30 results about "Mordant" patented technology

Natural turmeric and hibiscus inks were developed for use on fabrics and writing surfaces. Ethanolic extracts of turmeric and hibiscus were obtained and formulated with environmentally friendly mordants such as ferrous sulfate, ascorbic acid, and apple cider vinegar, and thickeners such as linseed oil and aloe vera. These treatments were tested on fabric, filter paper, and notebook paper. Color and color loss were evaluated using the Paint program when exposed to sunlight and washing (in the case of fabric), comparing the RGB and Hex pixel values ​​obtained before and after sun exposure and washing. The degree of similarity was assessed using a digital Color Matcher Tool with the Hex and RGB data. Once the best treatment with the aforementioned mordants was determined, the ink formulation was developed using thickeners such as gelatin, alginate, cornstarch, and honey.It has a pleasing color and good consistency for use on fabric and paper. It's possible to create inks for writing and dyeing fabrics with readily available ingredients, thus contributing to environmental protection.

The invention discloses an environment-friendly dyeing process method for paper products, and aims to solve the problems that a traditional environment-friendly dyeing process is large in chromatic aberration fluctuation, unstable in fastness and poor in adaptability of difficult-to-dye paper types. The method comprises the following steps: establishing a paper physical property database based on near infrared spectrum imaging and liquid absorption rate test; calculating an optimal dye liquor concentration gradient, dipping time and temperature through a dye penetration kinetic model and a Bayesian optimization algorithm; gradient permeation dyeing is carried out in the continuous dye vat array by adopting natural vegetable dye; a tannic acid-chitosan composite cross-linking agent is introduced for bio-based color fixation; and closed-loop self-adaptive adjustment is realized by combining hyperspectral imaging online detection and feedback regulation and control. According to the technical scheme, the dye uptake is remarkably increased to 91% or above, the rubbing fastness reaches 4.5 level, the color uniformity and batch consistency are ensured in high-speed continuous production, no heavy metal mordant exists in the whole process, the biodegradability of wastewater is high, and the clean production requirement is met.

The invention belongs to the technical field of textile dyeing, and particularly relates to an edible plant dyeing method based on ion modified cotton yarn, cation modified cotton yarn serves as a base material, stable fixation of edible plant pigment is achieved through electrostatic adsorption of cation groups and anion pigment, and the method specifically comprises the following steps that S1, the base material is prepared, the method comprises the following steps: weaving a base material by using pure cotton yarns modified by 2, 3-epoxypropyltrimethylammonium chloride, and modifying by immersing 20S-60S pure cotton yarns in a 8%-12% GTA solution according to a bath ratio of 1: 20-1: 30, soaking for 40-60 minutes at a constant temperature of 45-55 DEG C, pre-drying for 15-20 minutes at 80-90 DEG C, and then baking for 2-3 minutes at 120-130 DEG C, so that the zeta potential of the surface of the cotton yarns reaches + 15 mV to + 30 mV; the gram weight of the base material is 450 g / m, the warp density is 80-120 pieces per inch, the weft density is 60-100 pieces per inch, the breaking strength is larger than or equal to 180 N, the elongation at break is larger than or equal to 15%, and no obvious defects exist on the surface. According to the method, stable color fixation is achieved through the ion adsorption effect of the cation modified cotton yarn and the edible plant pigment, tatting jacquard is adopted, chemical color fixing agents and mordants are not needed in the whole process, and the method has safety and excellent dyeing performance.

The invention discloses a folium artemisiae argyi dyed multifunctional cotton fabric and a preparation method thereof, and belongs to the technical field of textile dyeing and finishing. The method comprises the following steps: firstly, carrying out reflux extraction on folium artemisiae argyi by adopting a 95% ethanol solution to efficiently obtain a functional dye with water-soluble and fat-soluble pigments; then, the cotton fabric is pretreated with alum as a mordant, and the pH condition is optimized to enhance binding sites of fibers and dye; and finally, dyeing at specific pH and temperature. The method successfully solves the key technical problem of poor washing fastness in natural dye dyeing, and synergistically endows the cotton fabric with excellent anti-ultraviolet performance (UPF value up to 160.3) and remarkable antibacterial function. The process disclosed by the invention is green and environment-friendly, realizes integration of dyeing and multifunctional finishing of the cotton fabrics, and has a good application prospect.

