Tint Strength Research Articles

Cashew (Anacardium occidentale L) bark extract for eco-safe dyeing of mordanted cotton fabric: Colorimetric and biomedical functional properties

Large volume of wastewater containing toxic chemicals often discharged into the environment by textile industry is adversely damaging the quality of the ecosystem. This study aimed to circumvent this unfortunate practice through replacement of toxic chemical-mordants with eco-safe herbal-mordants in the cashew bark (CB) naturally dyed cotton fabric. The high dye yield obtained within short period of time vindicated microwave (MW) radiator as a cost, time and labor efficient modern heating tool in dye extraction from natural source. The MW-assisted CB dye extract was chosen for dyeing cotton fabric based on its desired properties (like high yield, low moisture content and bulk density). It was discovered that dye exhaustion, dye-uptake and tint strength of cotton fabric were enhanced after 4 min MW treatment. Utilization of calcium (II) chloride (CaCl2) and iron (II) sulfate (FeSO4) as chemical mordants, Vernonia amygdalina and Sorghum bicolor leaf extracts as bio-mordants has given a set of attractive shades (yellow to chocolate). The mordanted CB dyed cotton fabrics have desired dye exhaustion, dye-uptake and tint strength. The good colorfastness and biomedical functional properties of MW induced CB dyed cotton fabric were enhanced to excellent after post-mordanted with the herbal-anchors. Overall, MW treatment and exploitation of herbal-anchors have showcased the cotton natural dyeing process as the potential industrial cleaner, ecological-friendly and sustainable practice.

Catechin-rich reddish-brown dye from cocoa (Theobroma cacao L) leaf for functionalizing herbal-anchored wool fabrics

Colorists are seriously worried about the long extraction time, low color yield and colorfastness of natural dye obtained via conventional extraction techniques. In this study, microwave (MW)-aided extraction technique was exploited as an alternative method to the conventional extraction technique. The cocoa leaf extraction parameters were varied for obtaining optimal extraction conditions. Likewise, dyeing and mordanting parameters were varied for achieving dyed wool fabric with preferred tint strength (K/S) and colorfastness. The colorimetric properties of MW-aided cocoa leaf extract (CL) dyed wool fabrics were compared to those of the conventional extract dyed fabrics. The antioxidant, antibiotic and ultraviolet protection properties (UPP) of un-dyed, MW-irradiated CL dyed and mordanted wool fabrics were evaluated for healthcare functional properties. MW-irradiation enhanced the dye yield by 33.82%, reduced the extraction time by 90% and increased tint yield by 44%. The optimal dyeing conditions were liquor ratio 1:20, pH 6, 45 min dyeing time and temperature of 65 °C. Post-mordanting with 5% Fe2+ and 9% Al3+ as chemical-mordants enhanced K/S and colorfastness of the dyed fabric from good to very good, while 3% neem and 7% moringa bark extract as herbal-anchors improved the dyed fabrics’ K/S and colorfastness from good to excellent. Dyeing enhanced the poor antioxidant and antibiotic properties of MW-irradiated fabrics to excellent, which was further boosted after mordanting process. All the fabrics possess desired UPP. Desired healthcare functional properties of MW-assisted CL dyed wool fabrics after fifth laundry cycle established CL extract as a potential future sustainable colorant for producing healthcare wears.

Stabilization and Dispersion of OSA Starch-Coated Titania Nanoparticles in Kappa-Carrageenan-Based Solution.

Titania is a white pigment used widely in papermaking, paints and cosmetic industries. Dispersion and stabilization of high concentration titania in water-based system remains a great bottleneck in industry nowadays, because aggregation of titania nanoparticles results in severe adverse effects to gloss, opacity, tint strength, color distribution and storage stability of end products. Because kappa-carrageenan (κ-CG) has excellent rheological properties such as emulsification, gelation, stability and so on, it has the ability to form gel and increase the viscosity of aqueous solution. In this work, Octenyl succinic anhydride (OSA) starch was utilized as wall material to encapsulate titania pigments using electrostatic spray drying processing. Transmission electron microscopy (TEM) showed that titania pigments were coated by OSA starch, with a final form of nanoparticle. Accelerating stability test found that around 60% OSA starch–titania particles were stably dispersed in κ-CG-based solution. All materials used in this work were natural ingredient, which would be preferred by cosmetic industry and consumers. The technique used in the present study could potentially be extended to other pigments for similar purpose.

