Packaging barrier

In addition to these applications in the food industry which are first and foremost a result of the improved barrier properties, there are other applications in the consumer sector in which the aesthetic value of products is enhanced by use of metallized films. A typical example is the use of metallized paper for drinks bottles. Numerous brands of bottled beer are promoted by use of metallized paper labels. This design of the bottle primarily serves the purpose of producing an eye-catching effect to capture consumers attention the bottles on the shelf are designed to stand out from other beers and give the impression of a superior and more precious product. This is also the reason for using metallic elements on brochures and promotional materials. 

Another application of metallized films for design purposes is the generation of metallic effects (car paneling, mobile phones, furniture, architecture, gift wrapping) which can be produced economically and without significant additional weight. The benefits of the synthetic material, for example durability and flexibility, are also maintained. 

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Jenkins, S. D., PET/PEN copolymers and blends for hot-fill and high barrier packaging applications, presentation given at the Specialty Polyesters 95 Conference, Brussels, June 27-28, 1995, Schotland Business Research Inc., Skillman, NJ, 1995. 

Weeren, R. V, and Gibboni, D. J., Barrier packaging as an integral part of drug delivery, available http //www.drugdeliverytech.com/cgi-bin/articles=52 (accessed June 1,2007). 

Laoubi S. Feigenbaum A and Vergnaud J M, 1995, Safety of Recycled Plastics for Food Contact Materials Testing to Define a Functional Barrier. Packaging Technology and Science 8,17-27. 

Catheters, probes, cardiovascular grafts, heart patches, ligaments for knees, sutures, blood filters, tubings, dental floss, barrier packaging films for drugs... 

As a consequence, three principally different situations for a functional barrier packaging system can be assumed as depicted in Fig. 9.2. The corresponding kinetic migration characteristics are outlined in Fig. 9.3 which categorises the kinetic migration behaviour possibilities for a migrant at time t = 0 (for instance the time of package fill) into three typical cases ... 

Fig. 9.2 Possible levels of contamination of functional barrier packaging structures at time of package fill (t = 0).

Fag time The time that a substance needs under given conditions to cross a functional barrier package construction and to reach the food contact surface. The migration kinetics of a functional barrier system are in general characterised by an initial time lag phase. 

Sample 1 - oxygen barrier packaging used for lidding films for meat and... 

However, replacement strategies are not straightforward with compromises on either performance and cost having to be addressed. An excellent example of this centres around the chlorine issue. Chlorine imparts a unique set of properties to addition polymers, such as the ability to crystallise on film formation. Vinylidene chloride copolymers have exeellent gas, odour and moisture barrier properties impossible to achieve from non-chlorinated waterborne film forming materials. In the barrier packaging area it has a unique position, with proposed replacements being unable to fully match its overall... 

The cheese from each mini-vat provided 7 to 8 lbs of sample, and after pressing each lot was split before barrier-packaging under vacuum so that two ripening temperature regimes could be evaluated (i.e., continuous 10°C, and 21°C for 21 days followed by continuous 10°C, through 4 months). The Cheddar cheeses were typical in average moisture (37.5%), salt (1.7%), fat (31.5%), and pH (5.10) levels even though they were manufactured on a miniature scale compared to commercial-scale batch operations. 

In barrier packaging, it is generally accepted that orientation of the barrier resin reduces its gas permeability. Most of the published data, however, corresponds to low barrier resins. No supporting data exists yet for either high or intermediate barrier resins. To fill that void, the orientability and the sensitivity of oxygen permeability to orientation for six competitive oxygen barrier resins were evaluated. The barrier resins evaluated in this investigation include an experimental... 

The preceding data, therefore, clearly show that package/product interaction in high gas barrier packages may... 

Extruded ethylene vinyl alcohol copolymer (EVAL) is used as an oxygen-barrier packaging material. Dry EVAL has extremely low oxygen permeability, but the vinyl alcohol part of the copolymer is hydrophilic, and in the swollen wet state its permeability becomes higher than that of PVDC (Fig. 11.5). 

Small amounts of synthetic zeolites (based on metal aluminosilicates) can be added to the system to adsorb unwanted organic odour-producing molecules and/or to remove the moisture that contributes to odours (by trapping them in their highly porous crystal structures). This technique is successfully used in extruded polyolefin pipes, injection and extrusion blow-moulded containers, barrier packaging materials, extrusion coatings, and sealant polymers. 

In addition, PA6 is a well-established plastic in barrier packaging, providing a barrier to oxygen and aromas as well as to microbials, and is used in food and medical packaging applications. New generation PA6 films with silicate nanoparticles with improved barrier properties are introduced to compete with the conventional barrier EVOH copolymer films. 

LCPs provide many important advantages to meet the needs of high barrier packaging, including ... 

Table 4 shows how th<-se advantages compare with other materials used in high barrier packaging. 

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