Paper: beneath the surface

From the invention of papermaking in China until the mid-1800s the industry relied on the use of rags. The exact composition of these rags depended on the origin of rag, but in the West it was mainly linen before the introduction of cotton. Their use was dictated by the basic requirement of minimum treatment to turn them into papermaking fibre. The slowness to develop alternative plant fibre sources was due to the lack of chemical technology to produce chemicals and materials resistant to chemical attack.

The second major stage in fibre usage for papermaking began in the 1860s with the discovery of pulping techniques for straws, esparto and softwoods, such as spruce and pine, first by the soda process, then by the sulphite process, and finally by the sulphate process. At the moment it is wood that supplies the vast majority of papermaking fibre but the variety and quality of the pulps available to the papermaker have greatly increased - high white hardwood and softwood pulps, high-yield semi-chemicals and mechanicals. Each pulp has its own particular property and it is the skill of the papermaker which gives the customer such a wide range of papers with differing characteristics.

The third stage in fibre development, if not with us now, is almost upon us. Both softwood and hardwoods are reaching the limit of their present economic exploitation, hence new methods of forestry, and more rapid growing species giving a better return on capital and land usage and improved pulping efficiencies are already under active research and development. Developments of non - cellulosic fibre from plastics, or even plastic papers are already on the market.

All the cellulosic fibres used in papermaking have been part of a plant and the final characteristic of a fibre in a sheet of paper is the product of its construction and subsequent separation, purification and papermaking history. It is important, therefore, to have a basic understanding of fibre structure to appreciate the final influence that the fibre has on the paper surface. Fibre structure and behaviour is called fibre morphology.

In the simplest form a fibre, or elongated plant cell, consists of a series of concentric tubes, each tube or layer having its own structure and function. The outer layer contains the least cellulose and most lignin, whereas the innermost layers contain the bulk of the cellulose. Each fibre in turn is bonded to its neighbour by lignin, or other binder, to form a matrix of fibres. The pulping operation leading to the chemical wood pulps must first remove this lignin and the lignin in the cellulose fibre with the least damage to the fibre structure. Damage to the cellulose fibre results in a weakened fibre. In the case of ground-wood, or mechanical pulp, such considerations do not apply because after bark removal the tree is ground to produce small chips of wood still containing all the lignin and resins.

The ratio of the length of the fibre to its diameter and the thickness of its cell wall are of great importance. The difference between softwood and hardwood fibres is shown by such considerations. Softwood fibres average 2 to 5 mm in length and 30 to 40 microns in width, while hardwood fibres average 1.5 mm in length and 10 to 30 microns in width. The hardwood fibres are also lighter than the softwoods. Such factors indicate that one gramme of a bleached softwood pulp contains about ten million fibres while a similar bleached hardwood contains twenty-five million. This difference in the number of fibres in a given weight is sufficient to alter sheet characteristics, particularly the evenness of formation and smoothness.

The thickness of the fibre cell wall and the ease with which it can collapse and bond with other fibres is related to the sheet density. Thicker walled fibres give high bulk, opacity, porosity, absorbency, tear, but lower tensile and burst, with thin-walled fibres giving dense, well-bonded sheets.

The hardwood pulps not only improve formation but improve bulk, smoothness, opacity, absorbency, require less beating and are cheaper than the softwood pulps. One of the most important fibres in this group is eucalypt, a fast-growing species which gives a fibre of almost constant properties. It is now found in a large number of printing papers since its properties resemble those of esparto-the traditional fibre found in printing papers. The ever-rising cost of esparto, compared with the more stable cost of eucalypt, has forced papermakers to use eucalypt fibre.

There are four different chemical pulping processes commonly used for treating plant fibres and these can reduce or reinforce the differences due to pulp-wood species.

The two main pulping processes are sulphite - an acid system and sulphate (or kraft) - an alkaline system. As a rule the quality of pulp can be altered in the sulphite process by alteration of the pulping conditions such as temperature, pressures and concentration of cooking chemicals, but this is not easy for the sulphate process where it is the wood species which has the major influence on quality.

Sulphate pulps, when compared with sulphite pulps, tend to have a higher tear, produce lower shrinkage at the same strength, have higher bulk, opacity, absorbency but require more beating to give a certain level of drainage, thus they generally allow the papermaker to run his paper machine faster at any given condition.

