Computer-to-Pia te:
`Automating the
`Printing Industry
`
`by
`Richard M. Adams II
`Graphic Arts Technical Foundation
`
`Frank J. Romano
`Rochester Institute of Technology
`
`Graphic Arts Technical Foundation
`PrrrSBURGH
`
`

`

`Copyright 1996
`Graphic Arts Technical Foundation
`All Rights Reserved
`
`Library of Congress Card Catalog Number: 96-78325
`International Standard Book Number: 0-88362-191-6
`
`Printed in the United States of America
`
`Order No. 1435
`
`Reproduction in any form by any means without specific written permission is prohibited.
`
`Individual trademarks are the property of their respective owners. Product names are
`mentioned in this book as a matter of information only and do not imply endorsement
`by the Graphic Arts Technical Foundation
`
`Graphic Arts Technical Foundation
`4615 Forbes Avenue
`Pittsburgh, P A 15213-3796
`United States of America
`Phone: 412/621-6941
`Fax: 412/621-3049
`
`

`

`Table of Contents
`
`Section 1
`1
`2
`3
`4
`5
`6
`7
`8
`9
`
`Section 2
`10
`11
`12
`13
`14
`15
`16
`17
`18
`19
`20
`21
`22
`23
`
`Technology
`Introduction ............................... 1
`Press Trends ............................... 7
`Origination ............................... 15
`Raster Image Processing ................... .35
`Proofing ................................. .55
`The Image Carrier ......................... 75
`Quality Control ........................... 97
`Digital Workflow ......................... 115
`Return on Investment ..................... 127
`
`Platesetter Profiles
`Barco Graphics ........................... 135
`Creo Products, Inc ......................... 143
`Cymbolic Sciences, Inc ..................... 151
`DuPont ................................. 155
`Gerber Systems Corporation ............... 159
`Krause America, Inc ....................... 171
`Linotype-Hell ............................ 177
`Misomex ................................ 183
`Optronics ................................ 187
`Presstek ................................. 195
`Scitex ................................... 199
`Screen .................................. 203
`Other Platesetters ......................... 209
`Comparisons ............................. 215
`
`Internal vs. External Drum Technology ...... 221
`Appen<lix A
`Platesetter Addresses ...................... 237
`Appen<lix B
`About the Authors ...................................... 239
`
`

`

`

`

`Factoid Foreword
`
`• The first computer-to-plate system was the Lasergraph in 1974. It used two high-powered lasers to
`bum off nonrelief areas of a solid block of plastic to produce a letterpress plate. It almost printed a
`newspaper in Utica, NY.
`• Computer-to-plate technology has been applied since the early 1980s for the Wall Street Journal, the
`New York Times, and the Christian Science Monitor. A pasteup of the pages was scanned to produce
`the data for exposing plates. The Journal and Monitor used satellites to send pages across the U.S.
`The Times sent them across the river to New Jersey.
`• The EOCOM flatbed platesetter was demonstrated in 1984 and later sold to Gerber. It was part of
`the Autologic APPS-1 system, which was the first system to assemble a newspaper digitally and
`expose the plate from that data. It was installed briefly in Morristown, N.J., on its way to
`obscurity.
`• Polyester plates were introduced in the mid-1980s and exposed in early versions of photographic
`imagesetters.
`• As of 1990 almost all printing plates were exposed in vacuum frames.
`• In 1991, Presstek and Heidelberg introduced the first on-press platemaking system with the intro(cid:173)
`duction of the GTO-DI. The system is now used for two-up and four-up presses as well as off-line
`platemaking for wet or dry plates.
`• The first publication produced completely computer-to-plate was Sports Car International in May
`1994. Publisher's Press in Florence, Ky., used an Optronics platesetter for the glossy four-color edi(cid:173)
`tion. Publisher's Press now uses Gerber platesetters and scans ad films to produce digital files.
`• The first publication with advertising supplied digitally and produced computer-to-plate was the
`April1995 The Computer in the 21st Century from Scientific American. Apple Computer was the oniy
`advertiser and their agency, BBDO, supplied digital ads for printer R.R. Donnelley's Creo plate(cid:173)
`setters.
`• In May 1995 there were more CTP systems installed at DRUPA (42) than in user plants around the
`world. As of May 1996 over 400 systems are installed worldwide.
`• There are now almost 20 digital plates and over 32 models of CTP platemakers.
`
`

