Shrink Wrap
The most common industry-wide sealant materials used are PVC and polyolefin. These strong heat-resistant materials come in rolls, tubes and bags.
PVC (poly vinyl chloride) is the most common and cost-effective shrink wrap film available. It is durable and best suited for wrapping individual products. This film shrinks at low temperature and works well with heat guns. PVC has a greater puncture and tear resistance than polyolefin although it is more brittle and less elastic. It produces a strong odor when sealing and is not recommended for food applications.
Polyolefin is suitable for packaging food (It is FDA compliant for direct food contact.) and bundling multiple products. It is durable, elastic, and produces little odor during the sealing process. Polyolefin film shrinks at a higher temperatures than PVC and performs best with most one step shrink wrap machines, L-bar sealers and fully automatic shrink wrappers.
Film rolls usually come in two varieties: Single-wound is simply a single layer wound onto a spool; centerfold is a double layer folding method that allows wider shrink-wrap to be wound onto a given size spool. The shrink-wrap machine unfolds the material as it comes off the spool. Film rolls are used in straight-bar, L-bar, tunnel, heat gun, and mail bagging shrink systems.
Shrink tubing is shrink material folded and sealed down the longest open side, forming a tube. It also comes in small one-piece molded tubes used to cover wires, cables, and connectors. It usually comes on a roll and used in various shrink systems.
Shrink wrap bags can be two pieces of shrink wrap material placed together and sealed on three sides, a single piece folded and sealed on two sides to form a pouch or bag, or fully formed and ready for sealing with continuous band sealers. Bags are available in various gauges and used to package things like food, various powders, herbs, and beverages.
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