The mechanical or groundwood pulp process is simple and consists of grinding a log, from which the bark has been removed, in the presence of water against a grindstone to produce a wood flour or a suspension of small wood chips. Traditionally only softwood species were used but now hardwood species are used. The quality of the pulp depends on the fineness of grind and the design of the grinding equipment. Normal chlorine bleaching techniques employed for chemical wood pulps cannot be used and special bleaching chemicals and equipment are required to give good coloured mechanical pulps; no high white mechanical pulps are made.

Mechanical pulps are cheap, low-coloured, have poor strength, little permanence, discolour in sunlight, have good dimensional stability but are cheap and are used as a filler pulp. They are used in newsprint, cheap mechanical printings and cheap banks.

With the current emphasis on pollution and the recovery of wastes, it is timely to consider the importance of waste paper as a fibre source. The use of waste paper is already well established in the UK for board making, but a higher recovery of waste could enable a major economic contribution to be made to a better sorting of waste. In this way better grades could be re-cycled after de-inking to make cheap printings, newsprint and the coated body stock papers as happens in Austria and certain other European countries where de-inking is more firmly established than in Britain.

In a discussion on papermaking's future the word “plastics” is bound to occur. The word means one of four processes: the use of synthetic fibres, the impregnation of fibre material with polymer, plastics paper or films, or grafting.

Papermakers already use rayon and nylon for making speciality papers such as filters, so their development for other uses is possible if the economics are right. The impregnation of papers is often used to produce such products as the inner soles of shoes, imitation leather and laminated surfaces.

Japan, fearing a shortage of wood pulp, developed the use of plastics papers - some of which are only plastics films - when the price of oil products fell and the price of wood products was rising. However, oil is rapidly rising in price and subject to political discrimination, which makes such a source of raw material unattractive to industrialists.

Упражнение 4. Переведите следующие словосочетания на русский язык:

type matter; land transport; magazine paper; gravure printing quality; excessive ink tack; press speed; plant fibre sources; hardwood pulp; softwood pulp; fibre structure; surface sizing; waste paper; coated body stock papers; plastics paper; speciality papers; imitation leather; wood pulp; plastics films; oil resistance; tear resistance; improved strength properties; hand correction; full-page newspaper plates; reproduction processes; standard thickness gauge; light source; water rate bill; halftone screen formation; sidewall protection; image areas; bath replenishment; full range screen negatives; powder additive; a modified copper powderless etch chemistry.

Упражнение 5. Переведите предложения согласно данным моделям.

it is necessary – необходимо, нужно

it is possible – можно, возможно

it is evident – очевидно, ясно

it is clear – ясно, понятно

it is important – важно, необходимо

1. It is important to have a basic understanding of fibre structure to appreciate the final influence that the fibre has on the paper surface.

2. It is evident that the most important paper properties that influence printability are: smoothness, absorption, surface strength, optical properties, moisture content and dimensional stability.

3. It is possible to use waste paper as a fibre source.

4. It is necessary to differ web papers and paper for sheet-fed printing.

5. It is clear that paper is a product of a complex manufacturing process.

6. It is very difficult to explain such terms as "printability" and "runnability" of paper.

7. It is necessary to remember that the two sides of uncoated papers have different surface characteristics.

8. It is quite clear that the profession of an engineer is very difficult but interesting.

9. It is important to use different kinds of paper for different printing presses and processes.

10. It is evident that if paper with a coloured coating is required, colour pigments are used in the coating mixture.

Упражнение 6. Переведите следующие предложения, обращая внимание на усилительную конструкцию.

1. It is the lack of chemical technology that explains the slowness of the development of alternative plant fibre sources.

2. It is wood that supplies the vast majority of papermaking fibre.

3. It is the skill of the papermaker which gives the customer such a wide range of paper with different characteristics.

4. It is the wood species which has the major influence on quality for the sulphate process.

5. It is because of the shortage of wood pulp that plastics papers were developed.

6. It is fillers that increase the opacity of the paper.

7. It is cellulose fibres alone that readily soak water and other liquids.

8. It is only better grades of paper that are made of rags.

9. It is tensile strength, flatness and ink receptivity that influence runnability and printability of papers.

10. It is the basic size and the basic weight of paper that are essential when paper is ordered by Print Shop.

Text 4 В

Задание 1. Прочтите текст, стараясь понять основное содержание.

(Этот текст надо прочесть за 5 минут).

There are many kinds and grades of paper, but most of them come under the five general classes such as: newsprint, book papers, writing papers covers and cardboards.

