Printing technology
The term printing technology encompasses all processes for the reproduction of print templates , such as letterpress , offset printing , gravure printing , flexographic printing and screen printing . In these printing techniques, different processes are used to transfer printing inks to a printing substrate .
The printing techniques explained here can be used for the mass production of printed matter by repeatedly using a single printing template. These can be offered on a market as a series product in the so-called “ edition ” (see mass media ).
Basics
"[Printing is the ...] reproduction of a textual or graphic representation in any number by transferring printing inks or coloring substances to the printing material using a printing form . DIN 8730 "
The preparation of this printing form takes place in the prepress stage . The reproduction technology deals with the reproduction of images and texts and creates the printing forms for the various printing methods. Images are reproduced as faithfully as possible in the standardized printing colors cyan (blue-green), magenta (red), yellow and black . These colors can be printed one after the other in one machine run. When printing spot colors , for example in packaging printing, ready-mixed printing inks are used.
The modern printing machines in offset and gravure printing transfer the printing ink from a printing cylinder to sheets or webs of the printing material. Printing presses in the printing processes, such as the web offset and rotogravure printing can reach speeds between 600 and 900 meters per minute. The sheetfed printing machines are generally slower, but can print sheets made of cardboard, sheet metal and plastic.
Since the 1950s, technical advances in photography and, from the 1960s onwards, in electronics have profoundly changed the production of artwork. With the help of the computer , the reproduction process can be accelerated to such an extent that texts and images can be transferred directly to the printing plate ( computer to plate ) or engraved on the printing cylinder ( Helio-Klischograph ) within a short period of time .
Printing principles
A distinction is made between three printing principles:
- Face against face (flat against flat)
- Cylinder against surface (round against flat)
- Cylinder against cylinder (round against round)
Surface against surface
It is the oldest of the three procedures. With this principle, the material to be printed is pressed onto a flat, colored printing plate by a flat counter-pressure plate (crucible) with great force. The color is then transferred. The disadvantages of the principle are the forces required for larger areas and the limited speed. Platen printing presses ( printing presses ) work according to this principle.
Cylinder versus surface
In the 19th century, Friedrich Koenig developed the stop cylinder press . He transferred the principle flat against round of the copper printing press from the gravure to the letterpress .
With the principle of round versus flat, the contact pressure on the printing material occurs through the rotary movement of the printing cylinder over the printing form. The cylinder rotates around its axis, while the printing material is moved synchronously under it during each printing process (print processing). As a result, the contact pressure is only effective within a narrow strip, namely the “tangential” contact area between the round cylinder and the flat printing form. In this way, higher printing speeds and larger formats became possible, which was particularly necessary for newspaper printing.
Cylinder against cylinder
Here the printing process works via two cylinders. The round printing form is attached to the printing cylinder. The printing material is pressed onto the forme cylinder either as a sheet or a roll via the impression cylinder and printed in this way.
The uninterrupted rotation of cylinder against cylinder means that there is no need to stop, retract and re-accelerate as with the heavy flat printing form. The printing form return with high-speed letterpress presses is only possible when the printing is switched off. For physical reasons, a substantial increase in the number of revolutions in rotary machines is possible with the principle around versus around. Modern printing machines work according to this principle both in the sheet and in the roll area.
The principle of round versus round can take place both directly and indirectly. Direct printing processes are characterized by the fact that the print image is transferred directly from the printing form to the printing material. Therefore, the print image must be reversed on the printing form. Examples of a direct printing process independent of the printing principle are doctor blade gravure, letterpress and flexographic printing .
In the indirect printing process, the print image is first applied to an intermediate carrier. The intermediate carrier is flexible and transfers the color to the substrate. For this reason, the printed image must be right-sided when using an indirect printing process. Examples of indirect printing process are the offset printing of Lettersetdruck and pad printing .
Printing process
| Flat printing | Gravure | Digital printing | screen printing | High pressure |
|---|---|---|---|---|
| 70% | 12% | 8th % | 6% | 4% |
Printing processes are distinguished according to the following aspects
- according to the relationship in which the printing elements are to the printing form , such as flat, letterpress, gravure and through printing. According to this feature, the printing processes are also differentiated in DIN 16500 into the main printing processes:
- Letterpress : Image areas of the printing form are higher than non-image areas, for example letterpress and flexographic printing
- Flat printing (see also lithography ): image areas and non-image areas of the printing form are approximately on the same level, for example in offset printing
- Gravure printing : image areas of the printing form are lower than non-image areas
- Through printing : Image areas of the printing form consist of the openings of a stencil mostly on a color-permeable stencil carrier, a screen made of plastic or metal threads. Non-image areas are impermeable to color, for example screen printing and risography .
