Page 412 - Solid Waste Analysis and Minimization a Systems Approach

390 PRINTING AND PUBLISHING APPLICATIONS

Printing machine operators, also known as press operators, prepare, operate, and
maintain printing presses. Duties of printing machine operators vary according to the
type of press they operate. Traditional printing methods, such as offset lithography,
gravure, flexography, and letterpress, use a plate or roller that carries the final image
that is to be printed and copies the image to paper. In addition to the traditional print-
ing processes, plate-less or nonimpact processes are coming into general use. Plate-
less processes—including digital, electrostatic, and ink-jet printing—are used for
copying, duplicating, and document and specialty printing. Plate-less processes usually
are done by quick printing shops and smaller in-house printing shops, but increasingly
are being used by commercial printers for short-run or customized printing jobs.
Machine operators’ jobs differ from one shop to another because of differences in
the types and sizes of presses. Small commercial shops can be operated by one person
and tend to have relatively small presses, which print only one or two colors at a time.
Large newspaper, magazine, and book printers use giant “in-line web” presses that
require a crew of several press operators and press assistants.
After working with prepress technicians to identify and resolve any potential prob-
lems with a job, printing machine operators prepare machines for printing. To prepare
presses, operators install the printing plate with the images to be printed and adjust the
pressure at which the machine prints. Then they ink the presses, load paper, and adjust
the press to the paper size. Operators ensure that paper and ink meet specifications,
and adjust the flow of ink to the inking rollers accordingly. They then feed paper
through the press cylinders and adjust feed and tension controls. New digital technol-
ogy, in contrast, is able to automate much of this work.
While printing presses are running, printing machine operators monitor their oper-
ation and keep the paper feeders well stocked. They make adjustments to manage ink
distribution, speed, and temperature in the drying chamber, if the press has one. If
paper tears or jams and the press stops, which can happen with some offset presses,
operators quickly correct the problem to minimize downtime. Similarly, operators
working with other high-speed presses constantly look for problems, and when nec-
essary make quick corrections to avoid expensive losses of paper and ink. Throughout
the run, operators must regularly pull sheets to check for any printing imperfections.
Most printers have, or will soon have, presses with computers and sophisticated instru-
ments to control press operations, making it possible to complete printing jobs in less
time. With this equipment, printing machine operators set up, monitor, and adjust the
printing process on a control panel or computer monitor, which allows them to control
the press electronically. In most shops, machine operators also perform preventive
maintenance; they oil and clean the presses and make minor repairs.
In contrast to many other classification systems that locate publishing of printed mate-
rials in manufacturing, the North American Industry Classification System (NAICS) clas-
sifies the publishing of printed products in subsector 511, publishing industries (except
Internet). Though printing and publishing are often carried out by the same enterprise
(a newspaper, for example), it is less and less the case that these distinct activities are car-
ried out in the same establishment. When publishing and printing are done in the same
establishment, the establishment is classified in sector 51, information, in the appropriate
NAICS industry even if the receipts for printing exceed those for publishing.