Shrink Film 101
Shrink Film 101: A Guide to Heat Shrink Film
Shrink Film- A material made up of polymer plastic film. When heat is applied it shrinks tightly over whatever it is covering. There are a variety of uses for Shrink wrap and shrink film. Some common uses of shrink wrap are for wrapping food, gift baskets, boxes, toys, books, soaps, etc. Below is a breakdown of the two most commonly used types of shrink wrap.
PVC Shrink Film- A type of shrink wrap used for a variety of applications. The PVC stands for Polyvinyl chloride. Polyvinyl chloride is the third most produced plastic in the world. PVC shrink wrap was the most commonly used shrink film, until replaced several years ago by polyolefin (POF) shrink wrap.
Common Uses of PVC Shrink Film- PVC shrink wrap uses include: packaging boxes, CD and DVD packaging, software, small canisters, and other non-edible items.
Drawbacks of PVC Shrink Film- Sealing Strength, storage issues, and sealing by-products are common drawbacks of PVC Shrink Wrap. The plasticizer in PVC Shrink wrap hardens in cold conditions and softens under hot conditions, therefore compromising the strength of the seal and the plastic. PVC shrink wrap also releases small quantities of hydrogen Chloride into the air and carbon deposits onto the sealer. Proper ventilation is required when sealing PVC shrink wrap.
Polyolefin Shrink Film - A type of shrink wrap that has become the preferred choice for packaging products both edible and non-edible. Polyolefin Shrink wrap is preferred for a variety of reasons including: fewer odors when sealed, stronger seal, and more flexible storage. Polyolefin shrink films do not have any chlorine; therefore they do not produce hydrogen chloride gas. Polyolefin shrink wrap does not have any plasticizers, so temperature is not an issue. Polyolefin can be stored in a wide range of temperatures and does not harden and soften in different environments like PVC shrink film.
Common Uses of Polyolefin Shrink Film- Polyolefin shrink film is used for almost every kind of application. Applications include: toys, sporting goods, printed wrap, foods, stationary and cards just to name a few.
Drawbacks of Polyolefin Shrink Film- Cost and machine compatibility are the two major drawbacks of Polyolefin shrink film. Polyolefin is commonly more expensive than PVC shrink wrap. Many packagers prefer PVC because of this reason. There are types of polyolefin shrink wraps that are more compatible with machines, but Polyolefin machine compatibility has been an issue of packagers.
Cross-Linked Polyolefin Shrink Film- Irradiation is applied to standard polyolefin shrink film to make the film stronger, and capable of better seal strength. Cross-linked shrink film is sterile and FDA approved for direct food contact. It offers excellent clarity to display packaged products. To view in further detail about the making and history of cross-linked shrink film view our blog post titled What is cross-linked shrink film.
Cross-linked shrink film also leaves less residue on sealers, promoting longer sealing blade or wire life. Cross-linked shrink film is made for use with high speed machines and high output operations.
Common Uses of Cross-Linked Polyolefin Shrink Film- Cross-linked shrink film is used with the same products as standard polyolefin shrink film. Cross-linked film is often used in high output operations. It can also be used for heavier products a standard polyolefin shrink film can not properly package.
Drawbacks of Cross-Linked Polyolefin Shrink Film- Cross-linked shrink film requires higher seal and shrink temps than a standard polyolefin shrink film. Higher temps can damage and deform products sensitive to heat. Higher seal and shrink temps. also require higher energy costs.