Influence of carbon black trimodal mixture on LDPE films properties: Part1 - DOE

In this study, the influence of carbon black (CB) trimodal mixture, with different medium particle sizes, on the colorimetric and rheological properties of polyethylene was evaluated. Three different types of CB were selected, with particle sizes of 15nm (S), 38nm (M), and 75nm (L) and combined, generating a Design of Experiments (DOE) with 19 formulations to be dispersed at 30% in low density polyethylene (LDPE) in twin screw extruder. Such formulations were evaluated in performance and process properties, such as Tint Strength, Melt Flow Index (MFI), and Total Transmittance (TT). It was observed that the mixtures between small (S) and medium (M) particles developed greater tinting strength and lower viscosity, demonstrating the synergy of the mixture, which was superior in the performance of the mixture containing only a particular of 15nm (S) that would have greater potential for results.

A spectroscopic method for quick evaluation of tint strength and tint tone of titania (rutile) pigment and factors affecting them

AbstractTitanium dioxide (TiO2) manufacturing industries measure optical properties such as brightness, colour, tint strength, tint tone, gloss, scatter coefficient, and others to ensure the quality of the product. Product characterization and process control generally focus on the optical properties, which determine its quality. In this work, titania rutile pigment with varying tint strength and tint tone is analyzed and a correlation is established between particle size and the optical properties such as tint strength and tint tone. It is observed that optical properties of titania pigment depends on the particle size as well as particle size distribution. A relatively faster evaluation of tint strength and tint tone can be made using the reflectance and particle size measurements. Analytical samples were prepared by ultrasonic dispersion of pigment in water containing calgon as dispersing agent. To verify the accuracy of the method, pigment tint strength and tint tone obtained from this study are compared with those resulting from traditional analysis. The results showed that the new method is viable.

Visible Attenuated Total Reflection (ATR): A New Technique for High-Strength Pigment Analyses

A visible-attenuated total reflection (visible-ATR) device was designed to provide a method for directly determining the relative tint strength in high-strength inks. This device showed good reproducibility and the spectra could be correlated to known values of relative tint strength in viscous, highly pigmented inks well within the industry-acceptable error (±5% tint strength). The results of the visible-ATR measurements were compared to those from mid-infrared (mid-IR) and near-infrared (NIR) spectroscopy and the capabilities of those techniques for determining ink strength. Mid-IR analysis was able to directly quantify relative tint strengths, as well as correlating to known values, and to qualify ink products by spectral matching. NIR analysis was able to quantify the tint strength based on the vehicle concentrations in the NIR region. The visible region of the NIR spectrometer was not able to be used for quantification. The vis-ATR and mid-IR spectra showed changes over the time scale of minutes, indicating self-stratification of the pigment and varnish.

Application of microcalorimetry to the study of interactions in coating formulations

Water-based coating formulations contain many components, such as latex binder, pigment, dispersant, thickener, and surfactant. Complex interactions between these components affect properties of the coating in both the wet and dried states. For example, rheology of the paint is dependent on the interactions of components in the formulation. Pigment interaction can affect the degree of dispersion and, therefore, have ramifications on end use properties such as hiding and tint strength of the paint film. Isothermal titration calorimetry has been used to determine the enthalpy of interaction of the coating components. Representative examples will be given to demonstrate structure–property relationships that correlate the interactions of latex, pigment, surfactant, dispersant, and thickener with paint viscosity as well as end use performance parameters such as adhesion and tint strength.

Effect of Carbon Black Morphology on Dynamic Mechanical Properties of Rubber.

Carbon black samples with almost all the same properties (i.e., nitrogen surface area, CTAB surface area, DBP absorption, compressed DBP absorption and tint strength) except aggregate size distribution were tested by disk centrifuge photosedimentometry. The effect of the aggregate size distribution on rubber vulcanizates was evaluated by the dynamic mechanical modulus as a probe. The values of c storage modulus (ΔE') decreased when the aggregate size distribution became broader. This occurred because the ΔE' levels were determined by the aggregate-aggregate interaction, rather than by the carbon black-polymer interaction, when the aggregate size distribution was broader, where ΔE' is the difference between the largest and smallest values of dynamic storage modulus E' observed under the dynamic strain amplitude dependence test.

