Printing is one of those inventions that have revolutionized our world and is the most important fundamental practices in our society. Nothing is more essential to civilization intellectually or commercially, than printing. Printing is widely used in our society to pass on information and to decorate objects. Printing is a process for reproducing text and images, typically with ink on paper using a printing press. It is often carried out as a large scale industrial process, and is an essential part of publishing and transaction printing. There are various types of printing methods such as screen printing, offset printing, rotogravure printing etc. Offset printing is a widely used printing technique where the inked image is transferred (or offset) from a plate to a rubber blanket, then to the printing surface. There is an enormous growth being witnessed in the printing industry. The emergence of the retail revolution and growing education across the country is acting as a fuel to the growth of the printing industry. The Indian Printing Industry is well established and presently growing at 12% per annum.
This book provides you details about the various methods and techniques involves in modern printing technology. Some of the fundamentals of the book are multi colours, paper publishing unit, screen printing, offset printing press, rotogravure printing, desk top publishing, computer forms and security printing press, printing inks, ink for hot stamping foil, aluminium printing plate for offset printing machine, screen printing on cotton, polyester and acrylics. The book also covers process, project profiles of different types of printings and printing inks manufacturing along with sources of machinery and raw materials.
The book provides you with comprehensive information on modern printing technology. Basic information in entering a market and the opportunities and requirements of the potential sector has been the best way to penetrate in a market. How and what if properly answered can take you to a long way. The first hand information on different types of modern printing technology has been properly dealt in the book and can be very resourceful for those looking for entrepreneurship opportunity in this sector.
MULTI COLOURS 8 PAGE PAPER PUBLISHING
UNIT
INTRODUCTION
It is
perhaps Edam realized that the twentieth century is not so much the atomic age
as the age of mass communication better, faster, more efficient international
communication: an age of which the atomic race is only aspect. Visual
communication a term coined only recently the graphic and typographic arts
output and standard of printing have grown to crude process used only for short
runs is giving way to an appreciation of the special characteristics effects and
advantages of offset printing.
Printing
Cycle for Direct and Indirect or Offset Printing
At the
preparatory or preparing stage the operation involved converting the original to
be reproduced into a printing plate or image carrier. The starting point in all
printing processes is the original or copy. In all other cases the original is
converted to the form for printing by photo mechanical means.
Letterpress
Letterpress
is a ‘relief’ process – that is, the printing surface holding the image to
be printed is raised above the non-printing background.
In
traditional letterpress, all the text is printed form metal type and pictures
from letterpress blocks. These, elements are assembled together (imposed) to
create a ‘frame’ inside a rigid frame (chase), which is placed in the press.
A development of letterpress uses ‘stereo’ or ‘electro’ plates for each
page or for the whole ‘forme’.
These
are four main types of letterpress printing machine, all combine the following
elements, inking, printing, feeding and delivering.
The
image areas of the letterpress block are raised while the non-image areas are
recessed so that they do not pick up ink. The plate is inked by a roller. Paper
is placed over the inked image and pressed on to image in the press by an
impression cylinder resulting in the image being printed on the paper.
Offset
Press Operation
Offset
presses are rotary in nature and use the principle that grease and water do not
mix to deliver the desired impressions on paper.
The
printing section of the press includes a plate cylinder, an impression cylinder
a blanket cylinder, linking rollers, a moisture system and a plate adjustment
(Registration) device.
That
all material to be printed is on one thin, flat, and pliable plate is one of the
various uses of the offset process.
Once
the plate is on the press the operation must apply, the moisture (water plus an
additive) to the surface of the plate. When ink greases is applied, it adheres
only to the image area and is repelled by the water wet portions. Because of the
water grease action and its photographic nature, offset printing is considered a
chemical process.
Bureau of Indian Standards
Specifications
The
following Indian Standards Specification are available for reference
I.S.
11610-1986
Rubber
rollers for offset printing size A4
I.S.
6830-1973.
Uses and Application
The offset
press is characterized by the following important advantages over other printing
methods;
1.
The rubber printing surface conforms to irregularities in the paper
surface. Less printing pressure is needed and print quality is improved. Half
tones of high quality can be printed on rough papers.
2.
Paper does not come into contact with the metal printing plate. Therefore
the plate is less subject to abrasive wear and can run much longer editions.
