Interesting Facts About Shrink Wrap

Modern forms of packaging are designed to be quick and easy to apply, protective and relatively inexpensive. While boxes, cartons and cans have a long history of use as packaging, current safety standards require a tamper-resistant overwrap that can keep products clean, dry and stable. A good example of such an overwrap is shrink wrap.

What is It Made Of?

Shrink wrap is made of polymer film. Many manufacturers use the plastic film to package their products. It is useful for display and protection. The material is used to cover everything from lollipops to whole buildings.

The most interesting characteristic of the film is its ability to shrink when heated. During the manufacturing process, the molecules of the film are aligned randomly and tend to be tangled. Heating and stretching the film causes the molecules to straighten and align in the direction of the stretch. TheĀ shrink label film is then cooled to keep the molecules in alignment. The molecules shrink back to their original tangled state when heat is reapplied for the wrapping process.

Once applied over a product, the wrap must be heated with an instrument called a heat gun in order for it to shrink and form a seal. Products are sometimes placed in a shrink tunnel or oven to complete the wrapping. The film must reach at least 300 degrees Fahrenheit to shrink properly.

Two Types of Shrink Wrap

There are two common types of the plastic film. They are polyolefin and polyvinyl chloride.

Polyolefin film is the variety that used by manufacturers of non-edible and edible products. The qualities that make it desirable for this application are its high-flexibility, capacity for forming strong seals and the fact that it is odor-free. Polyolefin film is resistant to an extreme range of temperatures and does not soften or harden. It is commonly used for wrapping food, printed material, sporting equipment and toys.

Polyvinyl chloride shrink wrap is used less frequently than polyolefin film. It has the tendency to soften in a hot environment and harden in a cold one. Over time, this weakens both the plastic and the seal. Polyvinyl chloride film also contains chlorine and is not used for wrapping edible products or products that are negatively affected by the odor of the film. It is more hazardous to use than Polyolefin because it releases hydrogen chloride gas when being sealed. Common uses for this film include non-edible products such as DVD and CD packaging, shipping boxes and canisters.

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Photo source: http://www.flickr.com/photos/joconnell/2421155632/

Advantages & Disadvantages

While there are advantages to using polyolefin film over polyvinyl chloride film, there are also some disadvantages. Manufacturers sometimes prefer polyvinyl chloride film because it is less expensive. Also, it can be easily applied by machine but polyolefin cannot.

In addition to its use as a product wrapping, shrink film has also been used in industrial applications. The weight and thickness of the film is much heavier, but the process of application is the same. Shrink film is routinely used to protect industrial equipment or freight during shipping. It has even been used to wrap damaged roofs or buildings to stabilize them for repair.

This post is brought to you by Darrell Rawlings, an avid mover. When it comes to his packaging and shipping needs he recommends HDA Packaging, providing service & selling products such as shrink labels and many more. Click here for more information.

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