In the offset printing process, due to the improper selection and deployment of the ink, a variety of printing failures often occur. Based on actual experience in printing, this article talks about personal understanding and opinions for reference by peers.
At present, there are many kinds of domestic offset printing inks sold on the market. Mainly can be divided into three categories:
1. Offset resin ink. Offset resin inks are mainly synthetic resin binder inks. For monochrome, two-color offset printing machine in offset paper, letterpress paper, whiteboard printing ordinary trademarks, advertising, books, cover, book block and other products, with good printability. Low price and so on.
2. Offset bright ink. Offset Bright Ink is a mid-range ink formulated from synthetic resins, dry vegetable oils, high-boiling paraffinic oils, and high-quality pigments. For monochrome, two-color or multi-color offset printing machine on the coated paper printing higher-level albums, color pictures and various types of trademarks, the ink of the standards are higher than the offset printing resin ink.
3. Offset light fast drying four-color ink. With good printability, fast drying, high gloss, colorful and so on. Suitable for printing advanced coated paper and all kinds of advanced paper, and the better the paper, the clearer the network, the better the quality of the print. In the high-speed printing, it is not necessary to spray powder or paper, and the printed product is not easy to be dirty, which not only reduces the labor intensity of the operator, but also improves the quality and yield of the product.
Under normal circumstances, the above three types of offset inks can be selected and used according to different conditions. In the printing process, due to the differences in paper, printing plates, equipment, and processes, it is necessary to properly formulate and print. If it is improperly deployed, it will cause many problems. Here are some suggestions for common ink failures.
First, the printing plate ink dirty
Many ink stains of different sizes appeared on fingerprint printing plates, and they quickly appeared in the original place or elsewhere after being wiped off. This is related to inks, plates, potions, etc. It is one of the common faults. In the case of inks, it is usually due to the addition of a detackifier and an overdose of overdose to make it too thin, resulting in a decrease in viscosity and water resistance. Therefore, it is necessary to strictly control the amount of release agent and dispersant, generally controlled within 50%, try to maintain the original performance of the ink.
Second, paste version
It refers to the spread of ink spread, the network of dots, and the unclear level, which prevents printing from proceeding properly. The reasons are various, in which adding an excessive amount of additives in the ink reduces the viscosity and viscosity of the ink and causes the emulsification of the ink to be the main reason. Therefore, during the printing process, the principle of color depth and thin printing should be followed, and the amount of auxiliary agents should be appropriately controlled to maintain the viscosity and viscosity of the ink as much as possible to control the moisture of the layout and avoid ink emulsification.
Third, the paper pulled hair, off powder
The paper and paper that are pulled down from the paper are often stacked on the plate, the rubber surface, the ink fountain and the ink roller, affecting the product quality. The reason is that the paper surface is rough and soft, and the viscosity of the ink is too high. Can properly reduce the viscosity of the ink, cleaning rubber and printing plates. Ink roller, or replace better paper.
Fourth, the ink is drying slowly
Fingerprints do not dry within a predetermined time or for a long time. The reason is to add an excessive amount of dissolving agent or dissolving agent to the ink. In order to make the printed materials dry according to people's wishes, it is necessary to select inks with fast drying properties to minimize the amount of additives, and add appropriate amounts of desiccants depending on the printing conditions. The maximum amount should be controlled at 5%.
Five, stained prints
When printing a large area of ​​solid printing on coated paper, it is likely to cause stains, which is more harmful to printed products. Usually due to the low ink grade or deployment negligence, the ink is too thin and the hue is light. Therefore, bright and fast-drying inks should be used, and the amount of auxiliary agents should be strictly controlled. It should not be too thin. Under the premise of ensuring the quality of printed products, the thickness of the ink layer should be reduced as much as possible. If 5% of corn flour is added in the ink and mixed after printing, the stickiness can be overcome.
At present, there are many kinds of domestic offset printing inks sold on the market. Mainly can be divided into three categories:
1. Offset resin ink. Offset resin inks are mainly synthetic resin binder inks. For monochrome, two-color offset printing machine in offset paper, letterpress paper, whiteboard printing ordinary trademarks, advertising, books, cover, book block and other products, with good printability. Low price and so on.
2. Offset bright ink. Offset Bright Ink is a mid-range ink formulated from synthetic resins, dry vegetable oils, high-boiling paraffinic oils, and high-quality pigments. For monochrome, two-color or multi-color offset printing machine on the coated paper printing higher-level albums, color pictures and various types of trademarks, the ink of the standards are higher than the offset printing resin ink.
3. Offset light fast drying four-color ink. With good printability, fast drying, high gloss, colorful and so on. Suitable for printing advanced coated paper and all kinds of advanced paper, and the better the paper, the clearer the network, the better the quality of the print. In the high-speed printing, it is not necessary to spray powder or paper, and the printed product is not easy to be dirty, which not only reduces the labor intensity of the operator, but also improves the quality and yield of the product.
Under normal circumstances, the above three types of offset inks can be selected and used according to different conditions. In the printing process, due to the differences in paper, printing plates, equipment, and processes, it is necessary to properly formulate and print. If it is improperly deployed, it will cause many problems. Here are some suggestions for common ink failures.
First, the printing plate ink dirty
Many ink stains of different sizes appeared on fingerprint printing plates, and they quickly appeared in the original place or elsewhere after being wiped off. This is related to inks, plates, potions, etc. It is one of the common faults. In the case of inks, it is usually due to the addition of a detackifier and an overdose of overdose to make it too thin, resulting in a decrease in viscosity and water resistance. Therefore, it is necessary to strictly control the amount of release agent and dispersant, generally controlled within 50%, try to maintain the original performance of the ink.
Second, paste version
It refers to the spread of ink spread, the network of dots, and the unclear level, which prevents printing from proceeding properly. The reasons are various, in which adding an excessive amount of additives in the ink reduces the viscosity and viscosity of the ink and causes the emulsification of the ink to be the main reason. Therefore, during the printing process, the principle of color depth and thin printing should be followed, and the amount of auxiliary agents should be appropriately controlled to maintain the viscosity and viscosity of the ink as much as possible to control the moisture of the layout and avoid ink emulsification.
Third, the paper pulled hair, off powder
The paper and paper that are pulled down from the paper are often stacked on the plate, the rubber surface, the ink fountain and the ink roller, affecting the product quality. The reason is that the paper surface is rough and soft, and the viscosity of the ink is too high. Can properly reduce the viscosity of the ink, cleaning rubber and printing plates. Ink roller, or replace better paper.
Fourth, the ink is drying slowly
Fingerprints do not dry within a predetermined time or for a long time. The reason is to add an excessive amount of dissolving agent or dissolving agent to the ink. In order to make the printed materials dry according to people's wishes, it is necessary to select inks with fast drying properties to minimize the amount of additives, and add appropriate amounts of desiccants depending on the printing conditions. The maximum amount should be controlled at 5%.
Five, stained prints
When printing a large area of ​​solid printing on coated paper, it is likely to cause stains, which is more harmful to printed products. Usually due to the low ink grade or deployment negligence, the ink is too thin and the hue is light. Therefore, bright and fast-drying inks should be used, and the amount of auxiliary agents should be strictly controlled. It should not be too thin. Under the premise of ensuring the quality of printed products, the thickness of the ink layer should be reduced as much as possible. If 5% of corn flour is added in the ink and mixed after printing, the stickiness can be overcome.
Collapsible Water Bottle,Stainless Steel Drinkware,Collapsible Silicone Bottle,Stainless Steel Food Containers
Jieyang Huiyi Hardware Products Co., Ltd. , https://www.chinagdhuiyi.com