BrassPack: Tape Guide

Steel Strapping
Steel is the strongest of all strapping materials. It is recommended where high strength is necessary, low elongation is important and where the product is extremely sharp or hot. Steel is sealed using mechanical seals and notch (sealless) joints. It is most commonly used in steel service centers, rail car applications and heavy construction applications.

Polyester Strapping
Polyester is the most rigid of all strapping materials. It elongates significantly less than polypropylene and retains tension over a longer period. Polyester is nick resistant and can be sealed with seals, heat or friction welds. Because polyester offers the greatest strength and highest retained tension of all plastic strapping, it is frequently used on heavy duty loads that need high initial tension along with high retained tension during handling and storage. Common applications are empty cans and bottles, lumber and heavy, rigid palletizing. Polyester has a smooth, shiny finish and is easy to dispose of and recycle.

Polypropylene Strapping
Polypropylene strapping is the most commonly used and least expensive of all strapping materials. It is light and easy to apply and recycle. Characteristics include high elongation and elongation recovery, but low retained tension. Polypropylene is an excellent choice for light duty palletizing, unitizing, carton closing and bundling. Because of its embossing (or waffle) pattern, strap thickness is not a useful measurement. A standard 1/2" machine grade strap can be embossed to a thickness of anywhere between .014 and .030, depending upon how deep the embossing pattern is. An overly embossed strap will be thicker, but will have a lower break strength.

Formulas
Carton Reinforcement: A 3:1 ratio of strap to carton weight is recommended. For a 100 lb package this could be done with (1) 300lb tensile strap or (2) 150lb straps.
Unitizing and Bundling: A 5:1 ration of strap to carton weight is recommended.
Palletized Cases: Required Tensile Strength = (Pallet Weight x 1.5) / # of Straps

Strapping Terms
Break (or tensile) Strength: The amout of force, expressed in pounds, required to break the strap.
Elongation: This is the amount of stretch in the strap as force or tension is applied. Elongation is generally expressed in the working range which is 40-60% of the break strength.
Elongation Recovery: This is the strap's ability to recover to its original state after tensioning.
Shock Resistance: This is the strap's ability to stretch and return to its original state without breaking when subjected to sudden impact.
Split Resistance: The strap's ability to withstand lateral tears.

S T R A P P I N G C O M P A R I S O N
PERFORMANCE FACTOR	STEEL	POLYESTER	POLYPROPYLENE
Break Strength	Excellent	Very good	Good
Tensile Strength (lbs)*	860-5650	600-1400	300-820
Elongation	1%	1-2%	8-10%
Ability to Retain Tension	Excellent	Very good	Poor
Elongation Recovery	Poor	Good	Excellent
Split Resistance	Excellent	Very good	Poor
Recyclability	Poor	Excellent	Excellent
Cost	High	Medium	Low
Shock Resistance	Poor	Very good	Good
* BrassPack Items