Water Soluble Polymeric Dyes for Enhaced Stability in Ink Jet Printing

Almost twenty years ago Dr. Dawson of Dynapol Corp. prepared many small samples of polymeric dyes for use as harmless food colorants and non-ingestable pharmaceuticals. The approach was to prepare a suitable polymeric backbone to attach common colorants. Many of these backbones were not workable for attachment of dyes or had stability problems. The approach proved to be much more difficult and costly for the applications proposed. The concept, however was not without merit since polymeric substances often exhibit improved stability over their monomeric counterparts.In this paper we will discuss the general preparation and application of classes of highly water soluble dyes, with high tint strength, for use in ink jet printing. Such factors as viscosity control, molecular weight, spectral properties and image stability will be covered. The use of polymeric dyes was reexamined, because new approaches are now possible and by the use of additives, critical properties can be adjusted.Examples of actual working dyes and their light and heat stabilities will be shown. To compete against existing systems such factors as availability, cost, stability and ease of use, will be presented. Many existing dye structures, with minor modifications, can be used as adducts to polymer backbones and some dyes are suitable without any modification. These chemistries will be illustrated with actual working examples, dye structures will be shown and samples will be available to show solid and solution properties. Because these dye structures are so new, there is limited data on light and heat stability; however the results are so encouraging that the general approach is being made available to have others take up the approach to verify results.Today pigmented inks are being used widely for their superior image stability. However, it has always been known that soluble dyes have a wider spectrum of color available for use and simplicity in the design and trouble free operation of low cost ink jet equipment has perpetuated the use of soluble inks.With soluble polymeric dyes it may be possible to bridge the gap between the stability of pigmented inks and preserve the wide color spectrum of soluble dyes.

From dicopper acetylide to carbyne

Freshly prepared dicopper acetylide, air-aged and Cu 2+ oxidized samples have been studied by FTIR and electronic spectroscopy. There is some evidence about the polymeric and semiconductive nature of dicopper acetylide, and it is proposed to represent this compound by the general formula (Cu2 C2 · nH2O)x in which n=0.5–1 and x is unknown but large. It has been found that upon oxidation, the acetylide ion C22+ in copper acetylide undergoes a coupling reaction with formation of a diacetylene derivative and/or its higher homologues. No definitive evidence about the presence of cumulenic isomers has been found. After hydrolysis of dicopper acetylide in HCl, acetylene (the main product) together with a mixture of polyynes having the general formula H(CC)nH with n=1, 2, 3, 4, 5, 6 has been identified by electronic spectroscopy. The carbonaceous insoluble matter, obtained from aged/oxidized dicopper acetylide, hydrolyzed in HCl is carbyne as indicated by the FTIR band at 2200 cm−1. It has been shown that carbyne is also formed by oxidizing dicopper acetylide with H2O2 in aqueous ammonia suspension (FTIR bands at 2203 and 2139 cm−1), and is recovered as insoluble carbonaceous matter. Carbyne is also formed by thermal decomposition of dicopper acetylide in vacuo. Under these conditions, carbyne is a fluffy, very fine carbon powder having a high tint strength, whose FTIR spectrum shows bands at 2220 and 2200 cm−1 due to triple bond stretching vibrations. Volatile compounds are sublimable from carbyne and have been studied by electronic spectroscopy. © 1999 Society of Chemical Industry

From dicopper acetylide to carbyne

Freshly prepared dicopper acetylide, air-aged and Cu 2+ oxidized samples have been studied by FTIR and electronic spectroscopy. There is some evidence about the polymeric and semiconductive nature of dicopper acetylide, and it is proposed to represent this compound by the general formula (Cu2 C2 · nH2O)x in which n=0.5–1 and x is unknown but large. It has been found that upon oxidation, the acetylide ion C22+ in copper acetylide undergoes a coupling reaction with formation of a diacetylene derivative and/or its higher homologues. No definitive evidence about the presence of cumulenic isomers has been found. After hydrolysis of dicopper acetylide in HCl, acetylene (the main product) together with a mixture of polyynes having the general formula H(CC)nH with n=1, 2, 3, 4, 5, 6 has been identified by electronic spectroscopy. The carbonaceous insoluble matter, obtained from aged/oxidized dicopper acetylide, hydrolyzed in HCl is carbyne as indicated by the FTIR band at 2200 cm−1. It has been shown that carbyne is also formed by oxidizing dicopper acetylide with H2O2 in aqueous ammonia suspension (FTIR bands at 2203 and 2139 cm−1), and is recovered as insoluble carbonaceous matter. Carbyne is also formed by thermal decomposition of dicopper acetylide in vacuo. Under these conditions, carbyne is a fluffy, very fine carbon powder having a high tint strength, whose FTIR spectrum shows bands at 2220 and 2200 cm−1 due to triple bond stretching vibrations. Volatile compounds are sublimable from carbyne and have been studied by electronic spectroscopy. © 1999 Society of Chemical Industry

