Closure (container)

A closure is a device used to close or seal a container such as a bottle, jug, jar, tube, or can.

Many containers and packages require a means of closing, which can be a separate device or seal or sometimes an integral latch or lock.

Secondary seals are common with sensitive products that may deteriorate or where extra security is needed.

Additionally, many closures feature ventilation to prevent bloating, collapse or explosion due to unequalized pressure during processing or storage.

These elements are preferred due to their ability to withstand temperatures of 260 °C and water intrusion pressure levels of 770 mbar.

For example, a mason jar often has a lid with a built in rubbery seal and a separate threaded ring or band.

Pour spouts, triggers, sprayer cap, measuring attachments, sifting devices, etc.

The narrow necks of ancient amphora were closed with a plug of cork, wood, or ceramic and sealed with mortar.

Some early tinplate cans were made with threaded necks for screw top closures.

These involved heavy wire bail attached to a bottle's neck that swung over the cork to hold it in.

The world's first modern bottle cap, the crown cork, was invented by William Painter in 1890 in Baltimore.

The International Society of Beverage Technologists (ISBT) is the main trade association for closure manufacturers.