How to maintain the printing plate roller
The printing plate roller, as one of the accessories of the offset printing brush machine, has a significant impact on the printing quality of the product. Without a good printing plate roller, it is impossible to print high-quality products. Therefore, how to scientifically, correctly, and reasonably use and maintain the printing plate roller is a manufacturing skill that printing operators and editors should master. It has a very important significance in improving manufacturing efficiency and ensuring printing quality.
Printing plate roller
1、 To maintain the cleanliness of the colloidal surface of the printing plate roller to enhance its viscosity and achieve good ink transfer and distribution.
In the printing process, to achieve uniform ink transfer and cloth ink, it is necessary to maintain a certain degree of stickiness on the colloidal surface. But because the printing plate roller is used for a long time, its surface will lose moisture and its adhesion performance will decrease. In addition, due to paper dust, paper fuzz, and other properties, it can affect the transmission of ink and easily cause uneven ink distribution. To maintain a certain viscosity of the printing plate roller, it is necessary to prevent the ink from drying too quickly and causing the printing plate roller to peel. For ink that needs to be dried, the amount of drying oil should be controlled properly. Generally speaking, the amount of resin ink added with white drying oil should not exceed 5%; Oil type ink with white dry oil not exceeding 10%; The appropriate amount of red drying oil should be around 2% to prevent the printing quality from being affected by the ink buildup on the printing plate rollers. To maintain the cleanliness of the printing plate roller, it is advisable to clean the printing plate roller in a timely manner to remove impurities and paper dust on the colloid, in order to improve ink transfer performance. In offset printing operations, ink emulsification is necessary, but the ink emulsification caused by "large water and large ink" will present a hydrophilic foundation on the smooth printing plate roller, causing the printing plate roller to deink and the fountain solution to corrode the adhesive surface. Therefore, on the premise of not sticking or getting dirty, the less lubricant should be used, the better.
2、 Ensure that the printing plate roller is in a suitable position on the printing machine at high speed to avoid damage and poor ink quality caused by improper use.
The appropriate position of the printing plate roller is directly related to the uniformity of ink transfer and brushing, as well as the durability of the printing plate roller. Therefore, the contact pressure between each ink roller should be kept uniform and moderate. The contact pressure between the bitter ink printing plate roller and the ink iron roller is too high, which can cause the printing plate roller to deform under pressure, and the colloid is prone to excessive heating and expansion. The ink is also prone to thinning when heated, affecting the quality of the printing ink color; On the other hand, it is easy to damage the printing plate roller shaft head (bearing) or shaft hole. If the height adjustment of the ink roller is not suitable, adjusting it too high will cause uneven ink distribution. Setting it too low can easily scratch the colloid and exacerbate the wear of the printing plate. Therefore, the inking roller should be adjusted to maintain balance with the printing plate layout to ensure uniform ink brushing throughout the entire layout. The contact between the high ink roller and the printing plate can usually be achieved by placing a piece of paper with strong toughness of about 40g on the printing plate. After the ink roller is rolled and pressed on, the paper can be pulled with a sense of pressure resistance.
3、 Several key points for the correct use and maintenance of printing plate rollers
1. The newly cast printing plate roller should not be put into use immediately
Because the internal structure of the newly cast printing plate roller is not stable enough, if it is immediately put into use, it is easy to reduce its service life. Therefore, the new printing plate roller that has just come out of the cylinder should be left for a period of time to maintain a relatively stable state after being exposed to the external temperature and humidity. This can increase the toughness of the colloid and enhance its durability.
2. Correct storage of idle printing plate rollers
Standby
