First, the overview and characteristics of pearlescent pigments
Pearl powder is a semi-transparent, micro-flaky pigment that produces a pearlescent effect. This type of pigment is divided into natural and artificial two major categories. As early as the 3rd and 40th generations, these pigments were produced. They were originally made from fish scales and were natural products. The use of fish scales to produce pearlescent pigments is expensive and is rarely used. After the extraction of natural pearlescent pigments, they began to develop similar pigments that chemically produce a pearlescent effect and even more brightness than fish scale products. In the early 1950s, research and production of pearlescent layers covered with titanium dioxide and iron oxide on mica sheets began. Pigments, titanium dioxide coated mica wafers are the most widely used pearlescent pigments today. This pearlescent pigment is different from other general pigment pigments. It emits light through the reflection and refraction of light. A piece of transparent mica is powdered by water milling. Each powder is about 3-150 μm in size. After the powders are sorted by size, titanium dioxide is chemically coated on the surface of these powders to form a smooth, Transparent and odorless wafers, after reflection and refraction of light, the luster of pearls and the illusion of rainbows, are eye-catching. The difference in color that we see with the naked eye has a lot to do with the thickness of the titanium dioxide coating. If you increase the thickness of the mica wafer, the wafer will produce a variety of color effects, from very soft white to bright rainbow colors.
Second, the application of pearlescent pigments in gravure printing
Pearlescent pigments have been available for more than 70 years, and have a long history in the printing industry. Pearlescent pigments have been widely used in paper printing in various parts of the world. Different types of printing processes and products, such as lithography, gravure printing, and flexibility, have been applied. Printing, letterpress printing, screen printing, etc. Products are mainly used in paper printing such as soap packaging paper, cigarette packs, cigarette holders, greeting cards, wallpaper, food packaging paper, etc.; film printing, such as PET, PE, OPP, PS, etc., due to the wide use of pearlescent pigments, now mainly introduces pearlescent The use of pigments in gravure printing. In the gravure printing, the pearl powder can be directly added into the printing diluent. The amount of pearl powder used can be added up to 30% (by weight). The printing manufacturer can purchase the pearlescent pigment and directly mix it into the printing thinner. Used in.
Pearlescent powder belongs to insoluble pigments, and it needs to rely on a very good diluting agent to make the pearl powder completely wet and dissolved. The effect can be perfect after printing.
1. Mix of pearl powder and rinse
Pearlescent powder is a kind of crystal powder. When it is blended with diluting agent, if it is handled improperly, it can easily stick into a spherical shape, resulting in the formation of pinholes in the printing, poor printing gloss and other ills. Therefore, it is very important to use a good diluting agent. In order to prevent the pearlescent pigments from sticking to each other and forming small balls, the required pearl powder must be weighed and then gradually added into the diluting agent to adjust evenly to avoid sticking of the pearl powder in the diluting agent. If the printing viscosity is too high, it may be appropriate. Add some diluent (such as isopropyl alcohol, ethyl ester).
If you need color pearl effect, you can add 0.5-1% of ordinary color ink in the adjusted pearl powder, you can achieve color pearl effect.
Pearlescent ink sometimes has a deposition phenomenon during its use. It adopts a cyclical operation of the storage tank and uses low-speed stirring to keep the pearl powder flowing. At the same time, the ink is used to guide the ink to the ink tray for printing. The remaining pearl ink is then piped. Return to the ink tank, this device can prevent precipitation of pearl powder, while maintaining color stability. The engraving depth of the plate roll is also related to the printing effect. If anti-settling agent is added to prevent sedimentation, the ink concentration will increase, the fluidity will decrease, and the printing requirements will not be met. This problem is worthy of attention by manufacturers.
2. Pearl powder selection
As mentioned above, the particle size of the pearl powder has a great relationship with the depth of engraving of the printing plate. If the depth of engraving of the plate is not enough, the ink will only be transferred during the printing, leaving the pearl powder remaining in the ink tank. Lead to more and more serious precipitation and common floating phenomenon.
Before ordering pearlescent pigments, it is necessary to understand the pearlescent effect required by the product in order to determine which type of pearl powder is most suitable.
Third, pearl powder in the gravure printing common problems and countermeasures
1. Print without pearlescent effect
2. The appearance of pinholes and small bubbles on the printed surface
Bubbles or pinholes appear on the printing surface. First, there may be moisture or particles in the diluting agent. Second, pearl powder must be mixed thoroughly with a dilute agent before mixing. There is a powder group in the diluting agent. Such powder group will break and fall off after the printing is dried to form a tiny pinhole phenomenon.
3. Streaks appear when printing
When the pearl surface is printed on a large area, vertical stripes sometimes appear. This is due to improper roll printing. Therefore, when printing a large area of ​​pearl surface, appropriate depth of mesh engraving or diamond-shaped engraving surface rolling should be used. The squeegee should be checked and replaced frequently.
4. Post-print pearl powder falls off
(1) The diluting agent has poor adhesion;
(2) excessive dilution;
(3) too much pearl powder;
(4) It can be protected by a layer of water-based gloss oil;
(5) The dilute agent has poor affinity with pearl powder, which means it is not very compatible.
