Ink is a colorant for printing. It is a kind of fluid substance that has a certain viscosity because the pigment particles are evenly dispersed in the binder.
1. Composition of ink
The ink consists of pigments, binders, fillers, and additives.
(1) Pigments
Pigments play a colorizing role in the ink, which in turn has a direct effect on some properties of the ink.
The pigment is a color, black or white highly disperse powder that is insoluble in water and organic solvents. According to its source and chemical composition, it is divided into organic pigments and inorganic pigments.
1 Inorganic pigments are oxides of non-ferrous metals, or some metal-insoluble metal salts. Inorganic pigments are further divided into natural inorganic pigments and artificial inorganic pigments. Natural inorganic pigments are mineral pigments.
2 Organic pigments are colored organic compounds and are also divided into natural and synthetic categories. Nowadays, synthetic organic pigments are commonly used. There are many varieties of organic pigments, and the colors are relatively complete. The performance is superior to that of inorganic pigments.
Dyes are organic compounds which are soluble in water and sometimes also dissolved in organic solvents. Insoluble color precipitates, called lake pigments, can be prepared from certain dyes for the production of printing inks.
The requirements for the pigments used in printing inks are quite high, especially the color, dispersion, light resistance, transparency, etc., and the hue of color pigments is required to be close to the spectral color, the saturation should be as large as possible, and the magenta, cyan, and yellow colors used for the three primary color inks should be used. The transparency of the pigment must be high. All the pigments should not only be water-resistant, but also should be quickly and evenly combined with the binder. The oil-absorbing ability of the pigment should not be too large. The pigment is preferably resistant to alkali, acid, alcohol and resistance.
(2) Connection material
The binder is the main component of the ink, serves to disperse the pigment, imparts proper sticking, fluidity and transfer properties to the ink, and serves to fix the pigment on the surface of the print after filming by printing. The connecting material is commonly known as varnish.
The binder can be made of various materials, such as various dry vegetable oils, most of which can be used to make binders for inks, mineral oils can also be made into binders, solvents and water, and various synthetic resins can be used to make them. The binder.
The rheology, viscosity, neutrality, acid value, color, water resistance, and printing performance of the ink are mainly determined by the binder. The same pigment, using different binders, can be used to make different types of inks; Use different colors. The ink produced is still the same type of ink, because it can not change the fundamental performance of the ink, so the quality of the ink is good or bad, but depends on the pigment, but mainly depends on the connection material.
(3) Packing
The filler is a white, transparent, translucent or unpleasant powder substance. Mainly from the filling, filling the pigment part, the appropriate use of some filler, can reduce the amount of pigment, reduce costs, but also can adjust the properties of the ink, such as thick, fluidity, etc., but also improve the flexibility of formula design.
(4) Additives
Additives are some of the materials added to improve the performance of the ink itself during the manufacture of the ink, as well as during printing. The inks formulated according to the basic composition still cannot satisfy the requirements in certain characteristics, or they must be added with a small amount of auxiliary materials when they cannot meet the requirements for printing use due to changes in conditions.
There are many additives, such as: desiccant, desiccant, diluting agent, remover, plasticizer and so on.
2. Kind of ink
The variety of inks can be classified by various methods:
(1) According to the printing method
1 According to the layout type: Letterpress, lithographic, gravure, photogravure, screen printing, etc.;
2 According to the printing methods: Offset, direct printing and other inks.
(2) Divided by printing materials
Divided by printing materials: paper, metal, plastic, cloth and other inks.
(3) divided by dry form
1 according to the drying mechanism: penetration drying type, oxidation polymerization type, volatile drying type, photo hardening type, thermosetting type, cooling and curing type ink;
2 According to the drying method, there are: natural drying type, hot air drying type, infrared drying type, ultraviolet drying type, cooling and drying type ink.
(4) According to ink characteristics
1 divided by color: yellow, red, blue, white, black, gold, silver, gold powder, fluorescent color, pearl color, etc.;
2 divided by function: magnetic ink, anti-counterfeiting ink, edible ink, foaming ink, aromatic ink, recording ink, etc.;
3 according to the resistance: light resistance, heat resistance, solvent resistance, abrasion resistance, alcohol resistance, chemical resistance and other inks.
