Nanotechnology improves gas barrier film properties
Researchers at Case Western Reserve University in Ohio, USA, have discovered a method of making plastics films less gas permeable by squeezing polymers into extremely thin layers, according to a report in the 6 February edition of Science.
By Mark Lewis
Posted 17 February 2009
Doug Leatherdale, Pira head of physical testing, said the research was “very interesting” but the substance would only bear applications if the cost of production was comparable to alternatives.
“For packaging the nearest thing would be a reasonably thin foil laminate, so it would need to be a similar cost or cheaper than that,” he said.
The research team found that squeezing thin layers of polyethylene oxide (PEO) between layers of polyethylene-co-acrylic acid (EEA), forces the PEO to form large crystalline plates, which are virtually gas impermeable.
The method is a modification of standard co-extrusion, but requires taking the extruded molten polymer and dividing it once more before recombining it – effectively doubling the number of layers. The more the process is repeated, the more impermeable the film becomes. Around 1,000 individual layers create a film about 25 microns thick, typical of common packaging films.
Leatherdale said making so many layers on an industrial scale was likely to prove challenging. “Of course, the film would also have to be heat sealable. But this is very interesting and we look forward to seeing how it develops,” he said.
[ Back ]