- according to the material of the printing form , for example stone printing, copperplate printing
- depending on the type of processing of the printing form , for example manually with woodcut or lithography , chemically like with etching ( etching , cliché ) or photo- mechanically like with collotype
- according to the degree of automation , for example artisanal, manual, semi-automatic, automatic or industrial printing processes
- According to the transmission path : Direct and indirect printing processes are differentiated here. Direct printing processes are characterized by the fact that the print image is transferred directly from the printing form to the printing material. Therefore, the print image must be reversed on the printing form. Examples of a direct printing process are doctor blade gravure, letterpress and flexographic printing. In the indirect printing process, the print image is first applied to an intermediate carrier. The intermediate carrier is flexible and transfers the color to the substrate. For this reason, the printed image must be right-sided when using an indirect printing process. Examples of an indirect printing process are offset printing and pad printing .
High pressure
Book printing spread quickly after Johannes Gutenberg improved various printing processes and tools in the 15th century. The printing press is today as high pressure called because the print elements are raised on the printing form.
With conventional letterpress printing presses , a fundamental distinction is made between platen printing presses , cylinder printing presses and rotary presses. With the platen press, the pressure is flat / flat, since the flat pressure surface of the platen is pressed against the flat printing form, which is usually clamped vertically in the platen printing machine. The cylinder printing press prints flat against round, i.e. the flat shape is usually pulled through under the round printing cylinder during the printing process. With the rotary press, the printing is done round against round, in that the pressure of the printing cylinder is applied against the round printing form, the so-called "round stereo". In the case of crucibles and cylinder presses, the paper is always fed in in single sheets, with rotary machines usually in webs from the roll. However, sheet-fed rotary machines are also used in letterpress printing for special production requirements.
From this basic form of letterpress, further printing forms developed:
Indirect letterpress, letterset
Letterset is indirect letterpress printing in which the artwork is printed from a correct-sided cliché. This is bent and attached to the printing cylinder. The high-pressure cliché transfers the print image to a rubber blanket, the so-called rubber cylinder , which creates the reversed image, which is printed from the rubber blanket onto the paper, similar to offset printing. However, the printing process takes place without the use of water, as is necessary in planographic printing. This indirect letterpress is also known as dry offset because of this similarity , but it belongs to the letterpress printing process . Indirect letterpress printing is used in the packaging industry and in continuous printing.
Flexographic printing
The flexographic printing is a newer high-pressure process in which the printing form of a flexible photo polymer plate is. The main areas of application for flexographic printing are packaging films. Flexographic printing is in close competition with copper gravure printing, which, however, achieves better quality results. Because of the high pre-printing costs when creating the copper plate, this is uneconomical for small and medium-sized editions. The efficiency in flexographic printing is considerably improved through the use of prefabricated continuous printing forms. These are rubber compounds specially developed and adapted to the application, which work with solvent inks, water colors or UV inks. After vulcanization on the carrier material (sleeve), the print motif is engraved into the surface using a CO 2 laser . This process is called flexo direct engraving.
Gravure
The gravure printing is a printing method wherein the printing elements by chemical or mechanical methods deepened be transferred to the printing form cylinder. The individual depressions , separated from one another by a uniform grid, are called pans . The cells used to be produced by etching, today by mechanical engraving using a small diamond stylus or laser engraving. During the printing process, the printing forme cylinder is colored with a relatively thin ink and the excess ink is wiped off the cylinder with a squeegee . The color for the printing process therefore remains only in the recessed areas of the cylinder; so only these parts print. The ink is transferred to the printing material by applying high pressure. The amount of paint applied to an image area is determined by the depth of the cells. The light-dark effect of an image in gravure printing therefore depends on the amount of color applied. This fact distinguishes gravure printing from letterpress and offset printing, where the optical result of halftone images is only determined by the different sizes of the individual raster points in the corresponding image areas.
