A 360 degree sign solution is likely to catapult the Indian signage industry, and the credit goes to a relatively new kid on the block i.e. UV-curable flexi/soft/stretchable ink.
As the signage industry grew, ink manufacturers were pushed to develop inks that can be heated, stretched, bent, folded, and cooled, and amidst all this, maintain its colour and cohesion (ability to resist cracking) during and after the forming process. To which the industry players rightly responded and came with a solution that relies on heat energy from the vacuum-thermoforming process to completely crosslink so as to attain a full cure keeping intact the material strength and durability to the final output. The resultant is an ink film with all the desired resistance properties. Thermoformers and signage printing companies can make use of this ink to print directly onto a wide range of substrates, which can then be formed without any fear of getting cracked or peeled imprinted layer in the finished product.
Going by records, the first such solution in the inkjet ink chemistry came only three years back in 2013 when EFI announced its VUTEk GS-TF UV-curable ink that withstands thermoforming, cutting and routing without cracking, chipping or losing adhesion, with moisture-resistance and a durable life resulting in long-lasting graphics. This high-elongation ink enables deep-draw thermoforming with excellent adhesion and superb retention of hue and opacity. It is designed to stretch as much as the plastic on which it is printed, and can easily be implemented even in instances where the ink touches the mould. The ink, which comes in an eight-colour process imaging set (with white ink), runs in EFI’s VUTEk GS3250 Pro-TF printer–a special version of VUTEk GS Pro series printers optimised for the purpose.
In the following year, another technology giant, Fujifilm announced its thermoforming UV-cured inkjet ink, Uvijet KV. The ink, so developed, is specifically meant for use with the company’s mid-range flatbed printers, Acuity Advance Select and Acuity Advance Select HS, to help maintaining the high quality, vivid colours and excellent performance, without compromising on the print speed. Once the printing of a flat plastic sheet is completed, it is placed on to a mould where it is heated up to take on the shape of the mould, and then cooled. The ink has outstanding elongation properties of 300-400% when heated, returning to a normal state when cooled.
It’s only recently that Mimaki also jumped on to the bandwagon with its UV-stretchable ink – LUS-350, suitable for a range of thermoforming applications. Available in cyan, magenta, yellow and black, as well as white and as a clear ink, it is compatible with the 710mm-wide Mimaki UJF-7151plus and 2.5m-wide JFX200-2513 printers. According to the company, the ink stretches up to 350% when heated to between 120˚C and 200˚C. After cooling to room temperature, its rigidity is restored and it adheres to the moulded product without cracking or peeling. This is the most stretchy ink developed by Mimaki, with the most recent inks brought out being the LUS-150, LUS-200 and LUS-120 inks.
Contrary to all these recorded facts, Mohan KT of UV Printers India Pvt Ltd –who has been serving this industry for over a decade and a half– claims that UV-curable flexi/soft inks are not new to the Indian market. “UV-flatbed printers have been there for not less than seven years, so are the soft inks for thermoforming purposes. However, their usage in thermoformed signage market as compared to most other forms of printing till date is limited because it’s a concept yet to pick up,” he shares adding that such scenario is actually restricting printers to opt for flexi inks despite the fact that they already have UV-flatbed printers installed in their premises. However, he firmly believes that sooner or later the market of thermoforming will get the needed momentum.
UV Printers India Pvt Ltd is the sole distributor of UV-flatbed printers from the Korean technology major, Dilli. “Ever since our entry in the trade, we have supplied more than 70 UV-flatbed printers in India,” asserts Mohan indicating that large format printing has for some time been expanding away from the traditional graphics markets delving on to create new applications based on the respective capabilities. “Though, the use of flatbed printing in thermoforming is not well-established, but there is an opportunity for early adopters to use their creativity and innovation to open up and develop exciting new markets. Soon, it will be there as the personalised branding is becoming a new trend, starting with the corporates.”