Fourth, the pearlescent color after printing is not bright, uneven
Pearlescent powder belongs to a translucent and insoluble wafer-like object, and its color is affected by the following factors.
Paper color
The same pearlescent ink is printed on two different papers, and the pearl color may not be the same. This is because the color of the paper affects the original color of the pearl powder.
2. The underlying printing color will also affect the pearl effect
Before purchasing pearl powder, it must be clear whether there are other background colors affect the pearl powder. If you need to print pearls on a background color pattern, you must first consider the color change of pearl powder. For example, printing a white pearl powder on a deep red pattern will fade the dark red background to a lighter shade, while at 45° you will see a white pearl effect. If it is replaced with red pearl powder, it will set off each other, but there are still some changes in the red color. Generally, it is advocated to print pearls first on paper, and then to print non-pearlescent patterns on it, the effect will be more vivid and perfect.
3 add other colors can also change the color of pearl powder
For the sake of cost savings, we advocate the use of white pearl powder combined with color inks to blend the desired pearlescent colors. For example, adding a suitable amount of primary red ink to white pearl powder will result in a bright light red color. This method can also enhance pearlescence. The hiding power of ink reduces the influence of the background on the pearl layer.
4. The color of the diluting agent itself also affects the pearlescent effect
Some manufacturers dilute the color is relatively deep, such as the dilute agent itself, the color will be deeper affect the effect of pearl surface, after printing, the color turns yellow, the effect of yellow comes from the quality of the diluting agent.
The Causes and Countermeasures of Printed Products without Pearlescent Effect
Cause and Countermeasure
1. Pearl powder and diluting agent have poor compatibility
2. Diluant gloss difference
3. Irregular prints
4. Edition is too shallow
5. Dilution too large
6. If you have added a large amount of pearl powder, but the printing surface pearl effect is still not enough, the problem may appear on the plate roll, because the depth of the plate is not enough, the plate roll is too shallow, only to transfer the finer pearl powder and leave a As a result of the coarse particles, the amount of pearlescent powder transferred to the printed product is insufficient, and the pearlescent effect is deteriorated.
7. There is enough pearl effect on the printing surface, but there is no gloss, because the diluting agent used is too dry.
Change diluting agent
Replace flusher
Change printing material
Re-engraved roll
Reduce dilution
Re-engraved roller
A slow-drying solvent should be added to allow the pearlescent powder to be arranged within the printing layer for a good time to form a good pearl reflection surface.
Pearl powder is a semi-transparent, micro-flaky pigment that produces a pearlescent effect. This type of pigment is divided into natural and artificial two major categories. As early as the 3rd and 40th generations, these pigments were produced. They were originally made from fish scales and were natural products. The use of fish scales to produce pearlescent pigments is expensive and is rarely used. After the extraction of natural pearlescent pigments, they began to develop similar pigments that chemically produce a pearlescent effect and even more brightness than fish scale products. In the early 1950s, research and production of pearlescent layers covered with titanium dioxide and iron oxide on mica sheets began. Pigments, titanium dioxide coated mica wafers are the most widely used pearlescent pigments today. This pearlescent pigment is different from other general pigment pigments. It emits light through the reflection and refraction of light. A piece of transparent mica is powdered by water milling. Each powder is about 3-150 μm in size. After the powders are sorted by size, titanium dioxide is chemically coated on the surface of these powders to form a smooth, Transparent and odorless wafers, after reflection and refraction of light, the luster of pearls and the illusion of rainbows, are eye-catching. The difference in color that we see with the naked eye has a lot to do with the thickness of the titanium dioxide coating. If you increase the thickness of the mica wafer, the wafer will produce a variety of color effects, from very soft white to bright rainbow colors.
Second, the application of pearlescent pigments in gravure printing
Pearlescent pigments have been available for more than 70 years, and have a long history in the printing industry. Pearlescent pigments have been widely used in paper printing in various parts of the world. Different types of printing processes and products, such as lithography, gravure printing, and flexibility, have been applied. Printing, letterpress printing, screen printing, etc. Products are mainly used in paper printing such as soap packaging paper, cigarette packs, cigarette holders, greeting cards, wallpaper, food packaging paper, etc.; film printing, such as PET, PE, OPP, PS, etc., due to the wide use of pearlescent pigments, now mainly introduces pearlescent The use of pigments in gravure printing. In the gravure printing, the pearl powder can be directly added into the printing diluent. The amount of pearl powder used can be added up to 30% (by weight). The printing manufacturer can purchase the pearlescent pigment and directly mix it into the printing thinner. Used in.
Pearlescent powder belongs to insoluble pigments, and it needs to rely on a very good diluting agent to make the pearl powder completely wet and dissolved. The effect can be perfect after printing.
