A 2017 report issued by the National Fire Protection Association shows that more than 358,000 house fires occur in the U.S. every year. House fires account for 75% of all structure fires in this country. Unfortunately, they also result in more than 2,500 civilian deaths, 12,000 injuries, and $6.7 billion in damage.
A big problem contributing to the devastation of house fires are the very materials we use to build our houses. Timber is flammable. So are draperies, upholstered furniture, and so many other things found in the typical American home. Wallpaper is another problem, but maybe not be for long. Thanks to some great engineering at a pair of Chinese universities, we may eventually be using a wallpaper that is fire resistant while also acting as a fire alarm.
That’s right, a wallpaper that works as a fire alarm alongside smoke detectors. The technology used to make this inorganic paper is quite fascinating. Scientists have figured out a way to combine a number of composite materials to create a new kind of paper that does not burn; a paper with embedded electrodes that can sense the presence of fire and trigger an alarm.
Wallpaper Is Highly Flammable
Wallpaper has been in use around the world for hundreds of years. Unfortunately, not a lot has changed in terms of its construction. Wallpaper is typically made of highly flammable plant cellulose fibers. Not only do they burn easily, but they also promote the spread of fire. Replacing cellulose fibers with vinyl may reduce flammability somewhat, but vinyl materials still burn. And when they do, they release toxic chemicals that can contribute to death by smoke inhalation.
Chinese researchers wanted to do better. So they set about developing a process of creating an inorganic wallpaper made of glass fiber and hydroxyapatite nanowires. Both materials are highly fire resistant inasmuch as their combustion temperatures are extremely high.
Knowing that glass fiber and hydroxyapatite nanowires are fire resistant was just the start of making a fire-resistant wallpaper. Scientists had to figure how to combine the two materials to actually create a paper product. Ironically, they discovered that feeding the materials into a commercial paper making machine the same way cellulose fibers are fed did the trick.
Adding the Tiny Sensors
The final piece of the project puzzle was fixing the sensors necessary for fire alarm capabilities to the back of the paper. Rock West Composites, a Utah company specializing in both composite materials and prototypes, says that this kind of fabricating is often the most difficult challenge in coming up with new composite products. Companies often have to invent entirely new fabrication processes. Then they have to produce multiple prototypes to find something that works.
In China, the researchers eventually settled on a process of adding tiny sensors to the back of the paper using a drop casting process with a specially designed ink. The process allowed them to apply the sensors in a way that makes them invisible once the paper is on the wall. Under normal operating conditions, the sensors are also inactive. They only turn active when exposed to high heat.
Rock West Composites says these kinds of applications will become more commonplace in the future. As scientists learn more about the properties of things like carbon fiber and glass fiber, they are also figuring out new ways to use them. Thanks to some great research in China, we may be papering the homes of the future with a product that is both fire resistant and a pretty nifty fire alarm.