Pallet strapping, or banding is the process of using a metal or plastic strap to unitize, palletize or bundle products together. Strapping is used in a variety of industries from shipping large industrial equipment and lumber to reinforcing cases in e-commerce fulfilment centres. For this reason, there are many grades and types of materials on the market today.
Strapping is applied either manually with a hand tool or automatically with a strapping machine. In both cases, a strap or band is feed around the product and pulled taught. A fastening method then secures the ends of the strap around the product and the excess material is removed.
Strapping materials are available in many different strengths with specific grades and classifications. It is important to understand these grades and how they can affect your material choice when choosing your packaging. How your product is transported will affect the rating system and materials used. The two associations who grade strapping are the American Association of Railroads and ASTM International. Although ratings can be similar, it is important to understand that the designations are not interchangeable.
Types of Strapping Material
What is Elongation?
Elongation refers to a straps ability to stretch and bend. This can be important as a straps ability to stretch and recover can help improve its strength during the initial tensioning process.
With a variety of applications and uses, it is important to understand the different types of strapping materials. The materials used come in multiple strength levels as well as elongation and recovery rates.
Elongation and recovery are important for loads that are susceptible to sudden shifting. The movement will apply tension to the strap as the load shifts. As the shifting occurs, a strap can stretch to reduce the impact of sudden inertia changes. The straps recovery ability of the strap will indicate the straps ability to return to its original state.
Steel strapping is the oldest and most commonly used banding materials to this day. Steel strapping is designed for extreme tasks that require a heavy or very heavy-duty strap. Steel strapping is optimal for packaging industrial equipment, heavy construction materials, and shipping steel coils.
Features & Benefits of Steel Strapping:
- Large Loads
- Hot Temperature
- Sharp Edges
- High Break Strength
- Low Elongation Capabilities
- UV Resistant
- Extreme Durability
Steel strapping is applied manually with a tensioning tool and then fastened together by crimping a steel buckle around the bands ends. The excess steel strapping is then cut and disposed of.
Plastic strapping materials are made from polyester, polypropylene and are available in a variety of strengths, styles, and finishes. Unlike steel strapping, elongation and recovery are a key factor for deciding which type of plastic strap to use.
Polyester strapping is the most commonly used polymer strapping material. Its strength and durability have made it the most commonly used material to replace steel strapping.
Features and Benefits of Polyester Strapping:
- Strongest of Plastic Strapping
- High Break Strength
- High Levels of Tension
- Greater Elongation
- High Recovery
Polyester Strapping is Ideal For:
- Medium to Heavy Duty Loads like construction materials
- Loads that may settle, expand or contract during shipping
- Loads that are susceptible to impacts or shifting environments like ships
- Reinforcing heavy packages and loads
The high level of elongation and recovery make polyester strapping ideal for packaging loads that are susceptible to shifting. The elongation provided by the polyester strap helps to minimize the effect of sudden shifts in momentum. As the load shifts, the straps elongate lessening the force of a sudden shift. The straps recovery capabilities then pull the load back into the original position.
Polypropylene strapping is an economical strapping material compared to other materials. It’s designed for light to medium duty unitizing, palletizing and bundling. Consistent pressure to polypropylene strapping can result in unrecoverable dead stretch and inability to return to its original length.
Features and Benefits of Polypropylene Strapping:
- Highest Level of Elongation
- Little Recovery
- Low Strength
Polypropylene Strapping is
- Light to Medium Duty Unitizing
- Short Transportation Trips
- Loads Protected from Environmental Conditions
Plastic Strapping Fasteners
There are many types of fasteners and buckles that can be used to fasten plastic strapping. Like steel strapping, metal buckles can be used with a crimping tool for both manual and automatic equipment. Strapping buckles are made in metal, plastic and wire. Some sealers interlock the strapping material and do not require an external buckle. Heat seal can be created with a friction or heat welding process where the straps are partially melted to form together.
With a wide assortment of materials and uses it is key to understand the goal of your strapping before deciding on the material its self. Will you be shipping short distances? Do you require less or more elongation? Does your transportation method require an AAR or ASTM International classification? If you are considering adding strapping to your packaging solution, contact one our highly trained and knowledgeable Packaging Specialist for a free packaging consultation today.
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