Specifications Packaging Materials

Volatile Compounds Identified in Specific Packaging Materials... 

Select package materials. Together with mechanical properties, permeability values for Oj, COj, Nj, HjO and organic vapors, as applicable, should be used to determine the best performance/cost ratio for specific package materials. Tables and charts of permeability values can help the packaging professional in the selection. A word of caution most values of P are approximate values and there is no substitute for the experimentally determined value of P. 

Great care is needed in the design of autoclaves and sterilization cycles because of the requirement for the presence of moisture. The autoclave must be loaded to allow complete steam penetration to occur in all parts of the load before timing of the sterilization cycle commences. The time required for complete penetration, the so-called heat-up time, varies with different autoclave constmction and different types of loads and packaging materials. The time may not exceed specific limits in order to guarantee reproducibility and, for porous loads, saturated steam. The volume of each container has a considerable effect on the heatup time whenever fluids are sterilized. Thermocouples led into the chamber through a special connector are often employed to determine heatup times and peak temperatures. The pressure is refleved at the end of each sterilization cycle. Either vented containers must be used or... 

Storage time by itself is not expected to affect the maintenance of stetiHty. However, longer storage times may increase the incidence of potentially harmful conditions. Frequent handling, wetness, and possible deterioration of the packaging material are typical examples of conditions that may compromise stetiHty and limit the shelf life of a package. The package contents may have a specific shelf life as weU. 

Vinyl compares favorably to other packaging materials. In 1992, a lifecycle assessment comparison of specific packages made from glass, paperboard, paper, and selected plastics concluded that vinyl was the material that has the lowest production energy and carbon dioxide emissions, as well as the lowest fossil fuel and raw material requirements of the plastics studied (169). Vinyl saves more than 34 million Btu per 1000 pounds manufactured compared to the highest energy-consuming plastic (170). 

As with textiles the principal reasons for the coloring paper are for aesthetic appearance and utihtarian purposes. Aesthetic appearance includes colored background for printed material, colored writing papers, colored household products to harmonize with interior decor, and many other diverse uses dictated by individual tastes. Utihtarian purposes include identification of multicopy forms, identification of manufacturer or marketer of specific materials or products, opaqueness or hiding power of packaged material, or to control consistency of paper manufactured from various colored raw materials. 

Biaxially stretched film has proved of value as a packaging material. Specific uses include blister packaging, snap-on lids, overwrapping, envelope windows and de luxe paekaging. 

Common packaging materials are a potential source of aggressive substance s, and careful selection is recommended to avoid surface deterioration. Where paper is in contact with aluminium, the chloride content should be below 0-05 7o, sulphate content below 0-25 7o, copper content below 0-01% and the pH of aqueous extracts in the range pH 5-5-7-5, in order to avoid corrosion in damp conditions. Papers and felts used in building applications should also conform to this specification as a minimum requirement and be of the highest quality, since metallic copper found in materials of inferior origin can result in severe local galvanic attack of aluminium. 

Plastics can also be combined with other materials such as aluminum, steel, and wood to provide specific properties. Examples include PVC/wood window frames and plastic/ aluminum-foil packaging material. All combinations require that certain aspects of compatibility such as processing temperature and linear coefficient of thermal expansion or contraction exist. 

This paper organizes some of the how and why of flexible package-food product interactions by discussing a few specific examples of food packaging development, as well as some overall factors of packaging material application. 

The American Society for Testing and Materials (ASTM) has many test procedures for the characterization of packaging materials. These methods are available individually or in specific books of ASTM standards. A list of typical tests may be found in Table 15. 

In addition to the various advice included in the development pharmaceutics guidelines there is also a specific guideline on plastic primary packaging materials (3AQ10a, adopted February 1994), which describes general requirements for all plastic containers but pays particular attention to those for parenteral and ophthalmic use. 

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