(5) According to ink composition
1 according to the raw materials are divided: dry oil type, resin oil type, organic solvent type, water type, paraffin type, ethylene glycol type ink;
2 according to the form: gelatinous, liquid, powdered ink.
(6) by purpose
Divided by purpose: news inks, book inks, packaging inks, building materials inks, trademark inks.
3. Ink characteristics
The ink is a pasty paste that is colored and has a certain degree of fluidity and can be printed and dried on the substrate. Therefore, color, rheological properties, and drying performance are the three most important features of inks.
(1) Viscosity
Viscosity is a property that prevents the flow of a fluid and is a measure of the ability of a fluid molecule to interact and create a barrier to the relative motion of its molecules, ie, the resistance to fluid flow.
The viscosity of the ink and the transfer of ink during the printing process are related to the nature and structure of the paper. The ink viscosity is too large, the ink transfer during the printing process is not easy to uniform, and the phenomenon of paper pulling is generated, so that the printing on the printing surface; the viscosity is too small, the ink Easy to emulsify, dirty, affect product quality.
The viscosity of the ink is related to the viscosity of the vehicle, the amount of pigments and additives used, the particle size of the pigments and additives, and the dispersion of the pigments and additives in the vehicle.
The requirements for the viscosity of the ink in the printing process are related to the printing speed of the printing press, the softness of the paper structure, and the change of the ambient temperature.
(2) Yield value
The minimum shear stress required to start the flow of liquid is called the yield value.
An ink with a large yield value has poor flow properties and is not easy to open. The ink whose yield value is too small is liable to cause haziness and unclear printing dots.
The yield value is related to the structure of the ink, and the size of the yield value has a direct effect on the flow of the ink. It is an important test indicator for the quality of offset and gravure printing inks.
(3) Thixotropy
The ink is stirred by the external force. It will be thickened by the action of stirring. After standing, the ink will return to its original consistency, called thixotropy.
Since the ink has thixotropy, when the ink is mechanically rotated on the ink roller, its fluidity increases, its ductility increases, and the ink is easily transferred. When the ink is transferred to the paper after printing, the effect of external force is lost, and the ink thickens from dilute and does not overflow to the surroundings, forming a good print. However, if the thixotropy of the ink is too large, the ink in the ink fountain is not easily rotated, which affects the ink transfer of the ink roller.
(4) Liquidity
The ability of ink to flow like a liquid under its own gravity is called the fluidity of the ink.
The fluidity of the ink is related to whether the ink can be poured from the container, conveyed from the storage tank to the ink fountain of the printing machine, smoothly transferred from the ink fountain, well distributed on the printing machine, transferred to the layout, and transferred to the printing. On the object, it also affects the effect of printing.
The fluidity of the ink is determined by the viscosity, yield value, and thixotropy of the ink, and is also closely related to the temperature.
(5) Length of ink
The process in which the ink is stretched into a filament without breaking is called the filament length.
The ink with short silk ink is good ink with good printing performance in offset printing and letterpress printing, because it will cause ink flying phenomenon. At the same time, the printing ink is uniform and thick, and the ink length is commonly used to measure ink performance. Bad.
The length of the ink is related to the thixotropy, yield value, and plastic viscosity of the ink.
(6) Drying of ink
After the ink adheres to the print to form an imprint, it must be changed from a liquid or pasty into a solid film. This process of change is usually referred to as drying of the ink.
The drying of the ink is accomplished by changing the binder in the ink from a liquid or paste to a solid. The binders used in various inks and their blending ratios are different. Therefore, the drying process for forming the ink from the different materials is also different. After the ink is transferred from the printing plate to the surface of the printed product, part of the connecting material in the ink penetrates. At the same time, the solvent in the connecting material begins to volatilize, and some of the connecting materials react chemically and physically to make the surface of the substrate imprinted. The ink layer gradually increases its viscosity and hardness, eventually forming a solid film layer.