`

`I
`I
`I
`I
`
`

`

`Acknowledgments
`
`The authors wish to thank the many vendors who supplied information and wrote sections on their products for
`this book.
`
`For information on platesetters we thank Chris DeJohnge, Barco Graphics; Mitch Prust, Cortron; Gary Yurkovich,
`Creo Products, Inc.; Ted Stitzer, DuPont Printing & Publishing; Bob Houlihan,. Gerber Systems Corp.; James
`Frisch, Komori Imaging Systems; T.Q. White IL Krause America, Inc.; Ray Cassino, Linotype-Hell Co.; Paul
`Bengtson, Misomex North America; Ray Mullen, Mitsubishi; Ed Chrusciel, Optronics; Sandy Fuhs, Presstek;
`Leigh Kimmelman, Scitex America Corp.; and David Mitchell, Screen U.S.A. For information on internal and
`external drum technology, we thank Ray Smythe, Creo Products, Inc.; and Ron Goulet, Gerber Systems Corp.
`
`For supplying information for the digital proofing chapter, we wish to thank Kent Schoenherr, Sarah Meek, and
`Mary Beth Leone-Getten, 3M/hnation; Dave Walter, DuPont Printing & Publishing; Barbara Jessup, Joe
`Murphy, and Denise Rayo, Eastman Kodak Co.; Lela Moore and Kristi Powers, Encad Corp.; Richard Beck, Fuji
`Photo Film U.S.A., Inc.; Don Rogers, Optronics, Inc.; Doug Gowell and Michael Phelan, Polaroid Graphics
`hnaging, Inc.; Mark Vanover, Sdtex Corp; Mike Pell and Souzie Monshi, Tektronix, Inc.; Dave Mitchell and
`Stacey Levinson, Screen. U.S.A., Inc. Information on the Digital Plate Control Wedge was provided by Dave
`Milburn, GATF.
`
`For information on plate material we would like to thank Kevin Harrell, 3M/hnation; George Barnacle, Agfa Div.
`Bayer Inc.; Dan Victory and Doug Seeley, Enco Products, Agfa Div. Bayer Inc.; Michael Moore, DuPont Printing
`& Publishing; Bruce Kaskey, Eastman Kodak Co.; Ben Butera, Fuji Photo Fihn U.S.A., Inc.; Richard Ferranti,
`Mitsubishi Paper International, Inc.; Dave Sorter, Polaroid Graphics hnaging. Inc.; Sal Lombardo, Polychrome
`Corp.; and Bob Verrando and Sally Fuhs, Presstek.- Inc.
`
`Information on imposition and trapping solutions was provided by Robin Mueller, DK&A, Inc.; Matt Cannard
`and Freda Cook, Luminous Corp. (formerly Adobe Prepress Group); Peter Gorgone and Kevin McSweeney,
`RAMP AGE Systems, Inc.; Lee Kyle, ScenicSoft Corp.; and Joanne David, Ultimate Technographics, Inc.
`Information on preflighting was provided by Ron Bertolina,. GATF.
`
`We wish to thank Lloyd DeJidas and Tom Destree, GATF, for contributing part of the writeup on press automa(cid:173)
`tion. Information on press automation was provided by Mary Lisi, Komori America Corp.; Randy Siver,
`Mitsubishi; and Tom Leibrandt, Sakurai USA. Inc.
`
`The diagrams comparing traditional and digital workflow were created by Tony Stanton.. Carnegie-Mellon
`University. Additional input on the digital workflow model was provided by Hal Hinderliter and Howie Fenton,
`GATF. Information on networks was also provided by Hal Hinderliter.
`
`Much of the historical and technical information is derived from Mike Bruno's "Printing in a Digital World" and
`Status of Printing papers.
`
`For information on other platesettters (Chapter 21), we would like to thank Edward Michaels and Norman J.
`Levy of Nation-Wide Plastics Co., Inc.
`
`Comparison data is provided by the Digital Printing Report, Box 170, Salem, NH 03079, (603) 898-2822.
`
`Finally, we wish to thank ,our GATF editors, Erika Kendra, assistant technical editor, and Tom Destree, editor-in(cid:173)
`chief, for their work in editing and formatting the book_. and Dave Watterson, who created the cover design.
`
`