The present application relates to blood trace detection technical field, specifically relates to a kind of blood trace developing agent and its developing method and application.The blood trace developing agent of the present application includes disperse dye and solvent;The concentration of the disperse dye is 2%~4%, and the solvent is water, methanol, anhydrous ethanol, mordant aqueous solution, glacial acetic acid aqueous solution, glacial acetic acid methanol mixed solution, glacial acetic acid ethanol mixed solution or disperse agent mordant mixed aqueous solution.The blood trace developing agent provided by the present application is widely applicable, can make the blood trace on various different types of object appear, the blood handprint line of appearance is coherent, high definition, object background is not dyed or slightly dyed, line and background contrast is big, with good appearance effect best.

The invention discloses a two-color paste dyeing method for plant dyeing teaching, which belongs to the technical field of dyeing, and is characterized in that a fabric with two-color patterns is prepared from materials such as dye-resistant paste, plant dye liquor, mordant and the like through dye-resistant paste scraping, dye-resistant paste scraping, plant dyeing and mordant dyeing. Especially, the fabric forms a color pattern which is darker than the color of the surrounding area in the area where the dye-resistant paste is scraped. According to the double-color pasting and dyeing method for plant dyeing teaching, the blank that traditional pasting and dyeing are single in color layer is filled up, and a course development mode integrating a traditional process, scientific exploration and art practice is provided.

The invention relates to the technical field of cosmetics, in particular to vegetable dye pigment and hair dye based on an alcohol-water system and an application method of the vegetable dye pigment and hair dye. The pigment comprises a vegetable dye extract; the raw materials of the plant dye extract comprise at least one of madder, pomegranate rind and rheum officinale. Compared with a traditional chemical synthetic hair dye, the hair dye completely adopts natural plant pigments, food-grade mordants, natural substances such as tannic acid, pH regulators and the like, does not contain aniline cancerogens, greatly reduces the allergy risk and irritation to scalp, and is safe to human bodies.

The application provides a functional paper dyed by Ampelopsis grossedentata and a preparation method and application thereof, and belongs to the technical field of dyeing. The raw material of the functional paper dyed by Ampelopsis grossedentata is composed of wood pulp, Ampelopsis grossedentata dye and mordant, wherein the Ampelopsis grossedentata dye is an ethanol aqueous solution extract of Ampelopsis grossedentata. The preparation method of the functional paper comprises the following steps: mixing Ampelopsis grossedentata powder and an ethanol aqueous solution, reflux extraction, combining filtrates, concentration, drying, grinding, and obtaining Ampelopsis grossedentata dye; mixing wood pulp and water, defibrating, separating and squeezing, dyeing by using the Ampelopsis grossedentata dye, and obtaining dyed pulp; sheeting the obtained dyed pulp, drying, and obtaining the functional paper dyed by Ampelopsis grossedentata. The functional paper dyed by Ampelopsis grossedentata provided by the application has good antibacterial effect and antioxidant effect, and has a certain color itself, and has a wide application prospect in product packaging and ancient book protection.

The invention discloses a method for dyeing a polylactic acid fabric. The method comprises the following steps: S1, modifying the polylactic acid fabric by using a modifier; s2, blending deionized water and sodium carbonate to prepare a dissolving solution; s3, coffee grounds are added into the dissolving solution in the step S2 to be fully soaked, suction filtration is performed after extraction, and a coffee grounds extracting solution is obtained; s4, selecting a mordant and performing pre-complexing on the mordant and the coffee residue extracting solution in the step S3 to form a mixed solution; s5, dyeing the polylactic acid fabric modified in the step S1 and the mixed solution in the step S4; s6, the mordant is added again for secondary mordanting, the technological process is simple and environmentally friendly, and the dyeing color depth of the polylactic acid fabric can be effectively improved.