In general, letterpress printing inks are mainly osmotic drying. Lithographic offset inks are mainly dried by oxidized conjunctiva. Gravure printing inks use a strong solvent as the connecting material, so it is mainly volatile drying.
Various ink characteristics
(1) Letterpress ink
Toppan inks include: lead-printing inks, letterpress printing inks, color inks for lead printing, plastic inks for printing, rubber letterpress plastic inks (ie, flexographic plastic inks), letterpress inks, and letterpress printing inks.
Lead-print books and periodicals inks are mainly used for printing books and periodicals, and they are also book inks. When printing on books on the platform machine, the ink is a penetrating dry ink with a certain degree of blackness. The viscosity is lower, and the yield value is lower, so that it can be used evenly for ink rollers. Printing press. The structure of books and papers is relatively rough, but they have better oil absorption properties, so they use a permeable dry ink.
Printed color inks are often used in copperplate color printing, and some are called copperplate inks. When the printing is carried out with a flat-press type smaller printing press, the pressure is relatively large and level, and the printing dots are mainly used, so the ink transfer performance is required to be good, the ink film layer within the dots should be uniform, and the ink fixing should be Fast, the ink film layer is not spread after embossing, so that the dots on the printed product have a good contrast contrast, and the print is consistent and full.
Such inks should have a relatively low yield value, have a certain degree of fluidity and viscoelasticity, and once the ink is imprinted on the paper, it should be able to fix and dry immediately. Therefore, the ink binder is mainly composed of an oxidized conjunctiva and a solvent, which is infiltrated and dried. This not only results in fast drying, but also the transferability of the ink.
Relief wheel transfer printing ink is also called press rotation ink. To adapt to high-speed printing, press rotation ink should have good flow properties and low viscosity. In general, he said, the faster the printing speed, the better the fluidity of ink is required. The lower it is.
Newsprinting inks are typically osmotic drying inks that are almost completely dry depending on the absorbent fibers of the paper fibers.
The letterpress rotary printing ink is suitable for printing speeds between the platform press and the news rotary press.
In order to adapt to high-speed printing of high-quality paper, infiltration drying type or oxidized conjunctiva drying type can not meet the requirements, and it is easy to produce poor drying, poor adhesion, chalking, scumming, etc. To overcome these drawbacks, thermosetting inks are used. That is, in the printing, after baking at a high temperature of 200 to 250° C., the solution in the ink is removed, so that the ink is fixed on the printed matter.
(2) Lithographic ink
Lithographic inks include various offset inks, lithographic printing inks, lithographic printing inks, inks of the Sala version, offset thermosetting inks, and the like.
One of the characteristics of offset printing inks is that the color tinting strength of inks is higher, because offset printing is indirect printing, and the ink blots printed on printed matters are very thin. Only a strong tinting strength can meet the requirements, because the printing speed is faster and faster. The ink should have good flow properties and good drying properties. According to the characteristics of offset printing, the ink must have good water resistance, so the water resistance of the pigment in the ink is very demanding. Most of the lake pigments are soluble in water and cause dinging. If the binder is hydrophilic emulsified, it will cause poor ink transfer and dryness, and the resin type binder is more resistant to water than the oil type binder.
(3) gravure ink
Gravure inks include various photogravure inks, engraved gravure inks, gravure plastic film inks, and the like.
Photogravure inks are typical volatile dry inks. Viscosity is the lowest among various inks. It has good fluidity and low surface tension. It is easy to fill in the recessed holes of the printing plate. The ink has strong adhesion and ensures the paper pressure. After printing, the ink can be transferred from the recessed hole to the surface of the print brush to the maximum, and the ink is dried extremely fast on the print, and must be thoroughly.
The characteristics of the engraving gravure ink are thick and not sticky, it is loose and short, and it has appropriate thixotropy. The ink can not only easily fill in the intaglio printing ink hole, but also can easily wipe off the ink on the blank part of the printing plane during printing. Some of the inks should also be easy to transfer to the prints. After the inks are printed on the prints, the dotted line of the graphic should not spread out, but should be dried quickly.
