Printing Methods – Electronic
Posted by admin at April 29th, 2016
The indigo E-Print is a combination of the copier and an offset press. The “printing” plate is an photoconductor that receives an image electronically through a computer RIP. The image is then “toned” by a fluid ink, one ink at a time. Six colors are available, the four process colors plus two special spot colors. The photoconductor then transfers the ink to a heated offset blanket which in turn transfers the ink to the substrate and the process is repeated. The heated blanket drives off the solvent in the fluid ink/toner.
indigo prints one color at a time. The indigo can perfect (Duplex) as well. Each turn on the photoconductor can produce a new image so each page (single color) can be a “new page.” Indigo can bind (stitch) and group for a completed publication or do a single page at a time. The indigo, however, requires a special coating on the paper on the paper used. The coating is known as a “Sapphire Coating” which can be done by Indigo. Maximum sheet size for the sheetfed version is 12.5″x 18.3″(A3 Max.). Maximum output for an 8.5″x 11″ sheet is 500 sheets per hour at a resolution of 800 dpi (150 lpi).
indigo has also develpod a web version which has also developed a web version which is known as the “Omnius.” This press was developed for on demand, high quality full color printing for fl exible packaging applications. Web speed is 120 ft/min with a maximum image size of 11″ x 17″. Like the sheetfed version, the Omnius must print one color at a time to produce up to 6 colors. Outside the fact the Omnius prints on a web, the mechanism is identical to that of the sheetfed version.
The Xeikon process is actually two color copiers that can duplex (perfect) both sides at once. The system prints magenta, cyan, yellow and black to produce four color images. The system uses the electropho-tographic process but prints from rolls and not sheets. The Agfa Chromapress, Barco Digipress, Xerox Docucolor 70 and the IBM Info 70 are near identical machines. At this time, most have qualified papers approved. The roll sizes for the Xeikon, Agfa and Barco systems is a 12.6″ wide roll, 16″ diameter on a 6″ core. The IBM version, however, has been retro-fi tted with a larger backstand to contain a 50″ diameter roll on a 3″ core 12.6″ wide. Xeikon has recently announced the new 32D and 32S version. This new version now has a units after the heater to gloss up the ink. The “D” version is a duplex system where as the “S” version prints only one side. The “S” version is a dedicated label press. There is also now a 50 cm (19.7″) wide version available doubling the output. A packaging version is also available in a 5-color configuration.
Once the copying process is completed, the web travels through a infrared dryer to fuse the toner. The web is then cut into individual sheets.
Xeikon receives information through a computer and RIP (Raster Image Processing) system, like the Indigo. These electronic printing systems can be thought as nothing more than very sophisti-cated “laser” or computer printers.
- The 32D Xeikon uses a roll measuring 12.6″ Wide, 16″ diameter on a 6?core; the 50D uses a 19.7″ wide roll with the same diameter and core size as the 32D.
- Speed is 2100 (A4 size) sheets per hour, duplex
- Page length variable up to 106.3″
- LED imaging with 600 dpi and up to 64 graylevels per basic dot per color.
- Other similar systems (using the Xeikon print engines) include:
- Agfa Chromapress
- IBM Infocolor 70
- Barco Digipress
- Xerox Docucolor 70
The newest short run color press on the market, as announced at DRUPA95, is Heidelberg’sQuickmaster DI-46-4 digital offset press. The Quickmaster DI takes its conception from the older Heidelberg GTO-DI press. The Qucikmaster DI is a press with a master dependent digital printing process, i.e.: copies with constant high quality are made at high speed from a print form. The press is waterless and is driven by a computer system. The press is unique in that, unlike the older GTO-DI, the four printing units are centered around a common impression cylinder that reduces space requirements.
After a job has been assembled in a program like Adobe Pagemaker, the job is then prepared in the TIP (Raster Image Processor) of tea Quickmaster DI and then deposited in a page buffer at the printing press. The operator can then select the printing job on the screen and start the print preparation. After the cycle has been started, the waterless offset plates are renewed in all four printing units. This occurs with a revolutionary system in which the plates are fed off a supply roll inside the plate cylinder. At the same time the printing foils of the previous job are wound onto the “take-up” roll. All this happens in all four printing units in a few seconds. The roll of plate material is sufficient to do up to 35 print jobs, and the roll can be changed easily.
Imaging, via Presstek’s Pearl Laser, is approximately 6 minutes for 1,280 dip and 12 minutes for 2,400 dpi (150 lip). The whole process is fully automatic at the push of a button. The plate mate-rial is similar to the older GTO-DI and made up of a polyester base with a silicone overlayer. The press has one feature not found in any other quick printing device. It uses any kind of paper from 100% recycled to high quality coated. This is because the process uses standard waterless inks with the waterless offset pro-cess.
