Топики По Английскому Языку (Воронов Р. И

Binding

A printing job is not complete until it is converted to a finished marketable product and delivered. These are the function of postpress: binding, finishing and distribution.

I would like to tell you about binding

The work required to convert printed sheets or webs into books, magazines, catalogs and folders is called binding.

There are generally five steps in pamphlet binding:

• scoring

• folding

• gathering (collating)

• stitching, cutting and trimming

Scoring. Folding is made easier by first scoring of heavyweight or cover paper. A score is a crease in a sheet of paper.

Folding. There are 2 kinds of folds: parallel and right angle. In parallel folding, each fold is parallel to the other. A right angle fold is 2 or more folds, with each fold at right angles to the preceding.

Collating. Collating can be done by hand or machine, depending on the size of the job.

Stitching. The booklet is placed on a saddle beneath a mechanical stitching head, and staples are forced through the spine of the booklet. This type of binding is the simplest and most inexpensive.

Cutting and trimming. Computer controlled guillotine cutters used to cut labels, paper and etc. trimming is usually done with 3 knives in a single cycle.

Digital

Digital printing is a combination of digital imaging and digital press. Digital imaging has already almost completely replaced conventional prepress. It has created an intermediate type of printing process with digital prepress and conventional press. Digital imaging has made possible the filmless imaging. There are 3 types of filmless digital imaging processes: computer-to-plate, computer-to-plate-on-press and computer to print.

Computer-to-plate create images directly on printing plates for conventional printing. This systems almost always used for gravure and flexography, and sometimes for lithography.

Computer-to-print create images directly on plateless presses. This systems, like ion or electron charge deposition, electrophotography, ink-jet systems and magnetography, now become very popular, because they do not nee sufficiently long operation like filmmaking and platemaking. Image from computer directly printing on paper- it is very big advantage of digital printing. But there are some disadvantage of it. First of all, that it has low speed of printing. Second, it is favourable to use only for medium and shot runs. And third, it is problematic to level the paper in process of printing.

FINISHING

Finishing is a general term that includes a number of different opera­tions and specialties. Most of these operations are highly specialized.

Some finishing operations are performed inline with printing on web-printing presses. Two finishing operations quite often used are embossing (stamping) and diecutting.

Embossing

The image is molded in embossing so that it is raised in relief. Mold­ing is achieved by pressing the material to be embossed between a brass female die and a male bed or counter mounted on a press.

Light embossing may be done without heat on a cylinder or platen press.

For heavy embossing and where fine detail is required, the die is fas­tened to a heated plate on a four-post press.

Diecutting

There are two methods in use today: high or hollow diecutting and steel-rule diecutting.

Hollow diecutting is a process used almost exclusively for labels and envelopes. A steel die is positioned on jogged pile of printed sheets. Pres­sure forces the die through the pile. The labels remain in the die until stripped out by hand.

Steel-rule diecutting is used for larger size dies or where close regis­ter is required.

The latest developments in diecutting are laser-cut dieboards and ro­tary diecutters.

Shrink-packaging

Bindery automation

Flexography

Flexography is a form of rotary web relief printing like lettepress but using flexible rubber or resilient photopolymer relief plates, and fast-drying low viscosity solvent, water-based, or UV inks fed from anilox: inking system.

Flexographic presses are web-fed machines of three types:

1. Stack type in which two or three printing units are placed vertically in stacks. A press may consist of two or three stacks, with unwind, rewind, sheeter or cutter and creaser;

2. Central impression cylinder which is like the common impression rotary lettepress and is used extensively for printing flexible films;

3. And inline which is similar to a unit type rotary press.

Almost anything that can through a web press can be printed by flexography.

Products printed by flexography range from decorated toilet tissue to bags, pressure sensitive labels, corrugated board and materials such foil, hard-calendered papers, cellophane, polyethylene and other plastic films.

Halftones as fine as 150 lines per inch can be printed on flexible films.

The improved quality of photopolymer plates, controlled inking of advanced ink metering systems with reverse angle doctor blades, and wa­ter-based and UV inks have favored flexography to replace letterpress, gravure and lithography in some printing markets.

GRAVURE

Gravure image areas consist of cells or wells etched or engraved into a copper cylinder, and the non-printing areas are the unetched surface of the cylinder. The image cylinder rotates in a bath of ink. Ink from cells direct transfer to the paper as it passes between the plate cylinder and the impression cylinder.

Three types of process are used for making gravure printing cylinders:

1. Chemical etching that produces cells of the same size or area with varying depths or cells with varying area and depth.

2. Electomechanical engraving (EME) which produces culinders with cells that vary in area and depth.

3. Derect digital caser etching presses which uses a special alloy and laser to produce cells of varying area.

Gravure printing produces exellent reproductions of pictures, but slightly ragged type.

Gravure is used for long runs of newspaper supplements, maganies, catalogs, special products like wallpaper and packaging.

HISTORY

Printing is a means of graphic communications. It is the reproduction of images mostly on paper which can be seen visually.

Modern printing has become highly complex. At presenr time printing process has been transformed from an art to a science. 30,000 years ago man tried to make a visual record of his life. These were wall drawings called pictographs.

Printing from movable type appeared in China and Korea in the 11* century. The oldest text known was printed from bronze type characters in Korea in 1397 A.D. Our common typefaces are either imitations of early handwritten let­ters.

The first books in Europe were printed in block letter or gothic type.

Italics were first used to print small, compact books. Early books were large and cumber­some.

When Roman type came into use, it was cast smaller than gothic.