Rotogravure printing, i.e. rotogravure printing with cylindrical printing forms, is economical for mass printing, magazines, decorative foils in the furniture industry and wallpaper in very large editions. The high costs of the printing form are offset by the low costs in the production run. The option of seamless continuous printing is particularly important for decor printing .
Flat printing
With planographic printing, the printing and non-printing areas are on the same level. The principle here is based on the chemical contrast between fat and water. While the printing areas are fat-friendly , the non-printing areas are moistened with a film of water and repel the fat-rich printing ink. The printing, grease-friendly areas are applied with ink, crayon, grease pencils or by photographic means and take on color. The non-printing areas, on the other hand, are made hydrophilic , absorb the fountain solution and repel the ink during the printing process. The printing areas are referred to as lipophilic , the non- printing areas as hydrophilic . For lithographic printing count of lithography , the offset printing , the light pressure , the Photochrom print and Polyfoliendruck . Offset printing is a further development of stone printing in that printing is done indirectly using a rubber blanket. Special forms of indirect flat printing use transfer paper or foils instead of a rubber blanket.
Sheetfed and web offset printing machines are used in practice today . The advantages of offset printing are the large variety of substrates and the fast and inexpensive production of the printing forms . Daily newspapers, mass printed matter, magazines and packaging are economical in web offset printing with high print runs or volumes. Posters, photo books, printed advertising material or highly refined print products are produced economically and with high quality in sheet-fed offset printing for small to medium runs.
Print through
The best-known print-through process is screen printing or serigraphy , in which the printing ink is pressed through a fine-meshed textile fabric onto the material to be printed with a wiper-like tool, the rubber squeegee . The printing form of the screen printing consists of a frame that is covered with a fabric made of metal or plastic. The fabric carries a stencil made of plastic, for the production of which the entire surface of the tensioned fabric is coated with a photopolymer and exposed to the motif to be printed via a positive film. The photopolymer hardens in the non-printing areas and the unexposed material is washed out. During the printing process, the printing ink only passes through the fabric where it has been washed free.
A wide variety of materials can be printed using the screen printing process, both flat foils and plates as well as shaped objects such as bottles, plastic containers and items of clothing. Depending on the material, special printing inks are used for this. Mainly paper products, plastics, textiles, ceramics, metal, wood and glass are printed. Compared to other printing methods, the printing speed is relatively slow. Screen printing is a direct printing process . There is a gap of one to a few millimeters between the printing form and the printing material, which is necessary to enable the jump to take place. This screen jump height is locally and temporarily canceled where the squeegee presses the screen down so far that the stencil rests on the printing material. At this point, the contours are sealed and the color is transferred to the substrate. If the squeegee continues to move, the fabric that has just been coated with the stencil is raised again.
When printing stencils without a supporting screen, the stencil itself must be sufficiently strong and, for example, made of steel and stretched directly into the frame. As with the stencil , the possible print images are limited. This process is used, for example, to apply the solder paste or the adhesive to mostly rectangular SMD connection surfaces on circuit boards. A clogging of meshes with printing paste components - as is possible with the otherwise almost identical screen printing process - cannot occur. With the screen printing process, on the other hand, thanks to the supporting screen, non-image areas can also be displayed that are completely and completely enclosed by image areas.
Other printing processes
Other printing processes that are special forms or derivatives of the printing types mentioned are:
Pad printing
The pad printing is an indirect gravure squeegee. With the help of a tampon made of porous silicone rubber, the template is transferred from a surface (gravure printing form) to an object, for example a cup or ballpoint pen, and can therefore also be applied to uneven substrates. That is why pad printing is used particularly in the production of promotional gifts , as well as in the fine printing of model railways and clock faces and in the labeling of electronic components and switches.
Stamp printing
The ram pressure is one of the oldest method of printing, in which the individual printing plates are pressed onto the print material. Stamp printing is a flexographic printing process and as such can be assigned to letterpress printing.
Pigmentography
The Pigmentografie is an independent graphical methods as opposed to pigment printing to look at. In the printing technique launched by Al Bernstein in the USA in the 1970s as trace print , the individual printing forms are cut and engraved using the positive-negative process, whereby, in contrast to the pochoir , very fine lines and dots can be printed. During the printing process, the printing ink is manually brushed through the printing stencil and then fixed.
