An offset printing press is a type of lithographic printing press . During printing, the printed images and text are first printed from the printing plate onto the rubber cylinder, and then transferred to the paper by the rubber cylinder.     Offset printing machines can be divided into sheet-fed offset printing machines and web-fed offset printing machines according to different paper feeding methods; according to the number of printing colors completed in one paper pass, they can be divided into single-color, two-color, four-color and multi-color printing machines; according to the printing substrate The maximum paper format can be divided into small offset printing presses , six-open, four-open, half-open and full-sheet printing presses.   In addition, there are double-sided printing presses that can complete two-sided printing at the same time in one paper pass. Sheet-fed offset printing press is a lithographic printing press , used for printing high-grade commercial prints and packaging prints, and is the mainstream of modern paper printing.   development path   birth   In 1904, Mr. Caspar Hermann of Germany was trying to improve lithographic printing technology, trying to find a new production method through countless experiments. The American Mr. Ella Washington Roubaix got involved in this research work by accident. During a printing job, Ira Washington Roubaix noticed that a piece of paper did not travel along the normal path during the printing process. He tried to print patterns on both the front and back of the paper. The image was first transferred from the printing plate to On the blanket of the impression cylinder , and then onto the paper. An unexpected scenario occurred: This indirect imprinting method produced a product with higher printing quality, and the elastic blanket surface transferred the ink to the paper more evenly. The printing method developed simultaneously by Caspar Hermann and Ira Washington Roubaix was born. This is the origin of what we often call offset printing. They separately designed sheet-fed offset printing equipment, but it was not immediately commercialized. It was not until 1912 that the world’s first web offset printing equipment, Universal, was launched, with a speed of 8,000 sheets/hour, and the offset printing machine was truly recognized by the world.   prototype   In 1911, KBA and Manroland , which had decades of experience in the production of letterpress and gravure printing machines , developed their first offset printing machines. From then on, they began to make more attempts in the field of printing.   In the 1920s, companies such as Manroland, KBA, and Komori all launched their own sheet-fed and web-fed offset printing equipment. In cooperation with related companies, we have developed various automated printing equipment with paper delivery units, refrigeration units, folding and drum drying components.   In 1932, KBA (Radebeul Company) launched the world’s first four-color sheet-fed offset printing press, Planeta-Deca, which took offset printing technology a big step forward.   World War II destroyed many factories, and the development of offset printing technology was also affected, stagnating for more than ten years. In the 1940s, the boom in American newspaper production and mass circulation further promoted the advancement of offset printing technology. After 1945, offset printing made it possible to achieve high quality and high requirements for commercial advertising. In contrast, producing four-color continuous-tone images using letterpress printing techniques became expensive and time-consuming. As the industry’s demand for image and printing quality continues to increase, offset printing technology has made new breakthroughs.   growing up   In the 1950s, printing technology emerged one after another and developed rapidly. The emergence of imagesetters broke the 540-year printing history of movable type typesetting for the first time and led to the emergence of digital image and text typesetting. Especially the emergence of the second generation imagesetters in 1954 made the typesetting technology Go to the next level. In 1956, the emergence of prefabricated photosensitive plates (PS plates) and plate-making equipment made offset printing technology a fish in water. At the same time, the demand for offset printing technology increased significantly. In the 1950s, manroland, KBA, Komori, Akiyama, etc. successively developed their own two-color and four-color offset printing equipment.   In the 1960s, the issue of ink balance during the printing process became the key to the development of offset printing technology. He invented alcohol dampening solution, and since the advent of the Dahlgren continuous dampening system in 1960, offset printing has begun to reach the level of clarity achieved by letterpress printing and compete with mature letterpress printing for the market.   