by Cassandra Balentine
Digital printing technologies help create flooring options that resemble traditional finishes like wood, tile, and marble. Equipment and treatments in this space continue to advance, making way for more digitally printed flooring opportunities.
Above: Agfa offers three primers, which are designed for different technologies.
“Digital printed flooring has grown in the last few years,” shares Mike Horsten, global business manager, InterioJet, Agfa. This is because more customers are asking for smaller batches and runs, which makes it ideal to print digitally as the cost for the gravure cylinders would make this financially impossible. “The growth in the 5,000 meter market is the dominant factor. We also see that suppliers as selling paper décor prints to manufacturers that have not yet invested in digital. So there is a big overlap in favor for digital.”
Stephen Sanker, manager, digital printing products, Koenig & Bauer US, also sees growth in digital adoption for décor applications on an industrial level. In Europe, he says décor printing is very robust and other markets are becoming more aware of the advantages digital technology brings to this segment.
Increase Awareness, Heighten Growth
As awareness for industrial printing capabilities grows, so does its projected use in décor, and as an extension—flooring.
Horsten predicts a growth of 12 to 15 percent in the next five years per annum. “This seems big but it’s only a fraction of the décor market,” he offers.
“Direct-to-product printing is increasing; so I would expect the same adoption in the flooring industry as well. There are many advantages to printing directly to a product, including versatility, cost, and consistency,” shares Wilson Lee, director of business development, and Tom Gilbertson, VP of application engineering, Enercon Industries Corp.
Dr. Anke Pankoke, head of marketing/PR, Hymmen GmbH, admits that while it took the market time to adopt to the technology, once one big player of the regional industry decided to invest into that new, innovative way of producing flooring, other market players followed very quickly. “This was the case in Europe, and it will be similar in the U.S. where the flooring industry around Atlanta/Dalton, GA is highly into digital printing by now. In the last 18 months alone, we have sold seven new flooring lines with our Digital Lacquer Embossing technology by Hymmen.”
Sanker says growth in North American depend on substrates and digital capabilities to adapt to synthetic materials.
“As with most markets, in flooring digital printing will see widespread adoption only when the economics work,” offers John Corrall, chairman, Industrial Inkjet Ltd. He says there are always niches within markets where print runs are short and a lot of variation is required—usually at the top of the quality scale. “Any segment of the décor market will have ‘designer’ product that is sold in small volume at high prices, and this is where digital print first becomes profitable. However the real interest for manufacturers is the mass production volume product.”
The drivers for digital print are zero setup time, no tooling, and vastly reduced waste. “The break on adoption is always running cost, which is mainly ink or toner cost—or click charge. There is always a Catch 22 here, if the production volumes can be higher, the ink manufacturing cost will fall. But no ink manufacturer is going to sell at a loss for years in the hope of future sales. The result is usually a gradually increasing production volume and a gradually decreasing cost per print. The slow trend continues until someone realizes that the economics have bettered conventional or analog print processes. At which point the digital process suddenly becomes compulsory for everyone,” shares Corrall.
A variety of surfaces and materials are printed on for digitally printed flooring.
Lee and Gilbertson point to PVC, vinyl, foam, and laminated structures of various composition as popular material. “We work mostly with plastics and other man-made materials. We also work with a variety of metals, but not for this application,” they comment.
Horsten says most of the prints are on paper with special inks for décor. “Think high-pressure laminate (HPL) and continuous pressed laminates. There is little luxury vinyl tile (LVT) at the moment but this will grow slower than HPL. Not because of technology but because of the post-treatment equipment they already have.”
“Most often the board materials are stone polymer composite, or LVT, as well as wood-based panels such as high density fiberboard,” shares Pankoke. “As for décors, wood and wood interpretations are the most common in the digital printing of flooring. But we also often see different variances of stone and concrete décors in the décor design departments of our customers.”
Certain surfaces require pretreatment. “Pretreatment is necessitated by image and print quality in combination with the type of substrate,” says Sanker. “Some of these substrates are very specific and have exceptionally consistent surfaces. In most cases the nature of the quality and color requirements for décor will require pretreatment to ensure color accuracy and color consistency. Brand managers and specifiers will not compromise in these areas,” he offers.
Horsten says papers often need to be a primed to accept the inks. “As the melamine penetrates the paper the inks need to be binder free. This way the melamine can fill the paper and make it ready to be used in the normal industrial way.”
