FESPA World Expo India 2007, organised by the Federation of European Screen Printer’s Association for screen, sign and large format digital printing, concluded on a positive note recently in New Delhi. The exhibition witnessed the presence of more than 150 exhibitors and 10,000 visitors from India, the Middle East, and various other countries across the globe.
A number of internationally recognised experts delivered educational seminars and demonstrations about their products. “The screen-industry in India has not grown as much as in other countries. Most of them are still using primitive methods and are not aware of the latest developments.
I believe the conduct of suitable seminars and workshops would definitely take the printing industry of the country to a higher level,” says Michael Caza, Guru of screen-printing and Board Member, FESPA.
Screen printed T-shirts have been a standard form of product advertising for major consumer products across the world. Printed T-shirts have always been a rage; companies, political campaigns and individual consumers, young and old, now create their own slogans based on their business or promotional needs to promote their message.
Once considered a craft, screen-printing is dictated by the type of ink used, the medium on which it isused and time taken in its drying process. Today, as the technology has advanced, highly automated machinery has been developed that print even 0-12+ colours at a very high speed, increasing printing efficiency manifold.
[bleft]In the recent years, a number of printing companies have installed automatic screen-printing machines that have given an edge to the printers for making remarkable innovations. Such multi-task machines, which are easy to handle, are available in India with local solution providers[/bleft]
Besides, dryer attachments have also helped in significantly increasing the production rates. Some specific innovations came with the development and improvement of plastisol and water-based inks, use of UV curable ink technology, and development of software that reduced ink wastage and helped in perfect colour matching.
Screen Printing Machines and their Specifications
In the recent years, a number of garment manufacturing companies have installed automatic screen-printing machines that have given an edge to for making remarkable innovations. Such multi-task machines, which are easy to handle, are now available in India with local solution providers.
The Sportsman E from M&R
The Sportsman E Automatic Textile Press from M&R machines, supplied in India by Dhaval Colour Chem, comes with the company’s patented ‘Revolver Print Program’, which simplifies hard-to-print jobs. The revolver automatically operates individual print heads in programmed sequence and allows multiple flashing without losing a printing position.
Standard features like independent squeegee and flood bar speed adjustments, adjustable rear screen holders, independently-set angle and calibrated pressure adjustments, and independent print, reset, and print speed controls on each print head further simplify the setup.
[bleft]Once considered a craft, screen-printing is a labour intensive printing technology, which is dictated by the type of ink used, the medium on which it is used and time taken in its drying process. Today, as the technology has advanced, highly automated machinery has been developed that print even 0-12+ colours at a very high speed, increasing printing efficiency manifold[/bleft]
Other features include a user-friendly control panel with digital keypad, onboard self-diagnostics, real-time production data, and an independent print-start/print-finish setting that automatically activates and stops print heads at the beginning and end of production runs. M&R’s patented Optical No-Shirt Detector (optional) minimises the misprints and press stoppage that result from improper shirt loading.
Schenk VARIprint 2002 CX/EX from Heinz Walz GmbH, Germany
Supplied in India by Magnum resources, the Schenk VARIprint manufactured by German manufacturer of screen-printing machines, Walz GmbH, can easily be operated through a multi language touch screen control panel. The machine can perform two different printing operations at a time. Through an inbuilt dryer, the first layer of ink gets dried before the application of the other, thereby giving a smooth three dimensional finish to fabric. There are six different programmes available in this equipment, of which two permit leaving the screen flooded after each print. Each station can be individually and independently configured with any of the available programmes and print/flood strokes set up to 9 strokes.
The RoqPrint Oval by S. ROQUE, Portugal
Supplied in India by Grafica Flextronica, The S. ROQUE RoqPrint Oval can be used for both water-based inks and plastisol inks, where quick print flash curing (infrared heating or drying) is required. Because of the oval configuration, the RoqPrint can accommodate as many as 52 pallets. In other words, it is a space saver too. Also, it has an added advantage as compared to standard machines, where flash curing is compulsory after each colour.
Its oval structure is ideal for providing large productions and the best industrial management. It offers two areas for placement and withdrawal of the pieces, enabling the user to accomplish two simultaneous productions. The printing resolution of this machine is 0.025 mm and it is easier for the operator to handle the printing stations, which rise up to 30 cm in height, enabling an easy access for cleaning or replacement of the frames.
