Reference Book
Web offset printing papers
Good quality paper is essential for web offset. Cleanliness and uniformity of
moisture content, thickness, substance weight and finish over the entire paper
surface are critical. The ink receptivity of the paper should be highly compatible
to the quick drying quality of the ink. The paper rolls must possess no weak
areas and must be able to withstand the greater stress the press equipment
impose. The rolls should arrive well protected and wound to proper tension
on well constructed cores of suitable diameter.Press console
Press console provide electronic control for register and image quality on the
moving web. Information such as web side lay, register, colour consistancy
etc. are computer controlled. Press adjustments can be made on the fly (as the
press is running at printing speed). Setting of each printing unit or couple,
such as ink and dampening settings and horizontal and vertical register can be
made directly from the console. The press operator monitors the console and
make adjustments by adjusting the switches on the console, which in turn
causes the appropriate adjustments on the press itself. Many presses have
automatic blanket washing units that are controlled by the press console.
Console reduces wastage of paper and the amount of press down time. Console
also reduces the number of people required to operate the press.
Assessment ActivitiesField visit
Student should visit a reputed web offset press.Record
Draw a schematic diagram of web-offset machine and mark its parts.
TE Qestions- Identify other operations besides printing done on a web press system.
- Perfecting blanket-to-blanket web presses use two __ cylinders
and two ___ cylinders. - Describe the construction and operation of common impression cylinder
presses. - Explain a web press operation in detail.
- Compare zero splicers and flying splicers.
- Explain the function of driers and chill rolls in a web offset press.
- Briefly explain about press console.