First, pay attention to the observation
sample
1 Sampling inspection in printing. Shortly
after entering the official book printing,
there will be some changes in the amount of ink supplied and the amount of
water that will be determined at the time of printing. It should be frequently
sampled and re-adjusted. When the printing speed remains the same, and the ink
supply amount and the water supply amount are all in a stable state, the
sampling inspection is performed at a ratio of 500 to 1000 sheets/time per
print.
2 Clip the warning tape. In official
printing, as a symbol, a slender warning strip should be inserted as a symbol
to facilitate the inspection in the post-process.
Second, pay attention to changes in water
1 Pay attention to the change in water
supply at the beginning of official book
printing. The amount of water applied during the trial printing and the
amount of water entering the official book
printing will change somewhat. Be sure to pay attention to the presence or
absence of ghosting and water scorpion while paying attention to mediating the
water supply of the printing plate.
2 Pay attention to the change of water in
the formal printing process. Too little water will make the plate dirty; too
much water will cause the ink to emulsified, which will bring a series of
problems. For example, the print is dull, the paper is stretched and the
overprint is not allowed, and the drying of the ink is delayed.
Third, pay attention to changes in ink
1 Pay attention to the ink of the ink
fountain. The amount of ink in the ink fountain directly affects the output of
the ink. In addition, printing inks have thixotropic properties. If it is
placed in the ink fountain for a long time, the fluidity will gradually
deteriorate. Therefore, it is often necessary to use an ink knife to stir in
the ink fountain or to install an ink agitator.
2 Prevent the ink from drying on the
machine. When the machine is stopped for a long time, such as eating or
resting, the ink on the ink roller and the surface of the ink in the ink
fountain are dried. A dry inhibitor can be sprayed on where it is desired to
prevent dryness.
3 Note that the ink is uniform, and the
density of the printed matter changes depending on the amount of water, room
temperature, and machine speed. It should always be checked against the
standard proofs. Take care to prevent uneven ink.
4 Keep the pH value of the dampening
solution. After adding the auxiliary agent to the ink, it will easily affect
the pH value of the dampening solution. If the pH value increases, the plate
will be dirty, so pay special attention.
Fourth, pay attention to the back of the
dirty
The back smudging is caused by the slow
drying of the ink, the excessive thickness of the ink layer, and the high
smoothness of the paper, so that the ink on the surface of the sheet sticks to
the back side of the previous sheet.
Five, pay attention to ghosting failure
1 Print twice, observe the overprinting
accuracy, check and adjust the paper feeding force of the side gauge, paper
feeding, pressure roller and paper pressing machine.
2 Check the tension of the blanket, the new
blanket is easy to loosen, pay attention to the tightening in several times,
but it should not be too tight.
3 Check the drum liner and printing
pressure.
4 Check the paper suitability.
5 reduce the viscosity of the ink.
6 adjustment of tooth decay.
Six, pay attention to check the overprint
situation
Remove 20~30 prints in succession, and then
pry open the paper edge to check whether the front gauge and side gauge are
positioned accurately (two overprint inspections can be performed).
Seven, pay attention to other work
1 ink replenishment, agitation and
replenishment of the wetting fluid.
2 remove dirty work.
3 cleaning blankets, wiping and gluing
operations.
4 Pay attention to the abnormal phenomenon
of the printing machine.
Eight, pay attention to confirm the number of prints
At
the end of the printing, it should be confirmed whether the number of prints
matches the production order. If there are any missing copies that need to be
printed, the production management personnel should be notified to make timely
arrangements for reprinting.
