Chances are that you wouldn’t use ordinary plastic bubble wrap in a helmet, automobile body panel, airplane wing edge or computer case. However, those are some of the applications that are being suggested for a new type of bubble wrap – one that’s made from metal. It’s reportedly lighter and stronger than regular sheet metal, so don’t go expecting to pop it with your fingers.
Developed by Dr. Afsaneh Rabiei at North Carolina State University, the metallic bubble wrap is designed to provided added protection in areas that are only a few millimeters thick. As compared to a same-sized piece of ordinary metal, it’s said to be 20 to 30 percent lighter while offering 30 to 50 percent more bending strength. Its tensile strength is essentially the same.
Additionally, it’s more heat- and chemical-resistant than plastic or polymer materials.
Rabiei created it by first dotting a thin sheet of aluminum with tiny indentations, using a studded roller. A foaming agent was deposited in those indentations, and then another sheet of aluminum was laid over top of the first one. Next, a heavy roller was used to bond the two sheets together, trapping the foaming agent between them. Finally, everything was placed in a furnace. The heat caused the foaming agent to decompose and bubble, transforming the indentations into bubbles between the two layers of the aluminum sandwich.
According to the university, the process should be inexpensive to run on a commercial scale. Any type of sheet metal could be used as the base material, while substances such as calcium carbonate or titanium hydrate can be used as the foaming agent.
While other types of “metal foam” do already exist, the metallic bubble wrap is claimed to have a more uniform consistency, making its deformation behavior more predictable. Rabiei is now working on further refining the technology.
Source: North Carolina State University