In 1962, Heidelberg launched KOR, an offset printing machine modified from a letterpress printing machine, on drupa, thus entering the offset printing market. The emergence of small offset printing equipment such as KOR, as well as the ABDick350 and 360 series of small offset printing machines, attracted a large number of offset printing machine users. Most of them are small printing companies, which drives the rapid development of offset printing on a global scale. At this stage, various offset press manufacturers continued to launch new offset presses. In 1965, KBA made a huge breakthrough in sheet-fed offset printing technology and produced the world’s first unit-type and double-diameter imprinting and paper transfer machines. Cylinder printing press, this design was adopted and is still the mainstream form of sheet-fed printing press today.   Although the offset printing process had not yet been widely adopted around the world at this time, a considerable number of people had realized that it was a better quality and more accurate printing method.   In the 1970s, commercial printing began to develop vigorously. Printing technology (color printing system) developed towards automatic high-end color separation technology and full-page typesetting design system. It gradually bid farewell to photographic color separation and manual color separation, making color images easier to transmit and Realize “what you see is what you get”. Although the color printing system is expensive and cannot be widely used in printing plants, it has been concluded that it is the future development direction of offset printing technology.   The electrostatic printing introduced by Xerox at that time also pushed offset printing technology to a new level in a sense. The convenience and speed of electrostatic printing are particularly suitable for the needs of short-run printing, forcing printer manufacturers to keep up with market demand and focus on To improve the printing speed and automation of the equipment. Therefore, in the offset printing presses launched during this period, the unit printing press, button control and mechanical automatic ink supply system became standard configurations, and the printing speed was also improved.   At this time, various offset printing rookies continued to appear. In 1971, Akiyama originally designed and developed a 3-diameter impression cylinder and a four-open, four-color machine Hi-Ace426 with a speed of 10,000 sheets per hour; in 1972, Manroland produced the first modular machine Printing press – Rondoset offset press and the first ROLAND 800 sheet-fed offset press with ink compensation control system, its printing speed can reach 10,000 sheets per hour, and the launch of COLORMAN, the largest rotary printing press in Europe at the time; in 1974, Heidelberg Launched the first model of a new generation of printing presses – the Speedmaster 72V four-color offset press ; in 1974, KBA (Planeta) launched the world’s first sheet-fed offset press with eight units.   Rapid development   In the mid-1980s, printing plants began to use computers to control the printing process. Most of the offset presses in this era realized automation of ink transfer, dampening, registration adjustment and plate reading, simplifying operations and improving printing efficiency. The application of computers in offset printing and the advent of film output machines have greatly improved the working efficiency of offset printing machines. Many offset printing machines launched in the 1980s were equipped with ink remote control systems, computer-controlled pre-inking systems, dampening unit control, alcohol-free dampening, color control systems, flipping devices, etc. Representative models include Heidelberg GTO52 and Akiyama HA1P40. , Hi-Ace432 and Bestech32, Komori Riselong L40, etc. as examples. It is worth mentioning that in 1985, KBA produced the Rapida 104, the world’s first split sheet-fed offset press with a printing speed of 15,000 sheets/hour.   In the 1990s, the birth of the direct-to-plate system (CTP) was the most important contribution to offset printing technology, bringing the work efficiency and application of offset printing machines to unprecedented levels. Offset presses are more automated and digital technology is more widely used. The highlight of this period was the GTO-DI, the world’s first on-machine direct-to-plate printing press jointly launched by Presstek and Heidelberg at the Print 91 Chicago Print Show, which represented the future development direction of short-run offset printing. At IPEX 98, the Heidelberg Speedmaster SM 74 DI direct imaging offset press was exhibited for the first time and caused a sensation around the world. Today, these configurations may no longer seem new, but at the time it was comparable to laser printers and met the needs of on-demand color printing. Even on drupa 2000, many printing press manufacturers launched their own DI solutions. In 1997, KBA launched the Compacta 215, the world’s first commercial web offset press that fully adopted shaftless technology, which was also an important breakthrough in the development of web offset presses. Since then, shaftless technology has been widely used in web offset presses. Heidelberg CP Window, the world’s first fully digital printing control system, also met users at drupa1990.   