`

`

`

`Chapter 1
`Introduction
`
`In Aprill995, Scientific American Inc., Apple Computer Inc and its advertising agency BBDO /Los
`Angeles, and the publications printer R.R. Donnelley & Sons Co. produced 300,000 copies of a 200-
`page publication in its entirety with a computer-to-plate process. 1his was the first time an entire pub(cid:173)
`lication, including its advertising, had been completely without the use of film for web offset printing.
`In 1994 an Optronics PlateSetter was used at Publisher's Press in Florence, Ky., to produce the
`May 1994 issue of Sports Car International, the first glossy four-color magazine in the world printed
`on a web offset press from plates imaged entirely without film.
`"The pioneering efforts of Apple and BBDO /L.A.'s production and media departments have
`made this a first for the web-offset printing industry," said Richard Sasso, associate publisher and vice
`president of production for Scientific American Inc. "We experimented with the basic technology in
`several editorial sections of previous issues of the magazine. But with Apple, BBDO ad R.R. Donnel(cid:173)
`ley's significant commitment to cooperation and communication_ we are all able to confirm the com(cid:173)
`puter-to-plate technology's viability for producing beautiful and more timely productions."
`Computer-to-plate technology (CTP), or direct-to-plate as it is sometimes called, is a digitized
`printing process. Publishers provide all editorial and advertising content in digital form (either on
`disk or by sending the data over telephone lines) to printers who, in turn, produce electronic web-off(cid:173)
`set printing plates, eliminating all the traditional intermediate film-preparation stages.
`Sasso expects this process to benefit Scientific American in the following ways:
`• Improve print quality by using first-generation digital data to expose the plate
`• Potentially reduce prepress costs, by eliminating film from the process
`• Reduce production time giving advertisers and editors more time to develop content
`
`Apple Computer is the sole advertising sponsor of the special anthology issue of Scientific Amer(cid:173)
`ican magazine entitled The Computer in the 21st Century. Apple and BBDO/Los Angeles provided 21
`pages of advertising to the magazine in digital format that R.R. Donnelley then converted to Post(cid:173)
`Script file format.
`"We were intrigued with the concept of completely digital print production. Working with Sci(cid:173)
`entific American on the anthology issue gave us an opportunity to test the technology's potential first(cid:173)
`hand/' said Mike Donne, vice president of worldwide communications and marketing services at
`Apple Computer. "We found that the efficiency and quality of this new printing technology, com(cid:173)
`bined with the magazine's fully-automated Macintosh publishing house, made this first-time experi(cid:173)
`ence a pleasurable one."
`"Our media and production department found this first-time process to be smoother than antic(cid:173)
`ipated," said Susan Kassman, print production supervisor for BBDO/Los Angeles. "As more publi(cid:173)
`cations embrace a digital production process, we anticipate it's just a matter of time before the
`
`

