1.
Introduction
The primary focus of this course is the study of the relationship between the storage life of packaged products (as it relates to the gain or loss of permeants such as water vapor, oxygen, odors, flavors, etc.) and the barrier characteristics (especially permeability) of sealed packages in various environments. However, before we delve into these concepts in depth, let's do a little refreshing on the functions of packages, and some related matters.
1.1
Packaging Functions
Basic Functions of a Package Different people categorize packaging functions in different ways, as you've probably noticed. One of the most common divisions is the following: 1. Containment
Containment is physically separating the product from the environment. This has been one of the most important roles of packaging, going back well prior to the beginning of history. We may recall, for example, amphoras and other ancient containers for oil, wine, and many other products. However, not all objects that fulfill the role of containment are thought of as packages. For example, a cup contains coffee but is not usually considered a package. In many cases, for packaging of food and other sensitive products, we imply that we separate the product completely from the environment. Can you think of some exceptions? 2. Protection
Often the packaging provides some type of protection for the product from various types of environmental exposures. Some common examples:
Mass barrier: protection against and/or control of mass transfer (diffusion of molecules) Sterile barrier: protection against entry of microorganisms. Electromagnetic radiation barrier: In food products we often need protection from radiation of particular wave lengths, e.g. UV radiation that promotes oxidation. Physical impacts: During transportation and storage, the product may need protection because
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It may be fragile Physical damage may shorten shelf life of and/or reduce acceptability. (For example, with fruits & vegetables, shelf life may be reduced because active enzymes are released from cells in response to damage. It is difficult to correlate
damage from transportation to shelf life for such products, as models and general correlations are not often available in the literature.) 3. Utility time utility, place utility: squeezable features, closures, of time and place
Utility is often described in marketing texts as having three components: utility, and form utility. It is easy to think of packaging examples of form bottles, upside down containers for condiments or shampoo, dispensing reclosures, etc. It is a little more difficult to think of packaging examples utility. Can you cite any?
Packaging texts often describe this function as convenience or functionality. It consists of those features that facilitate use, reuse, dispensing, storage, portability, etc. Packaging people think of modifications that facilitate filling, sealing, handling, storage, and distribution in this category. Often the utility is value added and consumers are willing to pay extra for it. Do child resistance and tamper evidence features belong in this category? Keep in mind that utility may not be for the benefit of the ultimate consumer; it may instead be focused elsewhere along the supply chain. Do the horribly-hard-to-open blister packages for items such as personal CD players provide utility? 4. Communication
Packages often need to convey a variety of types of information about the product, including:
product identification/manufacturer consumer information regulations directions on how to store or use the product
An important issue here is legibility, since the user should not have to guess what information is displayed on the package. Poor legibility may be caused by poor design, bad printing or poor handling. Remember also that communication is not limited to printing text. Shape and color can often provide important messages about the product identity, etc. Have you ever been in the grocery store and remembered the general appearance of the brand of a particular product you were looking for, but not remembered its name? Or have you ever been unable to find your favorite brand because the package changed? (Manufacturers hate it when that happens!)
