7.9.7 Plate Wear Plate wear is inevitable during the printing process, but if a regular operation is performed, the plate wear rate will be greatly reduced. The main cause of the wear of the printing plate is the relative slippage, that is, the frictional force, at the relative contact surfaces of the printing plate and other parts in contact with each other. Therefore reducing plate wear is to reduce friction.
1. Relative slippage between the water roller and the plate.
(1) The pressure between the water roller and the printing plate varies from the water roller to the water roller, and the pressure is equalized again.
(2) The water roller itself is not round with a caliper. Exceeding the requirements should be replaced.
(3) The glue on the watering roller is too loose. As a result, individual parts are out of regulation, causing the plate to wear.
(4) There are hard spots on the surface of the water roller, such as the ink sticking on it, etc., and the water roller is cleaned.
(5) The surface of the water roller has mostly been detached, replace the water velcro.
2. There is a relative shift between the ink roller and the plate. The cause of the failure and its removal method refer to "1."
3. The plate surface is uneven. The place where it protrudes is under pressure and is most likely to be worn. Replace the printing plate and choose a plate with good flatness (surface irregularity î±Â±0.02 mm).
4. The uneven underlay or gussets below the plate will cause the wear on the plate to wear faster. Replace the gasket.
5. Dirty or self-jumping above the plate cylinder can also cause plate wear. Keep the printing plate clean, if any off should be promptly wiped off; Check whether the plate roller's beating meets the requirements, if it exceeds the allowable value, it shall promptly find the reason and eliminate it.
6. The platen roll quotient after installation of the printing plate does not conform to the ideal plate cylinder diameter, so that the tangential velocity of the contact surface is not equal, resulting in wear of the printing plate. Re-select the drum liners so that their surface line speeds are as consistent as possible.
7. The runout of the blanket cylinder itself causes the plate to wear. Check the wear conditions of the bushes on both sides, and if it exceeds the allowable value, correct it in time.
8. The unevenness of the blanket accelerates the wear of the printing plate. Replace the blanket.
9. The diameter of the rubber roller shop package does not match the ideal diameter, which can also cause the plate to wear. The solution is the same as "5".
10. Printing pressure greater than the standard pressure will make the printing plate wear faster. Reduce printing pressure.
11. The high viscosity of the ink can also cause plate wear. Reduce the viscosity of the ink.
12. The stickiness of the blanket can also cause the plate to wear. Replace the blanket.
13. The vibration of the machine causes the plate to wear. Choose the right machine speed, use small printing pressures and other measures to reduce machine vibration.
7.9.8 Dot Slip (or Imprint Deformation)
Dot slippage refers to the fact that the dot distortion on the printed product exceeds the normal requirement. In fact, if you use any ruler to measure any print, you will find that it is not consistent with the print length on the plate. The cause of the dot slip is similar to the cause of the plate wear, and the elimination method is basically the same. However, after the transfer of dots from the plate to the blanket, the transfer from the blanket to the paper is also required. The transfer of this last step also has the problem of network slippage. This slip is related to the contact condition of the impression cylinder and the blanket. The troubleshooting method can be performed by referring to the above method.
7.9.9 Dirty dirt is the interaction between the surface of the printed sheet and certain parts of the machine during movement.
1. The pressure between the take-up roller and the pinch roller is too high. As the pressure between them is too great, as a result, the profile wheel of the pinch roller presses against the front side of the printed sheet, and an anilox line or cross fold on the pick roller presses against the back of the printed sheet. Because they are driven by friction, there is relative sliding between them and the printed sheets, so that the front or back side of the printed sheets are dirty. Reduce the pressure on the platen roller.
2. There is too much pressure between the paper strip on the transfer board and the platen. Therefore, there may be a slight relative slippage between the platen, the paper, the transport belt, and the paper feed, so that the front or back side of the print product wins. Tighten the belts to reduce the pressure on the rollers. In addition, the brush and other components on the paperboard should also be adjusted properly so as not to make the front sheet dirty.
3. The regulatory pressure plate lifted too late. As the film is too late, there is friction between the surface of the printed sheet and the regulatory plate and the gauge plate, so that the surface of the printed product will win. Adjust the pull time of the side gauge to make it lift earlier.
