By Alysa Hoffmeister vice-president and general manager of North America Dip-Tech
Digital printing technology opens new vistas for designers and glass fabricators.
By Alysa Hoffmeister vice-president and general manager of North America Dip-Tech
Emerging less than two decades ago, digital ceramic printing on glass is
a relatively new technology that uses ceramic inks to apply imagery, a
pattern or text to the surface of flat glass.
Emerging less than two decades ago, digital ceramic printing on glass is a relatively new technology that uses ceramic inks to apply imagery, a pattern or text to the surface of flat glass. Initially, the technology only printed with black ceramic ink and was mainly used in the transportation industry. Over time, a wider range of ceramic ink colours was developed and the printing technology became more advanced, enabling the digital mixing of these colourful inks. These advances paved the way for the first application of digital ceramic in-glass printing in architecture, and, in 2007, the glass designer Bernd “Bernie” Hoffman collaborated with the glass processor Interpane Sicherheitsglas to print a satellite image of the town of Eiserfeld on the Eiserfeld Municipal Bank glass façade. Today, digital ceramic printing is used to print any design on glass, and is ideal for both transportation and architectural glass applications.
|When reconstructing this cathedral in New Zealand, architects were able to replicate the original stained glass at a fraction of the cost with digital printing.|
Opening new opportunities for the glass industry
By combining the versatility and high-quality of digital printing with the durability of ceramic inks, digital ceramic printing technology has created new opportunities for glass fabricators to offer glass printing services that were previously out of reach either because of the limitations of earlier technology or due to prohibitive costs of production. This technology enables a high degree of customization, is suitable for long and short runs, and creates printed glass designs that are extremely durable and resistant to internal and external conditions. With digital ceramic printing on glass, glass fabricators can print any design their architect and interior designer clients might imagine, on panels of almost any size with complete predictability, repeatability, and accurate colour matching.
Digital ceramic printing on glass also supports a wide range of functional requirements, meeting the needs of architects and interior designers to integrate functional performance into the glass elements of their designs. With ceramic inks, numerous performance factors can be achieved and controlled, including light diffusion, light transmission, energy efficiency, shading control, slip-resistance and privacy levels. In addition, digitally printed glass is a recyclable and non-toxic material when using inks that are free of toxic heavy metals, thus offering a sustainability advantage that is an increasingly important consideration in many architectural projects.
Digital ceramic printing on glass also eliminates the typical constraints of traditional screen printing and UV digital printing. The process does not require screens, and the files are stored digitally. Therefore, there are no setup, storage, or maintenance costs. And, compared to UV digital printing, digital ceramic printing offers longer durability, enabling more exterior applications.
Applications for digital ceramic printing on glass
Digital ceramic printing can be used for virtually any application on interior or exterior architectural or transportation glass, including curtain walls, facades, windows, balustrades and balconies, signage, shower doors, dividers, wall cladding, doors and tables, backsplashes, flooring, canopies, roofing, public art in public spaces, and transportation glass for air and sea craft and land vehicles.
The following examples demonstrate the unlimited possibilities of digital ceramic printed glass in architecture applications.
Columbia College Chicago, Chicago, Ill.
The façade of 600 S. Michigan Avenue underwent significant urban renewal and restoration in the past century. In 2010, the college needed to redo the exterior façade namely for safety reasons. After exploring several replacement options, including replicating the original terra cotta (rejected due to cost), it was decided that digital glass printing would be used in the restoration. The ceramic frit, covering almost 46 per cent of the glazed area, significantly reduces the solar heat gain as well as bird collision risk, which is consistent with the owners’ commitment to environmental sustainability. Furthermore, they used ghost-like images of the building’s original façade, giving a nod to its extensive history.
Cardboard Cathedral, Christchurch, New Zealand
Christchurch’s original cathedral and its stained-glass rose window were destroyed in a series of earthquakes. The Transitional Cathedral, designed by Shigeru Ban Architects, was built nearby in 2013. It is nicknamed the “Cardboard Cathedral” due to its extensive use of cardboard tubes in its construction. Metro Performance Glass was approached to process the 12-metre-high glass facade. The original design called for coloured triangles, until Metro Performance Glass showed they could do so much more with digital printing on glass. Using photographs of the original rose window, the images were lifted and printed directly onto the glass, and the ability to easily adjust the transparency levels gives the glass a stained glass appearance. The new window pays homage to the past through the use of modern glass printing technology.
The Wire, Omaha, Neb.
The Wire is the first architectural project in the world to include glass windows digitally printed with Dip-Tech Extra Durable S1 Inks. The architects sought a solution to replace the existing insulated metal panels with glass that would increase the flow of natural light without compromising the look of the original facade of the historic building. To simulate the no-gloss finish of the metal panels, printing the custom dot pattern using a mixture of the black and white Dip-Tech Extra Durable S1 inks directly onto the external side of the glass was the only solution.