The invention relates to the technical field of tobacco resource utilization, in particular to a comprehensive treatment method of waste tobacco leaves and a dyeing incense thread for cigarettes. The comprehensive treatment method comprises the steps that waste tobacco leaves are smashed and then subjected to plasma treatment; performing reflux extraction on the waste tobacco leaf powder by using an ethanol water solution, and concentrating an extracting solution; diluting the first tobacco extract with water; the cotton fiber yarn pretreated by the metal salt mordant is soaked in the extract diluent for adsorption dyeing, and the dyed fragrant thread for the cigarette is obtained, collecting the residual extract diluent after adsorption dyeing, and concentrating; performing alcohol extraction on the second tobacco extract, performing suction filtration after alcohol extraction, and performing vacuum concentration on suction filtration liquid; and carrying out steam distillation on the tobacco absolute, and collecting organic fractions to obtain the neophytadiene. The method is easy and convenient to operate, high-cost raw materials or equipment are not involved, yarn dyeing and neophytadiene extraction can be achieved at the same time, the purity of the extracted neophytadiene is high, and therefore comprehensive utilization of the waste tobacco leaves is achieved.

This invention discloses a color matching and continuous dyeing method based on multi-source plant dyes, belonging to the field of natural textile dyeing technology. The invention includes pretreatment of natural fabric; extraction of pigments from six natural plants to prepare dye solutions; mixing iron mordant and aluminum mordant in a specific ratio to prepare a composite mordant solution; immersing the pretreated fabric in a single-color dye solution or a color-matching dye solution composed of two or more single dye solutions for dyeing; drying the dyed fabric; spraying the surface of the dried fabric with the composite mordant solution; steaming the sprayed fabric for color fixing; soaping the fixed fabric to remove excess dye; and drying the soaped fabric to obtain the dyed finished product. This invention, by constructing a color matching system based on six natural plant dyes, combining a continuous dyeing process, and employing composite mordant technology, can achieve diversified color matching and improve the bonding strength between dyes and fabric fibers.

This invention provides a black hair dye based on plant extracts and its preparation method. Effective components are extracted from plants such as rice roots, ginkgo leaves, arborvitae, rhubarb, cockscomb, chrysanthemum, mulberry, black tea, green tea, gentian, lichen, and catechu. It contains no harmful chemicals such as common paraphenylenediamine or ammonia. This hair dye enables even coloring of hair. The surfactant reduces the surface tension of the dye system, allowing the plant extracts and other components to disperse more evenly in the solution and better contact with the hair. During the dyeing process, it ensures that each hair strand fully absorbs the dyeing components, achieving a uniform coloring effect and avoiding uneven coloring. The color produced by this invention is natural and long-lasting, which is closely related to the synergistic effect of the plant extracts and the mordant ferrous sulfate. The hair dye of this invention performs better in maintaining color stability, allowing consumers to maintain their ideal hair color for a longer period.

An alternative to BPS-based mordants for use in textile dyeing. The mordant comprises a water-based, bio-inspired co-polymer with cationic moieties that become fixed onto the textile by UV curing. Polymers that can be modified to change solubility, ratios of UV-crosslinkable monomer and charged monomer, the type of charge (either positive or negative) by way of co-monomer selection, as well as blend with other bio-based polymers for color fastness improvement are utilized. A specific example of such a mordant alternative is Vinylbenzylthymine (VBT) which may be used alone or with chitosan in the textile dyeing process.

The invention discloses a formula and a preparation method of a magnesite handicraft antique dyeing solution. The formula comprises the following raw materials in percentage by weight: 100% of water, 1-2% of a penetrant, 0.3-0.5% of a permeation promoter, 0.3-0.5% of a dyeing agent, 0.1-0.3% of an adsorbent, 2-3% of a mordant and 5-8% of a coloring agent. The penetrant is nekal BX, the permeation promoter is table salt, the coloring agent is basic orange, the adsorbent is potassium permanganate, the mordant is ferric trichloride, and the coloring agent is ferrous sulfate. According to the formula and the preparation method of the magnesite handicraft antique dyeing liquid, the proportioning is reasonable, the operation is simple, and the raw materials are low in price. And the antique finishing operation is convenient, and the antique finishing effect of the artware can be achieved without other complicated mechanical equipment, so that the technological level of the artware is on the same level.

The invention discloses a roselle pigment extract for dyeing cigarette paper as well as a preparation method and application of the roselle pigment extract, and belongs to the technical field of cigarette additives. The roselle extract is prepared from a roselle raw material through the steps of alcohol solvent ultrasonic extraction, macroporous adsorption resin purification and the like in sequence, wherein in the purification step, an ethanol solution with the concentration of 65%-75% is adopted for isocratic elution. The extract and a natural mordant (such as a chaenomeles speciosa extract) are prepared into dye liquor, and the dye liquor is applied to cigarette paper, so that functional dyed cigarette paper can be prepared. After the dyed cigarette paper is used for cigarettes, the sweet aftertaste during smoking can be remarkably improved on the premise that the comfort degree of smoke is not affected, the limitation that only color retention and impurity reduction are concerned in an existing natural pigment technology is broken through, and a brand new coloring solution is provided for developing high-end characteristic cigarette products.

