Introduction
A pallet doesn’t fail in the warehouse—it fails somewhere on the highway, in a shipping container, or on a forklift three transfers later, when nobody’s around to catch it. The cause is almost always the same: a strap picked for its price rather than its width, break strength, and tension retention against the actual load it’s holding. PET strapping solves this problem better than PP in most palletized applications because it holds tension longer and absorbs shock better, but only when width, tensioning, and application match the cargo. This guide breaks down PET’s strength characteristics, how much tension to apply and why, and how to match strap selection to the specific load sitting on your pallet.
What Is PET Strapping?
PET strapping is made from Polyethylene Terephthalate, extruded and drawn to align its molecular fibers for high tensile strength. It differs from PP in one critical way: PET stretches under load and then holds that stretch, retaining tension far longer than PP, which relaxes and loosens as loads settle.
Standard PET strapping for pallet use runs from 9mm up to 32mm in width, with break strengths spanning roughly 400 lbs on the light end to 3,000 lbs or more for heavy-duty grades. That range is wide enough to cover everything from a single carton of retail goods to a fully loaded industrial pallet, which is exactly why width and thickness selection matters as much as the material choice itself.
Strength Characteristics of PET Strapping
Break Strength by Width
Width selection follows a fairly direct relationship with load weight:
- 9–12mm: Light cartons and small pallets, roughly 400–820 lbs break strength
- 16–19mm: Standard industrial pallets, 900–1,900 lbs
- 25–32mm: Heavy-duty and export loads, up to 3,000 lbs or beyond
Tensile Strength and Load Capacity
Break strength on a spec sheet isn’t the same as real-world holding power. Static pallet weight is only part of the equation—dynamic forces from braking, cornering, and vibration during transport routinely add well beyond resting weight, so a working load calculation needs a safety margin built in rather than a strap picked right at the edge of its rated capacity.
Comparison to Steel and PP
PET holds up better than PP for anything beyond short-haul, low-stakes shipping, and it does so without the sharp edges and rust risk that come with steel. Steel still wins on raw break strength for extremely heavy, rigid industrial loads, but for the overwhelming majority of palletized freight, PET’s balance of strength and elongation makes it the more practical choice.
Tension and Tension Retention
Why Tension Matters for Pallets
Tension is what keeps a pallet load together between the moment it leaves the dock and the moment it arrives. Too little tension and the load shifts in transit; too much and the strap crushes or deforms the product it’s meant to protect—both outcomes show up as damage claims later.
Optimal Tensioning Guidelines
Most palletized applications call for tensioning to roughly 40–60% of the strap’s rated break strength, adjusted for how rigid or fragile the load is. Calibrated tensioners produce far more consistent results than manual pulling by feel, particularly across multiple straps on the same pallet where uneven tension concentrates stress unevenly.
Tension Retention Over Time
This is where PET earns its reputation over PP. PP strapping relaxes as cartons settle, humidity shifts, or the load compresses slightly during a long haul, and the strap that was tight at loading can be noticeably loose by delivery. PET’s elastic recovery holds that tension far longer, which is exactly why it’s the preferred choice for long-haul and multi-stop shipments where nobody re-tightens the strap along the way.
Applications for Palletized Loads
Standard Distribution Pallets
Cartons and case goods typically run on 12–19mm PET in a simple vertical or cross pattern, tensioned enough to prevent shifting without denting packaging.
Heavy-Duty Industrial Pallets
Bricks, lumber, and metal bundles need wider strap—25mm and above—paired with higher tension settings, since these loads are rigid and non-compressible and won’t absorb tension the way softer cartons do.
Export and Long-Haul Shipments
Pallets crossing long distances or switching transport modes need tension retention more than initial tightness, since they’ll sit tensioned for days or weeks without adjustment. Moisture and UV resistance also matter more here, given the outdoor and marine exposure many export pallets face along the way.
Fragile and Compressible Loads
Glass, ceramics, and sensitive packaged goods need lower tension settings specifically to avoid crushing, often combined with edge protectors and corner boards to spread pressure across a wider contact area.
Selecting the Right PET Strap for Your Pallet
Assess Load Weight and Dimensions
Start with total pallet weight and divide by the number of straps planned to get load per strap point, then factor in pallet size and stack height before landing on a required tensile strength with margin.
Match Strap Width to Load Type
A rough but reliable pattern holds across most operations:
- 12mm for light cartons and small pallets
- 16–19mm for standard industrial pallets
- 25mm and above for heavy-duty and export loads
Consider Transport Conditions
Road, rail, sea, and air freight each impose different stress patterns—road transport deals with repeated vibration and braking, sea freight adds sustained rolling motion, and air freight compresses the whole journey into a shorter, sharper set of forces. Environmental exposure during storage and transit adds another layer that needs checking against strap coating and material choice.
Tooling and Sealing Compatibility
Manual, battery, and pneumatic tensioners all handle PET, but the sealing method—friction weld versus crimp seal—needs to match the tool being used, since mismatched tooling produces inconsistent joints regardless of how well the strap itself is chosen.
