David Kilpatrick Managing Director Sota Packaging and Dr Philip Button from RMIT University were at the annual joint meeting, organised by Australian Institute of Packaging (AIP) and the Australian Institute of Food Sciences and Technology Incorporated (AIFST) held in Melbourne in early April. There, they presented information based on the needs of delegates slanted toward food packaging.

According to David Kilpatrick almost all of the traditional packaging containment vessels developed over time can now be replaced by composite cans.  He explained that composite materials are part of our daily lives, and gave many examples of sophisticated materials in highly technical and innovative products

"In composites, materials are combined in such a way as to enable us to make better use of their virtues while minimising to some extent the effects of their deficiencies", Stated Bryan Harris, from the Institute of Materials in UK. He explained that composite cans similarly combine different materials to produce a set of outcomes (environmental, functional and aesthetic) unachievable by any single material.

The process to make a composite can is either a convolute wound, spiral wound or linear draw formed rigid body. Several layers of materials, including recycled and virgin paper, foil and plastics in various combinations come together to form a composite can. One or both end closures are permanently affixed during manufacture. 

Convolute wound cans consist of a series of layers of differing materials wrapped laterally around a mandrel. This process involves wrapping on the diagonal, whilst the linear draw method of body making consists of pulling (drawing) the component materials in the machine direction. 

Mr Kilpatrick contended that a composite can is a cost effective, alternative to folding cartons, metal cans, glass jars, plastic containers and "bag in a box" packaging. Composite cans are used either for primary or secondary packaging but will be based on the required specific needs for customers in terms of light, moisture and oxygen barriers, aesthetic appeal, weight, strength and cost.

Development in substrates by other material users now flow to closure options for composite cans. A high profile example of the membrane top close is the Pringles crisps composite can. The major advantages of film/paper closures are cost, weight, ease of access, good tamper evidence and reduced environmental impact. 

Non-round cans can be closed using special seaming equipment and metal ends; but more usually incorporate paper bottom closures and film seal top closures in conjunction with an over cap. A number of attributes of non round cans were given and also displayed when a Glenfiddich wiskey can was passed around. Significant in the list was the advice of a 20 to 25% volumetric advantage over round cans.

A composite can has recently been approved by German authorities for packaging a range of beverages, including fruit juice, carbonated soft drink and even beer.

Current aluminium can filling lines only need simple modifications to process the cans as standard aluminium ring pull can tops (closures) are used. This newly introduced production system saves up to 30% costs. It is not only the cardboard which is cheaper than aluminium but also, transport and storage. 

Dr Philip Button PhD, a Research Officer in Food Technologies at the School of Business IT and Logistics RMIT University, came along to advise about developments in Nanotechnology which is one of the buzz words of the 21st century, with global research interest, and commercial applications booming in all fields of science and engineering.

Philip's presentation focused on polymer nanocomposites (PNC) that maybe able to address gas permeability issues associated with traditional polymeric packaging.  Regulars will recall that at the February meeting one of the posters on display was also from RMIT University and covered a development of graphene. Graphene has antibacterial properties which show great potential to improve food safety and quality.

Dr Button explained that in the food supply chain the advantages are in all disciplines, with the benefits of nanotechnology in food packaging to address concerns with existing plastic packaging:

• Interaction between the product and packaging material
• Disposal or recycling of the packaging material and the possible contamination of other waste
• The economic costs benefit analysis of existing plastic polymers a problem with existing plastic food packaging.

Positive attributes were covered in some detail, and a specific graphic showed the diffusion benefits of a nano treated material where water vapour is dispersed through the structure of the material somewhat like passing through a maze. Silver additives as a counter for E. coli is being replaced by graphene enhanced plastic packaging.

One would imagine that the first Phoenician that showed off glass or the ancient Egyptian that converted papyrus into paper had a lot of detractors. Such seems to be immediate future of nano technology in the packaging of food but Philip was upbeat about public attitudes.

Studies overseas indicate that consumers are more accepting of nano-technology than genetically modified food. The indications are that nanopolymers used in food packaging have not had any adversities either by consumers or regulators. 

Ralph Moyle on behalf of AIP and Dr Jenny Robinson on behalf of AIFST concluded the evening which included a small presentation to the speakers.