`

`2 COMPUTER-TO-PLATE: AUTOMATING THE PRINTING INDUSTRY
`
`advertising industry universally supports digital delivery of ad material. Having worked with Scien(cid:173)
`tific Ammcan, we can all see how this process can save time in the future."
`Scientific American has been committed to the regular use of CTP technology since October 1994,
`publishing more than 60 million printed pages to date with the Mattoon, Ill. division of printer R.R.
`Donnelley & Sons Co.
`"Computer-to-plate printing for the web-offset process is a promising technology for the pub(cid:173)
`lishing industry," said Bob Pyzdrowski, president of magazine services for R.R. Donnelley. "This new
`technology that we've implemented for Scientific American benefits publishers, printers, and advertis(cid:173)
`ers alike with time-savings, efficiency, and quality."
`"As this new technology evolves, we face many challenges. Standards must be put firmly in
`place. Industry organizations such as Specifications for Web Offset Publications (SWOP) need to
`implement specifications for transporting digital data and proofing," said Sasso. "We've proven the
`technology works. Now all parties should work together to develop and embrace the techniques that
`will improve magazine publishing."
`Anyone who has been reading the trade press over the past two years, or has attended the most
`recent trade exhibitions, will be aware of the enormous interest in CTP. Potentially, investing in CTP
`can provide the following benefits:
`• Savings in supplies-film, carrier sheets, film chemicals, tapes, and adhesives
`• Savings in personnel-stripping, film exposure, retouching, and processing
`• Savings in equipment-film exposure, film processing, and processing
`• Savings in space of up to 50%
`
`And so, a market with roots back almost 20 years begins to have an impact on the printing and pub(cid:173)
`lishing industries.
`
`Computer-to-Plate Printing Systems
`
`The trend in printing is toward shorter run lengths, which means changing plates more often. CTP
`seems to be the primary method for conventional lithography to cope with the continuously growing
`demand for short-run printing and increased productivity. CTP means more than installing a plate
`imaging device. A CTP installation involves many additional devices and systems that enable the
`application of a digital workflow. New organizational and technological requirements are created
`(networking, storage and archiving, digital proofing, file transfer, preflighting), and it is important
`that each is thoroughly implemented in order for the whole system to operate efficiently. Imaging
`plates directly from computer files has been an approach to increased productivity in prepress and
`reduced makeready in the pressroom. Its time has come.
`What began in the late 1980s and early 1990s as a trickle has become a river. There are more than
`16 different engines sold by almost 40 firms with about 20 different plates. Some systems expose a
`variety of plates; some concentrate on one plate. CTP has now gone beyond confusion to a point that
`some consider maddening.
`You can quickly categorize the systems into eight or more-up, four-up, and two-up, although
`some systems can handle both four-up and eight-up. Then you can categorize them by dry or wet pro(cid:173)
`cessing. The wet processing can be water for the photopolymer plats or chemistry for the silver-based
`plates. Some of the dry processing requires a smidgen of water.
`These two categorizations get you into a reasonable ballpark in terms of comparison. We will
`assume that the system can produce 8-20 plates per hour (depending on size) from the time the file
`is sent to the RIP until the plates exit from the system. Price tags are still above $400,000 for eight-up
`
`

`

`INTRODUCTION 3
`
`systems, but there are a few below that. Digital plates started out about 50% more expensive than con(cid:173)
`ventional plates but that is changing.
`Three types of computer-to-plate printing systems are in use:
`• Plates or image carriers for gravure and flexography on which the images can be produced by
`etching with high-powered lasers or electromechanical engraving devices.
`• High-speed light-sensitive plates for lithography with coatings that have light sensitivities on
`the order of litho film and that can be exposed with low-power visible lasers.
`• Non-light-sensitive plates for lithography with coatings on which images can be produces by
`heat (infrared) radiation rather than light
`
`The Market
`
`Computer-to-plate technology is relatively young in terms of shipments. Based on our best estimates
`there were 271 CTP systems installed in customer plants worldwide at the end of 1995. It is predicted
`that there will be 566 units worldwide at the end of 1996. And by the end of 2000, there will be 2,054
`systems in the world, about half of them in North America.
`
`Worldwide Computer-to-Plate Installations*
`(based on aluminum platemaking systems)
`Through
`1995
`79
`12
`170
`10
`271
`
`1998
`194
`242
`590
`185
`1,211
`+355
`
`1999
`239
`372
`700
`230
`1,581
`+370
`
`Newspaper
`4-up
`8-up
`16-up
`Total
`
`1996
`99
`82
`290
`95
`566
`+295
`
`1997
`134
`142
`460
`140
`876
`+310
`
`2000
`299
`560
`980
`215
`2,054
`+473
`
`"'projections by the Digital Printing Report
`
`Earliest Computer-to-Plate Systems
`
`The first computer-to-plate system was Lasergraph, an ablation system for making relief letterpress
`plates shown in 1974. The company was funded by Gannett, and only one system was ever installed
`to our knowledge. It was discontinued because letterpress was declining in use, and the lasers used
`for ablation (two C02 lasers) used almost as much energy as it took to run a press.
`The following two years witnessed the introduction of a number of other digital plate systems,
`including systems by EOCOM (now Gerber), LogEtronics (from LogScan, now Datrax by Crosfield),
`Dest Data (Wall Street Journal), Azoplate (Kalle, now Enco or Hoechst, acquired by Agfa), and Chemco
`(now Konica). All of these early systems, except the Crosfield Datrax and Gerber, have failed for one
`reason or another. Among the main reasons have been slow exposure speed of early plate coatings,
`and the slow development of complete pagination with trapping programs, plate imposition soft(cid:173)
`ware, and digital color proofing systems.
`
`