Lee and Gilbertson point out that most of the flooring materials that you would print on are low surface energy products. “This means that in order for the print to stick to the surface, you need a pretreatment of some kind. Plasma allows you to treat inline, generally right before the print step.
This allows for the best adhesion of the print on the surface and increases the durability of the print long term.”
The need and type of pretreatment is determined by the absorbency or surface energy. If the surface is absorbent—e.g. some natural woods—then to get a high color density means a lot of pigment and therefore a lot of expensive ink. “It can make excellent economic sense to first print a primer that acts as a sealer and simply stops the ink penetrating too far. The cost of the primer is likely to be a small fraction of the cost of the ink saved,” notes Corrall.
When printing to non-absorbent surfaces, like plastics, Corrall stresses that the media surface energy is critical. “If the plastic has a low surface energy—for example, polypropylene or polyethylene—then typical UV inks will simply ‘reticulate’ or ‘bead-up’ on the surface. Getting a smooth, consistent ink layer that the ink needs to ‘wet’ to the surface requires a higher surface energy. Various techniques are used such as corona, plasma, or flame treatment. If none of these work, a primer might be the only solution,” explains Corrall.
Depending on the specifics of a job as well as the materials and equipment used to produce it, primers/pretreatments are applied in many ways.
The primer might be sprayed, applied by flexography, or even inkjet printed. “Note that inkjet is more demanding on material surface energy than conventional contact printing methods. A dyne level of say 36 might be fine for flexographic print, but 44 or 48 might be needed for inkjet inks,” says Corrall.
In Corrall’s experience, pretreatment is done all inline. “In the case of primers, customers are often keen that the pretreatment is applied digitally. This might be to save money by not applying primer where there is no inkjet, but it can also be because the primer itself might change the ‘look’ of the flooring. It might cause a color shift or more usually a change in the gloss level. Customers don’t like that so you want to restrict the primer so that it is only underneath the color print,” he recommends.
Lee and Gilbertson note that priming is often performed inline right before printing.
With the Hymmen digital printing technology, Pankoke confirms the pretreatments are applied inline.
Koenig & Bauer and the RotaJET also integrate priming inline. “Our customers are looking for industrial output—24/5 or 24/7—in most cases, which means in this case the nature of inline configurations are the most desirable and the most successful. This is what we are seeing in terms of adoption for décor applications overall,” shares Sanker.
On the other hand, Horsten sees many primers applied offline with a gravure system that has a blanket as a cylinder. “It applies the primer to the paper, which is later printed.”
Post treatment is also a consideration when it comes to digitally printed flooring. Often post-treatment options come from the print specifier, says Sanker.
“The post treatment is usually a varnish. Typically it is applied by flexography, spray, or digital print. It may be UV cured or water based,” offers Corrall.
With Hymmen, Pankoke says operators can put on one or more layers of top lacquer on the digitally printed surface, or go in with digital structuring that needs several pretreatment layers again, then digital structure printing, and in the end the final finishing process steps.
She points out that the more process steps you take, the thinner each layer can be and the higher the flexibility and, in the end, also the quality of the outcome e.g., in terms of gloss grades and depth of structure. “But—certainly—the more machines you include in your line the more expensive the technology,” says Pankoke.
She adds that in her experience, post treatment is always applied inline because it is the only way to control the production process.
Lee and Gilbertson say application really depends on the exact details of the product being made. “Speaking generally, inline treatment is the best as it reduces additional steps in the manufacturing process,” they comment.
“Today we see that post coat is often applied as a separate process, probably because the coating equipment already existed. Pallets of floorboards are moved from the inkjet station to a separate coating station. Longer term we would expect new flooring lines to install the post-coat inline with the digital print. This becomes more necessary if the post-coat is also used as a texture—i.e. the top coat is applied with varying thickness to highlight the grain of the wooden image, which can look very realistic. It’s much easier to match varnish print to color print if they are both in the same line,” explains Corrall.
Sanker feels the advantages of post treatment for digitally printed flooring are clear in that they compress the production workflow for printing and eliminate steps in the process. “Other than cost, they have few drawbacks,” he admits.
Digital print technologies continue to penetrate more industrial markets as they advance. Flooring is one area expected to see increased adoption of digital technologies. Depending on the material used and the specifics of the job, pre- and post-treatment options may be necessary.
Oct2023, Industrial Print Magazine