Nano method may enhance food packaging

By Jane Byrne

- Last updated on GMT

Related tags: Packaging

US researchers have found a way of keeping food fresher for longer while using less packaging material, claims an article in the journal Science.

The finding, according to the article, involves a nanotechnology-based technique to block the transport of damaging gases through a polymer, making it stronger while using less material.

Nanotechnology is a method of controlling matter at near-atomic scales to produce unique or enhanced materials, products and devices. With a different nanostructure, the gas and water vapour permeability of plastics can be engineered to preserve fruit, vegetables, beverages, wine and other food. With the use of nanoparticles, bottles and packaging can be made lighter and stronger, with better thermal performance and less gas absorption. These properties can extend the shelf life of products, as well as lower the transportation costs involved in shipping food.

Gas permeability

Scientists working at the Case Western Reserve University polymer research unit found that polyethylene oxide (PEO), when confined as nanolayers, crystallizes as a single layer, resembling very large, impermeable single crystals that reduce by 100 times the amount of gas permeability in polymer-based applications.

The team said that by using a new layer-multiplying co-extrusion process that takes two polymer melts and combines them as layers, multiplies the layers to four, and doubles that again as many times as desired, they discovered that a new structure emerges that is progressively thinner, thereby saving on material.

Anne Hiltner, lead author of the study and the Herbert Henry Dow professor of science and engineering at the university, claims this project is a step toward developing more flexible, optically transparent, ultra-high barrier polymers for several different applications.

Polymer coating

Meanwhile, a University of Warwick team, led by Dr Stefan Bon, claims a new process involving the layering of a polymer with silica-based nanoparticles has the potential to enhance the properties of pressure sensitive adhesive labels, water-borne coatings and biodegradable materials, claims a UK research team.

Bon told that the newly developed technology might be most applicable to multi-layered biodegradable packaging as it could gain more robustness and water barrier characteristics through the addition of a nanoparticle coating.

He said that the process would not be detrimental to the ‘green’ profile of these bio materials as the silica-based particles are derived from sand and clay.

“Our industrial partners including Unilever are very excited about this project and where it might lead.

“We would anticipate commercialisation of this new type of polymer in three to fours years, depending on the particular application,​” concluded Bon.

Source: Science Vol 323 No 5915Title: Confined Crystallization of Polyethylene Oxide in Nanolayer Assemblies​ DOI: 10.1126/science.1164601Authors: H. Wang; J.K. Keum; A. Hiltner; E. Baer; B Freeman; A. Rozanski; A. Galeski

Related topics: Processing & Packaging

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