New horizons for screen printable films
02 August 2010
As well as contributing to the aesthetic appeal of a product, the latest generation of film substrates also offer designers and screen printers opportunities to improve product performance and functionality. Three years have passed since we last reported on this subject, so Laura Bullmore provides a long overdue update
The financial crisis has hit the electronics and screen printing sectors hard. Even before the economic downturn design and production engineers had to cope with low cost foreign competition and the rise of digital print technology. Now, with their customers’ budgets being squeezed ever tighter, UK based companies are having to adapt to survive.
The good news is there are opportunities available for those willing to diversify into areas where specialisation and quality remain a priority. In these high value markets, such as electronics, healthcare and telecommunications, low cost competitors are generally unable to satisfy the needs of customers so price competition is less fierce. In particular, where there is a demand for precision production techniques, specialised finishes and fast turnaround, UK companies can prosper.
To meet these requirements and remain competitive, the right materials are essential. One area that offers considerable potential is screen printable film technology. A wide range of substrates are now available that solve specific problems, such as reflection and glare, graffiti and physical damage, and the risk of infection, while offering new opportunities in areas such as component production and surface finish.
Key to achieving these properties are the hard coated outer layers of the films, which are chemically bonded, at a molecular level, to conventional polyester or polycarbonate substrates. The result is a film that combines the mechanical characteristics of the substrate with the special properties of the coating. As well as being resistant to scratches and abrasions, coatings resist common cleaning chemicals and solvents, offer excellent optical characteristics, and allow the films to be handled easily using normal printing, cutting and installation techniques.
An important characteristic that can be specified in these new films is the ability to minimise reflection and glare. This is particularly useful for products and displays that need to be viewed easily in different light conditions and environments, such as handheld devices or electronic displays.
This latest film technology can also help protect screen printed displays against vandalism. Film materials are now available that make it considerably easier to clean away graffiti without affecting the surface finish of the display or reducing its quality, colour or clarity. The specially developed hard coat layers enable graffiti to be removed quickly and simply using conventional isopropanol solvents or aqueous detergents. Unlike conventional display materials that can become permanently damaged after cleaning, the new films can be restored without damage or degradation.
When specifying an anti-graffiti film, look out for ASTM D 6587 certification, which shows that a substrate has passed industry standard testing. This is especially important for larger scale or high value projects where it is essential that the materials used meet the required performance criteria. For example, a recent project at a major UK railway station used over 1,000m2 of MacDermid’s SIGMAGraff Shield for a large advertising hoarding in a main concourse. The specifications included anti-graffiti protection and UV resistance, the ability to be printed using conventional inks, and a minimum life of 15 months.
Screen printed control panels and displays used in hygiene critical environments can contribute to the spread of harmful bacteria if standard film materials are used. To resolve this problem, anti-microbial protection can be designed into the latest films, once again through sophisticated hard coat technology.
Products such as Autotex AM film or SIGMAGraF AM, with Microban technology, serve to reduce the threat of infection from common skin borne organisms, as well as inhibiting the growth of mould and mildew. The anti-microbial agent is distributed throughout the film hard coating as part of the production process, and the anti-microbial properties last for the lifetime of the film.
These films come into their own in medical environments and food preparation and storage areas. They can be used as a safer, more hygienic alternative to traditional materials that would otherwise be used in the construction of equipment control panels, displays or coverings on walls and doors.
The new films provide countless possibilities for achieving specific finishes. Substrates are now available with either a high gloss, antiglare or matt textured outer surface, and new finishes are being introduced all the time. A good example is MacDermid Autotype’s recently launched Autotex Steel film, which is a textured polyester film that replicates a stainless steel finish. As with all hard coated films, the second surface is receptive to screen printable graphic inks, and when printed with mirror inks produces an exact replication of stainless steel.
The latest generation of film substrates can be extremely useful to product developers looking to diversify and expand into new markets. By understanding the film technology available to them and working with suppliers to identify the right film technology for their product, designers are not only able to solve specific problems such as those outlined above, but also ensure that their products stand out from the crowd.
Laura Bullmore is with MacDermid Autotype
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