The pigment expression of gravure inks is mainly ink-based and cannot use transparent pigments. Engraving gravure is more commonly used in the printing of negotiable securities, so the various performance requirements for pigments are high, such as light resistance, water resistance, heat resistance, and oil resistance. In order to prevent counterfeiting, some special additives are often added to the ink.
(4) Ink printing ink
Stencil inks include screen printing inks, screen plastic inks, oil type inks, water type inks, and the like.
Because the screen printing is thicker with the squeegee ink and pressure, the flow characteristics of the screen printing ink should be thick, loose, and non-tacky, and the pigment content in the ink can be reduced accordingly, so that the ink can be smoothly Through the wire mesh.
Oxidation-drying type inks in screen printing inks, printed on prints, the quicker the better, volatile drying inks use a heating process to facilitate solvent evaporation.
Ink printing inks are generally less fluid and less viscous, relying primarily on osmotic drying.
(5) Special function ink
Microcapsule inks, substances with special functions, are sealed in capsules, inks are made of suitable binders, and printing is done in such a way that the capsules are not damaged, so that the prints have special properties. Such as liquid crystal ink, the use of the temperature and pressure to change the color of the liquid crystal, used to represent the thermometer, the calculator's figures; spices and inks used to make capsules perfume, the capsule is destroyed when issued fragrance; foaming ink using foaming agent, After printing, it is heated and foamed to print Braille and other printed matter.
Gold and silver ink, metal powder instead of pigment. In the past, gold powder and silver powder were attached to gold and silver inks. For gold and silver printing, ink varnish is mixed with gold powder or silver powder just before printing, and mixed ink is also available. Gold powder used brass powder, silver powder with aluminum powder, all made of sheet crushed to give metallic luster.
Fluorescent inks are inks that use fluorescent pigments. They bring a vivid and intense color effect. They are often used in eye-catching printed products such as posters, packaging materials, advertisements, and exhibits. Fluorescent pigments are used to dissolve fluorescent dyes in synthetic materials. In the resin, the particles are coarse, and the light resistance is also weak. Once the ultraviolet light is irradiated, a more brilliant effect can be obtained.
Magnetic ink, ink made of magnetic iron oxide powder, used for magnetic ink character reading, controlling the magnetic properties of magnetic powder, reading from the magnetic beams emitted from the printed special literature and fonts, mainly used for printing credit cards On-chip tape.
Security ink (anti-counterfeiting ink) is a printing ink of various securities, must have a variety of excellent light resistance, heat resistance, water resistance, oil resistance, gravure ink is a kind. In order to prevent counterfeiting and tampering, it must be equipped with a compound that can recognize a particular reaction, as well as a safety ink that can be used to eliminate, discolor, discolor, fade, or color ink.
Conductive inks are inks made of gold, silver, copper or conductive carbon black. The dried ink layer is conductive and used for printing circuits, electrodes, etc. Gold powder, silver powder and copper powder have their own conductive properties, but the gold and silver prices are too high, and copper is easily oxidized. Carbon black has different properties due to its different raw material properties. Graphite crystals have the best conductivity and are the most commonly used. One.
Rewritable ink, voucher replication ink, and printing by hot-melt heating and melting. Carbonless copying is colorless due to pressurization, unnecessary copying uses desensitized inks, reduces repetitive contact and loses copying, and uses chemical functional materials that prevent coloration.
There are many other functional inks. There are monitor inks that change color under the influence of gas. There are temperature-indicating inks that change color due to temperature changes, and there are color-developing inks that change from colorless to colored under the effect of light. Food inks printed on foods, fired inks printed on the friction part of a match box, etc.
1. Composition of ink
The ink consists of pigments, binders, fillers, and additives.
(1) Pigments
Pigments play a colorizing role in the ink, which in turn has a direct effect on some properties of the ink.
The pigment is a color, black or white highly disperse powder that is insoluble in water and organic solvents. According to its source and chemical composition, it is divided into organic pigments and inorganic pigments.
1 Inorganic pigments are oxides of non-ferrous metals, or some metal-insoluble metal salts. Inorganic pigments are further divided into natural inorganic pigments and artificial inorganic pigments. Natural inorganic pigments are mineral pigments.
