subject: The Role Of Offset Fountain Solution And The Control (lower) - Offset Printing, Fountain Solution, [print this page] The concentration of fountain solution control
Fountain solution is the concentration of fountain solution containing the amount of stock solution. Generally wet powder or liquid fountain liquid.
Many Printing The use of fountain solution, only pay attention to the pH of fountain solution to control the required range (pH = 5.0 ~ 6.0), neglecting the fountain solution concentration. As part of the fountain solution added to a larger buffer, the concentration of fountain solution in the great changes, its pH (the PH value) did not change significantly, so only the control of pH value is not scientific .
Because the fountain solution concentration in its chemical composition changes, which affect the ink-water balance. Fountain solution concentration, will cause Surfactant Concentration change, causing changes in surface tension. In the fountain solution in high concentration can cause Ink Emulsification, hinder blot dry, high-speed printing process, because the temperature factors make fountain solution of Mg (HCO3) 2, Ca (HCO3) 2 decomposition, generates insoluble CaCO3 Calcium carbonate , MgCO3 Magnesium, attached to the water roll on, easy transfer of water to prevent appeared dirty version fail, so it is necessary to make the water softening, further preparation. Therefore, the concentration of fountain solution is good or bad printing quality of key factors, we must maintain a stable pH (PH value), while controlling the concentration of a good fountain solution. In order to print graphic ink
bright, clear, blank pages can not afford to dirty, to be reasonable under the specific conditions for deployment of the printing fountain solution concentration, to ensure high-quality printing print.
1, paper properties and fountain solution concentration
Loose texture when printed paper or paper containing dust, due to large viscous printing inks, embossing the Central Standing Committee to make paper wool, paper powder piled Blanket , So that is bound to increase the friction plates, so easy to play dirty plates, in this case, should increase the concentration of fountain solution; in high and tight flat printing surface of paper degree, especially when printing Copper Version of paper and Glass When cardboard should be appropriate to reduce the concentration of fountain solution.
2, ink and fountain solution concentration performance
Different because the nature of the printing ink, the viscosity, mobility and acid resistance are different in nature, the size of the fountain solution concentration of the reaction will be correspondingly different, and should be appropriate to adjust the concentration of fountain solution. In general, the fountain solution concentration of the size of the use of principles: print red ink printed with black ink printing when the concentration is greater than the concentration; print printed with black ink printing when the concentration is greater than the concentration of green ink; the printing ink concentration of the dark is greater than the concentration of the printing light color ink.
3, Drier Size and amount of fountain solution concentration
Color printing plates stacked products, to enable faster drying ink, ink required to add up the dry oil, it also thicken the ink particles, viscosity increase, so parts of the printing blank pages to increase a sense of lipid, thus prone to paste version of ills. Because of this, liquid dosage should be increased appropriately.
4, plate and fountain solution concentration
Printing layout structure of a wide variety of products, both on the ground layout, but also the lines and textured pages. If the layout is the full version of the line, text-based, because of its larger set ink, fountain solution concentration to be appropriately adjusted larger. If all cable version, fountain solution concentration should be properly adjusted smaller.
5, ambient temperature and the concentration of fountain solution
When the printing environment temperature, the material necessary to accelerate the molecular motion, increased mobility of ink, and break down more of free fatty acids, so that printing pages from the dirty prone to the phenomenon of high temperature should be appropriately increased so Run version of solution concentration.
6, the printing speed and the concentration of fountain solution As the ink is thixotropic characteristics
, when the printing speed is high, the printer ink roller friction coefficient is large, easy to heat the ink thinning, its tinting strength fall, the black color hair short, this time inking a corresponding increase capacity to enhance the printing ink, printing plates so prone to play dirty on the phenomenon. Therefore, the printing speed is high, should increase the concentration of fountain solution.
7, if the printing pressure, blanket and pad material more rigid, they should consider appropriate increase in the concentration of fountain solution. To achieve better anti-dirty effect. Above shows that the concentration of fountain solution should be based on specific circumstances must be fully taken into account.
Fountain solution of Concentration:
Concentration of fountain solution conductivity measurement method can be used to determine, through experimental results show that the concentration of fountain solution and its conductivity changes in a linear relationship exists, that the greater the concentration, the greater the electrical conductivity, should be within the range to find a definite value as its value the best wetting results. We fountain syrup in the preparation of soft water should be used, ensure that its pH value between 4.5 to 5.5, while the conductivity should be proportional between 1200 ~ 600us/cm change. [Key words]: Offset printing Fountain Solution Print Comment Large In Small