3.
Speed of printing is increased. The effect of press improvements on
printing speed.
4.
The image on an offset printing plate reads right instead of in reverse
or wrong reading. This facilitates both hand and photomechanical preparation.
5.
Less
6.
Ink is required for equal
coverage. This reduces trapping problems and decreases to tendency of the
printed sheets to smudge/and set off i.e. produce a mirror image on the black in
the delivery pile. Also drying is quicker.
Photo
Offset Printing
Photo-offset
printing of increasing interest to everyone in the filed of communications
differs from letter press because it is:
1.
Photographic
2.
Plan Plano graphic (printing is done for a flat surface)
3.
Chemical is natural rather than mechanical
4.
Usually indirect rather than direct, each of the above can have an effect
on editorial as well as a mechanical procedures.
MARKET SURVEY
India is one
of the big country having about 900 million population. The estimation is made
that about 37% people are educated now. The growth in the percentage of educated
people is taking place day by day with establishment of new school, colleges,
education institutions and other. Similarly demand of books, publications etc.
is also increasing. This needs establishment of new printing process, viz.
Offset, Treadle Letter, Flexographic, Rotogravure, screen Printing etc.
For
publication or printing of books, advertisement materials, packaging materials
and others.
Presently
the South Zone had the highest number of commercial printing presses in India.
That is 30 percent followed by the North Zone is in the leading position with
South zone a close second.
Type
of presses :
Out of the
total of 72,137 presses, all except about 1,000 fall in the category of General
commercial Presses.
Ownership
:
About 90
percent of the printing presses in India are either proprietary of partnership
concerns.
Category
of work :
Jobbing work
accounts for over 60 percent of the income of the printing presses in India.
Next importance is book printing, packaging and publicity material.
Another
significant change that has take place is the increase in the share of publicity
material from four percent to nearly seven percent. This is mainly due to the
increase in the production of consequent increase in advertisement.
It
will be observed that of the 44 percent of the presses located in large cities,
the vast majority (over 70% are in the metropolitan towns) and the remaining 56%
a relatively small percentage, (below 30% is in semi-urban areas). There are
hardly any printing presses in rural area.
ROTOGRAVURE PRINTING
INTRODUCTION
Printing as
an art of graphic communication is so ancient that it is not certain when it was
invented. It is reported to have originated in China. Printing from stone
inscriptions and from wooden blocks, i.e. engraving in relief text and pictures
on stone or blocks of wood and printing the relief impression with ink on paper
was practiced in China as early as sixth century A.D. The oldest book in
existence is known to have been printed from blocks in A.D. 868 in Japan.
The
turn of the nineteenth century, there has been a phenomenal advancement in
science and technology, which radically changed the mechanism involved in
composing and printing techniques. Development such as application of power to
printing press and later adoption of photographic techniques to printing
processes, have enabled incredibly fast rate of reproduction in highly
mechanized presses, quick and precise preparation of printing surfaces and
tremendous improvement in quality of the printed material. The four process
families are Plano graphic printing, intaglio printing screen printing, gravure
printing.
The
modern commercial derivations of the intaglio process are based on photography
and photo mechanics. These are rotogravure and sheet-fed gravure. Of these the
largest and the most important commercially is rotogravure, which is used in
news papers roto sections for some of the big edition magazines and for big
commercial works.
Rotogravure
employees an exquisitely polished copper cylinder as the printing surface and
makes use of a screen to break-up the light and dark areas into small unshaded
dots.
The
etched cylinder is designed for running on a web-fed rotogravure machine. The
cylinder revolves in a through of a ink, the ink floods over the surface of the
cylinder and is at once scraped clear by a thin blade called ‘doctor’. This
blade of cylinder length keeps the surface free of ink, but leaces the cells
full.
Methods
of Plate Making
Printing
image carriers of plates or cylinders can be produced in any or a combination of
six different ways:
1.Manually:
-
By the use of
hand tools, engravers, knives etc. to produce image-carriers for the relief and
intaglio.
2.
Mechanically :-
With the help
of engraving and geometrical late ruling machines, pantographs etc. for the
relief and intaglio processes but hand transferring and Benday machines can be
used for lithographic plates.
3.
Electromechanically
4.
Electronically
5.
Electrostatically
6.