At this stage, the offset printing press products launched by major manufacturers have become more mature and complete, and have begun to develop in the direction of multi-color groups and multi-functions, making multi-color group double-sided printing, connected varnishing and drying no longer just a dream. Manroland launched the Roland 700 and Roland 300, medium-sized machines with a printing speed of 15,000 sheets/hour, and the Roland 900, a large-format sheet-fed offset press with an innovative concept; Komori was the first in the world to develop the Komori fully automatic plate changer (Full-APC) ; The new production line of Heidelberg Speedmaster SM74 offset printing press strives to dominate the four-format (52cm × 74cm) printing market; KBA launches the first ten-color (five-to-five) Rapida printing press; Akiyama designs and develops a unique high-performance roller arrangement , high efficiency, high value-added Jprint type sheet-fed double-sided printing press; Komori developed multi-color double-sided offset printing machine LITHRONE 40SP, etc.   Classification   Offset printing machines can be divided into single-color, two-color, four-color and multi-color printing machines according to the number of printing colors completed in one paper pass. According to the maximum paper format that can be printed, it can be divided into small offset printing presses, six-open, four-open, folio and full-sheet printing presses. In addition, there are also double-sided printing presses that can complete two-sided printing at the same time in one paper pass. According to the dampening system, it can be divided into alcohol machine (that is, the offset printing machine with alcohol dampening version), water truck (that is, the offset printing machine with water dampening version) and waterless offset printing machine.   future   The offset printing technology jointly invented by the German Caspar Hermann and the American Ella Washington Roubaix triggered a complete revolution in offset printing technology. This breakthrough enabled the offset printing technology to develop for a hundred years and occupy the entire The printing industry produces 70% of the market. As a technology that has lasted for a hundred years and is constantly improving, the development of offset printing technology is closely related to the development of the global economy and the progress of mankind. A hundred years of history have made it more mature and exciting.    

Pigments are substances that give colors to objects. Pigments are divided into soluble and insoluble, inorganic and organic. Inorganic pigments are generally mineral substances. Humans have long known the use of inorganic pigments, using colored earth and ores, to paint on rock walls and smear their bodies. Organic pigments are generally derived from plants and marine animals, such as mozambique, garcinia and purple extracted from shellfish in ancient Rome.   Introduction Pigment is a powdery substance used for coloring. It is insoluble in water, grease, resin, organic solvents and other media, but can be evenly dispersed in these media and can color the media, and has a certain hiding power. The basic requirements for pigments used in art are that the finer the particles, the better, the brighter the color, the better, and the longer it lasts without discoloration, the better (the stability is better). Watercolor paints Watercolor paints, except white, are almost all transparent. Only in this way can the needs of watercolor cover dyeing be met. Gouache paint was originally invented by adding white powder to watercolor paint to make the color opaque. Because watercolor paint is transparent, it is difficult to correct if you make a mistake. Gouache paint can be easily modified because it is opaque. Later, raw materials such as gum arabic were added to the gouache pigment to further improve its performance. Gum arabic can make the surface of gouache paint have a layer of luster after it dries. However, in special occasions where flat coating is required (such as rendering renderings and coloring animations), the glue will form irregular spots on the surface of the color, or make the color dull. It is uneven, so there are special degumming pigments. Oil paint is paint diluted with oil. Chinese painting pigments are very rich and come in various types, ranging from mineral powder to plant extraction to animal extraction, and the types are complex. Theoretically, as long as there are three primary colors of red, blue and yellow, all other colors can be mixed, but the purity of the mixed colors is always not high enough. Therefore, modern art paint manufacturers produce high-purity pigments for various hues and brightness colors. to meet various needs. From the most basic 12 colors to the usual 24 colors or even 48 colors to more than 60 colors. Special metallic colors are not included. use It is an indispensable raw material for the manufacture of paints, inks, oil painting pastes, cosmetic paints, colored papers, etc. It is also used for filling and coloring plastics, rubber products, and synthetic fiber solutions. Performance characteristics Pigments usually have the following properties: color. Color pigments are pigments that selectively absorb and scatter visible light energy and can present colors such as yellow, red, blue, and green under natural light conditions. Tinting power. The ability of a coloring pigment to absorb incident light. It can be expressed as a relative percentage equivalent to the tinting power of a standard pigment sample. Covering power. The ability of a film-forming substance