Short color jobs as low as 500 impres-sions, at 10,000 impressions/hour are possible (one side at a time). While the Quickmaster is much faster than the Indigo or Xeikon, it can only print one side at a time.
MAN Roland Dicoweb – CTPress
Entering also into the digital arena is MAN Roland with its Dicoweb or Digital Change over Web Press. The Dicoweb or CTPpress (computer to plate press), is a digital web press which can image on or off line. The Dicoweb uses lasers and a thermal ribbon to create images on a removable cylinder that are then printed by the normal lithographic process. On the press the four, or more, printing units are equipped for one-step imaging through direct thermal transfer process. All plate cylinders are equipped with an hydrophilic metal sleeve that needs to be replaced only in case of damage or wear. Varying cutoffs will be available and the press will be is avail-able in a half web confi guration (25″ +/-). The average run will be 10,000 impressions with the upper limit at 50,000 impressions.
The blank plate cylinder is imaged by a laser directly from the data thermal ribbon. The thermal material is then transferred to the plate cylinder. The thermal material transferred becomes the image or printable area. As the Plate cylinder is hydrophilic, the non-image areas will receive fountain solution keeping the non-image areas of the plate and print area clean. Once printing is complete the image material on the plate cylinder is removed, or cleaned off, and the cylinder reimaged for the next job. The process of imaging, printing, clean-ing and re-imaging is a continuous process allowing for quick change over high productivity. Resolutions up to 2400 dpi are possible and the size of the imaging dot is 11 µm. Change over time for cleaning and imaging will be approximately 10-15 minutes. The process may also be done off line by imaging the direct thermal ribbon and then mounting it on the press and transferring the thermal material to the plate cylinder.
The press configured below shows 4 printing units, however the press can be confi gured in as many printing unit the customer wants. Coating stations, punching/perforating, UV/EB ink systems, etc. will be also available. This press would be ideal for short run labels, postcards, letterheads, books, etc. As shown in the below diagram, the press is a web heatset unit printing rolls and cutting into sheets. While not on the market yet, it is anticipated that MAN Roland will enter into the digital press world very shortly. Another nice feature will be that the press will use any kind of paper! MAN Roland will target this press to the short run web and higher run sheetfed market.
A joint venture between Scitex and KBA to introduce their digital press – the 74 Karat. This press features some unique technology and a strikingly different configuration. It uses a digitally exposed waterless offset plate (currently from Presstek) and fall in the same direct-to-press category as the Heidelberg Quickmaster DI and the Omni-Adast DI series. This press is a 20.5″ x 29″ and is rated at 10,000 sheets per hour. It is a highly automated offset press featuring computer-to-onpress platemaking. There are virtually no press adjustments to be make, which means that the press is “dumb,” controlled almost entirely through prepress functions.
This approach is made possible, in part, through the use of a keyless, self-calibrating ink system that uses a full form diameter anilox or gravure-type cylinder. Dubbed “Gravuflow” by Scitex/KBA, the system is simple, but appears to noticeably reduce waste while producing good solids, a precise dot structure and repeatably consistent printing.
Goss Graphic Systems demonstrated, at the 1996 Print ’97 Show, a single-color unit of a 22-inch wide variable cutoff press. The press features a digitally imaged and eras-able cyinder and single fluid technology, which eliminates the use of a dampener. The press also is equipped with gapless image and blanket cylinders and shaftless/gearless individual cylinder drives. Known as either the Automated Image Makeready (AIM) web press or, more formally, as the Advanced Digital Offset Printing Technologies concept Press (ADOPT/CP), the unit employes a laser and printing cylinder coated with chemicals to form an imaging system that is erasable. Erasable it may be, but it is not intended to produce variable images.
The Concept press uses traditional offset materials with no special ink or paper requirements. The laser exposure writes an erasable copper image from solution onto a nickel-crystal coated cylinder to form a traditional ink/water lithographic surface. Printing cylinders – or what passes for reusable plates – can be imaged on or off press.
Goss has long been a proponent of single fluid lithography, but Print was the fi rst public showing of this technology. In and water are mixed in a compact unit on the press and fed to the inking roller train, which separates the two fluids at the last roller under a preset shear force. This allows the ink and water to be used on the plate in the normal way. A continuous fresh ink/water emulsion layer is metered out for every image cylinder revolution. The system is keyless, which, like the previously described Scitex/KBA inking system, puts the onus on the prepress function for achieving correct inking.
Kodak and Heidelberg have also formed a venture to develope a non-impact digital printing solution. It would seem that the goad is to design and market a “digital” press that can handle high volumes and variable data. Most likely no announcement will be herd before DRUPA 2000.