And, Mohan’s hope has valid reasons. As shares Nakul Sharma of West Delhi-based Mridul Satya Enterprises (MSE), “Over the past few years, we have noted a definite increase in the demand for digital thermoforming signage solutions. We installed our first 5ft Dilli Neo-Titan machine from UV Printers Pvt Ltd way back in January 2011 and got added another 8ft machine in 2014 with the aim to create innovative signage solutions for our valuable clients.” According to him, for the past five years, MSE is busy developing various applications for its customers using these UV-flatbed printing machines. “The ones, which stand out are the thermoforming applications, such as outdoor signage, POP signs & displays, day/night backlit signs, promotional products, beverage lights & signs, vending & gaming panels, and much more,” asserts Nakul suggesting typical substrates that could be used for the purpose include polystyrene and PETG, both of which mould easily into new shapes when hot.
Right from the very foundation, Nakul informs that at MSE, only the flexible UV inks from Dilli has been used as it gives excellent results with an incredible elongation limit of up to 1000%. “We are extremely delighted with the market response not only from the end-users, but also from a number of designers and relatively small printers across India who outsource their digital thermoforming projects to us. Our USP is that we can print on a wide range of materials, including PETG, acrylics, polycarbonates, polystyrenes and ABS so that the end-users get ample choices to play with,” he avers hinting that the association with UV Printers is going well. “We are very happy with the product quality, service and commitment of UV Printers and have plans to add another machine this year so as to increase our capacity to meet the anticipated surge in demand.”
Adding further strength to the future implications of thermoforming signage; comes forward Ankit Shrama, the co-owner of Rupak Graphics. “The key attribute of all these products lie in the hyper flexible inks rather than the printers, especially UV-curing that has helped by broadening the range of substrates that can be used,” he states adding that thermoforming is not a new invention, and that it has been in use for both signage and industrial applications for quite some time. “We are in this profession of thermoforming acrylics for over a decade, and the introduction of UV-cured flexi ink seems an outstanding discovery to us in this technological era. As per our knowledge, around 30-35 companies decorate the industrial thermoform signage in today’s time and only a few own or use digital printing process.”
Ankit underscores that this pre-forming UV printing on acrylics or any such substrate is a dynamic innovation for the entire industry. “One of its biggest pros is that it saves a lot of time in the process and for our Industry, time is money; we value it. Another plus point is it enables maintaining inventory and helps avoid job-repetition as whatever is printed today can easily be printed in the near or far future also,” he elaborates indicating that customisation to this extent was never possible. “Noting the future prospects of thermoforming to which almost all the manufacturers are now turning their attention to, is nothing but a clear indication that they are readying themselves to exploit the advances made in both inks and hardware.”
How does the UV-cured flexi ink work?
An initial cure from UV lamps installed on the printer changes the properties of the liquid ink film so it acts like a thermoplastic. At that point, it exhibits a glass-transition temperature in the range of all common thermoplastic materials and stretches without smearing or swirling. While the adhesion of the ink is high after the initial cure, it remains somewhat softer than traditional, UV-curable inks used in other inkjet printing applications. However, as the printed part proceeds through the thermoforming process, the heat of thermoforming changes the ink so it has a hard, glossy surface with excellent adhesion and scratch-resistance.
Quite a few manufacturers claim that the new inks developed specifically for thermoforming usage are capable of providing excellent imaging at a 600 dpi or a 1,000 dpi resolution or for even further higher-end graphics. The thermoforming properties of these special purpose inks add to the personalisation characteristics of a digital solution. According to them (ink manufacturers), the ink is used successfully in applications with 60 cm of draw, greater than 1,000% elongation, extremely high aspect ratios (<50:1), and very tight radii of curvature.
Thermoforming ink’s elongation capabilities are further enhanced by its high opacity on a broad selection of materials, including PETG, acrylics, polycarbonates, polystyrenes and ABS, plus derivatives and mixes. All this make it ideal for applications including outdoor electrical signage, point-of-purchase displays, backlit vending/gaming panels, automotive/RV recreational parts, consumer products, packaging and industrial product decoration.