`

`4 COMPUTER-TO-PLATE: AUTOMATING THE PRINTING INDUSTRY
`
`Early Lithographic Computer-to-Plate Systems
`
`These systems were used for making plates for newspapers and business forms. The Wall Street Jour(cid:173)
`nal is produced on such systems in most of its 17 printing locations. The systems use satellite trans(cid:173)
`mission of digital data to Chemco Newsplaters, which record the newspaper pages on Polychrome
`Laserscan plates. The New York Times uses similar concepts for its national newspaper. Crosfield
`Datrax laser platemaking and facsimile transmission systems are used which can produce newspaper
`page images either on Lasermark films or plates.
`Early computer-to-plate systems were not capable of printing commercial lithographic pictorial
`quality, primarily because of the unavailability of plates. The development of the 3M high-speed pho(cid:173)
`topolymer and the Nippon dye-sensitized photopolymer plates and upgrading of the Crosfield
`Datrax to a 150-line screen capability encouraged development of commercial or magazine computer(cid:173)
`to-plate systems. Business forms are being produced on Purup, Misomex, and Harris Digilabel elec(cid:173)
`tronic imaging systems by direct exposure of 3M Onyx plates or Mitsubishi Silver Digiplates (all
`polyester) by helium-neon lasers and printing on a press in runs up to 20,000 impressions.
`The first printing process to use computer-to-plate {image carrier) digital printing commercially
`has been gravure using image carriers made on electromechanical machines. This was followed by
`flexography, lithography, and stencil duplicating.
`
`The Evolution from Phototypesetting to Platesetting
`
`As the printing industry applied phototypesetting, it laid the groundwork for today' s platesetting.
`
`Computer to film. In 1978 Monotype introduced the Lasercomp, the first raster-based imagesetter. It
`was not, however, the first device to apply a laser for typesetting. The abortive Photon laser typeset(cid:173)
`ter in 1976 had that distinction. The term "imagesetter" did not become widespread until1985 when
`Adobe Systems and Linotype-Hell adapted the Linotron laser system to PostScript. From its intro(cid:173)
`duction in 1981, the Linotron, as well as the Lasercomp, suffered from the lack of a page description
`language that could integrate text and graphics. From 1985 onwards, virtually every imagesetter
`incorporated a PostScript raster image processor (RIP). Imagesetters then advanced to two-up film,
`four-up film, and today eight-up and even sixteen-up film sizes.
`
`Computer to imposed film. Optrotech oflsrael introduced an eight-up film imposetter in 1989. It was
`a device already in use for making semiconductor artwork and easily adapted for imagesetting. For(cid:173)
`tunately, the Linotronic 500 was a four-up machine and had been used by a Canadian printer with an
`interest in Ultimate Technographics. The latter company developed the first imposition program, thus
`
`Phototypesetters
`CRT phototypesetters
`Laser phototypesetters
`Laser imagesetters
`Laser imposetters
`Laser platesetters
`
`•
`•
`•
`•
`•
`
`•
`•
`•
`•
`•
`
`Evolution from Phototypesetters to Platesetters
`Characters
`Line Art
`Photos
`Color
`•
`•
`•
`•
`•
`•
`
`Imposed
`
`•
`•
`
`•
`•
`•
`•
`
`