Best Practices for PET Strapping Pallets
Load Preparation
Stack cartons evenly, remove unnecessary gaps between them, and consider stretch wrap or anti-slip matting before strapping begins. Heavy items belong low and centered on the pallet, not stacked toward one edge where they shift the load’s center of gravity.
Strap Placement and Pattern
Anchor the strap to the pallet base itself rather than just around the cartons, and use vertical, horizontal, or cross patterns depending on what the load’s shape actually needs. Distribute tension evenly across multiple straps rather than over-tightening one and leaving others loose.
Tensioning and Sealing
- Apply tension gradually, checking for product compression as you go.
- Seal using the method that matches your strap type—friction weld or crimp.
- Cut excess strap cleanly and secure loose ends so they can’t snag during handling.
Inspection and Quality Control
Check strap tension and joint integrity before the pallet leaves the dock, and look specifically for the visible signs of over- or under-tensioning before they become a problem in transit. Export shipments benefit from documenting the strapping pattern used, both for compliance and for troubleshooting if a claim comes back later.
Common Mistakes and Troubleshooting
Under-Tensioning
Manual tensioning without calibration is the most common cause of under-tensioned straps, and the load shift that results usually only becomes visible once the pallet has already arrived.
Over-Tensioning
Over-tightened straps crush cartons, deform products, and actually reduce the strap’s own elongation and shock-absorbing capacity—tightness isn’t the same as security.
Wrong Strap Width or Strength
Light-duty strap on a heavy pallet, or a strap mismatched to the tooling and seal type being used, both produce joints that look fine until the load is actually tested by real transport stress.
Poor Joint Integrity
Weak seals, incomplete friction welds, or surface contamination before sealing all undermine joint strength even when the strap itself was correctly chosen. Consistency across every strap on a pallet matters more than any single strap being perfect.
Tools and Equipment for PET Strapping
Manual tensioners and sealers suit low-volume operations where portability matters more than speed. Battery-operated combination tools tension, seal, and cut in one motion and hold up better across mid-volume pallet lines than manual pulling does. Pneumatic tensioners and sealers handle high-volume, heavy-duty work at fixed stations, and fully automated strapping machines integrate directly into conveyor lines for the highest throughput operations.
Safety and Operator Considerations
PET carries none of steel’s sharp-edge or violent-recoil risk, which shows up directly in reduced hand and eye injury rates among operators handling it daily. Ergonomic tool design also reduces fatigue over a full shift, and consistent training on tensioning and sealing technique matters as much as the tool itself in producing reliable joints.
Environmental and Cost Considerations
PET is recyclable, and a growing share of supply now comes with recycled content built in without sacrificing performance. Its lighter weight reduces shipping and handling costs measurably across high-volume operations, and longer coil life against PP means less material waste over time—advantages that show up in total cost of ownership even when PET’s per-meter price runs slightly higher upfront.
FAQs
What PET strap width is best for a standard pallet?
Most standard industrial pallets run well on 16–19mm PET, though lighter cartons on small pallets can use 12mm and heavier, rigid loads often move up to 25mm. The right choice depends on total pallet weight and how many straps you’re applying.
How much tension should I apply to a pallet strap?
Most applications call for roughly 40–60% of the strap’s rated break strength, adjusted downward for fragile or compressible loads and upward for rigid, non-compressible cargo. Calibrated tensioners produce far more consistent results than tensioning by hand.
Can PET strapping replace steel for heavy pallets?
For the large majority of palletized freight, yes—PET’s strength-to-weight ratio and shock absorption outperform steel in practical terms, without the rust and sharp-edge risks steel carries. Extremely heavy, rigid industrial loads at the top end of the weight range may still call for steel.
How many straps do I need for a palletized load?
Divide total pallet weight by the working load of your chosen strap and buckle or seal combination, then round up and distribute the straps evenly across the load rather than clustering them. Most standard pallets use at least two to four straps depending on height and stability.
Is PET strapping suitable for outdoor storage?
Yes—PET holds up to moisture and UV exposure considerably better than PP, which is part of why it’s the standard choice for export and long-haul shipments that spend time outdoors or in transit through variable weather.
What’s the difference between friction weld and crimp sealing?
Friction weld fuses the strap ends together using heat generated by rapid friction and often produces a stronger joint, while crimp sealing uses a metal seal crimped over the overlapping strap ends. Both work reliably when the tool and seal type match the strap being used.
Conclusion
Match strap width, tension, and application pattern to the actual pallet in front of you rather than defaulting to whatever’s already on the shelf—that single habit prevents the majority of transit damage claims tied to strapping. Use calibrated tools and a consistent sealing method across every strap on the load.
Amass Strap supplies PET strapping systems built for palletized loads of every weight class, matched with the tensioners and sealers needed to get consistent, reliable joints every time. Visit amass-strap.com to request an application-specific recommendation for your next palletized shipment.