Stretch film is wrapped tightly around pallet loads, packages, or objects to secure them together or keep them protected. Shrink wrap, on the other hand, is applied by first covering the item loosely; heat is then used on the shrink wrap, causing it to shrink tightly around the package.

The type of sealer used depends on the polymer material being sealed, its thickness, and desired production levels. Heat-sealed packaging is quick, efficient, and perfect for high-speed operations. It also provides all-around coverage and complete enclosure of individual or multi-product packs.

Seal jaw pressure is perfected when machines are built, but worn parts or misaligned jaws can affect it over time. As a test, put a white piece of paper in the seal area and engage the jaws to lower and seal.