Going by the current trends, the thermoformed signage market when compared with most other forms of printing is a low-volume market. Orders of such signage might be for a single sign or for very small batches produced on demand. For instance, a beverage brand despite being globally renowned might require only a few self-branded thermoformed backlit panels to reward select vendors in select cities. Or a small restaurant might require a single, branded thermoformed backlit panel with its name and logo for an entry sign or a vending machine in its lobby. Or, a bank with its expanded network across the country may demand for thermoformed signage to be used at their ATMs in metro cities only. “For circumstances like these, screen printing of thermoformed graphics is not only unprofitable but also unaffordable for those engaged in signage production. And, therefore, printers that go the digital route for pre-decoration can economically offer run sizes of one. No wonder, why there’s a clear shift towards the UV technology,” elucidates Mohan.
Screen – Not A Viable Option
Notably, few thermoformers feel that the invention of the UV-cured ink is meant to boost the usage of UV-flatbed printers. According to Akshay Talwar, co-owner of The Innovators, the invention in inks would only facilitate a new dimension to those who are using UV-flatbed printers for the purpose. “For us, screen printing still has a longer lease of life when it comes to providing thermoforming solutions for relatively larger order of 400 or 500 pieces,” he avers agreeing that when the order is not that big i.e. 100 to 150 pieces, screen printing solution is not viable as the substrate used in the process is very costly, besides high wastage in the due course of production adds further to the cost. “Nonetheless, for sampling purposes, UV-printing is having no match when comes to meeting cost and the lead time. Thermoforming is a substance, which is not approved unless the sampling is done,” he adds advocating that UV printers and specialty inks are the future, but will take some more time.
According to Talwar, The Innovators are there in this trade from around two decades now with strong infrastructure comprising printers and tooling that include latex, inkjet, eco-solvent, solvent, CNC routers, laser engravers, vacuum forming machines, etc. The company offers all kinds of printing solutions irrespective of applications. “We are planning to add UV-flatbed printers in our portfolio shortly, but not specifically for thermoforming as this market is yet to pick up and also setting-up cost of the printers with specialty inks won’t justify the ROI keeping in view the current market scenario,” he cautions adding that the move depends on market demand. This is nothing but an inclination towards the most certain, but awaited opportunity.
Further divulging his thermoforming screen printing experience, he says, “UV has its own limitations of CMYK format and can’t produce special colours such as gold and Asda green in their true shades, which screen printers can perform very easily with all the effects as screen printing can cope up with special effects much better than digital printers.” Despite all this, Talwar seems quite excited for a thermoforming project that it has delivered only recently on newly introduced UV-cured stretchable ink for a beverage brand, the name of which he didn’t agree to divulge. “I have never seen such an outcome on a thermoformed finished product. That was just amazing and full-proof thermoforming,” he asserts sharing that it could become possible only because of the newly introduced specialised ink, which is really a wonder.
Win-Win for Thermoformers
It won’t be wrong to mention that for signage thermoformers, the thermoformable UV inks present financial advantages not only in colour but also in response time. As we know that pre-forming decoration eliminates many time-consuming methods, including hand air-brushing, a process that prohibits full-colour imaging and requires time-consuming masking steps. Inkjet technology makes pre-forming decoration a possibility for markets that have low-quantity requirements or specific customisation and just-in-time fulfillment needs. Going forward, in today’s signage market, many thermoformed signs–such as fast food restaurants, petrol pumps, soft drinks producers–use simpler, one or two-colour logos because of the prohibitive cost of multiple-or process-colour decoration in screen printing process. This happens despite a great deal of evidence that full-colour imaging drives higher revenue and response across nearly any form of advertising.
