Lithography is the use of the principle of oil and water don't mix, plate
graphic department can oil-wet hydrophobic, gap department water before with
hydrophilic oleophobic selective adsorption. Another characteristic is using
indirect printing, offset printing using dot color way for color copy. Offset printing ink sure if appropriate, in
the normal transfer of imprinting, inky depth, color correct, print dry and
sticky dirty, etc is very important. Can accurately grasp and control the ink
balance, therefore, is to ensure that the print quality not disorderly of hub.
As a high-tech printing workers, should not only know the ink balance
relationship, more master ink balance technology and essentials should be
polished.
Ink balance refers to the certain and the printing pressure,
printing speed adjust the supply of education version liquid, emulsion to make
the ink contains education version after the volume of the proportional control
in 15% ~ 26%, and form a level slightly water-in-oil (W/O) emulsion inks, with
minimal amount of feed liquid on the plate printing ink.
Ink balance is the
most important thing in education version control fluid and ink. Education
version fluid is composed of water and surfactant, education version fluid can
be fully wetting layout, cleaning ability and not disorderly of pH value, ensure
layout doesn't dirty.
1) the role of education version fluid
(1) in the
department of plate gap formation water film on average, in order to prevent the
ink on the graphic to open branch of infiltration, to prevent dirty
version.
(2) using the education version in the liquid electrolyte with bare
metal versions due to abrasion produces chemical reaction, constantly create new
layer, maintain layout department of hydrophilic gaps.
(3) control the
temperature of the layout of printing ink. Because the new printing presses
faster and faster, with print speed too fast will make the ink in the high-speed
transmission temperature, the activity of the ink is increased, which resulted
in increased network. So puts forward new requirements for education version
fluid high-speed machine, namely the education version fluid in contact with the
ink forme roller through the layout, can reduce the temperature of the ink
roller and ink.
(4) do not make by larger or smaller. Education version with
not disorderly plate is required by department and the function of the relative
position vacancy department, guarantee in the whole process of printing, graphic
neither to expand or narrow.
Ink generally composed of pigment, filler, links
and auxiliary additives, selection of ink should be fully considered when ink
rheology function and optical function.
Ink rheology function to determine
whether the ink has good printing function of main basis. Ink rheology function
mainly depends on ink link, of course, also can be regulated by the appropriate
auxiliary additives. Ink rheology function evaluation can be reflected through
the main function of ink rheology indexes, namely, ink viscosity, viscosity,
thixotropy, yield, viscoelastic and activity and so on. In practical production,
only grasp the function index, to be familiar with various types of ink printing
property, so as to achieve the purpose of the selection to meet the requirements
of printing ink.
Print must exist at the same time, surface printing ink and
water balance, the purpose is to keep both graphic printing area maximum ink
quantity, make bright inky, saturated, points clear bright and clean, but also
to keep the printing area clean and tidy, which requires attention to adjust the
volume of water and ink in the produce of the relationship.
In printing, the
printing quality of imprinting inky depth, in addition to related to the amount
of the ink ink fountain, also directly affected by the water supply and layout
of ink balance. When the layout of water increases, the imprinting inky dodge
becomes shallow gradually. Conversely, reducing water supply section water,
imprinted ink is relatively deep than the original. So, more or less ink
quantity and layout of water supply will change imprinting inky depth. In the
printing process, should be adjusted according to actual situation. Should not
rely on to reduce the water supply to progress as required, because the water is
too small, loss of balance of ink, easy to make dirty with the vacancy
department.
But the need to prevent water on the big ink. When the moisture
of excessive, inky becomes shallow, must have to actual situation, mistakenly
assume that ink quantity is little, not to reduce the water supply, but to
frequent increase in the volume of ink. Ruth reciprocating to increase water
supply for ink, resulting in a vicious cycle, the ultimate water ink big all
ills, printing from otherwise normal operations.
Experienced printing
workers, in actual production, often under the condition of can't afford to
ensure plate dirty, control the water supply in the range of as small as
possible, and the amount of water and ink is not disorderly state, so it can
ensure the printing quality before and after the inky depth is consistent and
printing work. Advocate the practice of using water is small, the ink thickness,
the water of the little finger is conditional on the level of vacancy layout
department doesn't dirty minimum water; The so-called ink thickness, is built on
the basis of water small, water ink caused by excessive emulsification, thick
ink layer is impossible. (Gold Printing
Group)
Book Printing
Printing in China
Notebooks Printing
Printing in China
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