Heat shrink wrap is any material that shrinks when heat is applied to it. One of the most common materials mistakenly called shrink wrap is stretch film. Stretch film is the material stretched around pallet loads of products to secure loads during transport. Stretch film is made from LLDPE which stands for Linear Low-Density Polyethylene. LLDPE is often a thinner plastic that offers superior stretch and puncture resistance. There are a variety of resin mixtures and additives available to change the performance of a LLDPE plastic for stretch film.
Heat shrink wrap is a completely different product made from different plastics. As explained above, heat shrink wrap is any material that shrinks when heat is applied. The most common shrink wrap plastics are: PVC, Polyolefin, and Polyethylene. See more detailed descriptions for each below.
PVC – PVC stands for Polyvinyl Chloride and for years was the preferred shrink wrapping plastic for retail sales. A PVC shrink wrap is crinkly prior to heat being applied. The consistency resembles cellophane prior to heat being applied. PVC has a very low required shrink temperature. After heat is applied it becomes hard and rigid.
It is a favorite shrink wrap for low output productions concerned about affordability. During sealing and heating PVC emits a strong odor due to the chloride. Proper ventilation is recommended for anyone using a PVC shrink wrap.
Polyolefin – The term polyolefin can refer to a polyethylene or polypropylene plastic. For use in shrink wrapping, polyolefin shrink film differs substantially in characteristics from polyethylene shrink film. Polyolefin shrink film is quickly overtaking PVC as the most commonly used shrink film for retail packaging.
Polyolefin shrink plastic offers several benefits over PVC shrink plastic. A polyolefin shrink film is more shelf stable than PVC shrink wrap. It also offers better seals and less residue after seals are made on high-speed machines. One of the major benefits of polyolefin shrink film is FDA approval for direct food contact. Due to the chloride in PVC shrink film, it is not approved for direct food contact.
Polyethylene – Polyethylene comes in multiple variations. It is the most common plastic in the world. For shrink wrapping, polyethylene shrink film is most commonly used for heavier wrapping applications. For retail sales, polyethylene is often used for packaging cases of water bottles and canned goods. Retail polyethylene shrink wrap offers an excellent stretch rate and puncture resistance. The most common thicknesses used for retail sales is a 2-3 mil thickness.
Another very common use for polyethylene shrink wrap is industrial applications. Polyethylene shrink wrap is used for winterizing boats and other products. Most industrial polyethylene shrink wrap comes in very large and thick rolls. Rolls often range from 8-20 ft. wide and thicknesses are available from 6-12 mils. Most industrial polyethylene shrink wrap comes with UV additives to prevent the film from breaking down during outdoor exposure.
If you have any further questions about shrink wrap plastics, give us a call at 1-800-441-5090 or shop for retail shrink wrap packaging online at www.uspackagingandwrapping.com.