Analysis and elimination of the most popular doubl

2022-08-06
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Double offset paper printing: analysis and elimination of pasting rubber blanket

ensure the normal use of the experimental machine

when printing field or large-area graphic products of the external wall external insulation system with poor quality double offset paper, it is easy to paste rubber blanket, which is a headache for the operators. Pasting rubber blanket will not only affect the production speed, increase labor intensity, waste raw materials and materials, but also cause quality accidents. Below, the author analyzes the phenomenon of sticking blanket caused by various reasons in his work

1. the printing pressure is too small

the printing process is a process in which the printing plate selectively adsorbs the ink and transfers the ink to the substrate through the blanket. However, due to the addition of paper wool and paper powder, the transfer of ink is hindered, so that the ink can not be smoothly transferred to the substrate, but remains on the blanket. By properly increasing the pressure between the three rollers to force the ink to unconditionally transfer to the substrate, the problem of pasting the blanket can be solved. However, while increasing the pressure between the rollers, the printing plate's printing resistance should also be considered. When printing large quantities of products, plate drying can be carried out to increase the printing resistance of the printing plate

2. the rubber layout part is uneven

if the rubber blanket and pad are used for a long time, they will be uneven. It is easy to accumulate paper wool and paper powder in the concave place, resulting in local pasting of blanket. In the concave place, wipe the reducing agent or stick 1 or 2 layers of transparent plastic tape on the back of the blanket to make it smooth. If it still can not solve the problem of partially pasting the blanket, the blanket and gasket can only be replaced

3. poor fluidity of ink

if the fluidity of the ink is poor or too sticky, the stripping force on the paper surface will increase, and the paper wool and paper powder on the paper surface will be easily stripped off, and then transferred to the printing plate, ink roller or ink tank through the blanket, resulting in a vicious cycle. When printing a large number of products, it should be cleaned timely according to the amount of paper wool and paper powder in the ink roller and ink tank, so as to ensure the printing resistance of the printing plate

adding an appropriate amount of auxiliary materials (No. 6 oil or diluent) to the ink can increase the fluidity of the ink, and then adding an appropriate amount of diluent can increase the mobility of the ink, so that the ink can be well transferred to the substrate and reduce the phenomenon of sticking blanket

in case of the above situation, some operators may mistakenly believe that adding an appropriate amount of adhesive remover can increase the fluidity of the ink turntable installed above the rack, but adding the adhesive remover also reduces the ink mobility, making it difficult to clean the ink pasted on the printing plate and the blanket, and the phenomenon of pasting the blanket will not be reduced

4. unreasonable arrangement of printing color sequence

if it is a four-color machine, the side with less text and ink can be placed in the front, so that the paper wool and paper powder can be left on the previous print

there are various reasons for pasting rubber blanket. The above points are some experiences summarized by the author in practice and are only for reference by peers

source: keyin

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