The same can be said about glass: Nature invented it, man discovered it around 5,000 B.C. and has been working to improve upon it ever since.
Glass-related research still continues, and one of the most recent enhancements has been the application of specially formulated waterborne coatings to sheets of clear glass, which provides them with a variety of colors and hues. The furniture industry has been the first to adapt this concept but when the creativity of product development professionals, designers, architects and contractors becomes stimulated, it could have a range of other applications.
These of course are still just technology-driven enhancements as glass historians say that colored glass was accidentally discovered sometime around 3,500 B.C., architectural glass was introduced about 100 A.D. by the Romans and the 11th century saw German glass craftsmen create glass sheets.
When a manufacturer of small, painted glass tabletop items for restaurants was looking for a safer, more environmentally friendly way to coat their tables, they went to Finishes Unlimited about a solution. At the time, the tables were being coated with solvent-based paint, which provided adequate coverage and appearance, but the manufacturer wanted to avoid the environmental, health and storage issues these coatings presented.
Minimum drying times were important, and the waterborne formula allowed painted items to be handled in 6 min after spraying in ambient temperatures, depending on humidity, with no forced air circulation. When placed in an infrared oven at 125°F, coated items dried in 2 min. Field use determined that after a 1 min flash-off, coated items would dry in less than 40 sec when passed through air being circulated at 160°F.
It was important that the waterborne coating withstand cold, heat and high humidity without discoloring, cracking or peeling. For example, the table top items were frequently stored for extended periods in warehouses without climate controls and were eventually used in indoor and outdoor locations with similar environments. During one adhesion test, items painted with the waterborne coating were placed in a 125°F oven for 72 hr with no change in performance properties. In another test, coated products were placed in a humidity cabinet under ASTM D-4585 criteria to determine adhesion failure points. The water-based coating did not fail until 24 hr had passed.
Painted objects were also tested in accordance with ASTM D-2803-82 specifications by placing them in a 10-gal humidity chamber at 85 percent relative humidity. After 30 days, the water-based coating exhibited superior tape pull performance.
At the same time, "real life" conditions were replicated. No color deterioration or appearance change occurred in items exposed to direct sunlight or rain during a one-month outdoor test. They also resisted damage from variety of liquids such as coffee and alcohol.
The waterborne coating offered important production advantages as it presents no fire hazard and may safely be stored indoors without special combustion precautions. All cleanup of the painting area can be accomplished with tap water, eliminating the need for any solvent cleaners. From an environmental standpoint, the VOC levels of the coating ranges from 1.1 to 1.4 lb/gal sans water compared to 4 to 6 lb/gal sans water for solvent coatings.
Not Just for Appearance Sake
While one customer wanted color coatings, another was only interested in a clear coating for use in protecting etched glass windows, mirrors and furniture. These products are often magnets for soil and grime. Most people put their hands on glass entry doors when leaving or entering a building, leaving dirt deposits from their hand or gloves. When frosted glass banquet dividers are used in restaurants, airborne pollutants like smoke, grease and food particles settle onto the glass. Also, some people like to experience the tactile sensation of running their hands over the sandblasted portions. Even workers installing glass can leave dirt, oil and other marks so they can start out dirty.Cleaning dirty frosted glass is very difficult, if not impossible in some cases. The only viable option is to remove the glass and re-sand blast it, taking away yet another layer of glass.
For this company, a totally transparent waterborne coating was formulated that could be sprayed over the glass immediately after it had been etched to prevent soil and grease from penetrating into the porous designs. It had to be totally transparent so as not to counter the appearance of the etching but still allow the glass to be cleaned with a soft cloth and common glass detergent. As the client says, "most people put glass over art to protect it. We put coating over glass art for the same reason."
To test the clean-up feature of the product, a piece of etched, coated glass was dipped into cooking grease, which was easily removed with window cleaner. An unintentional test came when a glass installer used a power tool that was leaking lubricating oil. Droplets of oil that were sprayed onto an etched glass pane were easily removed. The waterborne coating also enabled the company to perform sandblasting on-site if necessary without creating any environmental or safety issues.
The most recent use of waterborne glass paint was the brainchild of a furniture company seeking to develop a distinctive new line of home and office furniture. Glober Furniture is a second generation, Chicago area manufacturer of contemporary dining room, bedroom and occasional furniture. Faced with growing competition from imports, it set about to develop a totally new line of difficult-to-import products with distinctive styles and features that could also be customized to a large extent. The company knew it wanted one of the key exterior materials to be anodized aluminum available in finishes such as bronze, silver, chrome and brass plus variations. It was searching for a companion material that would complement the metal and set the items apart from competitors' products.
"Using glass as a furniture component is nothing very new but it's more difficult to import large pieces of glass furniture," says John Glowacki, vice president of the company. "But, we couldn't achieve the look we wanted with clear glass so we wanted to try painting it. We were introduced to Finishes Unlimited and its waterborne paint for glass and we tried it. We achieved exactly the appearance we wanted. The prior research and testing assured us that it would be easy to apply in our factory without any environmental issues and that it would have excellent, long term performance features when our furniture was placed in a customer's home or office. The company assured us that they could create the color formulations we needed and that the color would be consistent batch after batch so that each piece produced in a specific color looked exactly like pieces produced weeks or months ago in the same color."
Today, Glober's furniture features metal panels and frames laminated to wood structures along with large pieces of glass painted on one side. The painted side is affixed to the furniture frame with the clear side facing the room. The result is a color surface with great visual depth, gloss and reflectivity that complements the metal. Both surfaces are also very easy to keep clean.
"We provide retailers with literature showing the range of metal and painted glass combinations we offer for that same piece," Glowacki says. "Consumers can then select the metal and glass combination they want to match whatever interior design plan they have. We can produce and deliver an order in four to six weeks."
While the company is completing the basic design for a new piece of furniture, it asks for a color formulation that will create the finished appearance a company wants. For example, the glass components of a line of recently introduced office furniture are painted jarama, a popular color for automobiles a year ago and one that also complements the design of computers and other office equipment. Actually two shades of the same color are always created. Glober will use a thicker sheet of glass for a furniture top and a thinner one for drawer or door fronts. Each thickness requires a different shade of paint to achieve a matching color.
The waterborne paint makes for a relatively simple furniture production process. Glober can order large glass panels cut to the size and shape it wants. When orders come in, the coating is applied with a spray gun to one side of the glass and it air dries quickly so it can be attached to the furniture within minutes. Depending on the orders, there can be several color changes throughout a single day. The spray system can be quickly cleaned with water before each color change. As production demand increases, the formulation can be altered and the company can add heat to shorten the drying process and speed up production.
Waterborne glass paint has a range of product design and architectural applications. It allows glass to become a design element for many types of electronic, office and home entertainment products for which appearance is a selling point. It can also be used to add color to glass doors, room dividers, display cabinets and even signs. Once the color flexibility, application ease and field performance of painted glass becomes more widely recognized, the applications will be limited only by the customers' imagination.
