Monday, May 17, 2010
Packaging material for foods that virtually blocks oxygen
A Tokyo University professor developed a film with high degree of sealing capacity using plant-derived substances alone in collaboration with Nippon Paper and Kao. He applied bionanofiber solution thinly on the surface of a 30 micro thick starch-derived polylactic acid film. Polylactic acid film without the application of bionanofiber easily allows oxygen to permeate and does not have enough strength. By applying a bionanofiber layer as thin as 0.8 micro on the polylactic surface, he successfully blocked oxygen as much as an existing packaging material made of oil. Fibers are usually in the state of a thick bundle in a plant. He created bionanofibers by dissecting out a bundle into nearly uniform ultrafine fibers, each of which is about 4 nanometers wide. It is possible to economize raw materials because each of the fiber is ultra fine, and polylactic acid can maintain transparency even if bionanofiber is applied on its surface. He plans to put this technology into practical use in a few years and use it for the display film of LCD TVs. He estimates that the price of the ultrafine fiber will be less than 500 yen per kilogram if pulps produced in the paper-forming process are used for the production.