Saturday, October 23, 2010

Thinner films and more functional packages

Intelligent packages that satisfy many criteria in addition to supplying the necessary consumer information are on the advance – and not only where foods are concerned. The plastic film industry has therefore been hit much less hard by the 2009 economic crisis than other branches of the plastics industry.

It’s flexible packages, i.e. film packages, that are in particularly strong demand because of the low cost of materials and production and their broad range of applications. Because of their low weight, they help to conserve resources and also offer good scope for recycling. The use of flexible packages in the food and beverages industry and in the pharmaceutical and cosmetics industry is encouraged by the materials’ hygienic qualities and long shelf life. Further development with breathable films, microwave- and freezer-safe films, and biodegradable films is also spurring their growing use. Even today, plastic films meet about three quarters of global demand for flexible packages.

According to a study by the US Freedonia Group, global demand for flexible packages will rise by an average of about 3.5% per annum in the coming years from a good 16 million tonnes in 2008 to ultimately almost 19.5 million tonnes in 2013. The market researchers expect the fastest growth in the developing regions of Asia, Latin America, Eastern Europe and Africa as well as in the Middle East.

Industrial films usually 3-layer
Industrial film is the term usually given to those films that are employed, for example, as shrink film hoods, stretch films or as packaging for industrial goods; and films sold by the film producer to industry as raw stock for converting. Polyolefins are mainly used for the production of industrial films and principally grades of PE. The market today is dominated by 3-layer film composites. By combining two or three different types of polymer, it is often possible to save on material while enhancing functionality at the same time – an important factor for a production line’s cost-effectiveness.

Consumer packages defy the crisis
In the industrialized nations, the reasons for the increasing use of flexible food packages made of plastic can also be found above all in changing consumer habits. There is constant growth in the consumption of ready-to-serve meals, the range of foods is fast-expanding and, finally, the growing desire for an appealing package exterior is becoming increasingly important.

Film composites have become established for consumer packages and particularly food packages. 5-layer films are standard, and 7- and 9-layer composites are by no means rare today. Extrusion line manufacturers are giving the processor extra flexibility by enabling him to produce as many different products as possible on a single line without retooling, e.g. 3- and 5-layer films. With the latest die technologies, cast films with strong barrier properties can be produced in up to 27 layers.

In both cast and blown film lines, virtually all machine makers today use energy-saving and maintenance-free AC motors or, in some cases for reasons for space, direct drives instead of conventional motor-gearbox versions. Always a crucial element in the production of blown films is the blow head. Together with suitable film cooling and gauge control, it ensures a high extruder rate and film quality. Most recently, considerable advances have been made in film cooling with a variety of approaches. At K 2010 from 27 October to 3 November in Düsseldorf, the No. 1 for Plastics and Rubber Worldwide, many of these new developments will be on show.

Bio- and recycled materials conquer food packages
While grades of polyolefin combined with barrier materials such as polyamides and EVOH are usually employed on a blown film line for the production of food films, PET has long established itself as the “mass plastic” for cast films. The endeavors of many companies to efficiently recycle PET have come to fruition. One obstacle, however, continues to be the approval of grades of so-called rPET (recycled PET) for repeat use in direct contact with foods. Already established are many processes for the production of multi-layer film composites in which rPET is employed as the middle layer. Thanks to ongoing improvements in machine technology, rPET made of processed post-consumer PET wastes and ground bottles is now in use for food packages and for the packaging of deep-frozen ready-to-serve meals.

Across the board, biomaterials have been on the advance for some time now, but only recently in connection with food packages. For instance, carbon-neutral film products made of PE and from renewable resources have been attracting attention. The main reasons for the expanding use of biomaterials can be found above all in resource conservation, compostability and sustainability. However, a biodegradable material or a material based on biological raw materials is not necessarily greener and more sustainable than a conventional plastic. All the same, growing environmental awareness and the discussion of the pros and cons of various categories of materials have initiated a multitude of innovations to conserve resources.

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