A Beginner's Guide to Strapping
The Basics of Strapping
If you’re new to strapping or just don’t know a lot about it, we understand. Everyone has to start somewhere, which is why we want to help you out with this convenient, easy to understand beginners guide to strapping. To start off, you should know that strapping is one of the most frequently used methods for unitizing and bundling products and pallets. There are many different types of strapping on the market and, along with that, there are many different ways to use strapping as well. Some of the most common applications include:
- Bundling items before shipping and handling
- Securing products to pallets, skids, or crates
- Reinforcing boxes or crates made from either wood or corrugated materials
- Securing products to flatbed trailers, flatcars, and more
- Bundling heavy loads like bricks, glass, metal, etc.
- Closing heavy-duty boxes and shipping containers
- Unitizing agricultural products and textiles
- Securing loads for transit, both domestic and international
How is Strapping Applied?
Most commonly, strapping is placed over the products or pallets in a horizontal or vertical layout and is paired with edge protectors that even out the strap’s tension on the corners of the load. Reduced tension helps to minimize damage. Additionally, when securing loads to railcars or trailers, strapping can be looped through various attachment points to reduce shifting and damage during transit.
What Kinds of Strapping are Available to Me?
There are two primary categories of strapping, steel strapping and poly strapping. Let’s take a look at both.
Steel Strapping: Steel strapping, which is also referred to as metal strapping, was historically the most common variety of strapping. It is the strongest of all strap and offers better tensile strength than any other kind. Because of this, as well as its wide range of availability in many sizes and dimensions, makes it a top choice for heavy-duty applications that require little stretch capability, and also for items that may be very sharp or very hot. If you think steel strapping might be best suited to your application, ask yourself these questions:
- Is your load both heavy and stable?
- Will your products be traveling long distances?
- Does the pallet need to be unloaded and reloaded multiple times during the transit process?
If you said yes to all of these questions, then it looks like metal strapping is the right fit!
Plastic Strapping: In the modern age, plastic strapping, which consists mainly of polypropylene and polyester strapping, is the most commonly used. Polypropylene strapping is cost effective, works well for light- to medium-duty applications, and is widely available in many widths, thicknesses, and polymer variations. It’s important to note that while polypropylene straps offer high elongations, they generally experience irrecoverable dead stress when placed under constant stress. Polyester strapping is the most rigid plastic strapping and provides impressively high strength, making it a great alternative to steel for a wide range of applications and industries. It gives the user outstanding retained tension on stable loads and offers exceptional recovery in order to absorb impacts without breaking. That said, polyester strapping provides less elongation than its polypropylene counterpart and retains tension over longer stretches of time.
Collectively, we call polyester and polypropylene strapping either poly strapping or plastic strapping. This may get confusing to some, especially those who haven’t worked with it before, so here are some easy ways to differentiate the two:
- Polyester strapping is smooth and glossy
- Polypropylene strapping is usually embossed with a matte finish and feels "plasticky” to the touch
- Polyester strapping is a better choice when higher initial tension is needed
- Polypropylene strapping is a better choice when only a low retained tension is required
What Strapping Properties Do I Need to Know?
Trust us, we know that strapping can seem daunting when you’re just starting out. Thankfully, there are only a few key terms to understand and once you get them figured out, it’s easy to determine what you need. Here are the main strapping terms you should know:
- Core Size: The diameter and depth of one strapping coil. This number must match up with the dispenser, tool, or machine that’s used to apply the strapping.
- Elongation: The amount of stretch in a given strap as tension is applied to it.
- Elongation Recovery: How much the strap is able to return to its original state after the tension is taken away.
- Tensile Strength or Break Strength: Measured in pounds, this is the amount of force needed to break a strap.
- Tension: Any type of pushing or pulling used to tighten a strap.
- Tension Decay: How much the tension reduces over time. Polypropylene strapping shows the most amount of tension decay and polyester strapping shows the least.
- Thickness: How physically thick a strap is, measured in fractions of an inch.
- Width: How physically wide a strap is, also measured in fractions of an inch.
- Working Range: The point at which a strap is stretched to where it wants to recover but not so much that it is unable to recover. Essentially, this is a so-called “sweet spot” where the strap performs at its very best ability.
How Do Elongation and Tension Affect My Strapping Applications?
It’s important to remember that steel strapping has no give whatsoever. This means that if you need any elongation at all (even just a little!), you’ll need to use poly strapping. Any type of plastic strapping can elongate when placed under tension and recover some of that stretch after the stress is taken away. As we learned above, this is called elongation recovery and it allows your strapping to contract as the package it’s wrapped around gets smaller. Plastic strapping is varied in its ability to stretch and recover, so before you determine which type of poly straps you need, ask yourself three simple questions:
- How much elongation recovery do my products require?
- How much tension can be placed onto my strapping before it damages my products?
- How much retained tension can be allowed?
Additionally, don’t forget these details:
- Polypropylene straps have an elongation recovery range of 20-40%, depending on the amount of tension initially placed on them
- Polyester strapping has an elongation recovery of about 70%
- Humidity does not affect the elongation recovery of plastic strapping, but extreme temperatures can negatively impact any kind of poly strapping (especially polypropylene strapping)
How Can I Learn More?
Now that you’ve got a basic understanding of strapping and its different varieties and terms, you’re ready to start purchasing. However, if you’d like some extra information before you begin, we can definitely help you out. Enter your contact information in this form and we’ll email you a free copy of our guide on the different characteristics of steel strapping and both kinds of plastic strapping.