Grafica News - August 2017
SCREEN PRINTING CHANGES… YES ... ENORMOUSLY!
By Michel Caza
The question – 'Screen Printing Process is Changing, but not becoming Obsolete. Why?' is a subject of great importance and fascinating too!
I would say: Screen Printing Changes… Yes ... Enormously! As for becoming "obsolete", it is a false belief. On the contrary screen printing is in full 'rush and gush'! Why?
Firstly, because the variety of screen printing applications is incredibly high, much more than all other printing processes. Secondly, because screen printing has evolved, by reducing or removing its weak points in the work flow. Also, because it has evolved technically, especially in the field of the fabrication of screens and its adaptability to the deposit of all kinds of products, not just inks.
What has changed in relation to the past is, if I may say so, take it as an image, its "change of environment".
What was the state of screen printing in a relatively recent past?
In its "modern" beginnings in the early twentieth century, screen printing was mainly "graphic", with some applications in textile printing "continuously" on the "long tables" that had begun earlier (1880) in France and Great-Britain. There were only a few industrial applications, on glass and on metal, among other things and often in "packaging".
The advent of plastics for which it was the ideal printing technique before flexography and offset was an opportunity for screen printing to adapt it better to these markets.
So, until the 60's / 70's, its 90% applications were graphics (advertising, artistic, decorative, marking, POS).
At that time also, textile screen printing with the appearance of carousels for the printing of "pieces", T-shirts and other clothes began to develop at full speed (direct printing on fabric, and transfer printing). As also, continuous textile printing namely, roll-to-roll (leaving the flat frames for rotary screens by printing many colours at very high speed) had also appeared.
Same as in the industrial field, glasses, bottles, ampoules, metal cases, plastic bottles and tubes, various objects, fascias and dials, electrical and mechanical equipment, CDs and DVDs: screen printing had taken an essential place.
Then with the changing times, with electronics, flexible and rigid circuits, transistors, keyboards, membranes switches, solar cells, tactile surfaces, then RFIDs, OLEDs, printing of nano-particles, etc, screen printing process became a dominant printing process.
The possibility of printing - or "depositing" - a product in thin or thick coats on something has led to the development of "special effects" using thermo-chromic, photo-chromic, UV-sensitive, luminescent, ferrous, scratches, fragrances, useful in decorative and advertising applications, but also for securing banknotes and other "sensitive" prints : games, lotteries, tickets, etc.
Advent of digital printing
The change took place in the mid-90s with digital printing, the advantages of which were to eliminate all the elements necessary for the prepress of the "contact" printing technologies of the Gutenberg era. Disappearances of films, screens or plates, reduction of the settings and start-up of the presses, possibility therefore to print at a reasonable cost of small series, so soon "to customize", to individualize the impressions on papers and plastics firstly, then on textile printed roll-to-roll and later per piece.
The screen printers were very afraid! At a major conference at the FESPA 96 exhibition in Lyon, France, I remember I said (and I also wrote it in 1995): "Do not be afraid of digital printing, buy-it! It is better to have this "supposed enemy" inside of your business plant than to see it compete with you across the street! "
Gradually, in the graphics area, digital printing has taken up more and more space thanks to its very low start-up costs and therefore its ability to print very small series. For those who, like me, saw it as a "complementary" tool, not a rival, no problem.
But for many screen printers who did not get digital equipment, their printing markets gradually narrowed and then sometimes disappeared. Very quickly, from 2000/2005 it was said that screen printing would disappear completely, devoured by digital printing!
A quite wrong thought!
This impression was all the stronger because in our exhibitions and our trade shows, screen printing seemed to be practically disappearing from the stands, except perhaps in the textile garment printing. The reason is simple: our trade shows, whether in Europe, the Americas, India or Asia, are mostly dedicated to "VISUAL COMMUNICATION" which is, of course, the most "visible" area of the graphics applications!
So 'EXIT' screen printing?
No! Read carefully here below my views.
People forget that in our current age, if we think of screen printing, we often and most think "graphic image", for advertising or other applications in art and decoration.
In reality, these applications represent only 20% of screen printing applications!
So where screen printing hides itself now? Where are its other applications?
At 35% it is in the textile, continuously, but especially in the piece, in the garment ...
... and 45% in the "pure" industrial applications in all the areas I mentioned above.