2 Organic pigments are colored organic compounds and are also divided into natural and synthetic categories. Nowadays, synthetic organic pigments are commonly used. There are many varieties of organic pigments, and the colors are relatively complete. The performance is superior to that of inorganic pigments.
Dyes are organic compounds which are soluble in water and sometimes also dissolved in organic solvents. Insoluble color precipitates, called lake pigments, can be prepared from certain dyes for the production of printing inks.
The requirements for the pigments used in printing inks are quite high, especially the color, dispersion, light resistance, transparency, etc., and the hue of color pigments is required to be close to the spectral color, the saturation should be as large as possible, and the magenta, cyan, and yellow colors used for the three primary color inks should be used. The transparency of the pigment must be high. All the pigments should not only be water-resistant, but also should be quickly and evenly combined with the binder. The oil-absorbing ability of the pigment should not be too large. The pigment is preferably resistant to alkali, acid, alcohol and resistance.
(2) Connection material
The binder is the main component of the ink, serves to disperse the pigment, imparts proper sticking, fluidity and transfer properties to the ink, and serves to fix the pigment on the surface of the print after filming by printing. The connecting material is commonly known as varnish.
The binder can be made of various materials, such as various dry vegetable oils, most of which can be used to make binders for inks, mineral oils can also be made into binders, solvents and water, and various synthetic resins can be used to make them. The binder.
The rheology, viscosity, neutrality, acid value, color, water resistance, and printing performance of the ink are mainly determined by the binder. The same pigment, using different binders, can be used to make different types of inks; Use different colors. The ink produced is still the same type of ink, because it can not change the fundamental performance of the ink, so the quality of the ink is good or bad, but depends on the pigment, but mainly depends on the connection material.
(3) Packing
The filler is a white, transparent, translucent or unpleasant powder substance. Mainly from the filling, filling the pigment part, the appropriate use of some filler, can reduce the amount of pigment, reduce costs, but also can adjust the properties of the ink, such as thick, fluidity, etc., but also improve the flexibility of formula design.
(4) Additives
Additives are some of the materials added to improve the performance of the ink itself during the manufacture of the ink, as well as during printing. The inks formulated according to the basic composition still cannot satisfy the requirements in certain characteristics, or they must be added with a small amount of auxiliary materials when they cannot meet the requirements for printing use due to changes in conditions.
There are many additives, such as: desiccant, desiccant, diluting agent, remover, plasticizer and so on.
2. Kind of ink
The variety of inks can be classified by various methods:
(1) According to the printing method
1 According to the layout type: Letterpress, lithographic, gravure, photogravure, screen printing, etc.;
2 According to the printing methods: Offset, direct printing and other inks.
(2) Divided by printing materials
Divided by printing materials: paper, metal, plastic, cloth and other inks.
(3) divided by dry form
1 according to the drying mechanism: penetration drying type, oxidation polymerization type, volatile drying type, photo hardening type, thermosetting type, cooling and curing type ink;
2 According to the drying method, there are: natural drying type, hot air drying type, infrared drying type, ultraviolet drying type, cooling and drying type ink.
(4) According to ink characteristics
1 divided by color: yellow, red, blue, white, black, gold, silver, gold powder, fluorescent color, pearl color, etc.;
2 divided by function: magnetic ink, anti-counterfeiting ink, edible ink, foaming ink, aromatic ink, recording ink, etc.;
3 according to the resistance: light resistance, heat resistance, solvent resistance, abrasion resistance, alcohol resistance, chemical resistance and other inks.
(5) According to ink composition
1 according to the raw materials are divided: dry oil type, resin oil type, organic solvent type, water type, paraffin type, ethylene glycol type ink;
2 according to the form: gelatinous, liquid, powdered ink.
(6) by purpose
Divided by purpose: news inks, book inks, packaging inks, building materials inks, trademark inks.
3. Ink characteristics
The ink is a pasty paste that is colored and has a certain degree of fluidity and can be printed and dried on the substrate. Therefore, color, rheological properties, and drying performance are the three most important features of inks.
