Many packaging types require sealing by heat. That sounds simple enough, but the choices and variety of heat-sealed packages are vast. In this article, we’ll get an overview of nine of the most important things to consider when planning heat-sealed packaging.
- Configuring the Ideal Seal
There are a multitude of parameters to consider when selecting a type of heatseal. Heavy-duty seals tend not to be produceable at the same speeds of more minor seals. There’s a classic trade-off between seal durability, cost, and production speed. Below is a list of ideas and relationships to think about:
- What shape do you need? Wide, narrow, or custom? Just seal or seal with a cut?
- Do you need a heavy-duty seal for something like a pressurised item, or will a minor seal do the trick?
- How important is appearance? This factors into that trade-off we mentioned earlier.
- Choosing a Band for Your Heatseal
The heatseal band is the component that communicates the heat into the packaging material. Depending on the film material, thickness, and other requirements, you’ll want to choose the right band. It has to be thick and wide enough to accommodate the film, but not too much. The band has to deliver enough heat in the least amount of time to create the seal, but too much heat will prolong cooling time, which in turn slows down production.
- Choosing a Modality
There are two main modalities for applying heat: impulse and constant heat. In impulse heating, the system is synchronized so that the jaw heats up at the right time, delivers the energy into the film, and remains clenched for a brief period during the cooling phase. This method leans towards strong seals with attractive appearances. Constant heat, where energy input is adjusted to maintain a constant temperature in the band, is usually used for production rates above 50 ppm.