Shrink film, also called shrink wrap, is a material made up of polymer plastic film. When heat is applied, it shrinks tightly over whatever it is covering. Heat can be applied with a handheld heat gun, or the product and film can be passed through a heat tunnel on a conveyor. Choosing the right, Shrink Film, Shrink Seal Machine and or Heat Tunnel and combination of, is vital to obtaining quality shrink packaging on your products.
PVC Shrink Film
PVC Shrink film is widely used for a variety of applications
The PVC stands for Polyvinyl Chloride. PVC is the third most produced plastic in the world. PVC Shrink Wrap was the most commonly used shrink film, until the introduction several years ago of polyolefin (POF) shrink wrap. Common PVC shrink wrap uses include packaging boxes, CD and DVD packaging, software, small canisters and other non-edible items.
PVC shrink film also works very well with automated machines. Sealing strength, storage issues and sealing by products are of the most common drawbacks of PVC shrink wrap. The plasticiser 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 gas into the air and carbon deposits into the sealer. Proper ventilation is required when sealing PVC shrink wrap.
Polyolefin Shrink Film
Polyolefin shrink film has become the preferred choice by many for packaging products both edible and non-edible.
Polyolefin shrink wrap is widely preferred for a variety of reasons including: fewer odour’s when sealing, stronger seal and more flexible storage. Polyolefin shrink film does not contain any chlorine; therefore, they do not produce Hydrogen Chloride gas. Polyolefin shrink wrap does not have any plasticisers, so temperature variation in storage is not an issue.
Polyolefin shrink film is used for almost every kind of application including toys, sporting goods, printed wrap, foods, stationary and cards to name a few. Cost and machine compatibility are the main drawbacks of Polyolefin shrink wrap. Polyolefin is commonly more expensive than PVC shrink wrap. Many packagers prefer PVC because of this reason. There are types of polyolefin shrink wrap that are more compatible with machines but polyolefin machine compatibility can be an issue for some packagers.
If you want to know more about what shrink film and sealing machines would work best for your application get in touch with our friendly packaging technologists and we can assess the best options for your packaging operation.