Pochoir
With the pochoir , also known as stencil or stencil art , graphics and texts are applied using stencils and are considered to be one of the oldest industrial color printing techniques. The process was used from 1796 in the French Épinal . This technology is still used there today. Pochoir occurs today in street art and is to be regarded as a subspecies of graffito . This printing process can be assigned to screen printing in the broadest sense.
Embossing
With embossing , patterns are embossed into the material to be printed. If this is done without color, one speaks of blind printing, blind pressing, blind embossing or embossing . The process is used, for example, for book covers, greeting cards and wallpaper. Blind printing in the form of roll and stamp seals existed as early as the 4th millennium BC. In Mesopotamia and Egypt .
Distortion pressure
The Zerrdruck is a method in which an image of a printing plate on a plasticine on silicone rubber-based transferred deformed, and is then printed as a distorted image. With this technique, developed in 1967, it was possible to generate distorted images even before digital image processing.
Electronic printing process
Electronic printing processes, also called non-impact printing or NIP processes , are processes without an explicit printing form and designate a steadily growing number of color thermal printers , plotters and inkjet printers . Laser printers or line printers are not counted as part of the NIP process, since there the color transfer cannot take place without pressure on the paper. Type printers are, for example, so-called transfer printers and represent a principle mixture of letterpress and screen printing. They have form components (types), but do not have the typical overall form constellation of a printing machine. The old dot matrix printer, and dot matrix printers , called also falls into this category. The classic laser printer can be counted among the electronic flat printing processes. The image of the print image on the toner drum gives it a printing form, albeit a temporary one.
Direct thermal printing
With direct thermal printing , the printing result is achieved through selective heat generation instead of mechanical stops or pressure. A temperature-sensitive special paper is used which blackens when heated. Thermal printing is often used in cash registers and was previously used in fax machines .
In 2017, the Japanese device manufacturer Brother introduced a two-color thermal printing process for labeling devices with black and red.
Thermal transfer printing
The thermal transfer printing is the evolution of direct thermal printing, especially in the field of CD and DVD -Bedruckung. For this purpose, a special printer is used which, by heating the print head, removes the color from an ink-bearing polyester film, called a ribbon , and transfers it to a special retransfer ribbon . A film is then melted from this retransfer ribbon onto the medium to be printed. This intermediate transfer enables a high resolution and the printing can take place over the entire surface. This means that even small quantities can be printed in photorealistic quality.
Dye sublimation printing
The dye sublimation printing has also been developed further by thermal transfer printing. The difference is the transfer of the color from the carrier film to the paper by sublimation . Since the color is briefly gaseous, real tonal gradations can be created without screening. A weakness in thermal transfer printing for photo printouts could be eliminated. However, the consumption costs for transfer foils are very high, so that these devices could not survive on the market. The printing process has recently been re-established as an accessory for digital cameras in small-format photo printers.
Laser marking
With laser marking , the material to be printed is treated with a high-energy laser beam. Depending on the material and process, this can lead to chemical changes, for example through combustion, discoloration, or material removal. Laser marking is now widely used to mark electronic components or keyboards. A particular advantage is the ability to create very small, machine-readable fonts. Another advantage is that, for example, Plexiglas plates can often be cut and labeled with the same laser.
3D printing
3D printing is a printing method from manufacturing technology. Three-dimensional objects are created digitally on the computer and printed out with a 3D printer . Certain materials are either built up in layers or removed. Since 2012 there have been online solutions that print 3D custom-made products and deal with digital construction instructions.
Printing ink
Printing inks are adapted to the printing process in terms of their composition and properties. Pasty and highly viscous inks are used in all planographic printing processes and in letterpress printing . In flexographic and gravure printing, on the other hand, low-viscosity, thin-bodied inks are used. In the screen printing process, the selected colors and their properties depend on the respective purpose. The historical book ink of the black art consisted of soot , which by vigorous Einspachteln in the self-solidified linseed oil dispersed was. Modern printing inks are highly complex mixtures of substances.