So, screen printing is far from being an "obsolete" or not an 'exiting' technique; it is 'existing' strongly!
It is predicted even in the next 5 years, always on this industrial sector for everything related to electronics. It is going to be the one that will develop most, a little in front of the inkjet, a little more than Engraving, and much more than other similar techniques ... And this enormous progress will be made especially in the countries of Asia... and India.
Few people know that there are dozens of elements in a mobile phone or a smart phone, in a computer or a pad, in a car or any other floating or flying mobile machine, where screen printing takes place. Same is in the medical industry.
Why is this market so difficult to pin down?
It’s because, this is not about "marking" only, even if there is a little of it in this market. But it is mostly in applications that are part of the development and manufacture of Industrial objects or other products. This market - except in some countries - is not only for a small part of the work - in the hands of independent screen printers - but it is "integrated" (in-plant) in the manufacturing processes of the companies that manufacture these products.
Here we are also dealing with "industrial secrecy" and many companies do not want their competitors to know that they use a particular technique, screen, digital or other for a specific manufacturing operation.
In addition, there are often obvious practical reasons such as manipulation, transport, automation, on-line production and the absolute specificity of certain screen printing applications, to have these types of screen printing generally "in-plant" in the Companies that use them, and therefore rarely "outsourced" to professional screen printers.
Only manufacturers of products, machinery, equipment, some others and consultants like me are aware... and we are bound by deontology to respect this secret. Sometimes even, working for competing companies at the same time, our right hand must ignore what our left hand does!
If they are subcontracted, it is only in hyper-specialized screen printing companies which are, in addition, sometimes even bought and controlled by the manufacturer, for example in the printing of labels on machines using different printing techniques or glass or metal bottles, or chromos (decals) for glass or ceramics and some special applications and of course in electronic applications.
Without claiming to establish an exhaustive list of all the applications of screen printing in the industry, here are a few:
- Glass, in sheets (automotive, architectural, etc.)
- "Hollow" glass (bottles and bottles)
- Ceramics (porcelain, faience, sandstone ...),
- Bottling and plastic packaging,
- "Membranes switches"
- Printed circuits, rigid or flexible, with the printing of protective masks for the engraving of the circuit or direct printing with conductive inks (silver, carbon, copper, nano-particles, conductors, etc.)
- Keyboards for computer, telephone and other items
- Soldering pastes, soldering saving, insulation
- "Sensors" and other detectors,
- RFID (Radio Frequency Identification)
- Rigid or flexible solar cells (photo- and thermovoltaic)
- Mobile phones, smartphones and others,
- Camcorders and digital cameras,
- Games, pinball machines, slot machines,
- Touch screens
- CDs and DVDs
- IMD (In Mould Decoration)
- "Fascias" or front panels of various apparatus,
- Lighters and other gadgets.
- The wood industry (decoration of furniture and others)
- Pharmaceutical and other laboratories,
- Dermal patches
- Portable electronic health checks and other electronic or dermal thermometers
- The automotive, aeronautical and maritime industry (internal and external parts of vehicles, Dials and other apparatus, at their subcontractors)
- The continuous label, for external and internal labelling
- The toy and games industry (marking and decoration)
- Skis, surf and ski-boards,
- The gift or object, whether advertising or not,
- Liquid crystals and other microencapsulated products for industrial applications
- All markings or decorations of "containers" and packaging of various industrial products
- "Thermoformed" elements,
- Leather (binding, bags, shoes, clothing)
- The food industry (decoration on pastry or chocolate for example)
And I forget many! New ones appear every day! (I understand that some footwear manufacturing companies in India have inhouse screen printing plant).
Another field where screen printing does not stop developing, even if the digital makes more and more incursions, is printing of textile in pieces. Large textile manufacturers often have sometimes enormous screen department. Again, these are mostly "in-plant" departments. They do not envisage at all go digital on their big markets merely because digital is: too slow, too expensive.
On the other hand, for thousands of small and medium textile screen printers, there is a superb niche in digital: clothes or decorations customized or in very small quantities. It is a good market, but one who’s marketing, targets and sales are completely different. They take only a few from screen printing but add a parallel and different outlet to it.
What about graphic applications?
Even more interesting for the classic "graphic" screen printers: the screen printing market is starting to recover in the world! An example: the five-colour presses are starting again to print and even starting to attract companies that are purely digital!