(1) Viscosity
Viscosity is a property that prevents the flow of a fluid and is a measure of the ability of a fluid molecule to interact and create a barrier to the relative motion of its molecules, ie, the resistance to fluid flow.
The viscosity of the ink and the transfer of ink during the printing process are related to the nature and structure of the paper. The ink viscosity is too large, the ink transfer during the printing process is not easy to uniform, and the phenomenon of paper pulling is generated, so that the printing on the printing surface; the viscosity is too small, the ink Easy to emulsify, dirty, affect product quality.
The viscosity of the ink is related to the viscosity of the vehicle, the amount of pigments and additives used, the particle size of the pigments and additives, and the dispersion of the pigments and additives in the vehicle.
The requirements for the viscosity of the ink in the printing process are related to the printing speed of the printing press, the softness of the paper structure, and the change of the ambient temperature.
(2) Yield value
The minimum shear stress required to start the flow of liquid is called the yield value.
An ink with a large yield value has poor flow properties and is not easy to open. The ink whose yield value is too small is liable to cause haziness and unclear printing dots.
The yield value is related to the structure of the ink, and the size of the yield value has a direct effect on the flow of the ink. It is an important test indicator for the quality of offset and gravure printing inks.
(3) Thixotropy
The ink is stirred by the external force. It will be thickened by the action of stirring. After standing, the ink will return to its original consistency, called thixotropy.
Since the ink has thixotropy, when the ink is mechanically rotated on the ink roller, its fluidity increases, its ductility increases, and the ink is easily transferred. When the ink is transferred to the paper after printing, the effect of external force is lost, and the ink thickens from dilute and does not overflow to the surroundings, forming a good print. However, if the thixotropy of the ink is too large, the ink in the ink fountain is not easily rotated, which affects the ink transfer of the ink roller.
(4) Liquidity
The ability of ink to flow like a liquid under its own gravity is called the fluidity of the ink.
The fluidity of the ink is related to whether the ink can be poured from the container, conveyed from the storage tank to the ink fountain of the printing machine, smoothly transferred from the ink fountain, well distributed on the printing machine, transferred to the layout, and transferred to the printing. On the object, it also affects the effect of printing.
The fluidity of the ink is determined by the viscosity, yield value, and thixotropy of the ink, and is also closely related to the temperature.
(5) Length of ink
The process in which the ink is stretched into a filament without breaking is called the filament length.
The ink with short silk ink is good ink with good printing performance in offset printing and letterpress printing, because it will cause ink flying phenomenon. At the same time, the printing ink is uniform and thick, and the ink length is commonly used to measure ink performance. Bad.
The length of the ink is related to the thixotropy, yield value, and plastic viscosity of the ink.
(6) Drying of ink
After the ink adheres to the print to form an imprint, it must be changed from a liquid or pasty into a solid film. This process of change is usually referred to as drying of the ink.
The drying of the ink is accomplished by changing the binder in the ink from a liquid or paste to a solid. The binders used in various inks and their blending ratios are different. Therefore, the drying process for forming the ink from the different materials is also different. After the ink is transferred from the printing plate to the surface of the printed product, part of the connecting material in the ink penetrates. At the same time, the solvent in the connecting material begins to volatilize, and some of the connecting materials react chemically and physically to make the surface of the substrate imprinted. The ink layer gradually increases its viscosity and hardness, eventually forming a solid film layer.
In general, letterpress printing inks are mainly osmotic drying. Lithographic offset inks are mainly dried by oxidized conjunctiva. Gravure printing inks use a strong solvent as the connecting material, so it is mainly volatile drying.
Various ink characteristics
(1) Letterpress ink
Toppan inks include: lead-printing inks, letterpress printing inks, color inks for lead printing, plastic inks for printing, rubber letterpress plastic inks (ie, flexographic plastic inks), letterpress inks, and letterpress printing inks.
