Barrier of flexible packaging films

A critical function of packaging is to protect the product. This often requires the inclusion of special barrier layers or coatings within a multilayer structure to manage gas and liquid permeation, provide oil and grease resistance, prevent loss or impartation of organic molecules affecting taste and aroma, and block light. This chapter examines the importance of barrier packaging, especially with respect to food packaging, describes methods for measuring barrier performance, and provides typical permeation properties of commonly used barrier materials. The science of permeation is reviewed with an emphasis on factors that control permeation in flexible packaging. The chapter concludes with a critical assessment of four emerging technologies: oxygen scavenging, layer multiplier technology, barrier nanocomposites and advanced coatings.