Ink chalking often occurs in book printing, so how can we avoid this
phenomenon? In order to avoid the chalking of the printing ink of the catalogue,
the first reason is to analyze the cause:
(1) When printing catalogue, the adhesion of the ink is too small, and the
surface of the paper is relatively smooth, so that the ink layer and the
surface of the paper are not well adhered, which further causes the ink layer
to be wiped off from the paper surface.
(2) Since the ink is too thin, the binder
is easily absorbed by the paper, and a large amount of the binder penetrates
into the paper, causing the binder and the pigment to separate in the ink,
causing the pigment particles to float on the paper surface, and the pigment
loses the binder. Adhesion, the degree of bonding is lowered, so that it does not
adhere well to the paper surface, causing shedding.
(3) The used ink is emulsified severely,
not only reducing the viscosity, drying speed, increasing the amount of
penetration, but more importantly, the emulsified ink is not bonded to the
paper surface after the film is conjuncted, the adhesion is poor, and the film
layer is firm. Very poor, a slight rub will cause the film to rupture and fall
off.
(4) Coated paper is coated on the base
paper. The paint and base paper have strong absorption, and the paper is
thicker and can absorb a large amount of binder. In addition, the surface of
the coating is smooth and the pores are very fine. It is possible to inhale the
pigment together and act as a filter layer, causing the pigment particles to
float on the paper surface and fall off due to the lack of wrapping of the
binder.
The above is the possible reason for the chalking
of the printing ink of the catalogue. Now we find the reason, and the next step
is to analyze the method. Summary of the treatment to prevent ink chalking:
(1) It is not necessary to print the
product without strong absorbent paper (absorbability is less than 30 seconds),
otherwise it must be printed with a strong resin ink.
(2) Add the No. 0 varnish or adhesive to
the paper to enhance the adhesion of the ink to the paper surface.
(3) Control the emulsification of the ink,
and the water consumption of the plate should be small. Frequently measure the
pH value of the water bucket solution and adjust it to the required value. The
dry oil should be added as needed to reduce the ink emulsification to
facilitate the drying time.
(4) Fine products that have been powdered
can be solved by glazing or filming.