Lead-print books and periodicals inks are mainly used for printing books and periodicals, and they are also book inks. When printing on books on the platform machine, the ink is a penetrating dry ink with a certain degree of blackness. The viscosity is lower, and the yield value is lower, so that it can be used evenly for ink rollers. Printing press. The structure of books and papers is relatively rough, but they have better oil absorption properties, so they use a permeable dry ink.
Printed color inks are often used in copperplate color printing, and some are called copperplate inks. When the printing is carried out with a flat-press type smaller printing press, the pressure is relatively large and level, and the printing dots are mainly used, so the ink transfer performance is required to be good, the ink film layer within the dots should be uniform, and the ink fixing should be Fast, the ink film layer is not spread after embossing, so that the dots on the printed product have a good contrast contrast, and the print is consistent and full.
Such inks should have a relatively low yield value, have a certain degree of fluidity and viscoelasticity, and once the ink is imprinted on the paper, it should be able to fix and dry immediately. Therefore, the ink binder is mainly composed of an oxidized conjunctiva and a solvent, which is infiltrated and dried. This not only results in fast drying, but also the transferability of the ink.
Relief wheel transfer printing ink is also called press rotation ink. To adapt to high-speed printing, press rotation ink should have good flow properties and low viscosity. In general, he said, the faster the printing speed, the better the fluidity of ink is required. The lower it is.
Newsprinting inks are typically osmotic drying inks that are almost completely dry depending on the absorbent fibers of the paper fibers.
The letterpress rotary printing ink is suitable for printing speeds between the platform press and the news rotary press.
In order to adapt to high-speed printing of high-quality paper, infiltration drying type or oxidized conjunctiva drying type can not meet the requirements, and it is easy to produce poor drying, poor adhesion, chalking, scumming, etc. To overcome these drawbacks, thermosetting inks are used. That is, in the printing, after baking at a high temperature of 200 to 250° C., the solution in the ink is removed, so that the ink is fixed on the printed matter.
(2) Lithographic ink
Lithographic inks include various offset inks, lithographic printing inks, lithographic printing inks, inks of the Sala version, offset thermosetting inks, and the like.
One of the characteristics of offset printing inks is that the color tinting strength of inks is higher, because offset printing is indirect printing, and the ink blots printed on printed matters are very thin. Only a strong tinting strength can meet the requirements, because the printing speed is faster and faster. The ink should have good flow properties and good drying properties. According to the characteristics of offset printing, the ink must have good water resistance, so the water resistance of the pigment in the ink is very demanding. Most of the lake pigments are soluble in water and cause dinging. If the binder is hydrophilic emulsified, it will cause poor ink transfer and dryness, and the resin type binder is more resistant to water than the oil type binder.
(3) gravure ink
Gravure inks include various photogravure inks, engraved gravure inks, gravure plastic film inks, and the like.
Photogravure inks are typical volatile dry inks. Viscosity is the lowest among various inks. It has good fluidity and low surface tension. It is easy to fill in the recessed holes of the printing plate. The ink has strong adhesion and ensures the paper pressure. After printing, the ink can be transferred from the recessed hole to the surface of the print brush to the maximum, and the ink is dried extremely fast on the print, and must be thoroughly.
The characteristics of the engraving gravure ink are thick and not sticky, it is loose and short, and it has appropriate thixotropy. The ink can not only easily fill in the intaglio printing ink hole, but also can easily wipe off the ink on the blank part of the printing plane during printing. Some of the inks should also be easy to transfer to the prints. After the inks are printed on the prints, the dotted line of the graphic should not spread out, but should be dried quickly.
The pigment expression of gravure inks is mainly ink-based and cannot use transparent pigments. Engraving gravure is more commonly used in the printing of negotiable securities, so the various performance requirements for pigments are high, such as light resistance, water resistance, heat resistance, and oil resistance. In order to prevent counterfeiting, some special additives are often added to the ink.
(4) Ink printing ink
Stencil inks include screen printing inks, screen plastic inks, oil type inks, water type inks, and the like.
Because the screen printing is thicker with the squeegee ink and pressure, the flow characteristics of the screen printing ink should be thick, loose, and non-tacky, and the pigment content in the ink can be reduced accordingly, so that the ink can be smoothly Through the wire mesh.