The Synchroprint from MHM
The Synchroprint 4000 AC (Auto-Reg) provided by European Nest in India with Automatic ‘GOTO’ Registration System from MHM is one of the fastest and most accurate printing systems available. The ‘GOTO’ system of the automatic device, with simple ‘finger-tip’ command for all main operator functions, has a full colour touch screen display and records and stores unlimited production data and designs, including all the individual screen directions, plastisol/water-based print modes, sequential start/finish, sample/test print facility, dual timer, remote flash cure unit programming, including pallet ‘warm-up’ facility, print speeds and number of strokes required on each print head along with the location, power and time settings of any flash cure units used.
These can be recalled at any time in the future at the touch of a button, thereby saving production time and making repeat production a pleasure. The super-rigid support arms of the Synchroprint have been constructed from two 30 cm (12”) section extrusions for zero pallet deflection and even print coverage over the entire image area with flawless registration accuracy. Besides, it has enhanced control keypads on every station with all main operator functions, including 6 directional keys, for fast, precise movement and adjustment of screens, using high speed, remarkably accurate step-motors (accurate to 0.01 mm).
The Hawk E Electric from TAS Australia
The Hawk E Electric from TAS Australia marketed in India by Batliboi comes with a 4-year guarantee for its products. TAS Australia is claimed to be the first company that introduced the industry’s first automatic screen-printing machine to successfully print on garments. The Hawk-E electric 6-18 colour station offers screen printers a lot of value-added extras not normally found on an entry-level automatic. With one of the smallest footprints (a tool for operator with which he can increase the loading time as per his convenience) in the industry at 13 feet 1 inch, the Hawk E promises to bring years of trouble-free production with minimal downtime.
It features pneumatic print heads. The quick-release pallets make job changeovers fast and efficient. The ‘Roto Print Program’, having flash curing facility, which can be attached to individual heads, allows multiple flashing with one flash cure. It also has two individual heads for loading and unloading purpose and central control of the pallets, and squeegee and flood bar (used to collect the colour, spread all over the screen, by the squeegee) angle adjustment. The micro-registration machine has been integrated with skip-shirt and no-shirt alarms, leaving no room for ink wastage and also for stopping the printing process, in case the palette is empty.
YH series Automatic Textile Screen-printing Machine from Spintex Corporation
Supplied by Spintex Corporation, the YH Series Automatic screen positioning system comes with precision turntables having placid & steady running, and an excellent localiser. Adopting automatic controller system with combination of mechanical, electrical and pneumatic control, and together with screen-printing principle, it is suitable for shirt, T-shirt and garment material for automatic and continuous multi-colour printing. The YH series that comes in four models offers perfection in every detail. These machines are combined with advanced technology, high speed and have a nice-looking appearance. This machine series has an automatic cleaner that cleans the colours and squeegee and can do high-density prints (up to 2.5 mm). The computer controller system of this series is integrated with multiple and interchange languages.
ATENAS Oval, the Automatic Garment and Textile Printer from Pannon
The Atenas automatic garment and textile printer from the Spanish manufacturer Panon and supplied by Appeal Print and Packs in India is suitable for all water-based, eco-friendly and plastisol inks. This oval automatic machine is ideal for long and narrow production sites, as it allows printing of a number of colours (14 or more) occupying only a width of 3.8 m. Atenas is also ideal for production sites with columns, as it can be installed leaving these columns in the centre of the machine. Another advantage of this machine is that it can produce two different jobs at the same time, because it has in-feed and out-feed stations at both sides of the machine. This way, a 14-colour machine can be used as two 7-colour machines. The machine comes with 14-44 pallets having a registering accuracy of plus minus 0.02 mm with a digitally controlled squeegee sun speed from 0.15 to 1.5 m/sec.
Cheran’s Manual Screen Printing Machine
One of the unique features of the Cheran’s Manual Screen Printing Machine manufactured by Cheran Machines, India Private Ltd, is that although being a manual machine, it comes with the micro-registration system that generally comes with automatic printing machines. The fire and waterproof pallets of this machine can be set minutely for giving accurate and error free printing on a garment. The machine has specially been developed for printing by using plastisol inks and comes with a double spring, electric/LPG/infrared flash curer.
Impress Zebra Manual Chest Printing Machine
Impress Zebra manufactured in India by Impress India is one of the most user-friendly manual machines that even a new operator can operate easily and without hesitation. Knobs can easily set all the axes of this machine; thereby, very less time is required to set the screens. The Impress Zebra comes with an infrared flash drier for quick drying of ink before application of another ink and is said to be one of the most user friendly manual machines available, as the frames can be set according to the printing needs, making it convenient for even a new operator to print with accuracy.