4. I would like to give the gift to the surface of the paper when I return. The timing of the preceding regulations is incorrect and readjust. The front cap is too high, reducing the height of the front cap.
5. The paper teeth do not return to the surface of the paper. The paper feed roller is not mounted, so that the paper is tilted upwards; the paper feed mechanism above the paper feed tooth is not flexible; the paper is too thick to bend, and the paper is replaced.
6. The front roller and the back transfer sheet are dirty.
(1) Anti-fouling cloth has not achieved the function of preventing flooding. The use of the surface's elasticity to prevent flooding is mainly used to prevent flooding. If it loses its elasticity, it will not achieve anti-fouling effect. In this case, it should be replaced. Dirty cloth.
(2) The anti-smearing cloth is too tight or too loose to prevent re-installation.
(3) The amount of ink and foreign matter floating on the surface of the anti-fouling cloth is too small to form a slight relative slip with the surface of the print, resulting in dirt on the surface of the print.
7. The prints will also be chased by their intimacy in the roller row. Check the bite force in the tooth row, reduce the viscosity of the ink and reduce the printing pressure.
8. The sheet is curled on the delivery roller surface. When printing onto the delivery cylinder, the thickness of the ink is the largest, and it is also the most likely to pick up the dirt. Therefore, the printing pressure of the last group should be as small as possible, so as to reduce the possibility of relative slipping of the sheet on the take-up roller.
9. Anti-mosquito institutions will not be able to prevent dirt. The anti-fouling mechanism for the delivery area is generally used for anti-road wins or anti-smashing wins. The role of the anti-Sai-Sheng cloth belt is similar to that of the anti-smeared cloth, and the cause of the failure and the method of elimination are similar. In theory, it is best to keep the paper suspended in the air at the delivery area, so now more gas is used to achieve anti-fouling. Blow under the printed sheets, use the pressure difference to float the paper, if the air is not working, it will cause the back of the dirty sheet.
10. The turbidity caused by the paper feeder. The paper feeder itself is used for the tail of the whole paper, but when the air suction of the paper feeder is too large, the back of the print sheet is brought into close contact with the paper feeder, which causes back rubbing. Therefore, when the paper is turned over, no paper is used. Device.
11. The surface flaw caused by the brake roller. The principles of the tamper are similar to that of the paper feeder, and the method of troubleshooting is similar.
12. The flush mechanism causes the surface of the printed sheet to become dirty. When the paper trimming mechanism neatly prints, the print slips a certain amount of slip on the take-up pile, so that the back of the print is dirty. Correctly adjust the position of the paper squeezing mechanism so that it has the least influence on the printed sheets.
13. Slides on the delivery pile can also cause surface smearing. Therefore, the printed products that have just been printed should be kept stationary at the delivery pile, and should not be turned by hand.
14. Other tapes cause the possibility of dirtiness. All parts of the printed sheet that go through the course of the printing process should be in normal working condition. However, some parts are loose or improperly installed and deviate from their normal positions. At this time, it may cause surface blemishes. Therefore, when you encounter a dirty fault, you should carefully check the cause.
7.9.10 Viscosity is the sticking of the upper and lower two sheets of printing. The essential cause of sticky ink is that the ink is not completely dry. Therefore, how to make the printed sheets fast dry is the fundamental measure to solve the stickiness.
1. Use quick-drying ink. Especially for multi-color printing, the quick-drying properties of the ink are particularly important. If you find that the ink is drying too slowly, add a small amount of desiccant.
2. Use a dampening treatment with a pH close to 7. The smaller the pH value, the longer the drying time of the ink. The concentration of the fountain solution should be reduced.
3. Increase the amount of dusting. The larger the amount of dusting, the greater the area separating the printed sheets, allowing the ink to have a sufficiently long drying time.
4. Ensure proper temperature. At a higher temperature, the ink oxidizes the conjunctiva faster.
5. Improve ventilation performance. The better the ventilation, the faster the ink will dry. However, it should be noted that this cannot be done for semi-finished products. In addition, the ventilation facilitates heat dissipation due to the heat generated when the ink oxidizes the conjunctiva.
6. The suction volume of the brake roller should not be too large. A certain amount of air should be present between the printed sheets to prevent partial vacuum of the sheets.
