Text 1 Ink

Unit 4 Paper and ink

IV. Speak on the Delivery of the SM 102, using the questions

Text 6 Delivery

IV. Speak on the Coaling and Drying, using the questions.

III. Translate the text into Ukrainian.

The delivery is one of the crucial factors determining how fast a press is able to produce. If not well designed, it will create a major glitch and will limit net hourly output. It must accommo­date high piles despite heavy ink application, and facilitate reduced use of anti setoff pow­der. In addition, it should ensure adequate drying at high speeds. The delivery of the SM 102 meets all of these requirements very easily.

The patented Heidelberg sheet guide plate with air blast jets generates a stabilizing, protec­tive air cushion beneath the sheet. Supported by this air cushion, even sensitive papers are guided into the delivery without any marking; whether printing in-line or in perfecting. The air volume can be fine-tuned to the press speed and the running properties of the stock. The distance from the last print­ing unit to the delivery pile is long enough to ensure good drying. A dryer module can be optionally added. If desired, the Speedmaster SM 102 can be supplied with a continuous delivery with descending secondary pile hoist carrying rake for non-stop oper­ation, or boards for hurdling jobs into small lifts. When the press is equipped with the Heidelberg Preset remote format adjustment system, both the feeder and the delivery are automatically set to each new sheet size. After it has been entered at the central control console, the lateral sheet jog­gers, the rear stop, and the sheet brake in the delivery move to the right positions. If you need to change sheet sizes frequently, the time savings you realize in this way add up to a significant gain in productivity. Adjustment of the powdering width is also computer-controlled (if sup­ported by the installed powder sprayer).

I. Answer the following questions:

1. What are the functions of the delivery?

2. Why is it necessary to generate an air cushion?

3. What modules and systems can be added to the Speedmaster SM 102?

4. How can you increase the productivity of the system?

II. Find in the text English equivalents of the terms:

Приймально-вивідний пристрій, високий стапель паперу, направляюча аркушів, повітродувні сопла, повітряна подушка, бокові зіштовхувачі аркушів, обмежувачі формату, централізоване налагоджування на формат.

ІІІ. Translate the text into Ukrainian.

Ink and paper are the two raw materials used in the printing process. Both have been continually refined and improved by succeeding generations. So many combinations of ink, paper and process are now available that it is therefore increasingly important for the printer to choose the right one.

Ink In the fifteenth century, when Gutenberg first printed from movable type, the ink he used was made of boiled linseed oil with resin, soap and lampblack. Modern inks are made of pigments and binding materials (like resins) combined in a varnish with solvents, The ingredients can be varied to give certain desirable characteristics to the ink, such as improved drying or good rub-resistance. Apart from all the different colours available, there are many different types of ink, corresponding to different printing processes, finishing requirements, toxicity restraints (as in food packaging) and drying methods.

Drying ink There are four main methods of drying ink: evaporation, chemical curing, penetration and oxidation,

Evaporation is used when inks contain volatile solvents such as paraffin, Evaporation is a very fast and effective method of drying, and is used for 'liquid' inks such as those used for gravure or flexography.

Chemical curing ^: dries' ink by linking the pigment molecules in the ink thereby solidifying it. This is done by adding a catalyst immediately before printing to start the solidification process, A similar method uses ultraviolet light to 'cure' the ink.

Penetration is used with paper and board, where the ink dries by being soaked down into the paper, rather like blotting-paper. It obviously cannot be used on plastic or foil, which are nonabsorbent.

Oxidation is a method of drying where the ingredients absorb oxygen from the air. This causes the ink molecules to join together, so that the ink film slowly solidifies. It is a slow process and, when the printing is on paper or board, is used in conjunction with penetration.

Specifying ink Unlike paper, the type of ink is not normally specified by the client, but is chosen by the printer after consideration of the process being used, the machine, the paper and whether any special finishing operations such as varnishing or laminating are involved.

Four-colour process inks are normally made to a standard within a particular country, so that a four-colour set will give the same result regardless of the printer. It is vital that the repro house works to the same ink standard as the printer.

Special colours used to be mixed by hand by the printer to match a swatch supplied by the client. Now a more exact method is available in the iorm of the Pantone Matching System (PMb), a proprietary system consisting of a book of colour swatches with reference numbers which relate to inks that the printer buys ready-made or can mix to exact instructions. This has made the matching of colours a much more exact process.

Metallic inks contain fine metallic powders such as aluminium, copper or bronze to give a gold or silver effect, or produce metallic blues, reds, greens and so on.

Exercises :

Дата добавления: 2014-12-23