Differences Between Steel and Poly Strapping

Which one should I use?

STEEL STRAPPING

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Steel straps are the oldest, strongest, and highest tensile strength strapping available. You can find steel strapping available in a variety of widths and thicknesses, as well as variations in the grade of steel. Steel is used for heavy-duty holding where high strength and minimal stretch are desired, as well as when the product may be sharp or hot.

Surface finishes for steel strap include paint, paint and wax, bluing, or zinc and wax. The wax is used to better transmit the tension around the bundle and for use with certain types of tensioners.

While it is still the preferred alternative in some industries, the market is declining largely because it is dangerous to work with (presenting sharp edges) and difficult to recycle. But, common applications still include steel coils, bundles of metal, baling wire, bricks and pavers, and roll end-binding.

pros / cons

POLYPROPYLENE STRAPPING

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Polypropylene 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). This product offers higher elongation but tends to have an irrecoverable dead stretch with constant stress.

What is not generally known to end users is that poly strapping will lose about 50 percent of the applied tension within one hour. This tension loss is accelerated with increases in ambient temperature. Poly strapping can be printed, offering security and marketing advantages to the strapped product.

pros / cons

  • Advantages: Most cost effective, lightweight, easy to apply, easy to recycle, high elongation, high elongation recover.
  • Disadvantages: Low retained tension, potential to split, susceptible to environmental factors, a higher rate of failure when used on “solid” products
  • Application methods:
    • Hand
    • Manual tools
    • Power or Battery-operated tools
    • Semi-automatic machines
    • Automatic machines

POLYESTER STRAPPING

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Polyester strapping is the most rigid option, offering the strongest hold of any plastic strapping, and is used as a viable alternative to steel in many industries. Polyester provides excellent retained tension on rigid loads and its excellent recovery properties help a load absorb impact without strap breakage. It also retains tension over a longer period of time.

Since polyester strapping offers the highest strength and greatest retained tension of all the plastic strapping, it is often used on heavy duty loads that need high initial tension along with high retained tension during handling and storage. Competitive pricing and performance characteristics have motivated many steel strapping users to switch to polyester. This type of poly strapping is available in both machine grade and hand grade and is easy to dispose of and recycle.

pros / cons

  • Advantages: Most rigid, long tension retention, high strength, nick resistant, easy to recycle
  • Disadvantages: Less elongation than polypropylene
  • Application methods:
    • Manual tools
    • Power or Battery-operated tools
    • Fully automatic machines

So…which one is for me?

The most important question to answer is “what type of load you are shipping?” If you are shipping a lightweight product, polypropylene strapping is probably the right choice. Its cost-efficient nature paired with easy application make it the most advantageous strapping for lightweight applications. If you are planning on shipping a heavier duty load, steel or polyester strapping would be the preferred choice. Due to cost and safety concerns, steel is becoming less and less favored among industry professionals. Polyester is becoming the preferred strapping in a number of applications. Unless your company needs the strength of steel strapping for applications such as railcar transit, polyester is probably the better choice.