7. The printed sheets should not be piled up too high. Too high Because the weight of the paper is too large, it may cause the underlying paper to stick together. (Finish)
1. Relative slippage between the water roller and the plate.
(1) The pressure between the water roller and the printing plate varies from the water roller to the water roller, and the pressure is equalized again.
(2) The water roller itself is not round with a caliper. Exceeding the requirements should be replaced.
(3) The glue on the watering roller is too loose. As a result, individual parts are out of regulation, causing the plate to wear.
(4) There are hard spots on the surface of the water roller, such as the ink sticking on it, etc., and the water roller is cleaned.
(5) The surface of the water roller has mostly been detached, replace the water velcro.
2. There is a relative shift between the ink roller and the plate. The cause of the failure and its removal method refer to "1."
3. The plate surface is uneven. The place where it protrudes is under pressure and is most likely to be worn. Replace the printing plate and choose a plate with good flatness (surface irregularity î±Â±0.02 mm).
4. The uneven underlay or gussets below the plate will cause the wear on the plate to wear faster. Replace the gasket.
5. Dirty or self-jumping above the plate cylinder can also cause plate wear. Keep the printing plate clean, if any off should be promptly wiped off; Check whether the plate roller's beating meets the requirements, if it exceeds the allowable value, it shall promptly find the reason and eliminate it.
6. The platen roll quotient after installation of the printing plate does not conform to the ideal plate cylinder diameter, so that the tangential velocity of the contact surface is not equal, resulting in wear of the printing plate. Re-select the drum liners so that their surface line speeds are as consistent as possible.
7. The runout of the blanket cylinder itself causes the plate to wear. Check the wear conditions of the bushes on both sides, and if it exceeds the allowable value, correct it in time.
8. The unevenness of the blanket accelerates the wear of the printing plate. Replace the blanket.
9. The diameter of the rubber roller shop package does not match the ideal diameter, which can also cause the plate to wear. The solution is the same as "5".
10. Printing pressure greater than the standard pressure will make the printing plate wear faster. Reduce printing pressure.
11. The high viscosity of the ink can also cause plate wear. Reduce the viscosity of the ink.
12. The stickiness of the blanket can also cause the plate to wear. Replace the blanket.
13. The vibration of the machine causes the plate to wear. Choose the right machine speed, use small printing pressures and other measures to reduce machine vibration.
7.9.8 Dot Slip (or Imprint Deformation)
Dot slippage refers to the fact that the dot distortion on the printed product exceeds the normal requirement. In fact, if you use any ruler to measure any print, you will find that it is not consistent with the print length on the plate. The cause of the dot slip is similar to the cause of the plate wear, and the elimination method is basically the same. However, after the transfer of dots from the plate to the blanket, the transfer from the blanket to the paper is also required. The transfer of this last step also has the problem of network slippage. This slip is related to the contact condition of the impression cylinder and the blanket. The troubleshooting method can be performed by referring to the above method.
7.9.9 Dirty dirt is the interaction between the surface of the printed sheet and certain parts of the machine during movement.
1. The pressure between the take-up roller and the pinch roller is too high. As the pressure between them is too great, as a result, the profile wheel of the pinch roller presses against the front side of the printed sheet, and an anilox line or cross fold on the pick roller presses against the back of the printed sheet. Because they are driven by friction, there is relative sliding between them and the printed sheets, so that the front or back side of the printed sheets are dirty. Reduce the pressure on the platen roller.
2. There is too much pressure between the paper strip on the transfer board and the platen. Therefore, there may be a slight relative slippage between the platen, the paper, the transport belt, and the paper feed, so that the front or back side of the print product wins. Tighten the belts to reduce the pressure on the rollers. In addition, the brush and other components on the paperboard should also be adjusted properly so as not to make the front sheet dirty.
3. The regulatory pressure plate lifted too late. As the film is too late, there is friction between the surface of the printed sheet and the regulatory plate and the gauge plate, so that the surface of the printed product will win. Adjust the pull time of the side gauge to make it lift earlier.
4. I would like to give the gift to the surface of the paper when I return. The timing of the preceding regulations is incorrect and readjust. The front cap is too high, reducing the height of the front cap.