The invention provides a natural hair dye and a hair dyeing method. Three natural raw materials, namely mulberry and gallnut, as well as a natural simulated melanin polymer polydopamine, are taken as dye core components, and an ultrasonic-assisted extraction technology is adopted to extract pigment effective components in the natural animals and plants. And carrying out one-bath simultaneous dyeing by combining a mordant through a medium dyeing method. The mordant formula comprises L-cysteine, polyvinylpyrrolidone, a mixed solution of ferric chloride and ethylenediamine tetraacetic acid disodium salt, and a small amount of ammonia water. The dyeing time is set to be 60 minutes, then determining and analyzing the L * a * b * color space value of the hair sample, and evaluating the dyeing effect. Compared with the prior art, the method has the advantages of short dyeing time, simple process, safe and healthy components, long color fixation time and uniform and natural dyeing. The E value after hair dyeing can be stabilized within the range of 76-82, a good hair dyeing effect is shown, and the color of the dyed hair is natural black brown.

The invention relates to the technical field of polyester natural dye dyeing, in particular to a polyester natural dye normal-pressure dyeing method which comprises the following steps: step 1, mixing, heating and stirring choline chloride and oxalic acid dihydrate to prepare a eutectic solvent; step 2, adding a mordant ferric trichloride hexahydrate and a natural dye into the deep-eutectic solvent to prepare a dye solution; step 3, dyeing polyester, washing with hot water, washing with cold water, dehydrating and drying. The deep-eutectic solvent is used as a dyeing medium, and fiber swelling and surface etching are caused by destroying the acting force between polyester molecules, so that the polyester can be dyed under normal pressure. Meanwhile, iron ions are used as a mordant of the natural dye, so that the color yield and the color fastness are improved. The method has the characteristics of being low in dyeing temperature, short in technological process, recyclable in dyeing residual liquid and the like, and has a good application prospect.

The invention belongs to the technical field of printing and dyeing production, and particularly relates to a manual printing and dyeing method which comprises the steps of S1, base cloth pretreatment, S2, layered template preparation, S3, dye-resistant layer drawing, S4, primary dyeing and S5, laminated printing, specifically, layered templates are sequentially aligned to base cloth, dye is scraped or sprayed, and laminated printing is performed. And S6, mordanting and post-processing: mordanting and fixing the dyed base cloth, removing the dye-resistant material, finally cleaning and drying, realizing fine layering and three-dimensional effects which cannot be achieved by traditional blue dyeing through a combined process of three layers of complementary templates, beeswax dye-resistant and ferric salt reaction, and cutting a layering template by adopting laser so as to obtain a three-dimensional layer. The three-time precise superposition of contours, details and textures is realized and is combined with natural dyes, so that the problem of precision of manual alignment is solved, and the problem of dislocation caused by manual operation is avoided.

A method of dyeing a textile, the method including depositing a metal-organic framework (MOF) on at least one surface of the textile thereby forming a MOF functionalized textile; contacting the MOF functionalized textile with a dye thereby forming a dyed textile; and optionally drying the dyed textile. Metal-organic framework functionalized textiles can be dyed with natural dyes effectively with higher dye uptake and colorfastness without the use of traditional mordants.

The invention discloses a bacteriostatic nylon textile and a preparation method thereof, the preparation method of the bacteriostatic nylon textile comprises the following steps: 1) dyeing a nylon textile by using a bio-based dye and / or a natural dye, the bio-based dye and the natural dye containing antibacterial active components; (2) carrying out complexing color fixation on the dyed nylon textile by adopting a mordanting complexing agent, wherein the mordanting complexing agent contains a copper sulfate solution with the mass concentration of 0.5%-3%; and (3) carrying out post-treatment on the nylon textile subjected to complexing and color fixing to obtain the antibacterial nylon textile. The invention further provides a bacteriostatic nylon garment and a preparation method thereof. The prepared nylon garments and textiles have high color fastness and also have excellent antibacterial performance.

