SET-OFF POWDERS WORK
The primary function of anti set-off powders
is to form a separation between the sheets of stock as they leave the
press. This separation traps air between the sheets to speed ink drying.
It also breaks the suction effects of wet ink and static and prevents the
ink from setting off onto the sheet above. This spray's ability to
perform this function is a result of a combination of particle size,
density and the number and nature of particles applied. The largest users
of anti set-off powders are folding carton printers, followed by label
printers, large letterpress printers, flexographic printers and large
offset printers. Usually, as the weight of the printing stock increases,
the recommended particle size also increases.
DO YOU USE COATED POWDERS, OR REGULAR POWDERS?
This data should help you identify the best
first choice spray powder.
powders represent the vast majority of applications. Select
coated powders for large corrugated printers, folding carton
manufacturers, most four color work done on four color presses and most
large sheetfed printers that run large heavy lifts of paper. The grade of
coated spray powder is determined by the weight of the paper stock, type
of printing and spray equipment. As a rule of thumb, the grade of coated
powder (and the micron size) increases as the weight of the paper stock or
height of the stack increases.
powders are usually used in work and turn printing, four color
printing on presses which do not have four units, multiple color printing
on presses with lesser printing units than the number of colors printed,
any printing that requires multiple passes through the press. There are
some exceptions, but trapping, especially on small presses, is a little
easier with regular spray powder.