computer to plate - presentation

INTRODUCTION:: Printing is the widest and fastest form of usual

communication. The word “CtP” defines -The Master of Image Transferring Techniques.

Necessity is the mother of Invention -ProverbIn this technological world “CtP” has become a buzzword for the Image Qualityin Printing Due to the necessary aspects such as

R.Dinesh Institute of Printing Technology

Short turn around time

High image quality

Easy access in Image transferring techniques

The full form of CtP is COMPUTER TO PLATE.

DEFINITION OF CTPDEFINITION OF CTP In the graphic arts industry, the computer-to-plate (CtP) has digitalized theprocess of plate making and the new platesetting systems use laser beams todirectly write images onto printing plates rather than first exposing a filmthen transferring the image to the plate. The digital direct plate imagingmethod eliminates troublesome film processes.


Computer to plate system for automatically imaging and developing Printing plates (Platesetter 3244, Heidelberg/Creo)

CTP TECHNOLOGYCTP TECHNOLOGY There are many different types of Plate setters used for Offset Printing in CtPsystems and there are three basic designs namely Flatbed, Internal drum,

Externaldrum. Each design has its advantage and each one is accurate in its imagingcapabilities. A Typical View of a Flatbed CtP System - working mechanism


Internal Drum CtPInternal Drum CtPThe internal drum plate setter design resembles the letter "C" because of its open concave design. A single laser beam write the digital image onto the plate. The laser beam is projected onto a spinning mirror that rotates at a very high speed. In order to change the resolution of the image on the plate, the diameter of

the laser beam is changed. A Typical View of a Internal Drum CtP System - working mechanism


External Drum CtPExternal Drum CtPExternal drum plate setters are designed to have the plate mounted on the outside of the drum.As the drum rotates on its axis, a multiple beam laser head moves parallel to the drum and burns the image on the plate.To achieve high quality results, the drum must spin accurately in order for the imaging head to maintain optimum beam intensity.

A Typical View of a External Drum CtP System - working mechanism


CTP eliminates the steps required for conventional plate making, which requires a film workflow and stripping operations and thus saves a considerable amount of time.Human error is reduced with the elimination

of manual stripping and plate making.Storing digital images is easier, safer and more efficient than storing film and flats which can be damaged by storage or handling and they also require large amounts of physical space where else digital images where look consistent, clear, and sharp and space savingPrint quality is improved because the dot gain associated with imaging plates

from film is eliminated. In fact, with a film workflow, dot gain may be as much as 5 or 6 percent.The reduction in potential dot gain allows denser inks to be used at the press, this provides improved color saturation and print quality.Copy changes are much easier with CTP because changes are made to a digital file, which is imaged onto a plate rather than having to produce new films and strip them into a flat for burning onto the plate.


ADVANTAGES OF CTP IN PRINTING PROCESSADVANTAGES OF CTP IN PRINTING PROCESS

EXPOSING EFFECT IN CTP TECHNOLOGYEXPOSING EFFECT IN CTP TECHNOLOGYLaser: LASER – “Light Amplification by Stimulated Emission of Radiation” is

the concept of stimulated emission first postulated by Albert Einstein in 1947where light is produced by atomic process. There are different types of lasers used in CtP


COMMONLY USED LASERS IN CTP SYSTEMSCOMMONLY USED LASERS IN CTP SYSTEMS


GLV TECHNOLOGYGLV TECHNOLOGY

When GLV (Grating Light Valve) technology is used in CTP

systems, it allows for the best image quality and speed in production. The technology is often used in external drum plate setters for CTP systems as well as in high definition

television. GLV technology uses Micro Electro Mechanical Systems

(MEMS), which allows for microscopic structures to form on silicon chips. The structures are reflective and are constructed of several

ribbon-like elements that can be moved up and down through the control of electrostatic forces. The motion of the ribbons covers only a small distance, which is equal to a fraction of the wavelength of light. The different ribbon elements are configured in a pattern that allows the structures to reflect and diffract light waves, which varies the level of light reflected from the surface of the silicon chip.