Technology on the Horizon
New digital press equipment on the horizon includeScreen’s True Press. This press uses conventional inks and a continuous feed dampening system. The True Press is a fixed image digital press using a flexible polyester plate material, such as Mitsubishi’s Silver Digiplate, fed from a cassette onto the plate cylinder. As shown in the diagram to the left, the press uses a “split” cylinder arrangement. In this arrangement, the plate is imaged for two colors, in this case, magenta and black. After exposure, the plate is processed in a developing apparatus that is located directly underneath the plate cylinder position. After processing, the first plate cylinder is moved down into the printing position where it will make contact with the first blanket cylinder. This process is repeated by moving the second plate cylinder up into the imaging position where, after plating, an exposure is made (cyan and yellow). After processing, this cylinder is returned to the printing position where it comes into contact with the second blanket cylinder. All ink key information is fed from the pre-press digital data.
To print, the images are transferred to the two blanket cylinders and a central impression cylinder is used in the transfer process of 4 colors to the paper. The press can print at a rate of 4,000 impressions per hour for four color (one side) work. An optional “perfector” unit is available to allow the press to print two colors on each side (2 over 2). If only printing one or two colors, the top press speed is 8,000 impressions per hour. Plate loading and unloading, imaging, developing, fixing, ink key setting, blanket cleaning and printing pressure adjustment are done automatically without operator intervention. As this press uses conventional inks and a dampening system, any kind of paper can be used. Heidelberg has introduced the Speedmaster 74-DI. This press is characterized as a fast make-ready, short-run press.
Heidelberg claims change over times of less than 11 minutes! This includes the removal of the old plates, imaging new plates, mounting, wash-up, etc. Like its conventional counterpart, the Speedmaster 74-DI is a 20 x 29-inch four-page format press with a maximum speed of 15,000 sheets per hour. Imaging of the waterless plates will be accomplished by Creo thermal imaging heads. Unlike previous DI models, which use waterless technology, the SM 74-DI prints with conventional inks and fountain solution. It can print with offset press-made plates, as well as in the on-press direct-imaging mode. The SM 74-DI will be available as a four, fi ve or six-color machine with in-line coating and perfecting as options. While “digital” the press will be able to print on any kind of paper from low end unocated to high end coated.
Technology on the Horizon
Would Gutenburg roll overin his grave?
“We don’t need no stinkin paper?” is the call from SoftBook Press. No paper you say? Well, SoftBook Press is pushing that concept with its new electronic book that they call “The SoftBook.” We have seen 3-Com’s electronic PalmPilot make major strides in the organizer market replacing the traditional paper organizer. Now SoftBook is trying to do the same with an electronic book. Publishers see this technology as a new way to boost profi t margins by reducing bloating costs for printing, paper, marketing, storing acres of books in warehouses, etc.
SoftBook will be introducing their “SoftBook” to the consumer market shortly. The new electronic book will weight all of 3 lbs and be about the size of Glamour magazine. The “book” will come in a leather cover that opens like a hard cover book. When open, the user will be looking at a touch sensitive screen that will display in black and white. On the perimeter of the screen will be four buttons to control the features of the “book.” One button will bring up a menu, another a list of books and articles stored in the book, another to go back a page and the other to go forward and back a page. The reader will be able to create “bookmarks” to save places in the book, mark up pages and even search keywords in the book. The book will operate on a rechargeable battery.
OK, you have SoftBook but how do you get the content? Using the touch screen and connecting via phone line through the Internet to SoftBook Publishing, you will choose and download the book of your choice. The SoftBook can hold up to 100,000 pages. Once a book is paid for and downloaded you can re-download at anytime. You can keep several books in the SoftBook as only the amount of pages, hence memory, is the limitation. How much does all this new technology cost? When Soft-Book hits the market it will cost $299 retail. Buyers will then have to buy at least $9.95 worth of products each month for two years from SoftBook’s on-line bookstore. This pushes the overall cost for the two year period up to around $540! SoftBook will target, initially, those readers who read high volumes of books such as college students, who typically have to lug around numerous fat textbooks, etc.
Another electronic book on the horizon is the Rocket eBook which was created by the designer of the PalmPilot. The eBook is smaller, simpler and, on the inside, more technologically advanced than the SoftBook. The eBook will have more in common with the PalmPilot than the SoftBook. To purchase a book, the user would plug the eBook into their computer, connect via the Internet to any on-line bookstore and download the book of their choice to their computer and then finally into the Rocket eBook. The eBook can hold around 4,000 pages and old books downloaded can be stored on your hard drive (or any other storage device). If you lose or want to re-read the book you can relink it to your eBook.
Technology is ever changing. Years ago many would have never believed we would be using elec-tronic organizers but today they are becoming more common placed. Is the electronic book for everyone? Probably not but there will be many the need fits the bill. It was only a matter of time before the computer would try and replace the printed book. The publishing industry is in constant change not only from the new electronic books but with the on-line bookstores such as Amazon Books (www.amazon.com), Borders (www.borders.com) and Barnes & Noble (www.barnes&nobel.com). This is a fascinating time which clearing moves at a rapid pace with no end in site.
Category: Printing Methods