Oxidation-drying type inks in screen printing inks, printed on prints, the quicker the better, volatile drying inks use a heating process to facilitate solvent evaporation.
Ink printing inks are generally less fluid and less viscous, relying primarily on osmotic drying.
(5) Special function ink
Microcapsule inks, substances with special functions, are sealed in capsules, inks are made of suitable binders, and printing is done in such a way that the capsules are not damaged, so that the prints have special properties. Such as liquid crystal ink, the use of the temperature and pressure to change the color of the liquid crystal, used to represent the thermometer, the calculator's figures; spices and inks used to make capsules perfume, the capsule is destroyed when issued fragrance; foaming ink using foaming agent, After printing, it is heated and foamed to print Braille and other printed matter.
Gold and silver ink, metal powder instead of pigment. In the past, gold powder and silver powder were attached to gold and silver inks. For gold and silver printing, ink varnish is mixed with gold powder or silver powder just before printing, and mixed ink is also available. Gold powder used brass powder, silver powder with aluminum powder, all made of sheet crushed to give metallic luster.
Fluorescent inks are inks that use fluorescent pigments. They bring a vivid and intense color effect. They are often used in eye-catching printed products such as posters, packaging materials, advertisements, and exhibits. Fluorescent pigments are used to dissolve fluorescent dyes in synthetic materials. In the resin, the particles are coarse, and the light resistance is also weak. Once the ultraviolet light is irradiated, a more brilliant effect can be obtained.
Magnetic ink, ink made of magnetic iron oxide powder, used for magnetic ink character reading, controlling the magnetic properties of magnetic powder, reading from the magnetic beams emitted from the printed special literature and fonts, mainly used for printing credit cards On-chip tape.
Security ink (anti-counterfeiting ink) is a printing ink of various securities, must have a variety of excellent light resistance, heat resistance, water resistance, oil resistance, gravure ink is a kind. In order to prevent counterfeiting and tampering, it must be equipped with a compound that can recognize a particular reaction, as well as a safety ink that can be used to eliminate, discolor, discolor, fade, or color ink.
Conductive inks are inks made of gold, silver, copper or conductive carbon black. The dried ink layer is conductive and used for printing circuits, electrodes, etc. Gold powder, silver powder and copper powder have their own conductive properties, but the gold and silver prices are too high, and copper is easily oxidized. Carbon black has different properties due to its different raw material properties. Graphite crystals have the best conductivity and are the most commonly used. One.
Rewritable ink, voucher replication ink, and printing by hot-melt heating and melting. Carbonless copying is colorless due to pressurization, unnecessary copying uses desensitized inks, reduces repetitive contact and loses copying, and uses chemical functional materials that prevent coloration.
There are many other functional inks. There are monitor inks that change color under the influence of gas. There are temperature-indicating inks that change color due to temperature changes, and there are color-developing inks that change from colorless to colored under the effect of light. Food inks printed on foods, fired inks printed on the friction part of a match box, etc.
Kraft Paper Bags supplier Richest Pack, wholesale high quality Kraft Paper Bag With Window, Food Kraft Paper Bag, Kraft Coffee Bag with competitive price and best service.
In order to better display the goods, shops tend to choose Kraft Paper Bags With Window to show products.
Kraft paper bags is usually divided into white Kraft paper type and brown Kraft paper type, different colors also including different thickness.
Detailed Production Description:
Material usually divided into three types:
2) Three layer materials composite;
3) Four layer materials composite;
Thickness: 50 ~ 250 microns by customized
MOQ: 10,000 PCS
Samples: Free Samples
Logo: Accept Custom Logo
Feature:Moisture proof
Sealing &Handle:Zipper top
Place of Origin: Shenzhen, China
Surface Handling: Gravure Printing
Color: up to 9 colors or customer requirement
Usage: healthy food, salted food, instant soup, etc.
Payment Term: EXW, FOB, CIF
Delivery Time: 12 ~ 15 work days
Packaging: Bundles/Cartons
Port of Loading: Shenzhen or Hong Kong
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