Photo mechanically
Gravure
Plate Making and Cylinder Making
The
adoption of the cross line screen for photogravure printing initiated the modern
commercial process. Modifications for multicolours printing have been made.
Printing
Surface
Modern
gravure printing is done principally from images etched in cylinder on web
processes and is generally referred to as rotogravure. On sheet-fed presses the
printing element is a thin copper plate, which is wrapped around the cylinder.
Preparation of the printing surface is essentially the same for cylinders and
for plates.
For
monochrome printing by conventional gravure, bichromate sensitized carbon tissue
or transfer film is contact-printed through a continuous tone positive and then
exposed a second time while in contact with a screen consisting of transparent
lines and opaque square dots. Warm water is applied and the paper for the carbon
tissue or backing of the film is peeled off. The gelatin thus transferred to the
copper surface is further developed with warm water to produce a gelatin relief
resist. The areas corresponding to screen lines remain unetched and provide
lands. Which support the doctor blade in printing. For long runs and to minimize
wear, the etched cylinder or plate is chromium plated.
For
multicolours printing the principal process involves a combination of halftone
and continuous-tone positives for each colour. The halftone positive has a
lateral dot formation, which is similar to conventional gravure in the shadows
but with varying dot sizes in the middle tone and highlights. In the direct
transfer process, only the special halftone positive is made. This is
contact-printed directly onto the copper cylinder, which has been sensitized
with a photopolymer of the cinnamic ester type. For long runs the cylinders are
chromium plated.
After
the gelatin layer has been transferred face down to the copper surface,
treatment with warm water dissolves the under-hand parts, leaving a gelatin
relief resist. The thinnest areas are penetrated first by ferric chloride
solution are etched deepest, the print the shadow tones of the picture. The
areas where the resist is thickest are penetrated last by the etchant, are
etched the least and print the lightest tones.
Limitations
The serious
problem with gravure cylinder making has been the difficulty of reproducing
identical cylinders from the same films due to difference in materials, etching
solution, impurities in copper, environmental conditions and other factors. As a
result, repress proofing has not been successful and corrections must be made on
the cylinder, which is expensive.
Gravure
Gravure
printing is from sheet-fed presses, which involves plates. By far the greatest
amount of gravure printing is from cylinders on rolls of paper or film. This is
desirable in packaging but not as necessary in magazine printing. The gravure
printing unit consists of a printing cylinder and an impression cylinder, and an
inking system. Ink is applied to the printing cylinder by an ink roll or spray
and the excess is removed by a doctor blade and returned to the ink function.
The impression cylinder is covered with a resilient rubber composition, which
presses the paper into contact with ink in the tiny cells of the printing
surface.
Gravure
ink consists of pigment, a resin binder and a volatile solvent. It is quite
fluid and dried by evaporation. For high speed printing, the solvents are quite
volatile and the linking system must be enclosed. In multicolours printing,
where two or more gravure units operate in tandem, each colour dried before the
next printed. The web therefore is passed through a heated dryer after each
impression.
Single-colour
rotogravure printing yields excellent picturial reproduction on a wide range of
papers. Its reproduction type matter and line drawings leaves something to be
desired.
Uses and Applications
Gravure or
intaglio printing finds applications in the production of newspaper,
supplements, book review sections, feature magazine, catalogues, illustrated
magazines, advertising literatures, calendars, greeting cards, wall papers,
patterns in textiles, linoleum and oil cloth, labels and wrappers on aluminium
foil, gasoline, cellophane, vinyl polymers, LDPE, HDPE, PP and similar other
materials, security papers, paper money and stamps etc.
Printing
Industry in India
Printing was
introduced in India in 1556 by the Portuguese when they established a press in
Goa. The first book ‘Doctrina Christas’ printed in India, in foreign
language, as is said to have come out of this press in 1957.
DESK TOP PUBLISHING
INTRODUCTION
Evolution of cheap and powerful microcomputers, development of comprehensive
word processing and page planning software and availability of near letter
quality laser printer with ability to mix various front styles and graphics,
have made concept of Desk Top Publishing a reality.
Over the last
few years, computers have penetrated every respect of industry, business and
education. They have totally changed the way in which information is processed.
Now with the advantage of desktop publishing (DTP), the method of presenting
information has also changed.
