The metallic seal is the fastener that secures the two ends of the plastic strapping once tensioned, and the choice between a PP seal and a PET seal is not trivial: applying the incorrect one will tear the strap or produce a seal that slips under real load during transit. This comparison of the two Fortemo seals will help you decide which one fits the strapping material you use in your operation.
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What to consider before choosing
Before purchasing, evaluate these four criteria. They determine whether the closure will withstand the entire shipping cycle or result in loose pallets mid-transit.
- Strapping material in use: PP strapping has a soft surface and requires a seal with a smooth interior calibrated for that hardness; PET strapping has a rigid surface and requires a seal with an internal serrated tooth that bites into the strap. Applying a PP seal on PET causes slippage under tension; applying a PET seal on PP tears the strap.
- Strapping width and tensioner compatibility: both Fortemo seals are sized for 13-16 mm (1/2 - 5/8 in) strapping, the standard palletizing widths in Dominican logistics. Always verify that the sealing tensioner's bite matches the seal before proceeding with serial closures.
- Operation volume: the box of 1000 PP seals covers continuous flow palletizing operations; the box of 600 PET seals responds to the lower volume typical of heavy strapping, where each pallet weighs more and fewer are sealed per shift. Calibrate your purchase to the actual rate of pallets sealed per day.
- Galvanization quality: a seal with poor galvanization will rust within a few weeks in the Caribbean climate and can stain adjacent product or reduce the mechanical integrity of the closure. Fortemo uses uniform galvanization that keeps the seal operational throughout the entire shipping cycle, even during outdoor transit.
Seal for PP strapping: smooth closure for polypropylene
- Smooth interior calibrated for the softness of PP strapping
- Uniform galvanized steel resistant to Caribbean humidity
- Compatible with standard sealing tensioners for 13-16 mm
- Box of 1000 seals for continuous palletizing flow
- Permanent, flat closure with no sharp edges
- Not suitable for PET strapping (slips under high tension)
- Limited compatibility to 13-16 mm widths
Galvanized metallic seal for 13-16 mm (1/2 - 5/8 in) polypropylene (PP) strapping, in a box of 1000 units. Smooth interior calibrated for the specific hardness of PP, where the serrated teeth of a PET seal would be counterproductive. Designed for warehouses, hardware stores, businesses, and palletizing operations where PP strapping is the dominant format: palletizing corrugated cardboard boxes, closing packages in daily flow, grouping light pipes, and sealing export boxes for regional shipments.
Seal for PET strapping: serrated closure for polyester
- Serrated internal teeth that bite into the rigid PET surface
- High-resistance galvanized steel for extended transit
- Compatible with standard sealing tensioners for 13-16 mm
- Box of 600 seals calibrated for heavy-duty strapping volume
- Permanent closure without slippage under real high tension
- Not suitable for PP strapping (the teeth tear the polypropylene)
- Higher unit cost than the smooth PP seal
Serrated metallic seal for 13-16 mm (1/2 - 5/8 in) polyester (PET) strapping, in a box of 600 units. Serrated internal teeth calibrated to bite into the smooth, rigid PET surface, maximizing friction to prevent slippage under the real tension of polyester. Designed for palletizing heavy materials (bricks, blocks, grouped bags), sealing wood loads and metal profiles for inter-island export, and agro-industrial operations with dense bags palletized with PET.
Comparative table
| Feature | PP Seal | PET Seal |
|---|---|---|
| Compatible strapping material | PP | PET |
| Compatible widths | 13-16 mm (1/2 - 5/8 in) | 13-16 mm (1/2 - 5/8 in) |
| Interior | Smooth | Serrated teeth |
| Material | Galvanized steel | Galvanized steel |
| Packaging | Box of 1000 seals | Box of 600 seals |
| Brand | Fortemo | Fortemo |
| Compatibility with standard tensioners | Yes | Yes |
Use case matrix → recommended product
| If your case is… | Recommended product |
|---|---|
| Palletizing cardboard boxes with PP strapping in a logistics warehouse | → PP Seal |
| Securing light package groupings with plastic strapping | → PP Seal |
| Sealing bundles in a hardware store with polypropylene strapping | → PP Seal |
| Grouping plastic pipes or light profiles in a workshop | → PP Seal |
| Sealing regional export boxes with PP strapping | → PP Seal |
| Closing brick or block pallets with PET strapping for construction | → PET Seal |
| Sealing wood loads or metal profiles with PET strapping | → PET Seal |
| Closing agro-industrial pallets with dense bags in PET | → PET Seal |
| Inter-island export with heavy-duty polyester strapping | → PET Seal |
| Closing bulky packages where a smooth seal slips | → PET Seal |
Before buying, determine two pieces of information: the strapping material you use (PP or PET) and your sealing tensioner's bite. The rule of thumb: PP plastic strapping → smooth PP seal; heavy-duty PET strapping → serrated PET seal. Mixing materials doesn't work — a PP seal on PET will slip, and a PET seal on PP will tear the polypropylene. If your operation handles both materials, consider keeping a clearly differentiated box of each type.
Do not use PP seals on PET strapping. The smooth interior cannot withstand the high tension of polyester, leading to seals that slip as soon as the load experiences vibration or braking during transport. The consequence is a pallet that arrives loose or open at its destination, with the associated risk of damage to unsecured products. The investment in the correct seal pays off with the first load that arrives intact.
Not sure which seal to use?
If you combine several strapping materials in your operation or have doubts about compatibility with your tensioner, ask the virtual assistant with details of the strapping in use (PP or PET), the width of the strap, and the tensioner model. You will receive an instant technical recommendation for the correct seal.
All compared products
Frequently asked questions
Why is a PET seal not suitable for PP strapping?
The PET seal has calibrated serrated teeth designed to bite into the rigid surface of polyester. On PP strapping (which is softer), these teeth tear the strap at the closure point, reducing the strap's strength precisely where it is most needed. For PP, always use a smooth seal.
Are Fortemo sealing tensioners compatible with both seals?
Yes, as long as the width is 13-16 mm (1/2 - 5/8 in). Verify that the jaw of your tensioner matches the geometry of the seal in use before serial closures. Fortemo's tensioners for PP and PET strapping respect the shared width standard for both seals.
How many seals do I need for a typical pallet?
It depends on the strapping pattern. A pallet with two horizontal wraps needs two seals; with cross strapping (two horizontal + two vertical) it needs four. Calculate your average daily consumption and purchase a full box to avoid running out of material mid-shift.