`

`INTRODUCTION 5
`
`making an eight-up machine, dubbed an "irnposetter," possible. Over time many suppliers developed
`irnposetting devices, which paved the way for computer-to-plate.
`
`Computer to imposed plate. As film-based imposetters evolved to larger sizes of output media, util(cid:173)
`ity software for automatic trapping and imposition evolved, as did digital proofing technology. The
`result was a digital infrastructure that was essentially in place when the first CTP systems were
`demonstrated in September 1993. But the genesis of CTP goes back before that time.
`
`The Variations of Computer-to Technology
`
`CTF
`
`Computer to Film
`
`CTIF
`CTP
`CTPP
`
`Computer to Imposed Film
`Computer to Plate
`Computer to Polyester Plate
`
`CTAP
`
`Computer to Aluminum Plate
`
`CTPoP
`
`Computer to Plate on Press
`
`CTPIC
`
`Computer to Plate Image Cylinder
`
`CTEP
`
`Computer to Electronic Printer
`
`CTECP
`
`Computer to Electronic Color Press
`
`Raster-based imagesetters, both capstan(cid:173)
`and drum-oriented
`lmposelters, 4-up and larger format
`Computer-to-plate, any kind of plate
`Imagesetters or imposetters, outputting
`film or plate, or dedicated devices that
`only output polyester plates.
`Platesetters using internal or external
`drum, flatbed or curved approaches.
`Presstek technology presently integrated
`on presses from Heidelberg and Omni(cid:173)
`Adast.
`Creo' s developmental technology that
`involves spraying a material on a press
`cylinder and imaging it with thermal
`lasers.
`Includes all digital printout devices, mono(cid:173)
`chrome or color.
`Specifically involves high-end higher(cid:173)
`speed color printing systems.
`
`Who Will Implement the Various Computer-to Technologies
`Type
`Printers
`Prepress
`CTF
`100%
`40%
`CTIF
`20%
`20%
`CTPP
`5%
`CTAP
`30%
`CTPoP
`10%
`CTPIC
`10%
`CTEP
`60%
`CTECP
`20%
`
`40%
`30%
`
`

`

`

`

`Chapter 2
`Press Trends
`
`Changes in sheetfed and web offset printing markets have been responsible for some modifications
`in sheetfed and web offset press design and operation. Both have directed their efforts at increased
`productivity and lower running costs. Sheetfed, with smaller sheets and shorter run lengths, has con(cid:173)
`centrated on faster makereadies and shorter changeovers. Web offset, with more durable plates and
`longer runs, has concentrated on higher speeds and waste reduction. In gravure, press developments
`are in smaller presses and wider presses with more automation and less manning.
`
`Press Automation
`
`More and more press functions are becoming automated. Many manual tasks, such as plate chang(cid:173)
`ing, are now being augmented or replaced by automated systems. Increased automation has a posi(cid:173)
`tive impact not only on makeready but also on the pressrun. Automation shortens makeready by 50%
`or more, enabling the press operators to mount plates quicker and to make adjustments in less time
`than if they were made manually. During the pressl'Uil, automation allows the press operators to
`adjust ink/water balance and register from a remote control console, instead of making manual
`adjustments to ink keys and ink ratchets, side guides, plate cylinders, and other press devices. In addi(cid:173)
`tion, automatic blanket washers allow press operators to wash blankets without stopping the press(cid:173)
`a critical production consideration especially with web presses. Automation can also result in
`decreased press crew sizes. Many of the sheetfed and web presses displayed at the DRUPA and Graph
`Expo '95 trade shows incorporated one or more of the following features:
`• Automatic plate changers on sheetfed presses
`• Robotic material-handling at both the feed and delivery ends of the presses
`• Automatic washup accessories for the ink trains, blankets, impression cylinders
`• In-line densitometers and spectrophotometers
`• Automatic registration
`• Ink pumping and distribution systems
`• On-line pH and conductivity control
`
`Among the functions that are becoming automated, which vary considerably from press to press
`and from press manufacturer to press manufacturer, are adjustments to:
`• Pile, feedboard, and side-guides on sheetfed presses
`• Roll stand and web guides on web presses
`• Register
`• Delivery
`• Ink/ water balance
`
`