to cover the surface color of a substrate. It is often expressed in grams of pigment contained in paint covering an area of ​​1 square meter. Lightfastness. The ability of pigments to maintain their original color under certain lighting conditions. Generally, an eight-level system is used, with level eight being the best. Weather resistance. The ability of pigments to maintain their original properties under certain natural or artificial climatic conditions. Generally, a five-level system is used, with level five being the best. Volatile. Mainly refers to moisture, which is generally not more than 1%. Oil absorption. Refers to the number of grams of refined linseed oil required to form a uniform mass of 100 grams of pigment. The one with the smallest oil absorption capacity is better. The oil absorption capacity is related to the specific surface area and structure of the pigment particles. water soluble matter. The water-soluble substances contained in the pigment are expressed as a mass percentage of the pigment. The water-soluble content of pigments used in paint making is often controlled below 1%. concept Pigment is a colored fine-grained powdery substance that is generally insoluble in water and can be dispersed in various media such as oils, solvents, and resins. It has hiding power, tinting power, and is relatively stable to light. It is often used in the preparation of coatings, inks, and colored plastics and rubber, so it can also be called a colorant. Pigments differ from dyes in that dyes are generally soluble in water (an old distinction), while pigments are generally insoluble in water. Dyes are mainly used for dyeing textiles and other materials. However, this distinction is not very clear, because some dyes may also be insoluble in water, and pigments are also used in pigment printing and pulp coloring of textiles. The chemical structure of organic pigments is similar to that of organic dyes, so they are usually regarded as a branch of dyes. Performance characteristics Pigments usually have the following properties: color . Color pigments are pigments that selectively absorb and scatter visible light energy and can present colors such as yellow, red, blue, and green under natural light conditions. Tinting power . The ability of a coloring pigment to absorb incident light. It can be expressed as a relative percentage equivalent to the tinting power of a standard pigment sample. Covering power . The ability of a film-forming substance to cover the surface color of a substrate. It is often expressed in grams of pigment contained in paint covering an area of ​​1 square meter. Lightfastness . The ability of pigments to maintain their original color under certain lighting conditions. Generally, an eight-level system is used, with level eight being the best. Weather resistance . The ability of pigments to maintain their original properties under certain natural or artificial climatic conditions. Generally, a five-level system is used, with level five being the best. Volatile . Mainly refers to moisture, which is generally not more than 1%. Oil absorption . Refers to the number of grams of refined linseed oil required to form a uniform mass of 100 grams of pigment. The one with the smallest oil absorption capacity is better. The oil absorption capacity is related to the specific surface area and structure of the pigment particles. water soluble matter . The water-soluble substances contained in the pigment are expressed as a mass percentage of the pigment. The water-soluble content of pigments used in paint making is often controlled below 1%. Basic classification Pigments can be divided into two categories based on their chemical composition: inorganic pigments and organic pigments. Based on their sources, they can be further divided into natural pigments and synthetic pigments. Natural pigments are derived from minerals, such as cinnabar, laterite, realgar, malachite green and heavy calcium carbonate, wollastonite, barite powder, talc powder, mica powder, kaolin, etc. Those from biological sources, such as those from animals: cochineal red, natural fish scale powder, etc.; those from plants include: garcinia, alizarin red, indigo, etc. Synthetic pigments are artificially synthesized, such as inorganic pigments such as titanium white, zinc barium white, lead chromium yellow, and iron blue, as well as organic pigments such as red pink, even light yellow, phthalocyanine blue, and quinacridone. Pigments are classified according to their function, such as anti-rust pigments, magnetic pigments, luminescent pigments, pearlescent pigments, conductive pigments, etc. Classification by color is a convenient and easy-to-use method. Thus pigments can be classified as white, yellow, red, blue, green, brown, purple, black, regardless of their origin or chemical composition. The famous “Dye Index” (ColorIndex) uses a color classification method: for example, pigments are divided into pigment yellow (PY), pigment orange (PO), pigment red (PR), pigment violet (PV), and pigment blue (PB). , Pigment green (PG), Pigment brown (PBr), Pigment black (PBk), Pigment white (PW), Metallic pigment (PM) and other ten categories. Pigments of the same color are arranged according to the sequence number. For example, titanium white is