You have just received a box of metal seals for PP strapping and are going to use them to complete the strapping cycle: after tensioning the strap, the seal is placed over the two layers and the crimper deforms it to secure the closure. This guide explains how to identify the correct seal, place it properly on the strap, distinguish it from PET seals, and recognize a well-made closure.
Product Specifications
Fortemo PP strapping seals are offered in boxes of 1,000 units, sized for 13 to 16 mm strapping. They are flat galvanized steel seals with a smooth interior—different from PET seals, which have serrated teeth. Here are the technical details:
| Specification | Value |
|---|---|
| SKU | 235623 |
| Material | Galvanized steel |
| Compatible with strap widths | 13 to 16 mm (1/2 to 5/8 in) |
| Internal type | Smooth (no serrated teeth) |
| Compatible strapping material | Polypropylene (PP) |
| Packaging | Box of 1,000 seals |
| Closing tool | Manual crimper for PP strapping |
| Brand | FORTEMO |
Step-by-step guide to using it
The seal is not applied alone: it operates within the complete strapping cycle. The following procedure assumes you have already wrapped the package with PP strapping and have the tensioner at hand to tension and the crimper to close.
Place the seal over the two overlapping layers of strapping
When the two ends of the strapping meet on the top face of the package, slide the metal seal embracing both layers. The seal should cover both layers of strapping along its entire length and be centered, not at one end. Leave approximately 5 cm of free strapping above the seal so that the tensioner can grip this excess when tensioning.
Distinguishing a PP seal from a PET seal by sight is simple if you know what to look for: the interior of a PP seal is smooth, while that of a PET seal has clearly visible serrated teeth. If you received a box without a label, inspect the interior of a seal before use. Applying a PET seal to PP strapping is a costly mistake: the teeth tear the polypropylene strap and weaken the closure from the first step.
Tension the strap without displacing the seal
Apply the tensioner to the free excess and tension progressively. The seal must remain in position during tensioning: if you notice it sliding with the strap, reposition it before continuing. Once the correct tension is achieved (firm against the package, without deforming it), keep the tensioner held to avoid losing tension before closing.
Position the crimper over the seal
While holding the tensioner firmly, open the manual crimper for PP strapping and center the jaws over the seal, perpendicular to the strap. The crimp should be symmetrical over the center of the seal: if one jaw crimps outside the seal, the closure will be crooked and will loosen in transit.
Close the crimper with full and even pressure
Squeeze the handles of the crimper all the way, in a firm and continuous motion. The PP crimper deforms the flat seal against the two layers of strapping, without the need for deep teeth (the PP seal is smooth inside). Do not close halfway or in two steps: a single complete compression produces the correct seal.
Verify the closure and release the tensioner
Inspect the closed seal: it should lie flat against the strap, with no visible gaps between the metal and the strapping layers, and no lateral deformations. Gently pull the closed strap: it should not slide inside the seal. If the closure is good, release the tensioner and cut off the excess. If you notice sliding, repeat the closure with a new seal next to it before releasing the tensioner.
Is your seal correct for your strapping?
If you are not sure whether the seals you have are for PP or PET, or if your strap width is within the 13-16 mm range, ask the virtual assistant. It confirms compatibilities before you apply seals to real loads.
Complementary products
The seal is only the closure of the system: to truly strap, you need the strapping, the tensioner, and the crimper. These are the products that complete the manual PP strapping cycle:
PP strapping is the material you will seal; order coils of the compatible width (13 or 16 mm). The tensioner applies pre-closure tension, and the crimper closes the seal. If you prefer a system without a metal seal, plastic buckles are an alternative that does not require a crimper, although they offer a less firm closure and are only suitable for low volume or light loads.
Maintenance and care
Seals do not require maintenance like a tool, but their storage does affect operation: oxidation or deformation of the box can lead to defective closures. These are the guidelines:
- Store the closed box indoors, in a dry place. Galvanizing protects against mild oxidation, but prolonged saturated humidity can cause superficial rust that affects the closure.
- Keep the box on a flat surface, with no weight on top: a crushed box deforms the bottom seals and produces irregular closures when you eventually use them.
- Do not mix PP seals with PET seals in the same dispenser or organizer box. The formats are visually similar, and a selection error during rapid operation is costly.
- If you notice oxidation on individual seals (after months in a humid warehouse, for example), discard those seals: rust reduces the adhesion of the galvanizing when closed and can stain the strap and package.
- Visually inspect the box upon receipt: packages should be uniform, with no loose metal debris. A box with loose seals at the bottom indicates shipping damage and should be checked before starting operations.
Do not use these PP seals with PET (polyester) strapping. The smooth interior of PP seals does not bite into the rigid surface of PET, causing the strap to slip inside the seal under the actual tension of the polyester. For PET strapping, exclusively use the toothed seals specific to that material; closures with the wrong seal are the most common cause of pallets arriving loose at their destination.
Frequently asked questions
What is the difference between a PP seal and a PET seal?
The interior. The PP seal is smooth because polypropylene is relatively soft and deformation closure is sufficient to secure the strap. The PET seal has internal serrated teeth because polyester is rigid and, without teeth, the strap slips inside the seal under the actual tension of the PET. Although visually similar, they are not interchangeable: each material requires its specific seal.
How many seals does a pallet consume?
One for each strap closure. A typical pallet is closed with two horizontal wraps and one vertical wrap, which means three seals per pallet. A box of 1,000 seals covers approximately 330 pallets in that configuration. Calibrate with your first 10 actual pallets to get an accurate figure based on your operation.
Is it mandatory to use a seal for PP strapping?
No. You have two alternatives. The plastic buckle allows you to close PP strapping without a metal seal or crimper, by folding the end over the buckle; it is valid for low volume and light loads. The battery-powered strapping machine welds the strap by thermal friction without a metal seal; it is the high-volume option. The seal + crimper is the most cost-effective professional system per pallet in manual operations.