A Complete Guide to Strapping Materials and Terminology

In the packaging industry, strapping is a widely used method for bundling products and securing loads. Whether it’s cartons, bottles, brick stacks, or containers, proper strapping ensures items are unitized and maintains load integrity during handling and transport.

Because strapping is used across a wide range of applications, it’s important to understand the different materials and key terminology. Strapping materials vary in strength, elongation, and recovery properties. Elongation refers to how much a strap can stretch under tension, while recovery describes its ability to return to its original length. These characteristics are especially important for loads that may shift during transit. As movement occurs, the strap absorbs tension by stretching, helping reduce the impact of sudden force. Its recovery capability then helps pull the load back into place.

Types of Strapping

Polyester (PET) Strapping
Polyester strapping is commonly used for securing heavy loads such as bricks, lumber, and tiles. It offers high tensile strength with controlled elongation, making it a safer alternative to steel. Its excellent elongation and recovery properties make it ideal for loads that may settle, expand, or contract during shipping. As the load shifts, the strap stretches to absorb impact and then recovers to maintain tension. Polyester strapping is typically green and available for both manual and machine applications.

Poly Woven Strapping
Made from woven polyester fibers, this strapping provides high tensile strength for medium to heavy-duty applications. It is lightweight, rust-resistant, and reusable, making it a safer alternative to steel. With no sharp edges and no risk of snapback, it helps reduce workplace injuries. Poly woven strapping maintains tension over long periods and can be easily re-tensioned during storage or transit. It is available in a range of widths and strengths.

Composite Strapping
Composite strapping consists of synthetic fibers embedded in a flexible coating, delivering high tensile strength with added flexibility. It offers the strength of steel while eliminating hazards such as sharp edges and dangerous recoil. This makes it a safer option for operators while still providing excellent load containment.

Steel Strapping
Steel strapping is a durable and cost-effective option for securing very heavy loads, including pipes, lumber, concrete blocks, and metal coils. It is applied manually using tensioning tools and secured with metal seals or buckles. Steel strapping is available in various grades, widths, and thicknesses to suit different applications.

It is supplied in two main coil types:

Ribbon Wound: Smaller, more manageable coils ideal for manual use, typically weighing around 11 kg.
Rope Wound: Larger coils designed for high-volume operations, usually weighing around 45 kg and requiring a dispenser for handling.

For environments where corrosion is a concern, stainless steel strapping provides excellent durability and weather resistance.

Polypropylene (Poly) Strapping
Polypropylene strapping is an economical solution for light to medium-duty applications such as palletizing and bundling. It offers high elongation but lower recovery and strength compared to other materials. Under constant tension, it may experience “dead stretch,” meaning it won’t return to its original length.

Type of application:

Hand Application: Hand-grade poly strapping is used with manual tools and comes in dispenser boxes for easy use. The strap is tensioned and secured with metal seals and a crimping tool.

Machine Application: Machine-grade poly strapping is designed for semi-automatic and fully automatic systems. Machines apply, tension, and seal the strap using heat or friction welding for fast, efficient operation.

Strapping Terminology

Understanding common strapping terms helps ensure proper material selection and application:

Linear Breaking Strength: The point at which the strap itself breaks under tension.
System Breaking Strength: The point at which the entire system (strap and seal/buckle) fails.
Core: The inner tube around which the strapping is wound, measured by diameter and width.
Strapping Closure: Seals or buckles used to join the ends of the strap.
Creep: Gradual loss of tension over time.
Strapping Weld: A method of joining strap ends by melting them together.
Camber: The curvature of the strap; excessive camber can cause machine issues.
Coil Face: The width of the strapping coil.
Elastic Limit: The point beyond which the strap cannot return to its original shape.
Elongation: The amount a strap can stretch under tension.
Elongation Recovery: The ability of the strap to return to its original length.
Embossing: A textured surface pattern that improves stiffness and joint performance.
Joint Efficiency: The strength of the strap at the joint, expressed as a percentage of its overall strength.
Knurling: A surface pattern on polypropylene strapping that improves machine feed performance.
Retained Tension: The strap’s ability to maintain tension over time.
Seal Joint: The area where two ends of the strap are joined.
Shock Resistance: The ability to absorb sudden force without breaking.
Split Resistance: Resistance to tearing across the width of the strap.
Yield Strength: The point at which permanent deformation begins.