Digital ceramic printing components and points of consideration
The foundation of digital ceramic printing on glass is digital glass printers, digital ceramic inks, and image processing software. We recommend that glass fabricators look for a single comprehensive solution where all three elements are fully integrated and have been proven to work together seamlessly for multiple glass printing applications.
A glass printer is a flatbed digital printer that jets ceramic inks directly onto glass panes. There is a range of digital ceramic glass printers on the market that offer varied functionality and support various pane sizes. Currently, the largest printable panel size is 3.3 by 18 metres, and panes as small as 10 by 10 centimetres can be printed on the same printer. Some key features to look for when purchasing a digital glass ceramic printer are a smooth colour-switching system, which enables machine operators to easily shift between print jobs and increase throughput; an inline dryer, which enables real-time drying, thus saving time and costs; and drop fixation, where ink droplets are dried immediately to enable a single pass of the print carriage even when printing multi-layer and multi-colour files. The drop fixation also makes inline double vision printing possible, which occurs when different graphics are printed one on top of the other so that the resulting image looks different from opposite sides of the glass.
Digital ceramic inks contain inorganic pigments and nano-particles of glass frit which encase the pigments and are fused into the glass during the tempering or annealing process. This results in glass that can be laminated, bent, double-glazed, or coated. It is important that the inks be manufactured in a highly controlled production process to remove any variability in the final product. This will ensure consistency in replication of the colour palette of ink, so panels may be replaced when necessary, eliminating the risk of colour variations. It is also important to understand what inks in the portfolio may be digitally mixed so that architects and designers will know the precise outcome of colour every time.
The image processing software bridges the glass printer and the inks and is the design tool for turning standard graphic files into ready-to-print images that are tuned for optimum results on glass. It ensures repeatable and consistent results across multiple users and sites. Colour matching capabilities, pattern generators, and automatic tile numbering are some of the key features that should be included in the software.
In addition to the features of the individual components, glass fabricators should also consider factors such as the reliability and consistency of the technology, and how well-proven it is in the market, looking at the number, range, complexity, and durability of projects already implemented with the technology. Also, when investing in large capital equipment, you are forging a long-term relationship, so additional factors to consider are the number of years the supplier has operated in the market and who are the customers in the company’s portfolio. Make sure the supplier is trustworthy, with a proven track record, and has a healthy forecast for future growth. Lastly, it is also advisable to seek out a supplier who will offer 24/7 technical service support, graphic support to achieve optimal printed results for projects, and marketing support to gain the tools to effectively promote printed glass to architects and designers.
The future of digital ceramic printing on glass
The digital ceramic glass printing field is one of the most exciting and fast-developing fields in the glass industry. Architects require a solution that delivers on both aesthetic and functional requirements, and glass fabricators need a solution that delivers accurate glass printing for a wide range of applications in order to maximize their business potential. With this in mind, glass printing technology companies are dedicating significant resources to developing specialized inks that offer additional functionality. For example, as part of its ongoing drive to expand its range of ceramic inks, Dip-Tech recently developed and introduced extra-durable inks for printing on the external side of glass and a slip-resistance ink that creates anti-slip surfaces for exterior or interior flooring applications. Dip-Tech CEO, Yariv Matzliah, says “Amidst the exciting developments of today, it is anticipated that glass will become a primary building material used to create everything from building façades and office furniture to interior structural and aesthetic décor, with improved sustainability and advanced results not achievable with many of the materials commonly used today. Digital architectural glass allows architects and designers to create high-end elegance on a tight budget by matching the look of textiles, wood grains, natural stone and so much more. We are moving into a digital age, and glass processors and architects alike must think about the future.” As time goes on, it is likely that more specialized inks will be developed, opening up new applications that today are only a dream.
Does ceramic frit weaken glass?
Matt Tangeman of Custom Glass Equipment says: “My personal hypothesis is that digitally applied frits impact glass strength less than ones applied via other methods. Why? Compare the large ice cubes in your cocktail to one that has crushed ice in it. The crushed ice has more surface area, and hence melts faster. The large, harder-than-liquid cubes still are present after the same amount of time and temperature, just like frit experiences in a tempering cycle. When large particles that are as hard or harder than the glass are impacted they become a concentrated stress point that initiates fracture. Has this been proven out quantitatively? No. Should it be? Let the industry decide, and maybe some fabricator would be willing to do just such a test for the good of the industry. If so, I’d be happy to collaborate, plan and interpret those results. My second hypothesis is that digitally applied frit exhibits thin film behavior while roll, screen, and spray applied frit mostly (there are some exceptions) exhibits thick film behavior. Again, the limited time-temperature exposure bodes well for digitally applied frit glossing out and fully melting into a thin coloured glass film. In my eight years of representing Dip-Tech technology, strength and breakage issues have never been an issue in a project. Also, frit adds colour which causes glass to absorb much more heat compared to clear and low-e glasses that transmit or reflect it. This causes differential thermal stresses that are accounted for when the glasses are heat strengthened or tempered.”