PW- 6. Zinc-barium white PW-5, lead chromium yellow PY-34, quinacridone PR-207, iron oxide red PR-101, phthalocyanine blue PB-15, etc. In order to find the chemical composition, there are other structural numbers, such as titanium white PW-6C.I.77891 and phthalocyanine blue PB-15C.I.74160, which allow manufacturers and users of pigments to identify the listed pigments. The composition and chemical structure of. Therefore, it has been widely used in the international pigment import and export trade industry, and some domestic pigment manufacturers also use this international classification standard for pigments. China’s national standard for pigments, GB/T3182-1995, also uses color classification. Each pigment color has a symbol, such as white for BA, red for HO, yellow for HU… Then combined with the code and serial number of the chemical structure, the pigment model is formed, such as rutile titanium white BA-01-03, medium chrome yellow HU-02-02, iron oxide red HO-01-01, zinc barium white BA-11-01, toluidine red HO-02-01, BGS phthalocyanine blue LA-61-02, etc. Pigments can be classified according to the types of compounds they contain: Inorganic pigments can be subdivided into oxides, chromates, sulfates, silicates, borates, molybdates, phosphates, vanadates, ferricyanates , hydroxides, sulfides, metals, etc.; organic pigments can be divided into azo pigments, phthalocyanine pigments, anthraquinones, indigo, quinacridone, dioxazine and other polycyclic pigments, arylmethane according to the chemical structure of the compound Department of pigments, etc. From the perspective of production and manufacturing, they can be classified into titanium pigments, iron pigments, chromium pigments, lead pigments, zinc pigments, metallic pigments, and organic synthetic pigments. This classification method has practical significance, and often one system can Represents a professional pigment production industry. From the perspective of application, it can be divided into paint pigments, ink pigments, plastic pigments, rubber pigments, ceramic and enamel pigments, pharmaceutical and cosmetic pigments, art pigments, etc. Various specialty pigments have some unique properties to match the requirements of the application. Pigment manufacturers can also recommend a series of pigment products to professional users in a targeted manner. acrylic paint Acrylic paint is a synthetic polymer pigment invented in the 1950s. It is made of pigment powder mixed with acrylic latex. Acrylic latex is also called acrylic resin polymerized latex. There are many kinds of acrylic resins, such as methacrylic resins, etc. Therefore, there are also many kinds of acrylic paints. Foreign pigment manufacturers have produced a series of acrylic products, such as matte acrylic pigments, semi-matte acrylic pigments, glossy acrylic pigments, acrylic matte oils, glazing oils, plastic ointments, etc. Acrylic paints are very popular among painters. Compared with oil paints, it has the following characteristics: 1. It can be released with water to facilitate cleaning. 2. Quick drying. The paint dries within minutes after being put down, unlike oil paintings that have to wait several months to be polished. Painters who prefer slow-drying paints can use retarder to delay the drying time of the paint. 3. The coloring layer quickly loses solubility as it dries, forming a tough, elastic, water-impermeable film. This membrane is similar to rubber. 4. The color is full, thick, and fresh, and it never feels “dirty” or “grey” no matter how you blend it. The colored layer will never absorb oil and cause stains. 5. The longevity of the piece is longer. The oil film in oil paintings is prone to oxidation over time, turning yellow and hardening, which can easily lead to cracks in the painting. Theoretically speaking, acrylic film will never become brittle or yellow. 6. The biggest difference between acrylic paint and oil painting in the way it is used is that it has the operating characteristics of general water-based paints and can be used as both watercolor and gouache. 7. Acrylic modeling ointment contains granular types, and there are coarse particles and fine particles, which provides convenience for making textures. 8. Acrylic paint is not very harmful to the human body. Just be careful not to accidentally eat it. 9. Acrylic paint can be used to design your own cultural shirts, which can highlight your personal personality. But it’s best to use cotton clothes and be white. It should be noted that acrylic painting should be painted on a base made of acrylic primer (GESSO), not an oil base. Material experts also do not advocate the mixing of acrylic and oil paints, especially not to paint oil paintings on an acrylic base. This is mainly for the permanent preservation of the work. There is no adverse reaction between acrylic and oil paints. When used alternately, their adhesion needs to be tested over time. water based pigments Water-based pigment is a new type of environmentally friendly pigment. Compared with traditional pigments, it has the advantages of non-toxic and odorless. Compared with traditional pigments, it is more in line with the concept of health and environmental protection, and has become a trend in pigments. Oil paints Oil paint is a special paint for oil