While papermaking is a separate industry, its product is so essential to printing that in order to obtain the best results in a job, a printer must have a thorough knowledge of the materials and processes used in the production of paper. A printed product consists in reality of two things: a printed impression and the paper upon which the form is printed. Both are equally important. A careful selection of paper is required for each job in order that the finished product may be harmonious and suited to its particular purpose.

Possibly no other substance is used so extensively as paper. That indispensable medium bears and preserves the printed word.

The most important part of paper is the fibre which forms the body and gives it strength. The fibre is always a vegetable product. Almost any kind of vegetable fibre can be used in paper-making, but those fibres which are strongest and most plentiful are commonly used.

Generally speaking, printing papers may be classified into two main groups: wood-pulp papers and rag papers. Many papers are also formed by a combination of these two basic fibres and are known as rag content papers.

Cheap printing papers such as newsprint, most book papers, cardboards and cheaper grades of writing papers are made from wood pulp. Pulp is produced by two methods: the mechanical process and the sulphite process.

In the mechanical process the logs are ground into fine sawdust, while in the sulphite process the wood is cut into small chips, and then the fibres are separated by cooking them in large kettles known as digesters. The latter process is used more extensively because of the superior quality of the pulp for printing and writing purposes.

Notes:

1. cardboard – картон

2. digester – котел

3. log – бревно

4. preserve – сохранять

5. sawdust – опилки

6. vegetable – растительный

Задание 2. Выберите утверждение, соответствующее содержанию текста.

1. The most important part of paper is:

a) sizing; b) the fibre; c) sulphite.

2. Cheap printing papers are made of:

a) wood pulp; b) rags; c) chemicals.

3. Pulp is produced by:

a) one process; b) two ргоcessеs; c) by three processes.

4.Sulphite process is used more extensively because of

a) its simplicity; b) its cheapness; c) the superior quality of the pulp for printing and writing purposes.

Задание 3. Ответьте на следующие вопросы.

1. What forms the body and gives strength to paper?

2. By what method is pulp produced?

3. What kinds of printing paper are made of wood pulp?

4. How is pulp produced in the mechanical process?

5. Why is the sulphite process used more extensively?

6. How are the fibres separated in this process?

Задание 4. Переведите на английский язык.

1. Волокно является основной частью бумаги.

2. Бумага изготавливается из тряпья и дерева.

3. Любой вид растительного волокна может быть использован в производстве бумаги.

4. Древесную массу получают либо механическим, либо сульфитным процесс-сами.

5. Сульфитный процесс даёт бумагу высокого качества.

6. Печатник должен знать, как изготавливается бумага.

7. Бумага сохраняет бумажное слово.

Text 4 С

Задание 1. Прочтите текст.

Printability of paper cannot be measured by one property alone. The individual properties that together constitute printability will depend upon the process used, the quality, and the rate of production required.

Nevertheless, almost all printing processes put ink on to paper under pressure. Therefore there must be some underlying principles that are common to all processes. The most important of them is the penetration of inks into paper. Fundamental work on printability being carried out at various printing research associations has been directed to a study of this property.

The problem of printability is to find the necessary paper requirements to enable a particular type of job of the required quality to be printed by a particular process at an economic speed. Because of demands (требования) made for certain properties in the paper by reason (причина) of its end usage it is often the case that it is not ideal from the point of view (точка зрения) of printing. It is then necessary to find the conditions, the process and the ink that enable the best possible result to be obtained from the paper. When papers are to be compared (сравнивать) for suitability (пригодность) for particular work, it is usually possible by means of testing to predict (предсказать) whether specific defects are likely to occur. Printability research, however, is a comparatively recent science and has not yet reached the stage where it would be possible to state (утверждать) definitely that one paper will give a better print on all counts than another. One of the difficulties at the present time is that there is no established method of assessing (определение) the factors that together make up print quality.

Задание 2. Ответьте на вопросы по тексту 4С.

1. What does printability depend upon?

2. What is the most important principle of all printing processes?

3. How can the best possible result be obtained from the paper?

4. What is the problem of printability?

5. Is printability research a new or an old science?

6. What is one of the difficulties at the present time?

Задание 3. Озаглавьте текст.

Text 4D

Задание 1. Прочтите текст.

Paper Properties

There are few papers which are suitable for all processes and most paper mills therefore depart from standard grades and develop papers specifically for individual processes.

