Free fall fluid flow
However, the coating is not “one size fits all” and must be custom developed for every application. Obviously, for the food industry, the coating material must be food safe. And as you may have guessed, this technology may provide solutions in the process as well as getting the last teaspoon of ketchup out of a bottle.
FE caught up with J. David Smith, inventor and cofounder of LiquiGlide, whose doctoral research project has resulted in real-world solutions.
FE: How did you get started with this unique application?
Smith: It began when I joined Professor Varanasi’s research group at MIT, which was exploring how to solve methane hydrate buildups in oil and gas pipelines by using super-slippery liquid-impregnated surfaces. Having success in this area, we began thinking of other applications for the slippery surface technology, including everything from consumer goods packaging to anti-icing aircraft, preventing clogs in oil and gas pipelines, and medical applications.
Developing a framework for giving liquid-impregnated surfaces this slippery effect became a broad research project for my PhD. I decided to try to apply this surface design framework to a ketchup bottle. So, I found some food-safe materials and liquids that had the right properties according to the design framework and built the coating on the inside of a bottle, and it worked. We filmed the ketchup bottle video, entered LiquiGlide into the MIT 100K Entrepreneurship Competition and took home the Audience Choice Award. The ketchup bottle video went viral, and we quickly received more than 2,000 inquiries about our technology from across industries. That’s what helped us launch the company.
FE: Are some of your MIT researchers now working for LiquiGlide?
Smith: LiquiGlide now has a team of about 25 employees. We expect that number to grow to more than 35 by the end of 2015, and we’re always looking for top engineering talent to add to our team. As the primary inventor of LiquiGlide’s technology, I was the only one who decided to put my PhD on hold to start the company; the amount of interest was too great to delay the launch. The remainder of the research team chose to continue to pursue their PhDs at MIT.
FE: When did you receive your patent on this technology?
Smith: LiquiGlide has been granted two patents related to this technology, with more than a dozen pending. Our US8535779 patent for self-lubricating surfaces for food packaging and food processing equipment was granted in September 2013, and our US8574704 patent for liquid-impregnated surfaces was granted in November 2013.
FE: How do you formulate coatings for different industries?
Smith: The coatings are custom designed for every application—partly because the chemistry of each product is different, making it necessary to use different materials to get that slippery quality. Also, there are different requirements to meet. For example, all coatings used in food processing or food containers must be safe for human consumption. So, when we consider liquids and solids for these applications, we only look at food or food additives that are already FDA approved.
FE: Most packaging today is some form of plastic. Will this technology work with glass bottles?
Smith: Of course! LiquiGlide’s coating technology can be customized to work on just about any surface, including glass, plastic, steel and aluminum.
FE: Freeing up a product’s flow out of a package certainly has consumer merit, but what advantages does it have for package designers?
Smith: If product flows freely, package designers can experiment with new shapes and designs and not be inhibited by the prospect of product stuck in tight spaces. For instance, LiquiGlide could enable peanut butter companies to create clear, plastic squeeze bottle packaging shaped like a popular cartoon character, as opposed to being limited to a standard jar.
In the health and beauty arena, getting viscous skin creams out of packaging has been a barrier to cream density. LiquiGlide will erase this barrier, allowing skin cream manufacturers to roll out entirely new product lines in unique, eye-catching containers.
FE: Could this technology work on process vessels, tanks and pipes—keeping in mind that most vessels and pipes are cleaned automatically after a process is finished?
Smith: It’s possible, but soapy water can wash the liquid coating off the surface, and a couple of washes would probably remove it entirely. However, there are definitely many processing applications where we can replenish the liquid layer. Say, a processor is pumping a viscous product through a pipe, for example, mayonnaise. We could inject a tiny amount of the liquid at the inlet of the pipe ahead of the product, and that would be just enough to replenish any liquid that was lost in the cleaning process. So, in that sense, we can make the coating more “permanent” for processing applications.
FE: If product flows more freely, would the cleaning process be more effective or require less water and chemicals?
Smith: It could save a lot of cleaning and, therefore, reduce energy requirements. Also, a processor might be able to use smaller pumps to move viscous liquids through pipes or get away with using smaller pipes without any additional resistance.
FE: Are there other food and beverage applications where this material could be used?
Smith: Definitely. For many products, processors mix different ingredients in a giant vat or bin before they get dumped into something else or flow out the bottom. These larger vessels must be cleaned, and applying our coatings to them would save on that. Also, the processor would have a better yield because all the product comes out.
FE: What applications for this technology most interest food processors?
Smith: LiquiGlide eliminates wasted product by allowing all of it to easily slip through pipes and out of vessels. The potential energy efficiencies and corresponding savings are also interesting to food processors. LiquiGlide can reduce the energy needed to pump viscous liquids through tubes by up to 90 percent, resulting in significant savings. Food processing companies are also impressed by how LiquiGlide’s technology can reduce the frequency and intensity of cleaning cycles.
FE: What’s the future of this technology?
Smith: Food processing and consumer packaged goods are just the tip of the iceberg for LiquiGlide’s coating technology. We think the potential is limitless. What the wheel was to transportation, LiquiGlide is to liquids—it changes how they move. We can custom develop slippery surfaces for any viscous liquid for anything from better packaging for consumer goods to applications in aviation, oil and gas, and high-tech medical equipment. Currently, we’re predominantly working with consumer packaged goods companies and manufacturers as that’s where we have received the most initial interest, but we’re exploring strategic partnerships in many other fields.
For more information: www.liquiglide.com.