Today man has
a tool, which allows him to design, layout and produce printed matter right at
his disk. One can create newsletters, reports, data sheets, and broachers in a
matter of minutes on a computer screen, and print it out on a laser printer in
seconds.
The
revolution in desktop printing started in 1985. Though the technology is just
Eleven years old, already plenty of hardware and software options are available.
Like any
other computer system the three main components of DTP are hardware, software
and printer.
The system is
equally comfortable with text or graphics. The both can be mixed at the same
time.
For IBM PC,
an additional RAM, a floppy disc and a colour graphics adapter (CGA), or
enhanced graphics adapter (EGA), or Harcules monochrome graphics adapter are
required.
Graphic tools
(for making lines, boxes and moving text etc.) are manipulated by an input
device such as a mouse or graphic tablet. Although one of these is recommended,
in most cases they are not absolutely necessary.
MARKET SURVEY
In the Indian
Market DTP System manifests itself in three distinct forms, and an end user who
accepts the quality of a laser printer has to select from the option available.
In
the IBM and its compatibles environment a PC/AT or a PC/XT can successfully,
support the various publishing software packages released. The user has to
select a compatible combination of a word processor, graphics and front
generator, page makeup and type setting programme and PDL as an integrated
package.
The
resolution of the monitor is improved by addition of a Hercules or EGA Card. The
software packages selected have to be mastered through manually.
Abacus
Computers Ltd. has released ‘Lions’ desk top publishing package. It
comprises a 20 MB hard disk, accessed by a PC/XT supporting a mouse, a
monochrome monitor, Hercules upgrade and Laser writer as the output device.
Linos
can typeset text in 34 different fronts supported by the laser writer plus, and
the text can vary in size from 4 to 127 points in steps of 0.5 points.
Graphics
files from Lotus 1,2, 3 and PC-Paintbrush can be incorporated anywhere in the
running text. Linos can also recognize files from word star 2000 and Microsoft
Word through suitable translations available.
Linos
power and shortcomings can be best appreciated by typesetting operation.
Apples
Machintosh DTP system is distributed in India by Raba Contel. The generation of
iscons and windows, the case of their manipulation with a mouse, the versatility
of the graphic packages.
The
mouse may at time feel clumsy and the cursor movement is not as efficient as in
the PC environment. Competent technical and training support with regard to the
system software is difficult to get.
Another
alternative is to look for a compatible phototypesetter. Linos can produce a
comugraphic compatible disc and Ginasho Overseas at Delhi is a commercial
center, which helps in switching from the PC-environment to commercial
typesetting. Set and send, a software package from Bree Communications inc.
converts a Macintosh diskette to an MCS compatible version.
To
sum up, desk top publishing has come to stay. But its full potential and
applications by only be realized by those conversant with the various packages
available.
Laser
Printers and Digitizers
Desktop
publishing involves many components, but without good output devices, all the
effort that goes into designing and laying out pages is wasted. Currently, the
primary high-resolution output device in a desk top publishing operation is the
Laser printer. Most good looking documents that result from desktop publishing
are nicely formatted type.
Laser
Printers and digitizers as much as computers and software-makes desktop
publishing a personal rather than a strictly corporate or industrial endeavour.
Laser
Printers
A laser printer is a photocopier. In fact, many such printers
use the same technology that photocopiers do, a photosensitive drum temporarily
holds an electric charge in the shape of an image transferred to it by a
computer-driven laser beam. The charges and the image carried within it are
transferred to a sheet of paper as it rolls across the drum. The paper then
attracts the toner (plastic ground into a fine powder) and heat bonds the toner
of the paper.
Digitizer;
Producing Graphic Images
A digitizer
transforms an image into digital information you can store in a computers memory
or on a mass storage device. You can then transfers that information to a
bit-mapped screen, whereas you can edit it repeatedly, or to a high resolution
output device such as a laser printer. Digitizers are of two sorts: Video and
Optical.
Video
digitizer use the standard video signal produced by, typically, a video camera,
but also by a VCR or even a television set that can emit a video signal. A video
signal digitizer scans an image and turns each element of the image into a
binary number.
An
optical digitizer scans flat art of with a tiny beam and converts the amount of
reflectance into digital information similar to that produced by a video
digitizer. The number translation process for displaying the image on a
big-mapped screen and printing on a printer are the same for optical digitizer
as for video digitizers. Thunder Scan is optical digitizers.