`

`8 COMPUTER-TO-PLATE: AUTOMATING 1HE PRINTING INDUSTRY
`
`Automation, greatly added by microprocessors, can also facilitate electronic monitoring of ink
`density, register, ink/ water balance, dot gain, and other printing parameters, and can control various
`makeready functions, plate changing, and troubleshooting.
`
`More Sophisticated Press Control Systems
`
`Press control systems are becoming more sophisticated with enhanced multitasking abilities and
`advances in automatic registration and in-line densitometry and spectrophotometry.
`The critical eye of the press operator has been supplemented, or even replaced, by sophisticated
`closed-loop controls. The trend in both sheetfed and web offset press operating is to replace certain
`human judgments and manual adjustments and operations with automatic functions-but the skills
`of the press operator are still integral to successful printing.
`At Graph Expo '95, Komori America Corp. displayed its 40-in. Lithrone press equipped with
`Komori's PQA (Print Quality Assessment) system and the KMS (Komori Monitoring System), a
`totally integrated system that incorporates control of automatic makeready, cleaning functions, auto(cid:173)
`matic plate changing, troubleshooting procedures, and statistical process control. The KMS monitors
`and displays essential data collected from the press and peripheral devices. The press was also
`equipped with Komori's PDC-S system, first shown at DRUPA '95. The PDC-S is a closed-loop scan(cid:173)
`ning spectrodensitometer.
`Fiber optics are being used increasingly in the pressroom in conjunction with control consoles. For
`example, MAN Roland's PECOM press center uses fiber optics to link the printing units to a central
`console, which features one simple keyboard and one monitor. The control center can direct the oper(cid:173)
`ation of Roland 700- and 300-series presses.
`Another example of a control system is the Heidelberg CPC 21, a colorimetric-based scanning sys(cid:173)
`tem for closed-loop control with color control bars. It takes a reference value from any original and
`creates a comparison of measured patches that produces results corresponding to human color per(cid:173)
`ception. This equipment can be connected online with up to six printing presses and is equipped with
`an open, standardized computer interface for data exchange.
`The Sakurai Color Control System is available on all Sakurai multicolor presses in three models.
`The sec I model features remote ink key control with job storage on floppy disks, including register
`control. The sec n and sec Ill will feature complete integration to the press with all color control
`functions on the console. SCC Ill includes a scanning densitometer. Sakurai predicts that 70% of its
`multicolor presses will be sold with one of the SCC options. On Sakurai's sec ll and sec ill systems,
`digital ink key presets can be determined from ripped data on the Sakurai computer-to-plate sys(cid:173)
`tems, the PlateMaster 52 and PlateMaster 72
`(OEM versions of the Presstek PearlSetters).
`The information can be saved and recalled
`when the job is ready to go to press.
`Mitsubishi offers Graphics Microsystems
`mc.'s (GMI) Autocolor system (shown at right),
`allowing the press operator to use an x-y scan(cid:173)
`ning densitometer to monitor ink densities.
`The press operator also has the option of clos(cid:173)
`ing the loop between scanner and Mitsubishi
`console to allow Autocolor to maintain ink
`densities automatically.
`
`Automatic x-y scanning densitometer for closed-loop
`color control
`
`

