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Join the computer-to-screen revolution
Natgraph’s sales director Alan Shaw; Kenton Instore director Peter Hughes; and CST’s international sales manager Oliver Leven
With two Sakurai cylinder presses and four Siasprint machines, Kenton Instore is wedded to the screen process. Screen Process and Digital Imaging visited Kenton’s Birmingham facility to explore the benefits of its newly installed CST computer-to-screen system
With over 50-years point-of-sale print experience, Kenton Instore is investing in new screen print technology to help grow its business in the retail advertising sector. With a focus on lowering production costs, reducing time-to-market and improving product quality, Kenton’s attention turned to its stencil production department.
Kenton Instore director, Peter Hughes, takes up the story: “Looking at material costs alone, we were spending up to £76,000 a year on film. This was the drive we needed to explore new computer-to-screen technologies. Our key goals were to reduce production costs and improve product quality, whilst also ensuring the system would pay for itself in two-years.”
After evaluating different technical options, Kenton decided upon the CST, DLE screen imaging system, (manufactured in Germany and now available in the UK from Natgraph). Using a digitally controlled mirror device (manufactured by Texas Instruments) the DLE (Digital Light Engraver) system directly images and exposes the screen.
Peter continued: “When printing vibrant, large format images, screen printing is unbeatable. Now, with the computer to screen system in place, screen printing can also compete with digital image quality. In fact, the improved resolution and registration offered by direct imaging is allowing us to chase even greater quality by focussing our attention on the mesh itself: both its quality and tensioning.”
Consumables are eliminated
By directly imaging and exposing coated screens, the DLE system entirely removes consumables from the exposing process, no need for masking with wax, or ink or film positives. The digital mirror device (DMD) modulates an ultra-high power UV light source with image data using approximately 800,000 micro mirrors. While the DMD moves over the screen, data scrolls continuously to produce a seamless image. As each mirror represents one pixel, high imaging speeds are possible, with resolutions up to 1,500dpi.
Screen Process and Digital Imaging’s screen features editor, Peter Kiddell, commented on the DMD: “The heart of the direct exposure systems is a DMD or digital light processing chip. This is a remarkable component developed by Texas Instruments. DLP technology is probably the world's most sophisticated light switch. It can contain a rectangular array of up to 2 million hinge-mounted microscopic mirrors. Each of these micro-mirrors measures less than one-fifth the width of a human hair.”
Kenton found additional bonuses in reduced set up time and labour costs. Its traditional exposure process required three qualified staff. The DLE system can be run single-handed. The operator simply positions the screen frame against the mechanical stop and locks it in place. Once activated, the system is fully automated, with the controller displaying the estimated completion time. During the imaging and exposure process the operator is free to complete other tasks such as preparing the next frame or taking completed frames through to production.
Two of the original three exposure system operators have already been redeployed to higher value roles elsewhere in the company.
Savings were also found on the printing machine itself. Thanks to the DLE’s mechanical frame stop, the positional accuracy of each image virtually eliminates the waste of time and material associated with on-press registration. CST can design bespoke frame stops to suit different frame and registration systems.
When discussing computer-to-screen technology, consumable and maintenance costs are often highlighted as potential limitations. Naturally, as a light based system, the DLE’s only consumable cost is the UV lamp.
Bulb management
Peter Hughes explained: “Lamp management is important. If well managed, lamps can last up to 2,000 hours. There are two important factors. Firstly, the system automatically starts the bulb on its lowest setting, monitoring its output and steadily increases the power as required. Secondly, if possible, group screens together for batch production so the lamp can be turned off when not required.
“Another unexpected benefit is the system’s carbon footprint. Our original exposure system consumed 8kW when running and 1kW when idle. The DLE consumes just 2kW via a normal single phase power supply. In fact, the savings are even greater because we have also eliminated the need for 16kW of air conditioning during the summer months. This energy saving is excellent news for Kenton’s customers, the environment and the company itself.”
By handling screens vertically, the DLE has also helped Kenton dramatically reduce the footprint of the screen production process. This free space has been turned over to storage.
Specialising in 3D display products, Kenton has also invested in a Zund
cutting table. Working together, the computer-to-screen and cutting table offer an unbeatable partnership for rapid prototyping and new product introduction.
A new product can be designed in the morning and in production in the afternoon.
Peter Hughes concluded: “Last year, I really thought we were going to have to install new digital printing machines. Following the installation of this computer-to-screen system I am now finding it difficult to justify the option of replacing screen presses with digital printers.”
DSPA seminars
Readers considering investing in a computer-to-screen system can learn more at the next DSPA seminars (Warrington 9 May and Oxford 10 May 2007), where CST’s international sales manager, Oliver Leven, will give a presentation on the different CTS processes (CST manufactures them all) including the Digital Light Imaging (DLE). Also making a presentation will be Alan Shaw, sales director of Natgraph, the UK distributor for CST.
Alan has over 30-years international screen printing experience and has been instrumental during the installation of thousands of pieces of screen process equipment and machinery. This places both Alan and Natgraph in an ideal position to advise on the specification, installation, operation and maintenance of computer-to-screen equipment.