Historical overview of the most important inventions in the printing sector
| year | invention | inventor | scope of application |
|---|---|---|---|
| 4th millennium BC Chr. | Blind embossing with roller and stamp seals | in Mesopotamia and Egypt | Sealing of jugs, certificates, clay cartridges, graves |
| 770 | Wooden board printing | developed during the Sui Dynasty | Printing of block books |
| 1040 | Movable type printing (fired clay) | Bi Sheng | Letterpress |
| 1234 | Print with movable type (wood, copper, lead or brass) | probably developed during the Goryeo dynasty in Korea | Letterpress |
| 1400 | Invention of the woodcut | - | Letterpress |
| 1440 | Movable type printing (lead) | Johannes Gutenberg | Letterpress |
| 1446 | first verifiably dated copper engraving | Peter Zamudio | Single sheet print , book illustration |
| 1457 | first dating of a publisher's information in a printed book | - | Letterpress |
| 1469 | oldest printing privilege | J. von Speyer | Letterpress |
| 1573 | first German book printer regulation | in Frankfurt am Main | Letterpress |
| 1719 | Three and four color printing | Jakob Christoph Le Blon | Book illustration, reproduction technology, wallpaper printing |
| 1780 | Copy press | James Watt | Copy |
| 1797 | Stone printing and lithography | Alois Senefelder | Single sheet print, book illustration |
| 1798 | Paper machine | Nicholas-Louis Robert | Papermaking |
| 1800 | first hand press made entirely of iron , the Stanhope press | Lord Stanhope | Letterpress |
| 1812 | Cylinder printing machine (high-speed press) | Friedrich Koenig | high volumes of books, newspapers and magazines |
| 1816 | Perfecting press | Friedrich Koenig | Letterpress |
| 1822 | first patent for a setting machine | William Church | Typesetting |
| 1830 | Platen Printing Press (Boston Press) | Isaac Adams | Letterpress |
| 1830 | Stereotype | Firmin Didot | Cliché making |
| 1837 | Chromolithography (color printing) | Godefroy Engelmann | Illustrations, art print |
| 1838 | Galvano | Moritz Hermann von Jacobi | cliche |
| 1838 | photography | Louis Daguerre | Portraits, postcards |
| 1840 | Line etching | Blasius Hofel | cliche |
| 1843 | Rotary printing | Richard March Hoe | high volumes of books, newspapers and magazines in a short time |
| 1844 | Patent on paper manufacture from wood | Friedrich Gottlob Keller | Papermaking |
| circa 1850 | Collotype (phototype) | Louis-Alphonse Poitevin | high quality facsimiles and art prints |
| circa 1850 | Boston crucible press standing principle | J. Golding | Letterpress |
| 1851 | Folding machine | James Livesey | Fold |
| 1862 | Complete casting machine | Johnson and Atkinson | Typesetting |
| 1863 | Web-fed rotary printing press | William Bullock | Mass print runs of books, newspapers and magazines with short-term publication dates |
| 1867 | typewriter | Christopher Latham Sholes | Office work of all kinds |
| 1873 | mimeograph | Thomas Alva Edison | Copy |
| 1879 | Hectograph | Kwaisser and Husak | Copy |
| 1881 | Autotype | Georg Meisenbach | Glass engraving grids and cliché production |
| 1886 | Typesetting machine ( Linotype ) | Ottmar Mergenthaler | Machine set |
| 1897 | Monotype | Tolbert Lanston | sentence |
| 1907 | Offset printing | Ira W. Rubel / Cašpar Hermann | Indirect printing on paper, foil, sheet metal |
| after 1920 | Schapyrograph | ?? | Copy |
| 1930 | Serigraphy / screen printing | Carl Zigrosser / Anthony Velonis | Posters, printing on a wide variety of materials |
| 1930 | Light setting machine ( Uhertype ) | Edmund Uher | sentence |
| 1938 | Electrophotography | Chester Carlson and Otto Kornei | Photocopying |
| 1948 | Rotofoto lighting equipment | George Westover | sentence |
| 1951 | Klischograph | Rudolf Hell | Plate making, letterpress and offset |
| 1961 | Helio-Klischograph | Rudolf Hell | Gravure |
| 1962 | EDP use in typesetting | Linotype | sentence |
| 1963 | Drum scanner | Rudolf Hell | Reproduction technology , offset |
| 1969 | Euroscale | - | Reproduction technology, offset, gravure printing |
| 1969 | Digital camera | Willard Boyle , George E. Smith | Reproductive technology |
| 1972 | Proof , cromalin | DuPont | Reproduction technology, gravure printing, offset |
| 1979 | EBV system | Rudolf Hell | Reproduction technology, offset |
| 1982 | Introduction of PostScript | Adobe | sentence |
| 1985 | Desktop publishing | Adobe, Apple , Linotype | Reproduction technology, offset |
| 1990 | Introduction of PDF | Adobe | sentence |
| 1993 | Digital printing | - | Book on demand |
| 1993 | Computer to plate | - | Offset |
| 1994 | Book on demand | - | Offset, digital printing |
| 2008 | Computer to Press | - | Offset |
See also
- Direct printing process
- Counter pressure
- Printer (profession)
- printing house
- Sublimation printing (process)
- 3D printer
- Bioprinter
literature
- Franz Severin Berger: From Gutenberg to the World Wide Web . Dachs-Verlag, Vienna 2002, ISBN 3-85191-190-3 .