A specific example: I did three years ago tests in some European countries to know at what level the screen became interesting in terms of prices in the printing of posters, decorations or elements of POS of 140 x 260 cm ... One had determined that up to 700 copies, digital printing was cheaper. From 700 copies and more and more as the quantities increased, screen printing became less expensive which most of the Indian graphics screen printers also agree. I came to know from Grafica News India articles that in India scores of small, medium and some big screen printers still run their graphics screen printing in full swing as they roll out advertising display boards, etc printed on flute-board, flute-board, acrylic, metal, etc.
New tests conducted this year show that now the tipping point of costs has fallen. It is from 300 copies, sometimes even less, that screen printing becomes cheaper than digital!
Other areas where screen printing is booming are: packaging, especially in countries (e.g. India) where special effects are appreciated (varnishes, glitters, reliefs, flakes, nacres, metallic, fluorescence, tilt, liquid silver, structured and tactile effects, etc.).
If this market is often outsourced to screen printers there are even offset printers who (India for example) equip themselves to create their own screen department. This is also true for the printing of textile - direct or indirect (heat transfers method).
All this is therefore extremely positive, and in practically all our fields of applications.
It’s because screen printing has greatly improved, among other things including prepress; because screen printers have improved their workflow, the quality of their printed images and the training of their staff; because manufacturers of machines like Grafica (here, it's me who said it, not them!) have created, improved, perfected a lot of reliable and imaginative machines that, at reasonable prices, can improve the quality of the prints.
Moreover - and it is always me who says so - Bhargav Mistry by creating DMI which is in my opinion the best screen printing school in the world, both for the apprentices and for the confirmed screen printers, allows, in India in any case, to reach a remarkable degree of improvement of the technical and practical knowledge of screen printers.
In addition, very good progress has been made by other manufacturers of equipment and products, too.
One of the handicaps of screen printing, in relation to digital, is the manufacture of its printing “plates", for us the screens of course.
Improvement in equipment, technology and products:
For several years, we have developed and continuously improved the stencilling with the CTS (computer to screen) which either by means of an in actinic ink or wax deposit on the emulsion, before exposure, or even better, using the direct exposure by UV or violet laser, without using films therefore. If films are still used, for very fine halftones for example (more than 115 LPI, for me up to 300 LPI) the big screen printers have equipped with “image setters”. The others, when the resolution of their work permits, use inkjet presses to create their films in digital on special polyester sheets, which is both cheaper and more environmentally friendly.
Screen fabrics (also called mesh) supporting the very high tensions, tensioning machines, self-tensioning frames, emulsions and capillary films have made enormous progress.
Automatic emulsion coating machines on the screens have been improved too.
The screening (coating, exposure and washing) of the screens can be automated as well as their reclaiming, degreasing, drying.
Large companies can pay for systems to automate the entire chain - coating, drying, exposure, washing, drying - then cleaning / degreasing, drying again, thus a new screen becomes ready to be coated.
Other factors: Tools involved
Screen printers have learned to use control tools at all stages of their workflow.
At the prepress, they learned how to better use their computers and drawing or photo software.
They learned how to create ICC profiles to compensate for colorimetric deviations related to screening, printing, inks and printed media. Then how to use these tools that are densitometers, spectrophotometers, tests, learn the difference between ISO-coated and Swop and a lot of other technical details.
For screens, they learned to use tension-meters, internal humidity meters, mesh calculators, or emulsion thickness meters.
For the machines they can have now, as I said above, very good machines at fair prices.
For squeegees and their blades, they know how to make the right choices in durometer, how to use sharpeners.
They have learned to master UV drying, to use here also the right control tools.
They have learned to optimize their workflow and thus to save money in production costs.
They have improved the ecological aspect of their production, to which their customers are increasingly sensitive.
And, cherry on the cake, improved training of their staff and that has resulted in enormous gains in quality, productivity, fewer losses and rejections.
You see, it is not, as always, the improvement of one single element that allows this rise or progress of screen printing: as always, it is the combination of a bunch of elements, at all stages of production and to that of the staff which has led to this return or advances in screen printing on the world market.
All of this – according to my advice and voice – explains that 'Screen Printing Process is Changing, but not becoming Obsolete!'