paintings, which is made by mixing and grinding pigment powder with oil and glue. Most of them are sold in the market in tubes, but you can also make your own. Oil paint is a material entity formed by mixing and grinding mineral, plant, animal, chemically synthesized toner and the blending agent linseed oil or walnut oil. Its characteristic is that it can be dyed to other materials or attached to certain materials to form a certain pigment layer. This pigment layer has a certain degree of plasticity. It can form various shapes and marks that the painter wants to achieve according to the use of tools. texture. The various hues of oil paints are determined by the hue of the toner. Oil can make the hue of the toner slightly darker and more saturated. Chinese painting pigments Chinese painting pigments, also called Chinese painting pigments, are special pigments used to paint Chinese paintings. They are generally sold in tubes and paint blocks, but also in pigment powder. Classification of Chinese Painting Pigments Traditional Chinese painting pigments are generally divided into two categories: mineral pigments and plant pigments. Historically speaking, minerals should be used first, followed by plants […]

Dyes refer to a class of organic compounds that can give other substances a bright and firm color. Since the pigments used today are all artificially synthesized, they are also called synthetic dyes. Dyes and pigments are generally compounds that have their own color and can make other substances obtain bright and firm colors in a molecular or dispersed state.   Dye classification   According to dye properties and application methods, dyes can be classified as follows. According to status Water-based color paste, oil-based color paste, water-based color, essential oil-based color essence According to use Ceramic Pigments Coating Pigments Textile Pigments Plastic Pigments According to source Natural dyes are divided into plant dyes, animal dyes, and synthetic dyes (also known as artificial dyes ) according to their usage. According to dye properties and application methods Direct dyes , insoluble azo dyes , reactive dyes, vat dyes, soluble vat dyes, sulfur dyes, sulfur vat dyes , phthalocyanine dyes, oxidation dyes, condensation dyes, disperse dyes, acid dyes, acidic mordants and acidic mordant dyes, basic and cationic dyes.   direct dyes   This type of dye gets its name because it can be dyed directly on various fibers such as cotton, linen, silk, and wool without relying on other chemicals. Its dyeing method is simple, the chromatogram is complete, and the cost is low. However, its washing and light fastness are poor. If appropriate treatment methods are used, the fastness of the dyed finished product can be improved.   reactive dyes   Also known as reactive dyes. This type of dye is a new type of dye that was only developed in the 1950s. Its molecular structure contains one or more active groups, which can chemically react with fibers under appropriate conditions to form covalent bonds. It can be used for dyeing cotton, linen, silk, wool, viscose, nylon, vinylon and other textiles.   Sulfur dyes   Most of these dyes are insoluble in water and organic solvents , but can be dissolved in alkali sulfide solution. After dissolution, they can be directly dyed on fibers. However, because the dye solution is too alkaline, it is not suitable for dyeing protein fibers. This type of dye has a uniform chromatogram, is cheap, and has good color fastness, but the color is not bright.   Disperse dyes   This type of dye has very low solubility in water, very fine particles, and is a dispersion in the dye liquor. It is a non-ionic dye and is mainly used for dyeing polyester with high dye fastness.   Acid Dyestuff   This type of dye is water-soluble, and most of them contain sulfonic acid groups, carboxyl groups and other water-soluble genes. Protein fibers can be dyed directly in acidic, weakly acidic or neutral media, but the wet processing fastness is poor.   coating   It is suitable for all fibers. Through the mechanical attachment of resin to fibers, dark fabrics will become hard, but the color registration is very accurate. Most of them have good light fastness and good washing fastness, especially medium and light.   Dye naming   The various types of dyes introduced above are not only numerous in number, but also have different properties and usage methods for each type of dye. In order to facilitate distinction and mastery, a unified naming method for dyes has been officially adopted. As long as you see the name of the dye, you can roughly know what type of dye it belongs to, as well as its color, luster, etc. Our country uniformly uses a three-section nomenclature for the naming of dyes. The name of the dye is divided into three parts, namely, the title, the color name and the endnote.   1. The title mainly indicates the name of the dye according to its application method or properties, such as disperse, reduction, reactive, direct, etc.   2. The color name indicates the name of the color that can be obtained by dyeing fabrics with this dye according to standard methods. Generally, there are four ways to express it:   (1) Use common physical names, such as red, green, blue, etc.   (2) Use plant names, such as orange, peach , grass green, rose, etc.   (3) Use natural phenomena to express it, such as sky blue, golden color, etc.   (4) Expressed by animal names, such as rat gray, goose yellow, etc.   3. The endnote indicates the shade, performance, status, concentration of the dye and the fabrics it is suitable for, etc. It is generally represented by letters and numbers.   The three-section nomenclature of dyes is more convenient to use. For example, vat violet RR, you can know that this is a purple vat dye with red light. The title is reduction, the color name is purple, R means red light, and the two R means the red light is heavier.   At present, the naming of dyes has not been unified in all countries in the world. Each dyeing factory has a name for each dye it produces. Therefore, the same dye may have several names.   Dye application   1. Select dyes based on fiber properties. Due to the different properties of various fibers, it is necessary to select suitable dyes when dyeing. For example , when dyeing cotton fiber , because its molecular structure contains many hydrophilic hydroxyl groups, it is easy to absorb moisture and swell, can react chemically with reactive groups, and is more resistant to alkali, so you can choose direct, reduction, sulfurization, and ice dyes. and reactive dyes. Polyester has strong hydrophobicity and is not resistant to alkali at high temperatures. Generally, the above dyes should not be used, but disperse dyes should be used for dyeing.   2. Select dyes according to the use of the dyed objects. Since the uses of the dyed objects are different, the requirements for the fastness of the dyed finished products are also different. For example, cloth used as curtains is not washed frequently, but it is often exposed to sunlight. Therefore, when dyeing, you should choose dyes with higher light fastness. For dyeing underwear and light-colored fabrics worn in summer, dyes with higher washability, lightfastness, and sweat resistance should be selected because they need to be washed and sun-dried frequently.   3. Select dyes based on dye costs. When selecting dyes, you must not only consider the color and fastness, but also consider the cost and supply of the dyes and additives used . For higher-priced dyes, you should try to replace them with other dyes that can produce the same effect to reduce production costs.   4. Selection of dyes when color matching When color matching is required, attention should be paid to their composition, solubility, color fastness, dye uptake rate and other properties when selecting dyes. Since the dyeing properties of various dyes are different, the dyeing effect is often affected by differences in temperature, solubility, dye uptake, etc. during dyeing. Therefore, when color matching, dyes with similar properties must be selected, and the closer the better, which can be beneficial to the control of process conditions and the stability of dyeing quality.   5. Select dyes based on the properties of dyeing machinery. Due to different dyeing machinery, the properties and requirements for dyes are also different. If it is used for jig dyeing, dyes with higher directness should be selected; for pad dyeing , dyes with lower directness should be selected. Otherwise, products that do not meet the requirements will be dark at the front and light at the back, with uneven color and luster.   Environmentally friendly dyes   In accordance with the requirements of ecological textiles and the ban on 118 kinds of dyes, environmentally friendly dyes have become the focus of the development of the dye industry and the printing and dyeing industry. Environmentally friendly dyes are an extremely important condition for ensuring the ecology of textiles. In addition to the necessary dyeing performance, applicability of the process, application performance and fastness performance, environmentally friendly dyes also need to meet environmental quality requirements.   Environmentally friendly dyes should include the following ten aspects:   (1) It does not contain azo dyes that are expressly stipulated by the German government, the European Community and Eco-Tex Standard 100 and will crack and release 22 carcinogenic aromatic amines under specific conditions, regardless of whether these carcinogenic aromatic amines are free in the dye or are produced by the dye. Produced by lysis;   (2) Not an allergic dye;   (3) Not a carcinogenic dye;   (4) It is not an acutely toxic dye;   (5) The content of extractable heavy metals is below the limit value;   (6) Does not contain environmental hormones;   (7) Does not contain chemical substances that can cause environmental pollution;   (8) Does not contain variable compounds and persistent organic pollutants;   (9) Formaldehyde content is below the specified limit;   (10) Varieties that do not contain restricted pesticides and the total amount is below the prescribed limit;   Strictly speaking, dyes that can meet the above requirements should be called environmentally friendly dyes. In addition to meeting the above requirements, truly environmentally friendly dyes should also be environmentally friendly during the production process and not produce “three wastes”, even if a small amount of waste is produced. The “three wastes” can also be treated through conventional methods to meet national and local environmental protection and ecological requirements.   