Four Color 20 Inch Perfecting Sheet-fed Offset
General
1. Press will be of heavy-duty design and manufacture consisting of four (4) individual printing units (see
specific specifications below). The Press must be new and of the current model configuration when
delivered. The design shall use continuous oil bath with filtration feeding oil to all critical internal
moving parts to insure long life with minimum downtime, and operate properly in conjunction with all
other specified hardware and software. Drive gears and cams are to be flame hardened to assure
longevity. Electronics are to be controlled by digitally controlled programmable controllers that have
the ability to accept a software program upgrade. The main drive motor shall be of a maintenance
free, brush free, inverter controlled style to minimize maintenance and downtime.
Feeder
2. Press feeder shall be of the continuous stream feed style using a rotary valve suction system and will
use telescoping pickup suckers. A separate set of forwarding suckers, an aluminum feed board, a
multi zone suction belt system, a vacuum hold down system at the in-feed position, and mechanical
pull side guide registration system will be utilized to insure smooth and reliable sheet feeding.
3. Press feeder shall provide an electronic (ultra sonic style) and mechanical double sheet detector, late,
early or skewed sheet detector, side guide detector, motorized feed board, electronic static eliminator,
sheet skew and sheet feeder timing adjustment, and drop down pull in wheel with pressure adjustment
shall be included to insure smooth reliable sheet feeding. An electronic diagnostic panel shall provide
the operator with information regarding feeder trip offs. The press shall include a remote feeder timing
adjustment to insure proper in-feed timing at all press speeds and paper thickness
4. Press feeder shall use a feeder table and have the ability to preload stock on an auxiliary pile. Two
feeder pile boards will be provided.
5.
Automation -The press shall be equipped with the following automation:
A. Sheet Size Presets - An auto set system that allows for the adjustment of the sheet size
components on the feeder and delivery will be automatically adjusted through the control
console and these adjustments should be selectable from either a stored menu of sheet sizes
or entered into a graphic user interface and these adjustments will include the following: side
guides at paper stacking section, feeder head position, pressure adjustments between
impression cylinder and blanket cylinder, side and rear edge paper stacking guides in the
delivery section.
B.
Automatic Plate Changer – An automatic plate changing system that can remove a plate
and mount a plate without the use of tools. The plate changer must be able automatically find
the tail of the plate, unclamp, reverse, and unclamp the lead edge with a single pushbutton.
The new plate will then be inserted, clamped, pressured, rotated to the tail that is
automatically inserted into the tail clamp, clamped, and tensioned with a single push button
operation. The plate cylinder will have register pins that are fixed in the cylinder at the 425mm
position in order to assure consistent plate fit and conformity with standard punch and CTP
systems. The plate changer will not require any tail bend and must be able to mount polyester
plates, eight mil material, allow for the use of two sided plates and be able to easily remount
and reuse plates. The automatic plate changer must have a redundant backup system to
easily manually mount plates in less that 2 min. per plate in the case of a automatic system
failure.
C.
Automatic Ink Roller Washers - Automatic ink roller washers will be used to automatically
rinse the ink and dampening rollers via a minimum of three different operator selectable
programs that alter the amount of solvent and the duration of the wash-up.
D.
Auto Sequence - An auto sequence button will be used to automatically initiate the startup of
the feeder, activate the dampening and ink rollers, put the press on impression, and up to
programmed running speed.
E.
Running Register – A remote running register system shall electronically control the fit and
register of the plates via touch panel controls located at the delivery or console control
station. This register adjustment shall be able to move the plate cylinder vertically,
horizontally and skew the position of the plate without stopping the press.
F.
Perfector -The perfector changeover will be fully automatic requiring no tools. The computer
will store common sheet sizes in an operator selectable screen. All units beyond the prefector
will utilize ceramic perfector jackets to minimize the wet side down marking. The perfector
changeover process will be monitored by computers and sensors to assure a complete and
accurate changeover.
Cylinders
6. Press cylinders will consist of heavy-duty chrome plated impression, blanket and plate cylinders.
Sheet transfer will take place via cam closed gripper shafts utilizing diamond gripper pads to assure
consistent and stable sheet transfer. Plate and blanket cylinders will have bearer to bearer contact.
The adjustment of impression cylinder pressure will take place through electronic motor that can be
adjusted from the press console. The blanket cylinder will utilize pre-clamped blankets and a double
real tensioning device to assure fast and accurate mounting of blankets.
Inking System & Console
7. Each press inking system shall consist of a minimum of 18 ink rollers, four ink form rollers each of
different diameter, drop down ink fountains, motorized ink fountain roller, remote fountain roller sweep
control, and programmable automatic ink roller wash up system. Ink rollers should have positive
settings to assure quality and consistency.
8. The ink fountain will consist of segmented ink fountains using a solid steel ink adjustment segment
without the use of a foil or liner to precisely adjust the caliper between the fountain roller and the ink
key. The ink ductors shall be programmable to different ratios in order to accurately control light
coverage jobs.
9. The press inking units will be remote controlled from the central control console and will be adjustable
for density level at each fountain key and overall at each print unit. The ink counsel will be configured
to accept a CIP3 file in order to create a calibrated pre-inking profile to pre-set the ink keys prior to
each make ready. Job storage will take via floppy disk or network hard drive.
Dampener
10. Each press dampening system will be of the continuous style using a pan, metering, form and two
oscillating rollers to insure consistent and smooth dampening of the printing plate, the dampening form
roller will be of the speed reduction design as a means of reducing the build up of debris on the plate
surface, (delta motion). The dampening unit will function without alcohol to reduce VOC emissions and
provide a safe work environment. The re-circulator will filter and cool the fountain solution to assure
proper water feed and print quality.
11. The press dampening system will be adjustable from the central control console for the following
adjustments: pre-dampening (to insure efficient/low waste start up), integrated or segregated ink-todampening system bridge roller position (to insure consistent ink/dampening solution balance and
avoid emulsification during light or heavy coverage production), and linearity adjustment between
press speed and dampening system speed (to insure consistent ink/dampening solution balance
during varying speed production). The ability to skew the metering roller (to control the amount of
water supplied across the width of the plate).
Delivery
12. The delivery system of the press will include the following: independent speed controlled vacuum
slow down wheels, sheet decurler, blow down bars and delivery air fans with individual zone control,
sheet removal system and a mid size delivery pile.
13. The press will be equipped with an anti-offset powder spray system providing consistent powder
distribution, and a separate air pump.
Minimum Specifications for 20” press
Printing Units:
Four (4)
Maximum Sheet Size:
14 3/16” X 20 1/2”
Minimum Sheet Size
7 3/16” X 10 1/8” straight printing
10 5/8” X 10 1/8” perfecting mode
Maximum Image Area
12 3/4” X 19 7/8” straight printing
Printing Speed
4,000 – 15,000 IPH straight printing
4,000 – 13,000 IPH perfecting mode
Stock Thickness Range
.0016 - .016
Feeder Capacity
22 ¾ “
Delivery Capacity
23 5/8”
Power Supply
208 – 220vac 3 phase 100 amps or less