5. The paper teeth do not return to the surface of the paper. The paper feed roller is not mounted, so that the paper is tilted upwards; the paper feed mechanism above the paper feed tooth is not flexible; the paper is too thick to bend, and the paper is replaced.
6. The front roller and the back transfer sheet are dirty.
(1) Anti-fouling cloth has not achieved the function of preventing flooding. The use of the surface's elasticity to prevent flooding is mainly used to prevent flooding. If it loses its elasticity, it will not achieve anti-fouling effect. In this case, it should be replaced. Dirty cloth.
(2) The anti-smearing cloth is too tight or too loose to prevent re-installation.
(3) The amount of ink and foreign matter floating on the surface of the anti-fouling cloth is too small to form a slight relative slip with the surface of the print, resulting in dirt on the surface of the print.
7. The prints will also be chased by their intimacy in the roller row. Check the bite force in the tooth row, reduce the viscosity of the ink and reduce the printing pressure.
8. The sheet is curled on the delivery roller surface. When printing onto the delivery cylinder, the thickness of the ink is the largest, and it is also the most likely to pick up the dirt. Therefore, the printing pressure of the last group should be as small as possible, so as to reduce the possibility of relative slipping of the sheet on the take-up roller.
9. Anti-mosquito institutions will not be able to prevent dirt. The anti-fouling mechanism for the delivery area is generally used for anti-road wins or anti-smashing wins. The role of the anti-Sai-Sheng cloth belt is similar to that of the anti-smeared cloth, and the cause of the failure and the method of elimination are similar. In theory, it is best to keep the paper suspended in the air at the delivery area, so now more gas is used to achieve anti-fouling. Blow under the printed sheets, use the pressure difference to float the paper, if the air is not working, it will cause the back of the dirty sheet.
10. The turbidity caused by the paper feeder. The paper feeder itself is used for the tail of the whole paper, but when the air suction of the paper feeder is too large, the back of the print sheet is brought into close contact with the paper feeder, which causes back rubbing. Therefore, when the paper is turned over, no paper is used. Device.
11. The surface flaw caused by the brake roller. The principles of the tamper are similar to that of the paper feeder, and the method of troubleshooting is similar.
12. The flush mechanism causes the surface of the printed sheet to become dirty. When the paper trimming mechanism neatly prints, the print slips a certain amount of slip on the take-up pile, so that the back of the print is dirty. Correctly adjust the position of the paper squeezing mechanism so that it has the least influence on the printed sheets.
13. Slides on the delivery pile can also cause surface smearing. Therefore, the printed products that have just been printed should be kept stationary at the delivery pile, and should not be turned by hand.
14. Other tapes cause the possibility of dirtiness. All parts of the printed sheet that go through the course of the printing process should be in normal working condition. However, some parts are loose or improperly installed and deviate from their normal positions. At this time, it may cause surface blemishes. Therefore, when you encounter a dirty fault, you should carefully check the cause.
7.9.10 Viscosity is the sticking of the upper and lower two sheets of printing. The essential cause of sticky ink is that the ink is not completely dry. Therefore, how to make the printed sheets fast dry is the fundamental measure to solve the stickiness.
1. Use quick-drying ink. Especially for multi-color printing, the quick-drying properties of the ink are particularly important. If you find that the ink is drying too slowly, add a small amount of desiccant.
2. Use a dampening treatment with a pH close to 7. The smaller the pH value, the longer the drying time of the ink. The concentration of the fountain solution should be reduced.
3. Increase the amount of dusting. The larger the amount of dusting, the greater the area separating the printed sheets, allowing the ink to have a sufficiently long drying time.
4. Ensure proper temperature. At a higher temperature, the ink oxidizes the conjunctiva faster.
5. Improve ventilation performance. The better the ventilation, the faster the ink will dry. However, it should be noted that this cannot be done for semi-finished products. In addition, the ventilation facilitates heat dissipation due to the heat generated when the ink oxidizes the conjunctiva.
6. The suction volume of the brake roller should not be too large. A certain amount of air should be present between the printed sheets to prevent partial vacuum of the sheets.
7. The printed sheets should not be piled up too high. Too high Because the weight of the paper is too large, it may cause the underlying paper to stick together. (Finish)
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