The Complete Handbook of Impulse Sealers

Chapter 1: Understanding Impulse Sealers

Every time you buy a loaf of bread in a sealed bag, open a new memory foam pillow, or handle a package of sterilized medical instruments, you are relying on a machine you have probably never noticed. It is the impulse sealer, a device so ubiquitous and so simple that it is often taken for granted. But "simple" is not the same as "trivial." Understanding precisely how an impulse sealer works—its physics, its materials, and its limitations—will directly translate into better seals, fewer rejected products, and lower repair costs for years to come.

At its core, an impulse sealer is a device that welds two layers of thermoplastic film together. It does this with a short, powerful burst of electricity, which heats a wire (or ribbon) until it is hot enough to fuse the film, and then lets that wire cool down before the seal is released. This is the critical difference between an impulse sealer and a constant heat sealer. A constant heat sealer keeps its sealing bar hot all the time, maintaining a steady temperature. An impulse sealer, as its name implies, pulses its heat. The wire is almost at room temperature when the machine is idle, and it reaches its sealing temperature only during the fraction of a second that the current is applied. This might sound like a fine technical distinction, but it is the reason why impulse sealers are preferred for a majority of packaging applications, especially for materials that