No more broken phone screens: New see-through film stronger than aluminum

April 1 (UPI) -- For those in the business of phone repair, researchers in England have some bad news.

Thanks to a new transparent polythene film, shattered phone screens "could be a thing of the past," according to Ton Peijs, professor at the University of Warwick.

Peijs and research partner Cees Bastiaansen, a professor at Queen Mary University of London, developed a new technique for creating the see-through film.

Material engineers have developed impressive high-strength films, including the hot-drawing of high-density polyethylene, HDPE. While these films can compete with the strength of industrial materials, including metals, they're not very transparent, making them poor replacements for glass.

"The microstructure of polymers before drawing very much resembles that of a bowl of cooked spaghetti or noodles, while after stretching or drawing the molecules become aligned in a way similar to that of uncooked spaghetti, meaning that they can carry more load," Yunyin Lin, a PhD student with Peijs and Bastiaansen, said in a news release.

Meanwhile, the most popular transparent plastic replacements for glass, such as polycarbonate, are quite weak.

Peijs and Bastiaansen found they could create polythene films that are see-through and high-strength by fine tuning the drawing temperature.

In the lab, researchers drew out HDPE polythene sheets at a range of temperatures. Scientists found the best balance between strength and transparency was achieved when drawing the sheets between 195 and 230 degrees Fahrenheit.

"We expect greater polymer chain mobility at these high drawing temperatures to be responsible for creating fewer defects in the drawn films, resulting in less light scattering by defects and therefore a higher clarity," Peijs said.

Tests showed the resulting films were 10 times stronger than conventional see-through films. The new transparent polythene film boosted a great maximum tensile strength to that of space grade aluminum. The films are extremely light in weight, making them ideal for uses in small electronics and as an added coating on windshields.

Scientists described their new hot-draw process this week in the journal Polymer.