by: Eric Finson and Stephen L. Kaplan

In almost every industry, the nature of a material's surface can drastically affect a product's success. The reasons can be quite different, varying from purely aesthetic to functional. This is particularly true for packaging applications. To the consumer at the point of purchase a package must appear attractive and clean as well as preserve its contents. Obtaining the appropriate balance of structural, aesthetic, and functional (barrier) properties often requires compounding specific additives into the bulk material or combining several separate materials into a composite structure. The type of specialty additives often used as bulk treatments may include but are not limited to antistats, antiblocks, slip modifiers, plasticizers, fillers, and stabilizers for UV, oxygen, and heat. The operations or procedures used to take various raw materials and fashion them into packaging structures is often referred to as "converting." A surface treatment is frequently employed as part of the conversion process to alter the surface characteristics of the specific material being used. Typical surface treatment processes include altering the wettability of a substrate, improving the bondability of an applied material or the elimination of accumulated static charge. Surface treatment technologies can play a key role in the preparation of surfaces of the most commonly used packaging substrates such as paper, plastic, foil, or metal/inorganic depositions for subsequent processing steps. In many cases, packaging producers are required to select specially formulated and expensive materials (eg, printing inks, adhesives, polymer films, or structures) to ensure satisfactory performance. The alternative to this scenario is to choose a material or combination of materials for their bulk properties and then modify their surfaces to achieve appropriate performance attributes. Surface treatments can allow the necessary modifications to packaging material surfaces without altering their bulk properties so that individual or multilaminate composite packaging structures can meet or exceed end use requirements.