This invention belongs to the field of natural plant dyeing technology for textiles, and discloses a method for natural dyeing and composite tie-dyeing color fixing of textiles based on Ningxia red goji berry pulp. This method uses cold-pressed pulp from fresh Ningxia red goji berries as the core dye. The dyeing process involves core steps including goji berry pulp extraction, fabric modification pretreatment, goji berry pulp dye liquor preparation, constant temperature dyeing, composite mordant color fixing, and color-locking and setting. Fabric pre-modification is achieved through a compound of alum and chitosan, combined with a formaldehyde-free cationic fixing agent to construct a composite mordant system. Low-temperature dyeing and baking setting processes are then used to create a three-dimensional cross-linked structure of dye, fiber, and mordant. This method is entirely free of harmful chemical reagents, improving dye uptake and color fastness. The finished product has a rich color and is suitable for various textiles such as cotton, linen, silk, and wool. The color fastness to washing and rubbing reaches level 4 or higher, and the color fastness to sunlight reaches level 3 or higher.

The present application belongs to the field of high-end textile processing and manufacturing, and particularly relates to a full-ecological processing and manufacturing method of functional silk fabric. Curcumin compounds are prepared into a dyeing solution, the silk fabric is immersed in the obtained dyeing solution, the dyeing solution is heated, when the temperature is raised to 65 DEG C to 75 DEG C, luteolin is dispersed in the dyeing solution according to the mass ratio of 3 to 4:1 of luteolin to curcumin compounds, the temperature is raised to 85 DEG C to 95 DEG C and then kept for a period of time, then the silk fabric is taken out from the dyeing solution, washed and dried. The silk fabric dyed by the present application has excellent and durable antioxidant activity and ultraviolet protection performance, and after repeated soaping, it can still reach more than 95% and more than 200 respectively. The problem of non-durable function caused by poor soaping fastness of natural dyeing is solved, and the full-process ecological and environmental protection processing avoids the pollution problem caused by the use of chemical dyes and metal mordant, and has good application prospect.

The invention discloses a dyeing process of a trapa acornis nakai shell natural protein fiber fabric. The dyeing process comprises the following steps: extracting a trapa acornis nakai shell pigment, pre-treating the natural protein fiber fabric, dyeing, fixing color and sizing. Dyeing the natural protein fiber fabric by adopting a direct dyeing method or mordanting method; the mordant at least comprises one of citric acid, plant ash, slaked lime, tannic acid, loess, bentonite, chitosan, alum, copper acetate and melanterite; a direct dyeing method is adopted to realize a good dyeing effect under the action of self acidic dye liquor by virtue of electrostatic attraction, the soaping-resistant color fastness meets the requirements of national standard superior products, and natural protein fiber fabrics and cloth covers are in a brown yellow spectrum range by adopting a mordanting method. Wherein copper sulfate can effectively improve the pigment fixation rate and the fabric color depth in various processes, and all mordants can improve the soaping-resistant color fastness of the dyed fabric to level 3 or above.

This invention discloses a lignin dispersion system, its preparation method, and its application, belonging to the fields of biomass material utilization and textile dyeing and finishing technology. This invention proposes a simple metal-free dyeing strategy. The preparation method of the dye bath includes: adding lignin to an alcohol-water mixed solvent to form a mixed system; heat treatment to disperse the lignin at high temperature; and then cooling to room temperature to form dispersed lignin aggregates in the system, thereby obtaining a lignin dispersion system suitable for fabric dyeing. The dispersion system can dye fabrics at room temperature without the need for metal mordants. Compared with existing technologies, the process steps of this invention are simple, the conditions are controllable, and the resulting fabrics have better dyeing effects and wash resistance.

The preparation method comprises the following steps: fully washing wall-broken ganoderma lucidum spore powder with water, drying, adding into a dilute acetic acid solution, adding ammonia water to adjust the pH value of a solution system to 8-9, finally adding a dyeing cross-linking agent and a mordant, and adding citric acid to adjust the pH value of the solution system to 3-4 to obtain a ganoderma lucidum spore powder dyeing working solution; then, under the ultrasonic action, the tussah silk product is soaked in the ganoderma lucidum spore powder dyeing working solution for padding treatment, finally, washing and drying are conducted, and the dyed tussah silk product is obtained. According to the method, under the cavitation action of ultrasonic waves, the tussah silk structure porosity is combined, dyeing of the wall-broken ganoderma lucidum spore powder on the tussah silk fabric is successfully achieved through the dyeing working solution, the dyeing rate is high, the color fastness to washing is excellent, the antibacterial performance is good, and the technical scheme is suitable for the tussah silk knitted fabric.