`

`PRESS TRENDS 9
`
`These are five examples of the many control systems from press and accessory manufacturers that
`are making the task of running a press easier.
`
`Automatic or Semiautomatic Plate Mounting
`
`In the last few years, several press manufacturers, including Komori, Mitsubishi, and Sakurai, have
`added automatic or semiautomatic plate mounting devices to their presses (see illustration on page
`10). Sakurai said that 98% of its new presses being sold are equipped with SPC. The exact procedure
`involved in using these devices varies with the level of the device's automation, as well as from man(cid:173)
`ufacturer to manufacturer. The basic procedure with one automatic plate mounting system includes
`the following steps:
`1. Press operator loads new plates into a plate cassette.
`2. Press operator selects a unit that needs a new plate and depresses a pushbutton to start the
`mounting procedure.
`3. Safety guard automatically opens, and rear of plate loader moves toward the plate cylinder.
`4. Plate clamp opens, and old plate is discharged into the loader.
`5. New plate leaves loader, is inserted into position, and is mounted on the plate cylinder.
`6. Plate clamp closes, loader retracts to original position, and safety guard closes.
`
`Automatic Blanket and Press Cylinder
`Cleaning
`
`The manual cleaning of blankets and press cylinders
`is a time-consuming procedure because the press has
`to be stopped. Automatic cleaning devices, such a'
`the device shown at the right, however, allow the
`cylinders to be cleaned while the press is operating.
`In addition to eliminating press stoppages, auto(cid:173)
`matic cleaning often results in a reduction in solvent
`consumption and a significant reduction in waste
`signatures. For example, the Baldwin IMPACFM
`Automatic Blanket Cleaner and Press Cylinder
`Cleaner, a winner of a 1995 GAIF InterTech Tech(cid:173)
`nology Award, is said to reduce solvent consump(cid:173)
`tion by 70%.
`
`Automatic Feeder Adjustments
`
`Automatic ink-roller cleaning system
`
`Setting the sheet-handling mechanisms on a sheetfed press is a time-consuming operation. 1f paper
`size and thiclcness are changed, practically all settings must be adjusted. Some newer presses have
`devices that automatically adjust the sheet-handling mechanisms when paper stock is changed, a
`major time-saver during makeready (see illustration on page 11).
`
`Automatic Registration Control
`
`Several manufacturers offer systems for automatic register control. An example is the Sakurai AutoSet
`system, available on Sakurai multicolor presses, which allows remote control of register. The opera(cid:173)
`tor can select a sheet size and automatically set up the feeder, delivery, and impression pressures.
`
`

`

`10 COMPUTER-TO-PLATE: AUTOMATING THE PRINTING INDUSTRY
`
`Automatic Plate Changing
`
`Automatic plate changing sequence on Komori Lithrone press
`
`1. Place a new plate in
`the loader.
`
`2. When the button is
`pressed, the safety cover
`opens and the loader is
`set in position.
`
`3. Both the front and
`back clamps open to
`start the plate-removal
`operation.
`
`4. With the plate drawn
`into the loader, the plate(cid:173)
`removal operation is
`completed.
`
`5. The new plate is
`inserted in register and
`gripped with the front
`clamp.
`
`6. The plate cylinder
`rotates to wind the new
`plate around it.
`
`8. The loader returns to
`its origin81 position and
`the safety cover closes.
`
`7. When the new plate is
`completely wound around
`the cylinder, its trailing
`edge is pressed down
`and gripped by the back
`clamp. This completes
`plate mounting.
`
`Lateral register, circumferential register, and skewillg can be controlled. Sakurai predicts that 50% of
`its multicolor presses will be ordered with SAS.
`
`

`

`PRESS TRENDS 11
`
`Other Automated Press Controls
`
`Sheet preset control
`
`7 8 9
`4 5 6
`1 2 3
`0 CLR 00
`
`Oscillating roller control
`
`OPERATJIJ<
`
`I Jill( LI(}IJ AIID SliDE fll)]!I~ FR a 1
`
`rnmrnrnmrnrn
`~~~~BBB
`
`Frontlay register control
`
`SIDE