A small world with a big future

Nanotechnology, the so-called 'science of the small', is one of the biggest industrial buzz words at the moment. This is not surprising really, considering that it is expected to create a global market of $1 trillion plus within 20 years. What is even more interesting, though, is that packaging materials constructed using nanotechnology are expected to be a large and important application.

But first, let's recap on the definition of nanotechnology, since there seems to be some confusion. Basically, it involves products that use the nanoscopic properties of materials where dimensions are less than 100 manometers. The nanoscale is far from the smallest unit of measurement but it is the smallest one at which matter can be manipulated: as a reference point, a nanometer is one billionth of a metre and a human hair is about 50,000 manometers wide.

In theory at least, nanotechnology has a lot going for it in terms of improving the performance of packaging materials. It can increase strength, durability and flexibility, so that less material is required, and manufacturing and transportation costs can be cut.

It can also enhance barrier performance, and can help improve the shelf life of products. For example, Bayer produces a transparent plastics film called Durethan containing nanoparticles of clay. These are dispersed throughout the plastics and are able to block oxygen, carbon dioxide and moisture from reaching the package's contents.

However, by far the most promising benefit of nanotechnology is thought to be active or smart packaging, whereby the nanoparticles respond to environmental conditions, or give an alert if the packaged food becomes contaminated. For example, it is possible to use the changing molecular composition of milk that is beginning to spoil to bring about a reaction with nanoparticles embedded in the packaging that will cause the colour of the packaging to change.

Another potential application is to use a bioswitch developed through nanotechnology to address outside environmental factors such as temperature or humidity. As an example, an ice cream carton could tighten its molecular structure to prevent heat from affecting the contents on a hot summer day. Dutch researchers are working on going even further, in that the packaging will not only be able to sense when food is beginning to spoil, but will release a preservative to extend its life.

Environmental

Other nanotechnology benefits include improved recyclability, giving packaging greener credentials, and increased security. In other words, creating materials that are hard to duplicate as well as providing tools for tracking or authenticating goods. For instance, it has been reported that Oxonica has undertaken trials with several US based packaging companies using its nano bar codes for authentication, and track and trace. The product is supplied as a powder and can be added to liquid or surface coatings.

Indeed, the use of nanotechnology is growing. There were less than 40 nanopackaging products in the market in 2002 which were worth around $150M. The value rose to $860M in 2004, while in 2005 it is estimated that there were some 250 products in the market. Even so, this is tiny considering the overall size of the world's packaging market.

So why is this? One reason is that nanotechnology raises a number of technical challenges, particularly the scaling up from lab to industrial scale. Although there are a large variety of nanoparticles available and there is no shortage of companies that have the ability to make the particles required, there need to be efficient ways to disperse them in commercial production.

It also requires collaboration between the different organizations involved, which is somewhat of a new concept for an industry that is highly competitive and consequently has the tendency to be very secretive.

Another reason could be the general public's concern. Indeed, it is generally recognized that there is a need to regulate, standardize, classify and risk manage the technology, if only to avoid a repeat performance of the handling of genetically modified organisms used in agriculture.

This in turn raises questions about the adequacy of current legislation. For exapmple, the UK and Germany have started studies and risk assessments into how to oversee the sector properly, while the Food and Drug Administration in the United States is evaluating the effectiveness of its regulatory approaches and authorities to meet the potential challenges presented by the use of nanomaterials in FDA regulated products. It expects to issue its findings in July of this year.

Making nano power work

Either way, it is obvious that nanotechnology cannot be ignored: it has been predicted that it will affect 25 per cent of the food packaging business in the next decade, equalling annual sales of more than $30 billion, and that active packaging will be a €2.2 billion market by 2012. As a result, research and development continue to thrive.

One of the largest European projects is Sustainpack. This is a four-year research programme with a budget of e36M, partly provided by the EU's Sixth Framework Research Programme. The project team consists of 35 partners representing packaging research associations, academia and industry. Its purpose is to establish fibre based packaging as the dominant player in the packaging area within a decade by applying nanotechnolgy solutions.

Although most of the large material manufacturers are keeping their activities quiet, it is understood that Kraft, Bayer and Kodak, amongst others, have R&D projects that involve applying nanoscience to packaging. Much of the work concerns development of smart packaging materials that will keep food fresh, and detect food pathogens such as salmonella and e.coli. Similar technology is also being developed for the US Government as a means of detecting possible terrorist attacks on the US food supply.

However, when it comes to actual applications, or at least ones which have been officially announced, these seem to be few and far between. One exception is the embedding of nanocrystals in plastics. Essentially, this creates a maze from which oxygen molecules find it difficult to escape. It is being used in the manufacture of plastics beer bottles, the benefit being that plastics is cheaper to transport than glass, but up until now it has not been possible to use plastics due to spoilage and flavour problems.

It is understood that Nanocor, a subsidiary of Amcol International, has developed nanocomposites that give the beer a six month shelf life, and the company and Southern Clay Products are now working on extending the shelf life to 18 months. It is also understood that several large beer makers, including South Korea's Hite Brewery and Miller Brewing, are using the technology.

Nancor has also been working closely with Nanopolymer Composite, which last year announced the full scale commercial production of nano-PA6 resins at its newly completed production facility in Tainan, Taiwan. The resins are designed for engineering and flexible film packaging applications and are sold under the Cress-Alon trademark. They are distributed worldwide exclusively by Cresset Powers, which claims that its Cress-Alon nano-PA6 is the first fully commercialized nanoplastics.

Another interesting development has been announced by Belgian based TopChim. It has signed an agreement with Mondi Business Paper to supply its NanoTope nano-hybrid technology to develop and produce coatings for colour laser printing paper that combine the gloss and smooth surface feel of a coated paper with the high whiteness and stiffness expected of a quality uncoated paper.

What makes this move interesting is that not only is this the first time that its nano-hybrid technology is being used in paper production, but also that TopChim's objective is to introduce it in a variety of surface performance applications, including barrier coatings for packaging.

Then there is the programme that is being undertaken by Chinese based Dragon International. In conjunction with its plans to build a new manufacturing facility for producing high isolation, alto-extruded multilayer film and packaging material, Shanghai Jinkui Packaging Material Co, a wholly owned subsidiary of Dragon International, has announced two packaging materials which use nanotechnology. Claimed to have the potential to replace materials such as PVdC and PVC for the pharmaceutical market, these materials are said to offer improved barrier performance and have 'green' advantages, not only in terms of lower waste emissions during manufacturing, but also recyclability.

So, it does look as if the business case for using nanotechnology in packaging materials is growing in strength. Maybe it won't become a major force for a few years to come, but there's no doubt that this small world is going to have a big impact on packaging materials in the future.

“These examples show the use of nanotechnology in packaging as part of a more attractive product, rather than improving packaging materials on their own. Cenamps' remit to work with scientists and industry to link technology to commercial needs and demands applies to all industries. We would certainly be delighted to engage with the packaging industry to offer our insight and advice as to what nanotechnology can offer this sector.”