Etymology

The word hermetic comes from the name of the Greek god Hermes, via the vocabulary of alchemy. The alchemists invented a process for making a glass tube airtight, which was used in distillation. The process used a secret seal whose invention was attributed to the legendary patron of alchemy, Hermes… Read More

Hermetic Packaging

Several types of packaging need to maintain a seal against flow of gases: foods, pharmaceuticals, several chemicals and some consumer goods. The term can be used to describe the food preservation practices such as vacuum packing and canning. Barrier packaging includes containers such as glass, aluminum cans, metal foils, and… Read More

Types of Glass-to-Metal Hermetic Seals

When the glass and the metal being hermetically sealed have the same coefficient of thermal expansion, a "matched seal" derives its strength from bond between the glass and the metal's oxide. This type of glass-to-metal hermetic seal is the weaker of the two types and is generally used for low-intensity… Read More