Packaging is mainly for the protection or preservation of contents—from physical damage or contamination and may experience wide variations in temperature from manufacturer to end user. Increasingly, it is designed to open easily by peeling rather than tearing. However, when peelable seals are bonded too strongly, elements can break off, the packaging can fail unpredictably or not open fully.
For fixing one thing to another, adhesive strength (or resistance) is usually what matters most. Some things must not peel apart, such as copper tracks on circuit boards. For others, such as labels, tapes, coatings, inks, laminated cards, or transdermal drug-delivery patches, consistent retention or removal by peeling can both be equally important. In many cases, peelable elements also carry important information that must not be destroyed or lost.
Aside from the direct cost of wastage from failure, seal and adhesive performance is part of a company’s brand, and reflects on perceived product quality and reliability. Peel testing is therefore a vital element in quality assurance at the production line level, as well as in the design of new packaging and closure methods. As packaging design changes in response to environmental concerns, containers need to be stronger whilst using less materials. And with an ageing population, many consumables, including medical items, need to be accessible to the less strong and dexterous. Peel strength really matters.