Breaking the Glass Ceiling: Powder Coating Glass

By Steve Houston

One aspect of our industry that frequently surprises industry outsiders is the willingness for companies and people to work together to push powder technologies further. Even competitors frequently work together to solve problems for customers. Not many industries adopt this mentality, but matching synergies and talent and working together is part of what it takes to keep our industry healthy and moving forward.

Sundial Powder Coating, located a short jog from California’s Hollywood Burbank Airport, was founded in 1982 when Hasu Bhakta, Shivie Dhillon’s uncle, began operating in the space of a powder coating shop where he was employed that went out of business. The immense growth of powder coatings in North America in the 1980s and ‘90s was an exciting time for powder coaters, and Sundial was positioned to make their mark on the industry. As powder manufacturers worked on improving formulations, new powder chemistries were introduced, and over time, various types of resin systems and crosslinkers became commercially available. By the time Shivie took over as president of Sundial in 2005, there were chemistries available that allowed powder coaters to experiment with the commercialization of processes to powder coat non-metal substrates like plastic, glass, ceramic, and wood products. There was also a lot more competition for powder coaters focused on processing steel and aluminum parts, but there wasn’t much appetite for the trial and error required to develop alternative substrate markets. Increased competition combined with the malaise of the Great Recession and local business conditions inspired Shivie to get creative. He believed for Sundial to continue a healthy growth trajectory that a new market needed to be pursued.

I recall an early conversation with Shivie, prior to my employment with Vitracoat. He said, “I want to powder coat glass,” and I replied with, “Why?” He explained it was a market where performance and aesthetics were critical, and he believed if they could develop a process with consistent outcomes, they could reshape the market and expand Sundial into a space with few competitors.

Proving the Technology
As they got further into planning, Shivie emphasized the need to develop a process that had predictive, consistent outcomes. After all, by this time, formulations, processes, and equipment for powder coating metal substrates were hitting their strides and, regardless of the economy, the North American powder coating market was spilling over the $2 billion mark in value.

At this point you may ask, why not use colored glass instead of trying to create a new process to powder coat it? The answer lies within. Using metal oxides, metallic salts, and other methods can achieve colored glass, but depending on the product inside, these methods may not provide the UV protection needed for proper storage and extended shelf life. In addition, you have to apply the five Es of powder coating: economy, efficiency, energy savings, environmental compliance, and excellence of finish.

Initial testing on common glass bottles took place at Vitracoat. Various transparent powder coatings were developed to accomplish an array of looks and designs, with some requiring extensive manual masking processes and finesse to achieve a workable product. Solid colors were also pursued with some success.

While early testing showed promise, scaling up to full production required further development and capital to achieve the level of consistency sought. They experimented with a single-coat system first, then elaborated on what was learned and developed an improved two-coat system to achieve full opacity. Besides developing a powder that will stick to glass in a uniform way, the powder coating also must offer the right amount of UV protection to preserve the contents. Conductive pretreatments and hot flocking are standard ways to make powder coatings stick to glass, but the team developed a proprietary method of attracting electrostatic powder to non-conductive glass.

Over time, the powder formulation was continually tweaked, including the addition of zinc and evaluation of various additives to help improve flow and appearance characteristics. Depending on the contents of the bottle, the powder coating also had to have a high level of chemical resistance. Abrading the glass surface was explored to achieve varied appearances. Film thickness was refined until they landed on an average two to four mil thickness, depending on the application. Various cleaning processes were explored, including the use of mild detergents, fast drying solvents, and hot water, also dependent on the end use product. Curing processes were tested, and they eventually achieved the most success with gas fired convection.

As products and processes were refined, Shivie found opportunity in the nail polish market with Van Nuys-based ORLY. This presented a challenge of how to hang nail polish bottles on a powder coating line for maximum efficiency while achieving a quality finish. Applying more ingenuity, a custom racking system was developed.

Kicking Glass
In 2012, with the process essentially ready for mass production, Shivie opened a subsidiary of Sundial called Bottle Coatings. Evaluating labor and logistics, Bottle Coatings and Vitracoat entered into a long-term joint venture agreement and planned to move the operation from the Vitracoat Innovation Center to Mexicali, Mexico, location of Vitracoat’s headquarters. Vitracoat funded the move as a loan and became their exclusive supplier of high-quality powder coatings developed for glass. This partnership continues today.

To date, Bottle Coatings has successfully powder coated over 25 million nail polish bottles, more than four million wine bottles, and over 5 million jars and tinctures, having worked with recognized brands like L’Oréal and Revlon in this space. Research continues at the Vitracoat Innovation Center in Houston to look for ways to continually improve products and processes. Bottle Coatings continues to look at ways to expand their offerings, such as working with customers on newer processes like digital inkjet printing to enhance label designs. With modern color matching capabilities, we are now able to match the exterior color of nail polish bottles with the exact color of the product inside.

Click to see glass bottles getting powder coated by Sun Valley, CA based Bottle Coatings.

This has been a great partnership, with both parties enjoying tremendous growth by expanding the use of powder coatings. We can᾽t wait for the next adventure! Powder manufacturers are always looking to differentiate our products and service offerings, and this is a prime example of how collaboration can and typically does pay off for the supplier, the consumer, and the industry as a whole.

Steve Houston is president of Vitracoat.