of DSDMAB than does polyester. In general, acrylic finished fabrics take up more DSDMAB, while DMDHEU finished fabrics take up smaller amounts of DSDMAB as compared to their unfinished controls. These findings indicate that ionic interaction forces play an important role in the sorption process. In order to investigate this, acid numbers were used as a relative measure of negative sorption sites on fabrics. A direct relationship between DSDMAB sorption and the acid numbers of the fabrics was established. Perceived fabric softness is generally improved by treatments with DSDMAB for all test fabrics. Although cotton fabrics finished with DMDHEU were perceived to be less soft than unfinished cotton, treatment with DSDMAB restored the softness level to that of unfinished cotton. The softness of both cotton and polyester fabrics was greatly lowered by the acrylic finish. The presence of even large amounts of DSDMAB did not restore softness ratings to levels comparable to unfinished controls. Electrical resistivity and electrostatic clinging measurements were used to assess the effectiveness of DSDMAB as an antistatic agent. DSDMAB reduced the electrical resistivities of all test fabrics. However, relative humidity played a much larger role in reducting the electrical resistivity of fabrics. Clinging times were also reduced by DSDMAB treatments. DSDMAB was particularly efficient in reducing the clinging time of polyester. Additional moisture related properties were investigated. The presence of DSDMAB on the test fabrics did not significantly alter moisture regain. The application of DSDMAB from aqueous solutions resulted in lower water retention values of the test fabrics after centrifuging at ag-factor comparable to home washing machines. This leads to energy savings during drying from 10–24%, depending on the fabric and finish type. However, energy savings due to fiber type were more significant than those due to the cationic surfactant treatment.     

Reusing textile waste as reinforcements in composites

Polyester (PET) has wide applications in textile industries as textile fiber and its share continues to grow. Substantial quantities of cotton/polyester blend fabrics are disposed every year due to technical challenges, which pose a big environmental and waste‐dumping problem. The aim of this study is to evaluate the potential of discarded cotton/PET fabrics as raw materials for composites. If their inherent reinforcement properties can be used in composites, an ecological footprint issue can be solved. In this study, we investigate three concepts for reuse of cotton/PET fabrics for composites: compression molding above the T_m of PETs, use of a matrix derived from renewable soybean oil, use of thermoplastic copolyester/polyester bi‐component fibers as matrix. All three concepts have been explored to make them available for wider applications. The effects of processing parameters such as compression temperature, time and pressure are considered in all three cases. The third concept gives the most appealing properties, which combine good tensile properties with toughness; more than four times better tensile strength than the first concept; and 2.2 times better than the second concept. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40687.     

Optimisation of Detergent Ingredients for Stain Removal Using Statistical Modelling

Artificially soiled test fabrics are widely used to study the cleaning performance of detergents formulations. In this study, artificial soiled cotton test fabrics were prepared in the laboratory using carbon black as a model soil. Design of experiments was used to optimise the concentration of detergent ingredients for stain removal. A multi‐factorial analysis of variance was used to model the effect of sodium dodecylbenzene sulfonate, nonylphenol ethoxylate, sodium silicate, sodium citrate and sodium carbonate as builders on soil removal. A colourimetric evaluation using the CIELAB system was used to measure soil removal. In general, performance increases with increasing concentration of surfactant, silicate and soda ash.     

Novel hydrolysable azo disperse dyes based on N‐ester‐1,8‐naphthalimide: dyeing of polyester–cotton blends

The dyeing of polyester–cotton blends with new alkali‐hydrolysable azo disperse dyes based on N‐ester‐1,8‐naphthalimide was investigated. Polyester–cotton blend fabrics were dyed using both one‐ and two‐bath methods. Dyes 3 and 4 offered lower colour yield on polyester using the one‐bath method. For the rest of the dyes, employing either the one‐ or two‐bath method resulted in a similar colour yield on polyester fabric. The results for fastness properties and colour yield of the dyeings showed that the dyes were suitable for dyeing polyester–cotton blends using the one‐bath method. The kinetic study of hydrolysis of the dyes in alkali media obeyed the pseudo first‐order reaction rate.     

Optical brighteners as detergent additives

Laundering with brightener-free detergents generally restores, but does not improve, the initial whiteness of soiled white fabrics. Optical brighteners are needed to increase the total spectral radiance, which normally results in better whiteness and an impression of superior cleanliness. Today's quality detergents therefore contain optical brighteners, often at levels higher than 0.5%. The outlay for brightener at this level represents a significant portion of the total raw-material cost. Proper evaluation and selection of brightener systems (1–5) is therefore important. Selection is related to detergent type, laundry habits, fiber content of the wash load, the hue of white preferred by housewives, and other factors. These factors tend to change. For example, in recent years, cold-water washing has become more popular in the United States; the capacity of washing machines has increased; bleach dispensers have been added; more polyamide and polyester, resin-treated cotton and blended fabrics have been introduced; and improved surfactant/builder systems have been developed for detergents. New brightener systems have, of necessity, been adopted. Changes will no doubt continue. The detergent industry will consider these changes carefully and will have to update brightener systems to comply with the new conditions.     

影响荧光增白剂在塑料中增白效果因素的研究

通过测色仪对注塑色板白度测试表征荧光增白剂的增白效果,研究了荧光增白剂在PP、ABS、LDPE中增白效果的影响因素。研究表明,荧光增白剂在各塑料基体中添加量超过一定值时会析出团聚,降低了增白效果,这个过程通过相差显微观察和试样反射光谱曲线加以证实;对比了R型和A型两种TiO2对荧光增白剂增白效果的影响,得出R型TiO2较A型TiO2降低了增白效果,试样白度提升率在ABS和PP中分别降低了45·6%和26·4%;将荧光增白剂的母粒形式与粉体形式的增白效果进行对比,得出母粒添加法试样的白度比粉体添加法试样高5~10的结果。     

Verification Concerning the Relative Superiority of a Cellulosic Fabric with Regard to Polyester in Terms of Flammability

In order to prove the superiority of cotton fabric to polyester with regard to flammability, we have studied the effect of Graham's salt as a moderate and nondurable finish on the flammability of pure polyester and cotton fabric. The laundered bone-dried, weighed fabrics were impregnated with suitable concentration of aqueous Graham's salt solutions by means of squeeze rolls and drying at 110°C for 30 min. They were then cooled in a desiccator, reweighed with analytic precision, and kept under ordinary conditions before the accomplishment of the vertical flame test. The optimum add-on value to impart flame retardancy was about 43.65% for polyester fabric and 36.78% for cotton fabric. The results obtained comply with the Coating Theory. Moreover, the superiority of cotton fabric to polyester fabric in terms of combustibility has been deduced.     

Flame-resistant polyester/cotton fabrics

New experimental results are reported for the modification of 50/50 polyester/cotton blend fabrics made from bromine-free and bromine-containing polyester with a reactive flame retardant compound of high phosphorus content. Reaction of the cotton in the blend with methyl-phosphonic diamide yields modified fabrics in which flame resistance is attained without impairment of fabric hand. The level of flame resistance depends on the amount of insolubilized phosphorus in the treated fabric, but the hand is essentially unchanged even for fabrics of high phosphorus content which pass the vertical test of DOC-FF-3-71. The results of this work provide a basis for improved definitions of future approaches to the development of flame resistant polyester/cotton blend fabrics.