The invention discloses a dark color dyeing process for a trapa acornis nakai shell cellulose fiber fabric. The dark color dyeing process comprises the following steps: extracting a trapa acornis nakai shell pigment, modifying the cellulose fiber fabric, dyeing and fixing, and sizing. Dyeing the cellulose fiber fabric by using a mordanting method; the used mordant at least comprises one of alum, copper acetate and ferrous sulfate; the concentration of a trapa acornis nakai shell pigment solution is 5-10 wt% and the bath ratio is 1: (30-50) during dyeing by the mordanting method, heating to 90-95 DEG C from room temperature at the rate of 1-2 DEG C / min, keeping for 45-60 minutes, cooling to room temperature at the rate of 1-2 DEG C / min, and washing with clear water; the dyeing K / S value of the cellulose fiber fabric can be effectively improved by adopting the mordanting method for the modified cellulose fibers, the dye uptake is improved, and the cellulose fiber fabric has good color fastness after being subjected to color fixation treatment.

The application discloses a hibiscus fabric and a preparation method thereof. The fabric is dyed by at least one of natural fiber fabric, chemical fiber fabric and blended or interwoven fabric of natural fiber and chemical fiber with hibiscus natural dye. The hibiscus natural dye is prepared by extracting and purifying hibiscus plant raw material with distilled water or pure water. The dyeing process of the fabric is carried out under the temperature condition below 60 DEG C. The dyeing wastewater can be recycled after treatment. The hibiscus fabric and the preparation method thereof adopt pure water to extract hibiscus pigment, and the dye does not contain heavy metal mordant and chemical synthetic components. The dyed fabric is skin-friendly and non-toxic, and meets the ecological textile standard. Through optimization of the extraction and dyeing process, the dyeing temperature is controlled below 60 DEG C, the damage of high temperature to anthocyanin pigment structure is effectively avoided, the natural color of the hibiscus dye is maintained, and the energy consumption is greatly reduced.

The invention belongs to the technical field of cosmetics, and discloses hair dye based on ampelopsis grossedentata extract and a preparation method of the hair dye. The hair dye is prepared from the following raw materials in percentage by mass: 0.04 to 0.05 percent of a coloring agent, 4.19 to 6.61 percent of a pH (Potential of Hydrogen) conditioner, 91.29 to 94.93 percent of a cosolvent and 0.84 to 2.05 percent of a mordant, the coloring agent is ampelopsis grossedentata extract, the pH conditioning agent is hydrochloric acid, the cosolvent is a Tris-HCl buffer solution, and the mordant is metal salt. The prepared hair dye is simple in process and convenient to use, and hair dyed by the prepared hair dye is uniform in color and good in washing fastness.

The application discloses a kind of natural mordant of dried coriander and its cotton fabric natural dyeing process, belong to textile ecological dyeing and finishing technical field.The application uses dried coriander stem and leaf as raw material, is prepared natural mordant by smashing, water bath extraction, solid-liquid separation.The natural mordant can effectively improve the dyeing rate and color fastness of natural dyes on cotton fabric, while imparting fabric antioxidant, anti-ultraviolet function, and will not damage fabric strength, air permeability and moisture permeability and other wearing properties.The application does not use heavy metal mordant throughout, green and environmentally friendly, raw material source is extensive, process is simple, production cost is low, solves the industry problem that traditional metal mordant pollutes greatly, existing plant mordant dye adaptability is narrow, natural dyeing effect is not good, is suitable for industrialized popularization and application.

The present disclosure relates to the use of a phosphate metal salt of the following formula: (Mz+)n(PO4 3-)m, wherein M is a metal provided that M is not nickel; z is 2 or 3; m is such that (n * z) – (m*3) = 0; as mordant. The invention also relates to a process for mordanting fibers using mordants of formula (Mz+)n(PO4 3-)m, wherein M is a metal, z is 2 or 3 and m is such that (n * z) – (m*3) = 0. The mordants are useful in fibers dyeing process.