What is cord strapping?
Commonly referred to by names such as polyester strapping, nylon strapping, fabric strapping and even the generic plastic strapping, but cord strapping differs from all these other straps by its own unique characteristics.
Cord strap is made from a high tenacity industrial polyester yarn that is held together by hot melt glue either in a woven or uniline pattern. This combination creates two important characteristics that differentiate cord from other strapping
a) low elongation
b) memory retention that acts like a big rubber band when your product encounters sudden shock from abrupt movements.
These are the common types of cord strapping available:
A woven pattern of polyester filaments that are held together with hot melt glue that result in a low elongation high strength alternative to some steel and polypropylene strapping applications.
A more recent development in cord strapping. Composite is made up of high tenacity polyester filaments that are embedded in a very strong polymer coating. This new combination creates an even stronger cord than traditional woven and bonded cord while still retaining the same low elongation and memory retention.
Strapping used on shipment of chemical weapons slated for destruction Soft goods strapped in a bale or bundle, Steel is the oldest and highest tensile strength strapping. It is 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. 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. Common applications include steel coils, bundles of metal, baling wire, bricks and pavers, and roll end-binding. Steel Strapping is sold by weight rather than length, due to the natural expansion and contraction of steel in the manufacturing process. A 3/4 x .020 Steel Strapping Coil yields approximately 19.6 feet per pound.
Polypropylene strap (oriented or tensilized) 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). Most polypropylene is embossed, some of which is also 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. Polypropylene strapping may be printed, either during production and pre-embossing for the highest quality and precision, or post production over the embossing for a reduced quality. Both offer security and marketing advantages to the strapped product.
Oriented or tensilized polyester and nylon are the strongest plastic strapping products and are used as a viable alternative to steel strapping in some industries. Polyester provides excellent retained tension on rigid loads. Its excellent recovery properties help a load absorb impact without strap breakage. There are specialized types available for specific applications. For instance, in cold climates a strap bonded in hot melt glue is used because it is weather-proof.
Nylon strap has the greatest specific strength of the three plastics, however it is rarely used due to its high price. In the past nylon strap used to be very popular, but over time polyester has replaced almost all of its use. One application that still uses this type of strap is cold room applications, because it does not creep as much as the other types of plastic.
Paper strap is used to strap paper products between industrial processes. This allows the bundle to be introduced into the process without the need to cut the straps, which can lead to the product falling apart prematurely. With the above definitions, you can already classify which type of strapping is suitable for your packaging operations as long as safety of worker, environment and product are considered plus ease of operations and most of all the Product/Load is properly secured.
For more information on Strapping please visit: http://www.sal-tech.dk/