Imaging optics for GLV based CTP systems provides a larger quantity of writing beams, which means that the imaging drum rotation speed can be reduced while still providing a greater degree of productivity. GLV technology is most often used in conjunction with several thermal (infrared) CTP systems.


DIFFERENT TYPES OF PLATES IN CTPDIFFERENT TYPES OF PLATES IN CTP Some of the major Printing Plate varieties used In CtP systems are

Aluminum-based Printing PlatesThermal-sensitive Aluminum PlatesPhotopolymer PlatesHybrid CtP PlatesSilver halide Plates.


WORKFLOW OF CTP TECHNOLOGYWORKFLOW OF CTP TECHNOLOGY The most common workflow is shown in this assumes that there is a print shop

that receives digitally printing data from outside and first of all checks it for completeness, correctness, and printability in the so-called “preflight check.” and then imposition is done and the file was send to raster image processor (RIP) and checked and agreed by the proffer and then the file is returned and ready to expose the command was given and the Plate was kept in the Platesetter and first it will be punched and then exposed with a laser light the exposed plate was immediately Processed in Automatic Plate Processor.


PROCESSLESS PLATES IN CTP TECHNOLOGYPROCESSLESS PLATES IN CTP TECHNOLOGY


Process less CTP plates have several advantages over chemically processed plates. Some of them are listed below.

Process less CTP plate systems require a lower initial investment

the plates are daylight safe, and because the system requires fewer steps than chemically processed CTP plate systems

process less plates are less labor intensive.

Less equipment is necessary because there is no need for large processing units.

There are no chemicals needed for development of the plates and so there are no environmental issues with the proper disposal of chemicals

Process less plates are ideal for smaller print providers that often produce jobs under 100,000 impressions.

All of these advantages add up to a significant long term cost savings, aprocess that is environmentally friendly and a system that is easier, safer, and less

time consuming for people to use.

ADVANCE TECHNOLOGY IN PRINTINGADVANCE TECHNOLOGY IN PRINTINGOffset printing systems have been developed that not only eliminate filmFrom the workflow, but also eliminate the plate as well. These systems are known as computer-to-press offset printing systems. The Man-Roland DICO web (DICOstands for "Digital Changeover") is one such system. The DICO web useslasers and a thermal ribbon to create images on removable cylinders.

A thermal material, which becomes the image area, is transferred to the plateA wetting agent keeps the non-image areas clean during the print run. A short run of 500 impressions can be produced immediately after imaging. When a longer run is required, the thermal material must be baked onto the cylinder, but this additional step requires only two minutes. When the printing is complete, the thermal image material is automatically cleaned from the plate cylinder so that the cylinder can be ready for reimaging for the next job.The entire process of imaging and cleaning requires less than 12 minutes to complete and a resolution of 3200 dpi can be achieved.


WORKING MECHANISM OF NEW TECHNOLOGY

Bibliography Computer to Plate Technology

Books Referred - Latest Trends in Printing, Basics of Computer to plate Technology.

Websites Referred - WWW.ModernCtpTechnology.com, WWW.Project Gutenberg. COM, WWW.Graphic Brain.com

Conclusion Printing Industry is a vast industry in which inventions blooms

day by day, in that CTP Technology is a wonder and we Printers should use it in an efficient and brilliant way. Though computer to printing has a rise, Computer to plate ever has its own market in all classes of business.

Acknowledgement I thank my college -Institute of Printing Technology for

encouraging and supporting to participate in this “State Level Technical Symposium”. And I also thank C.S.I Polytechnic College for giving me this marvelous opportunity.

R.Dinesh Institute of Printing Technology000

http://www.modernctptechnology.com/

http://www.project/

http://www.graphic/

R.Dinesh and K.Boobalan Institute of Printing Technology

computer to plate - presentation

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