For more than 400 years after the invention of printing, all type was set by hand. Many machines for replace hand composition were invented.

The first of these was designed by an American, Dr. William Church, in 1822...The first illustrations in books were made from woodcuts.

Books printed between 1570 and 1770 were usually illustrated by copperplate engravings.

After that photography began used for illustrations in books.

Today, photog­raphy is gradually being replaced by digital imaging. Papermaking was invented in China more than 1,800 years ago. By 1200 A.D., paper was being made in Spain, and 200 years later the art was well established throughout Europe

Ancient papers were made almost entirely from rags and were pro­duced with hand-operated devices.

Most papers currently used in printing are manufactured from wood pulp.

Letterpress

Letterpress is a relief method of printing that can print from cast metal type, molded duplicate plates (still used for some package printing) or photopolymer plates on which the image or printing areas are raised above the non­printing areas. Viscous oil-base and UV inks are used. The ink roll­ers come in contact with the raised areas only, and the inked image is transferred directly to the paper.

Letterpress, the first printing process, started with converted wine-press. Through the years three basic types of presses were developed and used for lettepress printing: platen, flatbed cylinder and rotary. In addition there is a belt press for continuous inline printing and finishing.

Platen presses carry both the paper and the type form on flat surfaces known as the platen and the bed which open and close like a clamshell.

Flatbed cylinder two-revolution presses with a moving flatbed that held the form abd a fixed rotating impression cylinder are now obsolete. Single revolution vertical presses where the bed is in a vertical position and both form and cylinder nove up and down in a reciprocating motion are still in use.

Rotary sheet-fed presses with two cylinders are fastest and most efficient of the three types.

Belt press is an automated inline press which prints, collates and binds a complete book in one pass through the press. It has two belts on which the plates for all the pages in the book are mounted.

The lettepress image is usually sharp and crisp, but grainly.

Offset lithography

This is the major plate printing process. It use thin metal plates with the image and non-image areas on the same plane. There are two basic differences between offset lithography and other processes:

• it is based on the fact that oil and water do not mix;

• it uses the offset principle in which ink is offset from the plate to rubber blanket on an intermediate cylinder, and from the blanket to the paper on an impression cylinder.

On a lithographic printing plate, the printing areas are oil or ink-receptive and water-repellent, and the non-printing areas are water-receptive and ink-repellent.

Lithographic inks are fairly stiff and require long ink roller trains on the press to get the proper flow and film thickness for printing.

Offset presses have three printing cylinders (plate, blanket and impression) as well as inking and dampening systems. On most offset presses the plate comes in contact with the dampening rollers first, and then the inking rollers. The dampening wet the plate so the non-printing areas repel ink.

The inked image is then transferred to the rubber blanket, and paper or other substrate is printed as it passes between the blanket and impression cylinder. Offset printing produced smooth print without embossing, an ink ring or serrated edges which are characteristic of letterpress, flexography, gravure and screen printing

Offset lithography has equipment for short, medium and long runs. Both sheetfed and web presses are used.

Lithography is used for printing advertising, books, catalogs, greeting cards, posters, labels, packaging, art reproductions, newspapers, magazines and many others/

Prepress

There are 3 stages of making printing products: Prepress,Press,Postpress.Now I would like to tell you about one of them-Prepress.It’s the first process in printing,which inclueds: making the original→original→repropreparation→film→platemaking→printing plate.

Prepress includes all the steps required(необходимый) to go from the preparation of the text,original images and graphics.A fundamental technological change has taken place within prepress.The use of conventional typesetting machines,reprocameras and film are has been replaced by computer technology in virtually all branches of this industry.Text and image are converted into standardized letter forms and assenbled into pages of books, magazines, newspapers and other printed matter..So there are 2 prepress technologies:conventional & digital.The main difference between them is the way the films are used.

The first step in producing a printing plate is the creation of the film copies.Film copies contain all the informathion to be print on the printing sheet,corressponding(соответствующих) to each colour. Main colours are:cyan,yello,magenta .Typesetting is carried out on computers in combination with powerful software and imaging systems to produce the text film masters.Today;s typesetting begins with the inpreting of the text into a computer.This task is incresingly(больше и больше) being undertaking(обязательство) by author himself.Text input is followed by word processing the design parametrs such as choice of the font,size and others.Word processing is followed by text output.The next stage is correction of the output text.The main function of the correction is the placing of the pictures in the correct position on the page the arranging(классифицирование) of heads(заголовок) and footers(обычные строки) including page numbering.

Screen hrinting

I want to tell you some words about screen printing. This method employs a porous screen of fine silk, nylon, dacron or stainless steel mounted on a frame. Printing is on paper or other substrate under the screen by applying ink with a paint-like consistency, spreading and forcing it through the fine mesh openings with a rubber squeegee.

The amount of ink applied by screen printing is far greater than in let­terpress, lithography, or gravure which accounts for some of the unusual effects in screen printing. The production rate, formerly limited by the drying time of the ink, has been greatly increased through the development of automatic presses, improved dryers and UV inks.

The screen presses now are power-operated presses of two types. One uses flat screens. The other uses rotary cylindrical, screens with the squeegee mounted inside the cylinder, the ink pumped in automatically, and magnets used opposite the screens to control squeegee pressure.

Screen printing usually can be recognized by the thick layer of ink and sometimes by the texture of the screen on the printing. It’s adapted to the printing of leather, metal, glass, wood, ceramic materials and plastics, in both flat and finished molded form.

It is used for art prints, posters, greeting cards, labels, menus, wallpaper and textiles.