Stopper (plug)

A stopper, also known as a plug, is a device used to close an opening or orifice, typically in a container or pipe, to prevent the passage of fluids (liquids or gases), solids, or other substances. Stoppers are typically designed to fit snugly into the opening, creating a seal that restricts or prevents leakage.

Stoppers can be made from a variety of materials, depending on the application, including:

• Rubber: Offers good flexibility and sealing properties.
• Cork: A traditional material, particularly for bottles, providing a natural seal.
• Plastic: Can be molded into various shapes and offers resistance to many chemicals.
• Glass: Used in laboratory settings for its inertness.
• Metal: Provides a strong and durable seal, often with threads for tightening.
• Silicone: Offers excellent temperature resistance and flexibility.

The shape and design of a stopper vary depending on the opening it is intended to seal. Common shapes include cylindrical, conical, and flanged. Some stoppers have handles or loops for easy removal.

Stoppers are used in a wide range of applications, including:

• Bottles: To seal beverages, chemicals, and other liquids.
• Test tubes and flasks: In laboratories to prevent contamination and evaporation.
• Pipes: To temporarily or permanently block the flow of fluids.
• Sinks and bathtubs: To prevent water from draining.
• Ears (earplugs): To prevent noise or water from entering the ear canal.
• Fuel tanks: To seal the opening of fuel tanks in vehicles and machinery.