Certain paper properties affect all printing processes since they concern runnability and the visual impact of the finished work. Most printers, whether dealing with sheets or reels, demand good runnability first, while their customers look for quality of reproduction. In many cases it is simple for a paper mill to satisfy one or the other but the difficulty comes in meeting both requirements simultaneously. This is due to the fact that nearly all desirable printing properties of paper conflict with each other. By altering one property, one or more other properties are also changed. Thus to improve the printing quality of newsprint by increasing the finish, also compresses the sheet and renders it less porous to the black news ink, increasing second impression set-off, ink piling on turner bars and smeared copies. Similarly, to improve the gravure printing quality of a magazine paper by increasing its moisture content to make super - calendering more effective, sometimes leads to difficulties of level on reels, with subsequent bad runnability on the rotogravure press.

Consistency of quality is most important and a printer expects this of every sheet or reel of a delivery, since variations within sheets, reams or reels cause far more trouble than a paper which, though it may be slightly below standard is a similar quality throughout the order.

Colour and whiteness of paper are of prime importance to the paper buyer, the printer and the inkmaker, since they affect the appearance of the finished job.

Colour, unfortunately, is so much a matter of individual preference that there is no such thing as the "best" paper in this respect. What is important is that the inks, plates, and paper combine to produce the most satisfactory result. Obviously, the whiter the paper, the better the printing result.

Opacity is also of great importance, since paper of low opacity detracts from the appearance of the print in several ways. First, the printing onthe reverse side of a sheet shows through; secondly the effect of ink penetration is greater than on a more opaque paper and thirdly it reduces the apparent printing contrast, giving the impression of low print density.

Papermakers have many methods of improving opacity but these usually increase costs, lower the brightness, or change other desirable properties of a paper.

Flatness of a sheeted paper is important in all printing processes, particularly in litho and gravure due to the fact that the paper is in contact with the printing nip over its entire width. In these circumstances, any surplus paper in the form of a wave or cockle must form into a crease or cause misregister. Lack of flatness can appear in several ways, i.e. tight-edges, wavy, cockled, or curled sheets and except for the latter two, the reasons may not be the same on all occasions, and the cause may be impossible to ascertain.

Wavy and tight edges are the most common and fully understood flatness defects since paper can pick up or release moisture according to the relative humidity of its surroundings with corresponding expansion or contraction. Only the fibrous portion of the paper is thus affected, so it follows that heavily loaded imitation art papers will change less than those without loading.

If paper is brought into а warm pressroom from a cold atmosphere and immediately unwrapped, moisture from the warm pressroom air will condense on the exposed edges of the stack causing swelling of the fibres and wavy edges. Stacks should therefore be left wrapped to come to equilibrium with the pressroom temperature. Unwrapped sheeted paper with a moisture content higher than that at which it would be in equilibrium with the relative humidity of the pressroom will release moisture from exposed edges and leave the stacks with surplus paper in the centure (a defect known as tight edges).

From the above, it will be seen that paper should not only be allowed to stand until in equilibrium with temperature, but should be left unwrapped until just before printing. Between workings, covering the stacks with polythene or other waterproof material, keeps dimensional change to a minimum, but these measures only apply to unconditioned pressrooms.

Various instruments are available for checking the condition of paper before printing and these are discussed later.

Paper which is not flat causes difficulty in feeding and delivery and introduces the troubles of creasing and misregister. Paper expands or contracts considerably more in the cross than in the machine direction due to the method of manufacture and the properties of individual fibres. This is why litho printers and high quality letterpress colour printers, normally require long grain paper which implies that the machine direction of the paper is parallel to the axis of the printing cylinder. Although very limited in the amount of change he can mаkе, the printer can often compensate for stretch or shrinkage of paper when it occurs round the cylinder by altering the circumference of cylinders with packing.

Formation. - Another property affecting all printing processes is formation. This term means the distribution of fibres within the sheet as seen when holding the paper up to the light. Thus, a good formation is one that appears even and clear, while a bad formation exhibits point-to-point variations in translucency due to fibres coagulating in clumps, instead of being evenly distributed.

It affects printing since variation in fibre density results in uneven ink vehicle absorption. In cases of bad formation, the effect shows particularly in solids and to a lesser extent in the mid-tones of half-tone prints.

Paper gloss frequently has a considerable influence on the appearance of printing and with transparent inks the reflection from a paper with a high gloss noticeably enhances the printing result.

Having dealt with paper properties which concern all printing processes, it is now necessary to consider those relating to specific ones. Letterpress printing is influenced by numerous paper properties apart from those mentioned above. Of these, smoothness is very important, since lack of it results in incomplete ink transfer. Lack of smoothness may be tolerated if the paper has sufficient compressibility enabling it to become smooth under printing pressure.

