Glue is so good at sticking to things that it inevitably clings to the one place we need it the least: the inner wall of the bottle. But after more than 65 years holding school art projects together, one of the leading glue manufacturers has found a way out of this sticky situation. Elmer’s will coat the inside of their bottles with a new, super-slick coating that will ensure every last drop goes where you need it. The company recently signed an exclusive license with LiquiGlide, the makers of a magically slippery substance. But of course it's not magic — just some pretty amazing science.
Keeping it Slick
We use a wide variety of products that like to stick inside their containers, such as ketchup, hand lotion, toothpaste and maple syrup. These products are stubborn container clingers because they are Bingham plastics, or materials that behave like a solid but flow like a viscous fluid when force is applied. But even when you apply force, it’s still impossible to completely empty a glue container. That’s because liquids closest to a container’s wall adhere to it, while the liquid in the middle of the container flows more freely. The key, then, is to place a barrier between the container wall and its contents, allowing everything in the bottle to flow freely. LiquiGlide is a porous material that’s sprayed inside a container to form a thin layer between the container’s wall and its contents. From the side, this barrier looks like a line of undulating ridges. To make it slippery, a lubricating liquid is sprayed onto the porous material, and the liquid nestles into the open spaces between ridges. The ridges hold the lubrication in place so that liquids, like ketchup, can easily slide over the coating:
A World of Opportunity
The team have a higher purpose in mind for their product, apart from consumer applications. They want to coat pipelines with LiquiGlide to reduce the energy and cost needed to pump viscous material — like oil — to its destination. Here’s how oil flows on a sheet coated with LiquiGlide:
According to a 2009 Consumer Reports investigation, roughly 17 to 25 percent of skin lotion never leaves the bottle, making it the most felonious container-clinging product. But we also leave up to 10 percent of liquid detergent and condiments just hanging around. So, it seems, there are a lot of containers that could use a slippery upgrade. And for everyone who ever rolled, folded and smashed a toothpaste tube in a futile effort to get every last minty bit, there’s hope: easier-to-squeeze toothpaste may be coming in 2017, according to the New York Times. In the meantime, let that smooth, tingly feeling race down your spine as you watch toothpaste glide out of this bottle: