You have just acquired a manual PET strapping sealer and will use it to seal the joint that holds heavy loads: polyester is the strongest material for manual strapping and requires a tool specifically calibrated for its thickness and hardness. This guide explains the complete procedure to ensure each seal is symmetrical and the clip maximizes the PET strap's retaining force.
Product Specifications
The PET sealer is not interchangeable with the PP sealer: it has reinforced jaws, deeper teeth, and a multiplied lever to deform the thicker clips required for polyester. Here are its technical details:
| Specification | Value |
|---|---|
| SKU | 478640 |
| Compatible strap type | Polyester (PET) |
| Strap/seal width range | 13 to 20 mm (1/2 to 3/4 in) |
| Jaw material | Reinforced steel with deep teeth |
| Mechanism | Long handles with multiplied lever |
| Seal type | Metal seal (clip) for PET strap |
| Grip | Reinforced non-slip |
| Brand | FORTEMO |
Step-by-step instructions
The sealer is the sealing tool, not the tensioning tool: it operates in sequence after the PET tensioner. The procedure assumes that the PET strap is already tensioned against the bundle and the metal PET clip is placed over the two layers, ready to be sealed.
Confirm the strap and clip are in position
Before operating the sealer, check that the PET strap is tightly tensioned against the bundle and that the metal PET clip is placed over the two overlapping layers, centered and flat. The PET clip is thicker and more rigid than the PP clip: if it is twisted or displaced, reposition it before sealing (the force of the sealer will not allow you to adjust it once deformed).
Position the jaws perpendicular to the strap
Open the handles of the sealer and center the jaws exactly over the metal clip, perpendicular to the strap. The bite should be symmetrical: with PET clips, a crooked alignment leaves part of the seal unbitten and the closure gives way in transit. Take a second to properly seat the jaws before applying force.
Squeeze the handles with firm, full pressure
Close the handles all the way, in a firm and continuous motion. The PET clip requires more force than the PP clip, but the multiplied lever compensates for the difference: close to the mechanical stop without shortcuts. Do not half-seal or do it in two steps: a single complete compression deforms the clip symmetrically and produces the correct seal. If you notice that the lever does not reach the stop, check that the clip is not twisted or that the strap material is thicker than the tool allows.
For heavy loads or straps 19 mm and wider, reinforce the final pressure with both hands on the handles. The PET clip requires the sealer's teeth to fully penetrate both layers of polyester (a more rigid material than PP), and a single-handed closure on wide straps can leave the bite superficial. With two hands on the lever, the force reaches the mechanical stop without excessive wrist effort.
Maintain pressure momentarily and release
Hold the closure closed for two or three seconds to ensure complete metal deformation. Then open the handles in a controlled motion, without lateral tugging (a sudden twist when removing the sealer can deform the newly closed clip or misalign it from the strap). Remove the tool cleanly upwards.
Verify the seal and release the tensioner
Inspect the closed clip: it should have deep and symmetrical marks on both strap layers, with no gaps or lateral deformations, and it should lie flat against the strap. If the seal is good, you can now release the tensioner and cut the excess. PET strapping has higher elastic memory than PP: if you notice the clip giving slightly when tension is released, it is normal; if it slides or separates from the strap, repeat the closure with a new clip next to it before releasing the tensioner.
Can your load handle manual PET strapping?
If you are unsure if manual PET strapping is sufficient for the weight and frequency of your operation, or if it's worth upgrading to a battery-powered strapping tool, ask the virtual assistant. It will help you decide between manual and motorized systems based on your volume.
Complementary products
The sealer is the sealing tool in the manual PET strapping system, but it operates in conjunction with the strap, metal seals, and tensioner. If your volume grows, the battery-powered strapping tool integrates all steps into a single tool. These are the products of the complete system:
The 16 mm × 1,200 m PET strap is the main consumable for this tool. The metal seals for PET (box of 600 units) are the clips that the sealer closes; order seals specifically designed for PET, not PP, as they have different thickness and strength. The manual PET tensioner applies tension before sealing. If your daily volume exceeds 100-150 closures, the battery-powered strapping tool for PP and PET strap integrates tensioning, sealing, and cutting into a single operation and significantly reduces physical effort.
Maintenance and care
PET clips are more demanding on the tool than PP clips: the teeth and hinge work close to the calibration limit with each closure. These are the care steps that keep the tool in professional operating condition:
- After each use, clean the jaws with a dry brush to remove any strapping residue, dust, or metal particles; accumulated debris in the teeth distorts the seal over time, especially with PET buckles.
- Every two weeks (intensive use) or every month (regular use), apply a drop of multi-purpose oil to the central joint; open and close the handles several times without a buckle to distribute the lubricant throughout the mechanism.
- Visually inspect the teeth at least once a month: if you notice rounded teeth, nicks, or uneven wear, the seals will no longer be symmetrical. PET tensioners work with higher loads than PP, and wear appears sooner; replace it when the seals start to become superficial.
- Store the tool in a dry place. If working outdoors in humid conditions, dry it before storing to prevent rust in the joint, which is the first point of failure.
Do not use this tensioner with metallic PP strapping seals. PP buckles are thinner and softer than PET ones; the deep teeth of this tensioner would pierce them without closing them correctly, leaving a deformed and unstable seal. To seal PP strapping, use the specific manual polypropylene tensioner, which has jaws sized for that buckle.
Frequently asked questions
Can the PET tensioner also be used to close PP strapping buckles?
We do not recommend it. The teeth of this tensioner are calibrated to penetrate the thicker and more rigid PET buckles; if you use it on PP buckles, it is very likely that the teeth will pierce them without closing them properly, leaving the seal deformed and open. Use the manual tensioner for PP strapping when working with polypropylene.
When should you switch from a manual tensioner to a battery-powered strapping tool?
As an operational reference, for more than 100-150 seals per day, a battery-powered strapping tool justifies the investment due to its speed and reduced fatigue (tensioning + sealing + cutting in a single motion, without metal buckles). Below that volume, the manual system with a tensioner is more economical and sufficient for occasional or low-volume strapping operations.
What happens if the tensioner lever doesn't close all the way?
This generally means something is misaligned: the buckle might be crooked, the strap might be wider than the tool allows (more than 20 mm), or the jaws might be worn. Stop before forcing the lever, open the tensioner, check the buckle's position, and try again. Forcing the mechanism when something obstructs it is the most common cause of joint damage.