How to judge quality rubberized shaft products

For a high-quality rubberized shaft products, its roller surface should be fine, smooth, slightly sticky and have good ink transfer performance. In the production process, the roller of high-quality rubberized shaft products is affected by fountain solution, ink, paper and other factors for a long time. In addition, it is impossible to clean thoroughly every time, and the remaining impurities accumulate on the surface of the rubber roller layer by layer. Over time, the original pores on the surface of the rubber shaft products will be closed, forming a smooth crystalline layer similar to calcium, which will seriously affect the ink transfer Water transmission performance, unable to stably control the ink color of printing. For this, after washing with car washing water every time, wash it with citric acid water again to make some calcium impurities on the surface of rubberized shaft products react chemically and form soluble substances for cleaning.

The roller surface of rubberized shaft products is easy to have scars and pockmarks. Because the rubberized shaft products are relatively soft, a little hard objects will be scratched during high-speed operation. In particular, alcohol fountain solution depends on the plate water roller. Once there are scratches, it can no longer be used. In order to avoid such failures, first, check whether the printing plate is tightened or the plate clamp is clamped, resulting in cracks and cracks at the trailing tip of the printing plate and scratches on the plate water roller and ink roller; The second is to see whether there is a large accumulation of impurities such as ink skin and ink residue due to the untimely maintenance of the ink roller, which accelerates the friction, heating and aging of the rubberized shaft products, and makes the surface of the rubber roller full of hemp eyes. This situation is generally more serious at both ends of the rubberized shaft products.

There are many reasons for premature chapping and aging of rubberized shaft products, such as excessive dry oil in the ink, which makes the ink dry and heat on the cot; The cleaning agent used to clean the rubberized shaft is improperly selected, and the cleaning time is too short, so the impurities on the roller of the rubberized shaft products can not be completely cleaned; The ambient temperature of the workshop is high, the fountain cooling system works poorly, a large amount of heat generated during the operation of rubberized shaft products cannot be dissipated in time, and the internal temperature of rubberized shaft is high; The rubber roller bearing has poor performance and is rotated by the inking roller, resulting in jumping friction, extrusion, etc.

Deinking

In offset printing operation, ink emulsification due to "large water and large ink" forms a hydrophilic foundation on smooth rubberized shaft products, and deinking will occur. The solution is to shovel off the emulsified ink, wash the deinking rubber roller, mix 5% aqueous solution with talc powder to polish the surface, remove the hydrophilic layer, and restore the hydrophilic characteristics of the ink roller. At the same time, the metal roll (or hard roll) shall also be treated accordingly. The hard roller can also be polished with fine water sand in the water drenching state. It cannot stay at the same position, otherwise the rubberized shaft products will be damaged. The fundamental way is to control the pH value of water bucket liquid, do a good job in water ink balance and reduce the emulsification degree of ink.