Software
Two main
types of DTP software are: the Page Make-up program and the Type setting
program. Such programmes combine the conventional roles of the typesetters and
the paste up artist. Text can be typed, arranged in columns and blocks on a
page. It is also possible to break up to text, add headlines, captions and
subheads.
The
graphics may be as simple as a box or a line, or as complex as a line drawing,
or digitized photograph.
Macintosh
page make-up programs are: Ready Setgo, Page Maker and Mac Publisher. The allow
mixing of text and graphics freely and are compatible with together Mac
programes such as Mac Write, Mac Word, Mac Draw and Mac Point.
Typesetting
software is for creating galleys, which are cut to proper lengths to be pasted
manually on a page.
Typesetting
programs offer more features and flexibility then page make-up software. Two
most desirable features are kerning and letter space justification.
Page
Make-U Programs
Page
Maker: Aldus
Corp’s Page Maker for Mac got DTP off the ground. It has simple menu commands,
WYSIWYG (what you see is what you get) displays, the ability to incorporate text
and graphics from other programs and to output to high resolution printers and
typesetters.
Pager
Maker permits working on a WYSIWYG view of a page in three different sizes –
normal reduced and enlarged. Each view gives accurate presentation of what will
appear at the laser printer.
Commands
which, are displayed on the top of the screen are : file, edict, tools, page,
type, lines and shades. Toolbox has eight tools (arrow, angled line, straight
line, text, rectangle, round-edged rectangle oval and picture cropper) for
creating some simple graphic image.
Selection
arrow is used with the mouse to move elements around the page to resize objects
and to select them for cutting, pasting, editing. The line tools create lines of
any thickness, with or without shading. The rectangle, round-edged rectangle and
oval tools make basic shapes, which can be black or which, open or filled with a
pattern. Any shape can be resized and moved by arrow. Picture cropper is for
pasting graphics anywhere on the page. It does not resize the graphic but blocks
of parts that are unwanted.
Page
Maker has three blue pencil tools to align elements on the pager. The first is a
snat-to grid, with which size of the grid is specified and all elements
automatically line up to this grid. If it is turned off, elements will no longer
line up with the grid. However it can be turned on the realign the elements.
The
second alignment tool is the column guides which align text and other elements
to the left, centre, or right side of the column margins.
Finally,
there is set of ruler guides which help to line things up. Ten guides per page
can be used. It has a built-in ruler (metric, inches or points).
COMPUTER FORMS AND SECURITY PRINTING PRESS
INTRODUCTION
Two
incidental discoveries set the stage for what rightly be called the ‘Age of
completion’ in graphic communication, both incidents, through many year aparts,
brought about a new printing process, called photo offset litho graphy, commonly
known as offset or photo-offset.
The
process picked up its most common name “offset†printing, as the second
incidental discovery. Ira Rubel, New Jersy Lithographer.
Printing
is important in the line of education (books, magazines), sociology (wedding
cards and greeting cards, birth day cards, politics posters etc.). Every day
more and more people are adopting this phenomena and is now an internal part of
every organization and business house.
Computer
forms are ordinarily blank ruled or reprinted papers, according to the
requirements. The papers are in the form of long sheets of definite width with
holes on both sides for feeding it to the printer. The sheets are perforated at
definite intervals to make handling easy. The width of the sheet is subject to
the particular requirement and varies widely.
MARKET SURVEY
In India the
growth of the printing industry had been comparatively slow during the first 25
years after independence. According to Govt. of India statistical obstructs, the
growth rate from 1961-62 to 1968-69 in the number of printing processes was
about four percent. However, the growth rate has been faster since than due to
increased industrial activity, growing literacy and mass communication
programmes concerning health agriculture etc.
Today
there are approximately 2,00,000 printing presses in India and the estimated
investment in these is around Rs. 300 crore. However more than 65 percent of
these presses are in small and tiny sectors, with annual turnovers in the
neighourhood of only 2.5 lakh per year. The return do not encourage
re-investment in either technology or human resources skills.
Considering
the Government’s approach towards massive expansion in Indian industry, the
printing industry has to grow in a similar way and there is a large scope for
expansion in the following areas.
