A heat sealer is a device used to seal plastic bags or packaging by applying heat to create a secure bond. It works by melting the edges of the plastic, which then cools and solidifies, forming a tight seal. Heat sealers are commonly used in food packaging, medical supplies, and various industrial applications. There are different types of heat sealers, including impulse sealers and continuous sealers. Impulse sealers heat only when the sealing bar is pressed down, while continuous sealers create a seal as the material moves through the machine. Both types help ensure products remain fresh and protected from contamination.