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[tab title=”Some Popular Screen Printing Effects”]
A significant characteristic of screen-printing is that a number of interesting effects such as flocking, velvet printing, rubber printing, foil and metallic effect, etc, can be achieved by using different methods. Besides, a wide range of innovative drying and curing processes are available that increase the productivity manifold.
Thermography, also called ‘Raised Printing’ has an added advantage of getting the effect by using quick drying inks. In this process, thermo-resin powder is sprayed over the wet prints and after whisking it, is heated in the conveyor. This melts the powder stuck on the wet prints. By this the print gets raised and begins to glow. Thermo-resin powders are available in clear transparent, silver and golden colours. For any other colour, printing is done in that particular colour and a clear transparent powder is used. ‘Pigment printing’ is another effect widely used across the world. It is done with PVC or water based synthetic for non-raised effect.
‘Rubber Printing’ is another trendy popular effect. In this printing, a layer of plastisol compound and latex is applied on the fabric and then heat pressed, in order to obtain the adhesion of the glued side, leaving a rubber effect on the garment.
The ‘velvet’ effect is given by ‘Flock’ powder. For getting this effect, printing is done in the same colour as of the powder, with self-thickening acrylic emulsion used for pigment printing. Special effects can be printed by spraying special powder with a spray gun. After the powder is sprayed every fabric is whisked and heated in the conveyor. The embroidery effect on the garment is also given by this method. It gives an impressive and innovative look.
‘Foil printing’ is another popular effect. In this effect, polyester films are coated on the screened adhesives and are then heat transferred under pressure leaving a foil effect. Another effect is the ‘Metallic Shade Effect’, which involves printing with silver and golden inks that are available in the market and can be used straight away. Sometimes the design is first printed in the colour of the fabric and again on the same registration printing.
It is done with silver or golden ink to achieve a raised effect called ‘Over Printing’. ‘Pearl Effect’ is another effect that has also got a high demand. For this effect, Pearl powder of one or two tones and ready-made pearl inks are used to give a shining and rich impression on the fabric.
‘Beads’ is also one of the most important printing effects that are possible with screen-printing. For this effect, either Plastisol or PVC is applied on the garment and then beads are sprinkled and heat transferred under pressure.
Besides, ‘Frog effect’ or ‘Bubble effect’ is also another unique effect, generally given with the plastisol based inks.[/tab]
[tab title=”Inks There are two main types of ink used for textile printing: “]Water-based Ink Systems
The water-based ink utilises either dyes or pigments in a suspension with water as the main solvent. Water-based ink is the ink of choice for the printing of yard goods; either in piece form or on the roll.
Advantages of Water-based Inks
Water-based inks are a good choice when a “soft hand” is desirable. A soft hand is the condition where the ink film cannot easily be felt with the hand when passed across the surface of the fabric. Water-based ink also has the advantage of being an excellent ink system for high-speed roll-to-roll yardage printing.
Water-based ink is a good choice where ink penetration is desirable, such as in towel printing. Towels have a high nap fabric that must be printed in a manner where the ink penetrates or wicks through to the base fabric for adequate coverage. Ink wicking is not a desirable affect in most other fabric printing, as it will destroy the design and registration of multiple colours.
The Plastisol ink is a PVC (Polyvinyl Chloride) based system that essentially contains no solvent at all. Along with UV ink used in graphic screen-printing, it is referred to as a 100% solid ink system. It is necessary to heat the printed ink film to a temperature high enough to cause the molecules of PVC resin and plasticizer to cross-link and thereby solidify, or cure. The temperature at which most plastisol for textile printing cures at is in the range of 149 °C to 166 °C (300 °F to 330 °F).
Advantages of Plastisol Inks
Plastisol can best be described as ‘user-friendly’ ink because it is very easy to manage. Plastisol can be left in the screen for extended periods of time without clogging the mesh. In most applications, it can be printed wet-on-wet, which allows for increased production speeds.
The plastisol inks can be used directly from the container without ever adjusting the viscosity or the strength. Plastisol comes in strengths from transparent to very opaque. The various opacities of ink also vary greatly in price, with the most opaque being the most expensive, mainly due to the cost of the increased pigment.[/tab]