(i)
Commercial Printing
(ii)
Book Printing
(iii)
Business Forms Printing
INK FOR HOT STAMPING FOIL
INTRODUCTION
Printing inks
are complex colloidal solid liquid dispersion consisting of pigment particles, a
binder (usually a polymeric resin), a solvent or solvent blend and sometimes
filler particles, which can act as rheology modifiers. The complex nature of
these materials means that slight modifications in the formulation. By changing
the source of the pigment can have marked effect on the properties of the inks.
ER 125 is an
almost totally pure aliphatic hydrocarbon with less than 0.05% impurities
content. Raw material for ER 125 is gilsonite resin a natural occurring
hydrocarbon mineral.
Phenolic
alkyd resin commonly found in black heated ink recipes. The makers produces a
heat set ink by first making free flowing varnish, then a grinding media and
finally gel varnish using one resin each ER 125 Phenolic and hydrocarbon. These
varnishes essentially 50% resin plus 50% aliphatic solvent except for free
flowing, which required extra solvent to yield the desired viscosity.
Properties of Hot Stamping Ink
1.
It has greatly increase inflow.
2.
It has low tacking property and excellent tack stability.
3.
It has low tack and high gloss level at the same time.
4.
High gloss level at lower solid level.
5.
It has excellent carbon black wetting.
USES
1.
It is used for printing in the hot foil for marking outer packages. It
replaces expensive preprinting costly labels.
2.
It is possible to mark messages in varying sizes and in different colours
(red, blue, green, black etc.,)
3.
It may be used for marking date of manufacturing, expiring date, name and
address of customers/manufacturer. Product name or code shipping instruction.
Packing details net/weight/gross weight. Price in voice number/challan number,
statutory number.
4.
It improves finish and legibility.
B.I.S. SPECIFICATION
There is no
B.I.S. Number availability ink for hot stamping foil.
I.S. No Ink –
Duplicating for single drum machine
|
1333
|
For twin cylinder
machine
|
1222
|
Printing containers
for round
|
3680
|
Ink for using
glossary
|
4724
|
ALUMINIUM PRINTING PLATE FOR OFF-SET PRINTING MACHINE
INTRODUCTION
Printing is
all around us. It is part and parcel of our lives twenty four hours a day. Is it
possible to imagine our civilization without printing when the alarm rings you
look at the clock to see the time, the face of clock is printed. You stretch and
slide out from the between printed sheets and go to the bathroom. There you are
surrounded by printed materials, tooth paste-tube, counter top, various bolts,
containers, paper products, showers, curtains, soap wrappers, towels and
possibly the wall paper. Even your tooth brush and comb having printing on them.
There are four main printing processes, relief or letter press, interglo or
gravure, stencil or porous printing plates are used in offset on lithographic
printing. It offset printing the matter to be printed is utilized in the plates.
These plates are made up of various metals.
Most
lithographic printing is done from aluminium plates.
PROPERTIES
Crystals
structure of aluminium is closer and finer, gives fine grain surface with better
hold for water, but shorter in life than zinc. Aluminium takes slightly sharper
and deeper grain than zinc and due to relative hardness is capable of giving
longer impression.
Aluminium
plate weights less than half of zinc and less cumberled carefully to prevent
kinking, which cannot flatter. Aluminium being whiter and brighter makes the
image areas visible.
Aluminium
dissolves rapidly in caustic soda and caustic potash solutions with the
evolution of hydrogen and formation of alkali aluminate.
MARKET SURVEY
In the early
part of the twentieth century, there was a great support in the printing
industry all over the world because of spread of literacy and growth in trade
and commerce. However the progress of the industry in India was very slow owing
to foreign domination. The bulk of the print was obtained from Europe. But after
independence situation changed rapidly. The bulk of the print which we were
importing now we started producing in India itself. Government’s various
educational programme, nation building activities and the rapid development of
trade and industry during the successive five year plans give a stimulus to the
printing press.
Production
of printing plate, which is normally confined to small scale production. With
the tremendous increase in the printing process the demand for printing plates
is vast with the increase in literacy, educational activities and all around
development of the nation, the printing industry is getting the proportional
boost. Different type of press which may be under private or public sector are
buyer of the printing plate in comparison with other metal plate closer and
finer gives fine grain surface with better hold for water; are in much demand in
the market.
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