[China Packaging Network News] The rubber roller as one of the accessories of the adhesive printing press has a great influence on the printing quality of the product. Without a good rubber roller, it is impossible to print high-quality products. Therefore, how to scientifically, correctly and reasonably use and maintain a good quality printing roller is a production skill that should be mastered by the printing operator. It improves the production efficiency and ensures the printing quality. , has a very important significance.
First, it is necessary to keep the surface of the colloidal rubber cleaner to increase its viscosity, and to achieve a good ink transfer and cloth effect.
In the printing process, to achieve ink transfer, ink uniform, the surface of the colloid must maintain a certain viscosity. However, since the rubber roller is used for a long time, its surface will dissipate with moisture, and the adhesive performance will be reduced. In addition, due to the paper dust, paper hair, and Other properties that affect the ink transfer, it is also easy to create uneven ink defects. To keep the cohesive roller sticky, it is necessary to prevent the ink from drying too quickly to make the roller crust, and to control the amount of dry oil to be used for the ink to be dried. In general, the amount of resin ink plus white dry oil does not exceed 5%; oil type ink plus white dry oil does not exceed 10%; red dry oil plus volume is about 2% is appropriate, so as not to affect the printing quality of the roller roller knot ink. In order to keep the rubber roller clean, the rubber roller should be cleaned in due time, but the impurity and paper dust on the colloid should be removed to improve the ink transfer performance. In the offset printing operation, ink emulsification is necessary, but the ink emulsification produced by “great ink and large ink” will form a hydrophilic basis on a smooth rubber roll, deinking the rubber roll, and etching the glue surface by the dampening solution. Therefore, the fountain solution should be as small as possible without stickiness.
Second, it is necessary to accurately and quickly use a suitable position on the printing machine to avoid damage and ink damage caused by improper use.
Whether the position of the rubber roller is suitable or not is directly related to the uniformity of the ink transfer and the brushing, and also relates to the durability of the rubber roller. Therefore, the contact pressure between the ink rollers should be kept even and moderate. The contact pressure between the bituminous rubber roller and the skewer iron roller is too large. On the one hand, the roller is pressed and deformed, and the colloid easily spreads due to heat and ink. Heat and easy to thin, affect the quality of printing ink; on the other hand, it is easy to damage the roller head (bearing) or shaft hole. If the level of the ink roller is uncomfortable, adjusting it too high may result in maldistribution. Adjusting it too low will scratch the colloid and increase the wear of the plate. Therefore, the ink roller should be adjusted to keep a balance with the plate layout, so as to ensure uniform ink brushing across the entire layout. A high degree of contact between the ink roller and the printing plate, generally can put a 40g or so high toughness paper on the printing plate. When the ink roller is rolled up, the note can be pulled to have a sense of pressure resistance.
Third, the right way to use and maintain the rubber roller
1, the new cast rubber roller should not be put into use immediately
Because the internal structure of the newly cast rubber roller is not stable enough, if it is put into use immediately, it is easy to reduce the service life. Therefore, the new rubber roller that has just been released should be placed for a period of time so that the roller can maintain relative stability after being exposed to the ambient temperature and humidity. This can increase the toughness of the colloid and thus improve the durability.
2, the correct storage of idle rubber roller
After the cots to be used are to be cleaned, seal the parcels with plastic film and store them in a cool, dry and ventilated place in a vertical or horizontal position. Do not stack them together or place them upright next to the wall. In order to avoid undue loss of colloids, it is also necessary to avoid storing them with acids, alkalis, oils and sharp hard substances, so as to avoid corrosion and damage to the rubber roller. After the rubber roller is stored for 2 to 3 months, it should be changed in the direction to avoid long-term bending deformation in one direction, and to prevent the shaft head from rusting. In the process of transporting waste rubber rollers to the processing and casting process, it is strictly forbidden to throw chaotic pressures or heavy pressures to keep the cores of the roller cores from being eccentric or bent so as to ensure the normal use of the roller cores.
3, rubber roller shaft, bearings should maintain good lubrication
We know that the accuracy of the rubber roller shaft head and bearing directly affects the effect of ink transfer and ink printing. If the lubrication is bad, the roller shaft head, bearing wear and clearance, will inevitably lead to uneven printing ink. At the same time, it will also cause print marks due to bad conditions such as rubber dispensing and slipping. Therefore, usually should be ground to the rubber roller head, bearing lubrication oil to prevent the normal wear of the machine wear roller to ensure print quality.
4. When the machine stops, the platen roller and the plate cylinder should be detached and contacted to remove the load in time to prevent static pressure deformation.
5. When installing and disassembling, it should be handled with care, not touching the roll neck and the rubber surface, so as to avoid damage, bending or damage to the rubber surface of the roll body. The roll neck and the bearing must be tightly fitted. If the looseness should be promptly repaired and repaired. .
6, after the end of printing, the ink on the roller should be cleaned. Cleaning ink should choose special cleaning agent, and check whether there is still paper on the rubber roller, paper powder has not been washed away, paper hair, paper powder generally stay in the uniform ink roller, need to take a cloth to wipe.
7. A hardened film of ink is formed on the surface of the rubber roller, that is, when the plastic surface is vitrified, pumice powder is used to grind it off. When cracks appear on the surface of the rubber roller, grind it off as early as possible.
In summary, scientific and reasonable use and maintenance of the rubber roller can maintain its stable mechanical properties, chemical properties and printability, and prolong its service life. It plays a decisive role in improving production efficiency and ensuring product printing quality.
