Are you paying for “more” strapping than you need?
After doing a Corrugated 101 post last month, I got to thinking this is probably a good style post for other product categories. Strapping is one where I see a lot of companies overspending by using the same strap they’ve used for years and years. It’s probably not a killer to their bottom lines but often, an example of overpaying “because we’ve always done it this way.”
Again, this is not meant to be extremely in-depth or all-encompassing. Rather just a quick overview or reference sheet. Feel free to reach out if you have further questions or want a deep-dive on your current strapping.
How many different types are there?
The short answer is three primary ones. Polypropylene (PP), Polyester (PET), and steel. Least to most expensive and lightest to heaviest duty.
They each have their pros and cons. Below is a brief overview of each.
STRAPPING TYPE | SUMMARY | BEST USE CASES | KEY TERMS |
Polypropylene (PP) | Lightest duty but has a wide range of grades that still cover a large swath of applications. Excellent elongation and recovery characteristics. | Lightweight boxes, daily parcel shipments, or automated tabletop strapping machines. While sticking within a budget. | machine vs. hand grade smooth vs. embossed |
Polyester (PET) | Nearly as heavy duty as steel but without the rust and safety concerns. Does not indent product like steel will and has solid elongation and recovery characteristics. | Heavy pallets, lumber, or rigid materials. Especially if they will sit outdoors or travel long distances | machine vs. hand grade AAR smooth vs. embossed |
Steel | “Legacy” strapping. Heavy duty but can be a safety hazard. Most expensive per foot. Few applications require steel strapping. | Crazy heavy loads, sharp edges, or exposed to extreme environments like super high heat. | Standard duty vs. High-Tensile. Oscillated vs. Ribbon Wound. |
In addition to the above three types of strap, you might see a cord strap or a nylon strap. These are less common but do have their specific applications.
Seal types:
There are also a variety of ways to seal your strapping. I won’t go into the weeds but you of course have the manual tools and multiple types of correlated seals. The most common and lowest cost way of sealing any strap is using a tensioner and separate sealer with seal. It’s slow but the tools are cheap and very long lasting.
Alternatively, all-in-one sealless tools.
To speed things up, there are “all-in-one” tools which do not require separate seals. For steel, one option would be the STL-105 tool. For PP or PET strap, you could get a battery operated friction weld tool like Fromm’s P329 or P328 tool. Not only are these faster and remove the cost of seals but the resulting seal is stronger. Of course, there are also fully automated systems for higher throughput. In those instances, reach out to a trusted partner to vet out the right system and then a corresponding maintenance program.
Most Critical Term: “Break Strength”
If I had to pick one thing to takeaway from this article - it is the importance of break strength.
The formula to determine the adequate break strength relative to your application is:
The Safety Multiplier for a standard pallet of boxes with the product individually packed inside said boxes is 1.5. If you have a box where the strap is direct reinforcement…maybe to prevent a heavy product inside bursting out, use 3. And if the strap is the packaging, like strapping lumber or steel pipes - use 5.
An 1,800lb pallet using 4 straps could require a minimum break strength of 675 (probably 900# to be safe) if it’s palletized boxes. But if that pallet is of loose lumber, pipes, or concrete blocks, you want a minimum break strength of 2500#.
One last note - seal method / join efficency! Standard metal or crimp seals have an efficiency of 55%-75% whereas an all-in-one or automatic tools that do not use separate seals will achieve 75-80%. There’s some nuance here but keep this in mind.
Width & thickness:
Rather than the focus being on break strength, many still focus on the width, thickness, and material type (PP vs. PET). The width and thickness inherently play a big part in determining the break strength but are just factors. Outside of ensuring the width and thickness fit any sort of equipment you have now, whether battery operated handheld tools or automatic equipment, the main focus should be the break strength.
Other Terms & Factors:
Machine vs. Hand grade - Machine grade strapping is made with extremely tight tolerances. Using hand grade in a machine will technically work but runs a high risk of equipment jams.
Smooth vs. Embossed - In my opinion, if it’s not spec’d in, this is nitpicking at the fringes but there is a difference. Smooth strap tends to be stronger and have a better seal. But embossed has anti-slip and flexibility benefits.
AAR - Do you send product via rail car? If so, you should use an AAR certified strap. This would be steel or PET only but not all steel and PET strap are AAR compliant.
Exposed to elements? - If you will be strapping a product and letting it sit outside for an extended time, it is important to get the right strap. Typically that would be PET but certain steel and PP strap formulations can fit too.
Oscillated vs. Ribbon Wound (steel only) - ribbon wound is like tape…it’s a single layer whereas oscillated has a wider core and the strap is “weaved” back and forth. In short, you’re trading capacity and length for a more manageable weight
Core size - More specific to your current equipment than application. 16×6 is the most common and means it has an ID of 16” and a width or “face” of 6”. You just need to make sure the core size fits your current equipment (whether automatic equipment or manual carts).
Edge Protectors - Just an FYI. If you’re strapping corrugated boxes or product that can be easily damaged, you might want to use edge protectors so proper strap tensions doesn’t cause damage itself. You’re probably already doing this if it’s required but I wanted to call it out.
Good info but my strap works and I don’t want to risk changing anything. I’ll just get quotes on my current spec.
I’ve no idea who this person is other than he’s on The Voice. Just really liked the gif.
There’s probably nothing overly wrong with that. For most this isn’t a concern but make sure that the strap you’re using isn’t specialized. Ie. a PP strap that is made to withstand outdoor elements, you have and require an AAR compliant strap, or your strap runs on automated equipment.
The good thing about strapping is it’s not guesswork or trial and error. There is a formula to determine the required break strength. Everything else is a handful of yes or no questions and it’s quick and simple to come up the “correct” strap. For me, “correct” = safely adequate for the application without overpaying for more material than is needed.
Quick Example:
A few years ago I met with a company who mentioned wanting a battery operated handheld tool but being a small company, his boss was pushing back on spending a few grand for one. By taking them from a 5/8” PET with 1100# break strength (wayyyy overkill) to a 1/2” PP with 600# break strength, we were able to nearly cover the cost of the unit in just a year. And that was at a handful of coils per month.
Beyond that, when I brought the tool in, I set it up so that it would provide the right tension each time. This eliminated product indentations from them “tensioning the crap” out of it manually.
Is there a chance a similar savings could be had in your company because “we’ve always used this strap and it hasn’t broke”?
Want to learn more?
If you have questions, want to learn more, or maybe you want to do a deep dive on your strapping - reach out! You can reply to this email, book a conversation here, or reach out to me at the info below.
(812)244-9393 & [email protected]
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