Used primarily to secure the contents of pallets prior to transportation and storage, the chemical discovery that led to stretch film is nearly 100 years old. The plastic film is also used in packaging, protecting smaller items during shipping.
Chemical Composition: Linear Low-Density Polyethylene
Stretch wrap is manufactured from linear low-density polyethylene and should not be confused with shrink wrap, which is a slightly different version of the low density polyethylene, possessing different stretch properties and having heat-activated shrink characteristics. The low-density polyethylene is extremely resistant to chemical reactions with many common substances, increasing its attractiveness for use in storage applications.
Multi-Industry Useful Properties
It is widely used in North American manufacturing, construction and warehousing. Being puncture resistant, providing shielding from ultraviolet light and being non-reactive with many corrosive compounds are factors that make stretch wrap an ideal choice for use with pallet loads that can be exposed to the harsh storage environments in warehouses and at construction sites.
Film Characteristics from Manufacturing Process
Stretch wrap comes in different grades of thicknesses having a range of between 37 gauge and a max film gauge of 150. There are two primary stretch film manufacturing techniques that result in different tear-resistant and load-securing properties.
- Blown Stretch Process
Blown stretch wrap is created using the blow extrusion manufacturing process. This technique creates a high quality wrap possessing strong resistance to tears. It also has “memory” properties that maintain its cohesiveness of the load it is used to secure.
- Cast Stretch Process
Cast stretch wrap is created by the cast extrusion process. It is less expensive than its blown stretch counterpart. However, it does not posses the tear resistance or securing properties of the blown process films.
Hybrid film is a newer cost efficient variety of the wrap that is manufactured using a process that replaces petroleum with very strong resins. Its layered construction gives the wrap comparable strength to standard stretch wrap for securing loads up to 1800 pounds.
There are other specialized types of stretch film such as the opaque variety, that is used in environments requiring extra protection to the sun’s ultraviolet rays. Micron film provides the benefits of both standard stretch wrap and hybrid film. It is manufactured using a layered process making it resistant to tears and having cohesion properties comparable to regular stretch wrap.
Stretch film is widely used in manufacturing for shipment packaging and pallet wrapping applications. The wrap’s strength and resistance to tears is determined by the manufacturing process used in its creation. North American estimates place the market for the wrap at approximately $3 billion. Demand for new applications drives innovations in manufacturing processes creating specialized versions of the film. You may be interested in the Malpack Ltd website if you would like more information.