Pick Resistance. - There are three types of pick, all of which are troublesome to printers, and these are: coating pick occuring within the coating layer itself, due to insufficient and/or unsuitable binder (adhesive); coating pick occuring at the interface between the coating layer and the base paper due to poor bonding of the two; and body pick occuring within the substrate of the base paper due to its physical weakness. Picking of any kind can be due to factors other than weakness of the paper, for example, excessive ink tack and printing pressure. In letterpress printing the demands on paper are less critical in this respect than for offset lithography. Nevertheless, with increasing press speeds the greater use of colour and wet-on-wet printing, severe demands are made on the pick strength of paper.

The absorptive properties of paper for letterpress printing influence numerous print characteristics.

Liquid is absorbed into paper by capillary attraction into the interfibre spaces. It follows, therefore, that the absorptive properties of paper are altered most by supercalendering. But the type of fibre, loading, surface treatment (Pigmented or otherwise) and the amount of beating all have significant effects on absorption. These factors are particularly important in newspaper and similar types of printing which rely entirely on the high absorption of the paper for "drying".

Surface treating paper at the size press, being film forming, also lowers its absorptive capacity, as does roll-coating which relies on heavy supercalendering to obtain the requisite smoothness. Both types of treatment resulted in problems of ink-setting until modified inks were developed.

High speed wet-on-wet sheet-fed rotary letterpress printing has also caused problems for both paper- making and ink manufacture. The absorptive properties of coated papers which were satisfactory on slower presses were insufficient in some cases causing set-off and sticking in the delivery stacks.

A paper which is too absorbent can cause chalking or powdering by the vehicle of the ink being absorbed into paper too rapidly leaving pigment on the surface with insufficient binding medium.

It is well known that coating paper with a layer of pigment and binder is one of the most effective ways of improving its surface for letterpress printing end generally speaking, printing qualities improve as coating weight increases. Thus, the best art papers have up to 30 g.s.m. of coating on each side while the lowest weight applied to cheaper papers may be as little as 5 g.s.m. on each side. An average coating weight for good results is about 16 g.s.m. per side. Coating, being principally china clay or other finely ground pigment accepts ink more readily than a fibrous surface and results in higher print density and when supercalendered gives higher print gloss. Type of body paper, method of coating and the formation itself all have a considerable bearing on the printing quality.

Web-fed paper troubles. - Apart from any of the above properties which affect either sheet-fed or rotary letterpress printing, there are those which can cause trouble in web fed work only. The common faults are those or piping, stretched edges, generally bad level and uneven tension through the reel. It is a mistake view that web breaks are caused by weak paper, that is, paper of low tensile or other strength properties. The "pull" on a reeler in the paper mill is higher than on any printing machine and paper which continuously breaks on a reeler could not be sent out. Breaks are almost invariably caused by faults in paper, for example, edge tears, incorrect printing press tension, out-of-line reel stands or too much printing pressure.

Overdry paper can cause breaks due to its rather brittle nature but, more serious, dry paper is prone to the generation of static electricity which often causes troubles on newspaper and magazine presses, especially at the folder. Static troubles can also be a dry pressroom atmosphere.

Задание 2. Сделайте доклады в соответствии с прочитанным текстом:

1. Важнейшие свойства бумаги.

2. Свойства бумаги, оказывающие влияние на высокую печать.

3. Способы улучшения поверхности бумаги для высокой печати.

4. Преодоление трудностей, связанных с бумагой, при рулонной подаче.

Lesson 5

Грамматика: Словообразование.

Основной текст A: General Characteristics of Inks.

Словообразование

В английском языке имеется несколько типов словообразования: аффиксация, т.е. прибавление к корню суффикса или префикса; конверсия и словосложение.

Основные префиксы и их значение

Основные суффиксы существительных

Основные суффиксы прилагательных

Основные суффиксы наречий

Основные суффиксы глаголов

Упражнение 1. Образуйте с помощью суффикса -еr (-or) существительные от данных глаголов; переведите их на русский язык:

sail, act, write, read, visit, speak, sleep, found, lead, direct.

Упражнение 2. Образуйте при помощи суффиксов -er, -or, или -istсуществительные от нижеприведённых слов:

burn – гореть

receive – получать

compose – сочинять музыку

drive – вести машину

regulate – регулировать

accumulate – аккумулировать

special – специальный

social – социальный.

