Strapping Introduction

Strap is used to secure bundles of product especially for shipping and storage. It’s not only can extends the life of the product by keeping it safe and protected during shipping or storage, but will also can free up space by keeping like materials together in neat bundles for easy location and retrieval. Moreover, it’s also a safety precaution if Strap together bundles of material when the materials are stored in racks. If you don’t do that, there is a risk that one or more pieces could fall from height and injure somebody. 

But there are so many strapping you can choose. For example steel strapping, polyster straps and polypropylene strapping. What is the difference between them? The differences are below, price, how much they can hold (strength), and how long they can hold the strapped product. Also, the steel has a separate cutter, whereas both the polys have the cutter built into the tensioner. Operationally they are all very similar.

Polypropylene strap is an economical material designed for light to medium duty unitizing, palletizing and bundling. It is available in various widths, thicknesses, and polymer variations (e.g., copolymers). Some polypropylene is embossed or printed. This product offers higher elongation at break but tends to have irrecoverable dead stretch with constant stress. What is not generally known to end users is that polypropylene strapping will lose about 50% of the applied tension within one hour, and that this tension loss is accelerated with increases in ambient temperature, consequently although suitable for packs with a degree of stored energy that will take up any relaxation that occurs in the strap, unacceptable strap slackness may occur after time if used on product that is 'Solid' such as bricks or concrete. Furthermore, polypropylene strapping is susceptible to UV degradation and can quickly degrade if left outside exposed to the elements. The sensible choice of color will retard the process, such as specifying black strap. Similarly, a UV inhibitor can be specified.

Polyester strapping is the strongest plastic strapping material of the two (polyester vs. polypropylene). The highest initial tension can be applied and retained over a longer period of time compared to other plastic strapping materials. Polyester is also available in machine grade and is very easy to recycle. 
Steel Strapping
Typical applications are unitizing compressed fiber bales, securing heavy steel coils and open top railcar and trailer loading. High Tensile strapping provides more footage per coil than heavy duty sizes of comparable break strength.

The article come from:http://www.metal-tinbox.com/index.php/strapping-introduction.htm 
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