direct dyes   Direct dyes account for the majority of banned dyes. Therefore, in recent years, the development of environmentally friendly direct dyes has become the focus of the development of new varieties in the dye industry. Specific direct dye varieties include the following:   (1) Diaminostilbene disulfonic acid direct dyes: These dyes have bright colors and moderate fastness. Direct lightfast orange GGL (CI Direct Orange 39) is an environmentally friendly dye with good performance. Direct Lightfast Yellow 3BLL (CI Direct Yellow 106) is a triazole direct dye with a sunfastness of level 6~7. Direct light fast green IRC (CI direct green 34) has a high dye uptake rate and excellent dye fastness, with sun fastness reaching level 6~7 and washing fastness reaching level 3~4.   (2) 4.4`-diaminodiphenylurea direct dyes: These dyes are non-carcinogenic and have high light fastness. There are many application varieties and it is an environmentally friendly dye. Such as direct light fast yellow RSC (CI direct yellow 50), direct light fast red F3B (CI direct red 80), CI direct brown 112, CI direct brown 126, CI direct brown 152, etc.   (3) 4.4`-Diaminobenzoylanilide direct dyes: These dyes have good fastness and are environmentally friendly dyes. Such as direct green NB (CI direct green 89), direct yellow-brown N-D3G (CI direct brown 223), direct black N-BN (CI direct black 166), etc.   (4) 4.4`-Diaminobenzenesulfonanilide direct dyes: This type of dye is a black direct dye synthesized from diamino compounds, and its dyeing performance and fastness are very good. It is widely used for dyeing cotton, linen, viscose fiber, silk and leather. Products that can replace banned direct dyes have been developed and screened, such as CI Direct Black 166 (Direct Black N-BN), CI Acid Black 210 (Acid Black NT), CI Acid Black 234, etc.   (5) Diaminoheterocyclic direct dyes: These dyes are direct dyes synthesized from diaminoheterocyclic compounds , such as dibenzodioxazine direct dyes. These dyes have bright colors, high tinting strength and fastness. , the sun fastness reaches level 7. Representative varieties include CI Direct Blue 106 (Direct Lightfast Brilliant Blue FF2GL), CI Direct Blue 108 (Direct Lightfast Blue FFRL), etc.   (6) Environmentally friendly direct dyes for polyester/cotton (polyester/viscose) fabrics: Polyester/cotton, polyester/viscose blended fabrics and other fibers with different properties are dyed in the same bath. This requires direct dyes to have excellent high temperature stability and good It has good lifting power and reproducibility, good fastness and environmental protection performance. The direct blended D-type dye developed by Shanghai Dyestuff Company is an environmentally friendly dye that can achieve the above performance. Currently, there are more than 25 varieties, such as CI Direct Yellow 86 (Direct blended yellow DR), CI Direct Yellow 106 (Direct blended yellow D -3RLL), CI224 direct blended red D-GLN, CI direct purple 66 (direct blended purple D-5BL), CI direct blue 70 (direct blended blue D-RGL), CI95 direct blended brown D-RS, CI direct black 166 (Directly blended black D-ANBA) etc. Some of the varieties are copper complexes, and free copper should be within the limit value (250mg/kg) specified by ETAD.   (7) Kayaelon C-type dyes developed and screened by Nippon Chemical Company: CI Direct Yellow 161 (Yellow C-3RL), CI Direct Red 83 (Rubine C-BL), CI Direct Blue 288 (Blue C-BK), CI direct green 59 (Caeen C-CK), CI direct black 117 (Crey C-RL), etc.   Thailand’s Modern Group has launched the Modern Direct series of advanced direct dyes, Dystar has developed the Sirius Plus series of direct dyes, Ciba has launched Cibafix ECO direct dyes, BASF has launched the Diazol series of direct dyes, Yorkshire has launched the Benganil series of direct dyes, etc. These dyes have similar functions, such as bright colors, high light fastness, environmentally friendly dyes that do not contain heavy metals, excellent high temperature stability, and are suitable for one-bath and one-step dyeing of polyester-cotton blended fabrics.   Acid Dyestuff   (1) Red, orange and yellow acid dyes. Among the acidic environmentally friendly dyes that have been developed, red acid dyes include: CI acid red 37, CI acid red 89 (weak acid red 3B, 2BS), CI acid red 145 (weak acid red GL )wait. CI Acid Red 336 and CI Acid Red 361 are both important varieties of the red spectrum. Orange acid dyes include: CI acid orange 67 (weak acid yellow RXL), CI acid orange 116 (acid orange AGT), CI acid orange 156 (weak acid orange 3G). The main yellow acid dyes are: CI acid yellow 42 (weak acid yellow Rs, acid yellow R) and CI acid yellow 49 (acid yellow GR200).   (2) Blue, green, and purple acid dyes. Most of the environmentally friendly acid dyes in the blue spectrum are bromine derivatives, and there are many new blue varieties, such as CI acid blue 277, CI acid blue 344, CI acid blue 350, CI acid Blue 9 (Brilliant Blue FCF) etc. Green acid dyes are of the anthraquinone type. New products that have been developed in China include CI Green 17, CI Acid Green 28, CI Acid Green 41, CI Acid Green 81, etc. The purple ones mainly include CI acid violet 17 (ac […]