Reflectometry—A New Method of Measuring Filler Dispersion

Abstract A new method of measuring carbon black dispersion in rubber is presented. This method is based on the measurement of the light reflectivity from the rubber sample using standard equipment used in the evaluation of the tint strength of carbon black (ASTM D3265 procedure). This method can be applied for both uncured and cured samples; however, the uncured sample measurement has significant advantages in the simplicity of the sample preparation and obtaining important filler dispersion information of the compound. It is shown that samples with better dispersed carbon black reflect less light as compared to samples with poor carbon black dispersion.

The use of spherical extenders in VOC compliant coatings

The results of this study clearly show that definite advantages exist with using hollow light density spheres to replace an extender on an equal volume basis. There are additional monetary benefits to replacing TiO2 as seen by the results of the tint strength study. The corrosion study was probably the most convincing display of the benefits of hollow spheres. Almost one-third of the inhibitive pigment was removed while achieving better corrosion resistance at equal volume solids and PVC. The ability to lower VOCs was demonstrated by the equal Stormer viscosity matches possible by removing solvent in the modified formulations. Addition of microspheres alone, which reduced VOCs faster, was not always practical due to the higher PVCs obtained. The overall results show large benefits attributable to the use of spherical extenders which are well worth the investigation.

Usersʼ and Nonusersʼ Evaluations of the CPF 550 Lenses

Thirty-six subjects completed questionnaires on their experiences wearing the CPF 550 lenses. Twenty-six subjects [21 with retinitis pigmentosa (RP)] were users of the 550's and 10 subjects (6 with RP) were nonusers who had rejected the 550's after a trial period. Subjects were asked about such factors as effects on adaptation time, ocular comfort, visual functioning, acceptability of tint strength in various lighting conditions, cosmetic appearance, effects of weather, and replacement intent. Users reported reduced adaptation time in changes of illumination, increased ocular comfort, improved visual functioning with the exception of poor color discrimination, and cosmetic acceptability. Satisfaction with tint strength varied with degree of illumination; usefulness in different types of weather also varied depending on the condition. Nonusers' responses were mixed; they were less likely to report improvements with the CPF 550 lenses compared to the users' group.

A Comparison of Methods for Determining Surface Areas of Carbon Black

Abstract 1. The various tint tests correlate with each other—it does not make much difference which of the three procedures is used. The discrimination between similar blacks is comparable. Specific surface areas obtained by the three methods are comparable and differences appear to be due to experimental errors. (Compare Figures 5–7). 2. Surface areas larger than some 90 to 100 m2/g cannot be reliably determined from tint strength measurements alone. 3. Structure exerts a pronounced effect on tint strength of furnace blacks, especially above 90 to 100 m2/g. Porosity and/or composition are apparently also variables which affect tinting strength. 4. Densichron reflectance on the dry carbon black can be used to estimate specific surface areas up to about 140 m2/g; but, since theabsoluteerrorincreases as the specific surface area increases, this method loses some of its reliability at values above about 110 m2/g. The relative error in reflectance determinations does not vary greatly over the furnace-black range. Densichron reflectance is influenced by composition, evidently due to composition-related differences in optical properties of the carbons. 5. In CTAB adsorption measurements, titration errors and handling errors tend to be rather constant for blacks of different surface area. Hence, CTAB permits better discrimination among blacks of small particle size. 6. The errors in Densichron reflectance surface area increase with specific surface area. Hence, the deviations between CTAB and reflectance surface area which are due to experimental error increase with the surface area of the sample.