Sisu is located in the Technology Incubator at NC State University’s Centennial Campus

“There are a lot of advantages to an emulsion-based polymer compared to solvent-based polymers,” said Stark. “They are typically lower cost materials, plus you have improvements in safety and handling, and reductions in hazardous waste, which allow customers to realize savings in disposal fees and insurance costs.”

Most of Sisu’s products are adhesives, coatings or binders used in applications such as pressure-sensitive adhesives, concrete additives, nonwoven fabric binders, medical tapes, fabric back-coating, coatings to make fabrics ink jet receptive, and more Solvent-based polymers are homogenous and they are inherently stable systems. Conventional emulsion polymers, however, require an unbonded soap to stabilize the oil-in-water system. This makes them unsuitable for certain adhesive applications, clean room filters, or any application where the level of leachable materials must be minimized.

“What I have done is develop an internally stabilized system for developing water-based polymers,” said Stark. “My system is actually a part of the polymer itself and not a free soap that is typical of traditional emulsions. That’s what distinguishes Sisu’s products.”

Sisu’s first commercial product was a coating for vinyl film that is universally receptive to all commercial inks, including UV inks. UV inks are gaining widespread use and Sisu’s product is the only water-based coating on the market that can be used with UV inks.

“Vinyl labels are being used to replace paper labels in many applications because of their superior durability,” said Stark, “but achieving acceptable printing on vinyl has been a challenge. If you tried printing on uncoated vinyl film, the ink would bead up like water on a freshly waxed car. You need a primer coat and I’ve developed a coating that works extremely well.”

The first company using Sisu’s coating had been trying to find a water-based coating with these characteristics for more than 10 years. They had run trials with several major companies and had not found an acceptable coating.

“Product superiority is what gets us in there,” said Stark. “We are able to solve problems no one else has been able to solve.”

All of Sisu’s products are custom products, made to customer specifications. “A lot of companies are cutting back on their research efforts,” said Stark. “We are one of the few companies willing to work with a customer to develop a new product.

“I am currently running a pilot trial at a major German ink company with a polymer that I developed for durable inks that require resistance to solvents, as well as to boiling caustic solutions. To achieve this, I developed a unique internal epoxy cross-linking system. It was an extreme challenge, but it seems to work,” Stark said. Since the European company started evaluating the product, Sisu has received requests for samples from other major printing ink companies who are also evaluating the product.

Stark expects to have a water-based adhesive for transdermal patches go commercial in 2006. “I started working with the customer three years ago when I sent them samples,” he said. “It worked, but they took two years going to the major suppliers to see if they could find another product that worked in this application. They couldn’t, so they came back to me and now we’re in the final stage of qualification.” Sisu now has samples of their adhesives being tested at other companies that produce transdermal patches.

“That’s an indication of what you’re up against when you are a small company in this industry,” he said. “My competitors include companies like Rohm and Haas, Dow Chemical and National Starch. So you have to have something special. You have to have solutions to problems that no one else can achieve.”

Being located in the Technology Incubator has been good for the young company. “It has given me the facilities to develop and prove my own products at a reasonable price,” Stark said. “If I had to go out and get commercial lab space, it would have been more than I could have afforded as a startup. So it’s been very beneficial.”

Being on campus also enabled Sisu to file a Small Business Technology Transfer (STTR) proposal for a National Science Foundation grant with the Mechanical Engineering Department to develop a lubricant for cold forged metals. The primary lubricant currently used contains heavy metals and is applied as an exhaust bath. When the concentration of the active ingredients falls below an effective level, the entire bath has to be disposed of as hazardous waste, which makes it expensive to use. “The prototype I developed is a water-based, polymeric system that is applied as a coating, so there’s no waste and it is environmentally friendly,” said Stark.

For the lubricant, Stark developed a unique chemistry that enables Sisu to make the stearyl methacrylate lubricant in a water-based co-polymer. “I can make a high stearyl methacrylate polymer using standard emulsion polymerization equipment,” he said. “That’s what makes it a commercially viable product.” Sisu has samples out with several companies and the initial feedback indicates that this product out-performs the lubricants currently in use.

“The lubricant is a significant technical breakthrough,” said Stark, “And it is an unusual application for an emulsion polymer.”

Scale up from the lab to commercial production is often a significant challenge for new products, but Stark says that has not been a problem with Sisu products. “I’ve been fortunate in that most of my scale ups have been relatively linear,” he said. “I assist the chemists at the contract manufacturer in scaling it, but at that point it’s just a matter of determining the optimal run conditions and feed rates.

“But you have to have a feel for it,” he said. “That’s what is unique about this chemistry. You have to have a good understanding because this isn’t chemistry that you can model with techniques such as computational chemistry. It requires experience and I’ve been through the trials and errors with it.”

Stark started Sisu in 2001 and the company has been self-funded from the start. “I looked at venture capital early on,” he said, “But venture firms don’t really understand this business. The first thing they look for is an exit strategy in 5 to 7 years, but it can take that long to commercialize products in this industry. I was lucky that the vinyl film coating went commercial early on. That product and some contract research projects have provided revenue and I don’t have the debt burden that start-up companies often have.”