Lightweight Paper Performance Package
In the printing industry, lightweight paper is generally understood to be a group of substrates from 35-60 gsm, mostly uncoated mechanical paper grades and occasionally glazed (calendered). Although this is a niche application, these substrates are used in almost all industry segments: in commercial printing for bulk mailshots and inserts, in publications printing for songbooks and loose-leaf binders, in packaging printing for packet inserts, and in forms printing for billheads.
Printing lightweight paper by sheetfed offset generally does not permit high speeds because the material is less stable than material between 0.1 and 0.3 mm thick and cannot run reliably through the press. In addition, there are often quality constraints with lightweight paper: dog-eared corners, creasing and small tears. For printing companies who process a relatively high proportion of jobs on lightweight paper, these constraints and higher risk of press damage are annoying.
manroland has now introduced a Lightweight Paper Performance Package for the ROLAND 700 series. The result of extensive research and field tests include numerous technical solutions that focus on the feeder, infeed, delivery, and antistatic equipment. The performance package can increase production output by 30 percent or more. The increased output not only comes from a higher average printing speed but in particular through reducing or avoiding press stoppages in the feeder or infeed area through optimization of sheet separation and sheet feeding. The performance package provides straight-edged delivery stacks which increases productivity in the finishing operations.
A series of tests with the Lightweight Paper Performance Package have proven that production output is considerably higher – with 50 and 60 gsm paper, speeds of 15,000 sheets per hour and more are achievable depending on paper quality. However, there are other related factors that are critical for efficient printing of lightweight paper. The most important are room temperature (ideal 18-22 °C), air humidity (ideal 55-60%), pile humidity (ideal 45-55%), pile storage (separate, not stacked) and pile acclimatization time in the pressroom (ideal at least 48 hours).
The field tests have shown that printing lightweight paper is now possible with much fewer press stoppages which increases productivity. Furthermore, printers confirm that the sheet travel settings for ROLAND 700 presses are now much more user-friendly and “forgiving”.