Упражнение 3. Образуйте с помощью суффикса -ian существительные от данных слов, переведите их на русский язык. Обратите внимание на изменения в произношении:

technic, mathematics, statistics, politics, music.

Упражнение 4. С помощью суффикса -ment образуйте существительные от следующих глаголов:

develop, achieve, equip, move, arrange, treat, state.

Упражнение 5. Переведите следующие слова, определите, к какой части речи они относятся. Обратите внимание на суффиксы:

difference – different

violence – violent

magnificence – magnificent

excellence – excellent

resistance – resistant

importance – important.

Упражнение 6. Образуйте прилагательные с помощью суффиксов -full и -less, переведите их на русский язык:

beauty, thank, hope, doubt /сомнение/, саге /забота/, aim /цель/, use, shape /форма/.

Упражнение 7. Образуйте прилагательные с помощью суффиксов -able, -ible, переведите их на русский язык:

extend, change, convert, resist, prevent, break, compare, desire.

Упражнение 8. Найдите суффикс в данных ниже словах. Определите, к какой части речи они относятся. Переведите их на русский язык:

British, English, boyish, Scottish, foolish, reddish, understandable, heartless, pitiless, limitless, classless, successful.

Упражнение 9. Образуйте прилагательные с помощью суффикса – al(ial):

experiment, profession, form, nation, function, fundemental, office, classic, music, industry.

Упражнение 10. Переведите следующие слова на русский язык, обращая внимание на значения префикса и корня:

untrue, decompose, demilitarization, discover, antibody, noninductivity, non-resistance, invariable, antiparticle, disappearance, disjoin, rearrangement, reconstruction, prewar, prefabricate, postwar, extraterritorial, ultramodern.

Vocabulary Notes

Задание. Переведите следующие предложения.

1. oil – масло

Petrolium oils and rosin oils are non – drying oils.

2. varnish – лак

Varnish viscosity can be adjusted by using different quantities of thinners.

3. drier – сушильное устройство, сиккатив

Metallic additives serve as oxidation catalysts and are commonly called driers or siccatives.

4. viscosity – вязкость

Letterpress inks have moderate viscosity.

5. tack – липкость

Tack is the force required to split an ink film between two surfaces.

6. flow – текучесть

Resistance to flow or viscosity refers to the consistency of inks.

7. to distribute – распределять: растирать, раскатывать (краску)

Inks must distribute evenly on the press and transfer properly from the type form to paper.

8. to handle – транспортировать (листы)

The printed sheets must be handled within a reasonable time.

9. to smudge – мазать, пачкать

Fresh printed sheets can be easily smudged.

10. resistance – устойчивость

Resistance of ink to acids, sunlight, alkalies may be required.

11. solvent – растворитель

Years ago the number and amount of solvents consumed by the printing ink industry was practically insignificant.

12. formulation (of inks) – рецептура (печатных красок)

Many properties of inks are obtained through formulation and selection of ingredients.

13. cut – клише

Typographic inks are used to print from ordinary type, line and halftone cuts.

14. vehicle – растворитель, связующее (вещество)

Varnishes and oils form the vehicles.

15. to disperse – рассеивать, распылять

Pigments are well dispersed in the ink vehicle.

16. resin – смола

Synthetic resins are dispersed in drying oils.

17. yield value – величина текучести (краски)

Planographic inks have higher yield values than typographic inks.

18. to impregnate – пропитывать; насыщать

A smooth limestone slab was impregnated with a gum arabic solution.

19. to adhere – прилипать

Part of the liquid will adhere to the solid when the two are separated.

20. moist – влажный

Non-printing areas of the plate are kept moist to repel ink in planograhic printing.

21. to possess – иметь

Hand printing of fine engravings requires an ink which possesses a buttery consistency.

22. to wipe off – стирать

The excess ink is wiped off the face of the plate.

23. to exhibit – показывать

The inks must exhibit no tendency of dissolving in water.

24. to bleed – растекаться (о краске)

The property of ink bleeding is not desirable in intaglio ink.

25. evaporation – испарение

Drying by evaporation depends on the ability of solvents to evaporate readily from the ink film.

26. thin – жидкий

Intaglio inks must be very thin.

27. to suspend – взвешивать

Pigments are suspended in a highly fluid vehicle.

28. fluid – текучий

Drying means the change from the fluid to the solid state.

Text 5A

Задание 1. Прочтите текст.

Date: 2016-05-14; view: 713; Нарушение авторских прав