1. Mix of pearl powder and rinse
Pearlescent powder is a kind of crystal powder. When it is blended with diluting agent, if it is handled improperly, it can easily stick into a spherical shape, resulting in the formation of pinholes in the printing, poor printing gloss and other ills. Therefore, it is very important to use a good diluting agent. In order to prevent the pearlescent pigments from sticking to each other and forming small balls, the required pearl powder must be weighed and then gradually added into the diluting agent to adjust evenly to avoid sticking of the pearl powder in the diluting agent. If the printing viscosity is too high, it may be appropriate. Add some diluent (such as isopropyl alcohol, ethyl ester).
If you need color pearl effect, you can add 0.5-1% of ordinary color ink in the adjusted pearl powder, you can achieve color pearl effect.
Pearlescent ink sometimes has a deposition phenomenon during its use. It adopts a cyclical operation of the storage tank and uses low-speed stirring to keep the pearl powder flowing. At the same time, the ink is used to guide the ink to the ink tray for printing. The remaining pearl ink is then piped. Return to the ink tank, this device can prevent precipitation of pearl powder, while maintaining color stability. The engraving depth of the plate roll is also related to the printing effect. If anti-settling agent is added to prevent sedimentation, the ink concentration will increase, the fluidity will decrease, and the printing requirements will not be met. This problem is worthy of attention by manufacturers.
2. Pearl powder selection
As mentioned above, the particle size of the pearl powder has a great relationship with the depth of engraving of the printing plate. If the depth of engraving of the plate is not enough, the ink will only be transferred during the printing, leaving the pearl powder remaining in the ink tank. Lead to more and more serious precipitation and common floating phenomenon.
Before ordering pearlescent pigments, it is necessary to understand the pearlescent effect required by the product in order to determine which type of pearl powder is most suitable.
Third, pearl powder in the gravure printing common problems and countermeasures
1. Print without pearlescent effect
2. The appearance of pinholes and small bubbles on the printed surface
Bubbles or pinholes appear on the printing surface. First, there may be moisture or particles in the diluting agent. Second, pearl powder must be mixed thoroughly with a dilute agent before mixing. There is a powder group in the diluting agent. Such powder group will break and fall off after the printing is dried to form a tiny pinhole phenomenon.
3. Streaks appear when printing
When the pearl surface is printed on a large area, vertical stripes sometimes appear. This is due to improper roll printing. Therefore, when printing a large area of ​​pearl surface, appropriate depth of mesh engraving or diamond-shaped engraving surface rolling should be used. The squeegee should be checked and replaced frequently.
4. Post-print pearl powder falls off
(1) The diluting agent has poor adhesion;
(2) excessive dilution;
(3) too much pearl powder;
(4) It can be protected by a layer of water-based gloss oil;
(5) The dilute agent has poor affinity with pearl powder, which means it is not very compatible.
Fourth, the pearlescent color after printing is not bright, uneven
Pearlescent powder belongs to a translucent and insoluble wafer-like object, and its color is affected by the following factors.
Paper color
The same pearlescent ink is printed on two different papers, and the pearl color may not be the same. This is because the color of the paper affects the original color of the pearl powder.
2. The underlying printing color will also affect the pearl effect
Before purchasing pearl powder, it must be clear whether there are other background colors affect the pearl powder. If you need to print pearls on a background color pattern, you must first consider the color change of pearl powder. For example, printing a white pearl powder on a deep red pattern will fade the dark red background to a lighter shade, while at 45° you will see a white pearl effect. If it is replaced with red pearl powder, it will set off each other, but there are still some changes in the red color. Generally, it is advocated to print pearls first on paper, and then to print non-pearlescent patterns on it, the effect will be more vivid and perfect.
3 add other colors can also change the color of pearl powder
For the sake of cost savings, we advocate the use of white pearl powder combined with color inks to blend the desired pearlescent colors. For example, adding a suitable amount of primary red ink to white pearl powder will result in a bright light red color. This method can also enhance pearlescence. The hiding power of ink reduces the influence of the background on the pearl layer.
4. The color of the diluting agent itself also affects the pearlescent effect
Some manufacturers dilute the color is relatively deep, such as the dilute agent itself, the color will be deeper affect the effect of pearl surface, after printing, the color turns yellow, the effect of yellow comes from the quality of the diluting agent.
The Causes and Countermeasures of Printed Products without Pearlescent Effect
Cause and Countermeasure
1. Pearl powder and diluting agent have poor compatibility
2. Diluant gloss difference
3. Irregular prints
4. Edition is too shallow
5. Dilution too large
6. If you have added a large amount of pearl powder, but the printing surface pearl effect is still not enough, the problem may appear on the plate roll, because the depth of the plate is not enough, the plate roll is too shallow, only to transfer the finer pearl powder and leave a As a result of the coarse particles, the amount of pearlescent powder transferred to the printed product is insufficient, and the pearlescent effect is deteriorated.
7. There is enough pearl effect on the printing surface, but there is no gloss, because the diluting agent used is too dry.
Change diluting agent
Replace flusher
Change printing material
Re-engraved roll
Reduce dilution
Re-engraved roller
A slow-drying solvent should be added to allow the pearlescent powder to be arranged within the printing layer for a good time to form a good pearl reflection surface.
Maochun Plastic & Ruber Hardware Co., Ltd. , http://www.gdmakeuppackaging.com