Now, with the introduction of UV-cured flexi inks, number doesn’t really matter, and that makes the job easy for thermoforming solution providers. Sunil Arora, director of Roop Sign & Graphics (P) Ltd couldn’t conceal his happiness while showing the outcomes of the new UV-curable flexi inks from Fujifilm that he has just started using. Roop Sign is equipped to deliver high resolution digital prints in three different media using printing methodologies such as Solvent, Eco-Solvent and UV. “We have recently installed a machine from Fujifilm for pre-printing on substrates for thermoforming purposes using which we have delivered a project for PepsiCo for its thermoformed 360O branding. This installation has provided me a visible edge over the other solution providers present in this part of the country,” he avers adding that the company is now capable of delivering thermoforming projects of any strength.
Roop Signs boasts of its prestigious assignments of in-stadia signage at several select venues during the 2010 Commonwealth Games in New Delhi. At Roop, UV printing is versatile enough to be executed on a wide range of surfaces like ACP sheets, MDF, sun-board, acrylic, yupo translite fixtures, textiles cotton and polyester, canvas, and even ceramic tiles! Speaking about the benefits of using UV-cured flexi inks for thermoforming, he adds, “Due to high-quality printing, the impression of backlit transmission is 100 times better than the screen printing, which doesn’t really a viable option when it comes to producing small number of thermoformed articles. In fact, the advent of UV-cured ink has eliminated the number barrier enabling printers to never say ‘No’ to any of such jobs. It has added a life to the outdoor branding activities which with screen printing was not possible at all.”
Switch to become a total solution provider
Combining UV inks, multi-colour presses, and sophisticated modern forming machines have increased the complexity of print designs and moulded shapes that can be achieved with thermoforming. A key advantage that UV technology brings is the ability to fully automate the entire production process, from printing through forming provides an option for the thermoformers to become total solution providers. With the right combination of equipment, even forming can be added as a direct post-printing process, with prints moving directly from the final curing station into the vacuum-thermoforming system. Of course, this applies vice-versa.
Experts are of the view that by doing so the solution providers can complement their printing or thermoforming capabilities. Rather than working with a separate complementary company, which increases the chance of image-to-mould alignment problems and other processing errors, they can maintain complete control over the entire printing and forming process. This would also give them the flexibility to quickly produce prototypes so that they can predict how images will distort during moulding and accordingly adjust the artwork, a process that involves printing grids and measuring how the patterns change due to forming.
What’s more, having the entire process under one roof allows printers to fine tune their procedures and deliver accurate and intricate thermoformed products faster than if thermoforming or printing were outsourced. And when the print shop is also the forming shop, it becomes much easier to accommodate design modifications, seasonal product changes, and other adjustments or alterations requested by customers. Thanks to advancements in UV inks, which have facilitated an ideal position to the stakeholders to expand their production capabilities and make vacuum thermoforming a profitable venture of their businesses.
What is Vacuum Thermoforming?
Vacuum thermoforming is a manufacturing process wherein plastic is heated at malleable temperature, vacuum is formed in a mould, and then it is cooled and trimmed to create the finished product. This process developed into a commercial reality at the end of the 1950s, which grew over the last six decades to become an accepted system for producing large quantities of commercial-grade products like pre-production proofs and prototypes. Today, thermoformed products feature high-quality decoration and intricate shapes that belie the overall simplicity of the vacuum-thermoforming process. Delving in to the pastshows that only the formed articles were printed or decorated that too with process of transfers because of the non-availability of suitable processes or materials to decorate the flat material prior to forming.
However, as the thermoforming process evolved, so did the screen-printing process and screen-ink technology. By the early 1970s, solvent-based screen inks were developed to withstand the temperature and stresses of thermoforming for the next two decades following continued developmental processes. It is the past few years that witnessed shifting focus of ink development for thermoforming applications enabling the jump over to UV-curable inks which, once thought to be unusable in forming applications, eventually came to revolutionize the production of vacuum-thermoformed products. Those shifting from screen to digital printing will enjoy greater savings as this eliminates extremely labour-intense methods such as post-process hand airbrushing, besides enabling to profitably print short runs and on-demand jobs.