- Hubert Blana: The production. A manual for the design, technology and costing of books, magazines and newspapers (= basic knowledge of the book trade - publishers 5). 4th revised and expanded edition. KG Saur Verlag, Munich 1998, ISBN 3-598-20067-6 .
- Claus W. Gerhardt : History of the printing process. Volume 2: The book printing (= library of books 3). Anton Hiersemann Verlag, Stuttgart 1975, ISBN 3-7772-7521-2 .
- Helmut Hiller, Stephan Füssel: Dictionary of the book. 6th fundamentally revised edition. Vittorio Klostermann Verlag, Frankfurt am Main 2002, ISBN 3-465-03220-9 .
- Kaj Johansson, Peter Lundberg, Robert Ryberg: Grafisk kokbok. Guiden till grafisk production. Arena i samarbete med Kapero grafisk utveckling, Stockholm 1998, ISBN 91-7843-128-X (German: “Well done, please!” The complete menu of the print production. Schmidt, Mainz 2004, ISBN 3-87439-632-0 ; 2 . Revised edition. ibid 2008, ISBN 978-3-87439-731-5 ).
- Harald Küppers : Theory of colors. The various possibilities of image reproduction (= DuMont pocket books 563 crash course ). DuMont Literature and Art Verlag, Cologne 2005, ISBN 3-8321-7640-3 .
- Dieter Liebau, Hugo Weschke: Polygraph technical lexicon of the printing industry and communication technology. Polygraph-Verlag, Frankfurt am Main 1997, ISBN 3-87641-267-6 .
- Bernhard W. Panek: Printing materials - printing - finishing and alternative reproduction methods. Manufacture and selection of paper, cardboard and paperboard. Classic printing processes, finishing, photocopying and full-color copying. Measurement and testing technology. Security, fire protection. 2nd revised edition. facultas wuv universitätsverlag Vienna 2004, ISBN 3-7089-0154-1 .
- Hans Jürgen Scheper: Examination knowledge printing technology. Prepress, postpress. Verlag Beruf und Schule, Itzehoe 2005, ISBN 3-88013-623-8
- Anton Turtenwald: About the main types of reproduction of pictorial representations. In: Weekly of the Austrian Association of Engineers and Architects , year 1891, No. 35/1891 (XVI. Year), pp. 309–313. (Online at ANNO ). .
- Hans-Jürgen Wolfsturm, Hermann Burkhardt: High pressure. Ravensburger Buchverlag, Ravensburg 1994, ISBN 3-473-48382-6 .
Web links
- FHTW-Berlin Overview of the most important printing processes
- Color reproduction in print
- Information and communication in the past and present
- Graphic techniques: book in PDF
Individual evidence
- ↑ Helmut Kipphan (Ed.): Handbuch der Printmedien. Springer Berlin, Berlin 2000, page 29 ff., ISBN 3-540-66941-8 .
- ↑ Printing and advertising ( Memento of the original dated August 4, 2009 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. , geomix.at, accessed on July 19, 2009.
- ↑ Jürgen Zeidler: Lithography and stone printing. Ravensberger Buchverlag 1994, page 7. ISBN 3-473-48381-8 .
- ↑ EOPA 2017 Innovation of the Year: Brother International Europe.
- ↑ Specification Brother QL-820 .
