User guide | Manual plier for PET strapping
This guide covers sealing with the manual sealer for PET strapping: checking that the strap and seal are in position, aligning the jaws perpendicular to the strap, applying firm, full pressure on the handles, holding the crimp and running the final check. Follow these steps so the seal withstands PET tension on heavy loads without opening during transport or export.
Product specifications
The PET sealer is not interchangeable with the PP one: it has reinforced jaws, deeper serration and compound leverage to deform the thicker seals that polyester requires. Here are its technical specifications:
| 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 serration |
| Mechanism | Long handles with compound leverage |
| Closure type | Metal seal (clip) for PET strapping |
| Grip | Reinforced non-slip |
| Brand | MAXTENS |
Step-by-step instructions
The sealer is the closing tool, not the tensioning tool: it operates in sequence after the PET tensioner. The procedure assumes the PET strap is already tensioned against the load and the PET metal seal placed over the two layers, ready for sealing.
Confirm the strap and seal are in position
Before operating the sealer, check that the PET strap is properly tensioned against the load and that the PET metal seal is placed over the two overlapping layers, centered and flat. The PET seal is thicker and more rigid than the PP one: if it is crooked or out of place, reposition it before crimping (the sealer's force will no longer let you adjust it once it is deformed).
Position the jaws perpendicular to the strap
Open the sealer's handles and center the jaws exactly over the metal seal, perpendicular to the strap. The bite must be symmetrical: with PET seals, a crooked alignment leaves part of the seal without a bite and the closure gives way in transit. Take a second to seat the jaws properly before applying force.
Squeeze the handles with firm, full pressure
Close the handles all the way, in one firm, continuous motion. The PET seal requires more force than the PP one, but the compound leverage makes up the difference: close to the mechanical stop, no shortcuts. Do not crimp halfway or in two stages: a single complete compression deforms the seal symmetrically and produces the correct joint. If the lever does not reach the stop, check that the seal is not sitting crooked or that the strap material is not thicker than the tool accepts.
On heavy loads or straps 19 mm and wider, reinforce the final pressure with both hands on the handles. The PET seal requires the sealer's serration to fully penetrate the two layers of polyester (a more rigid material than PP), and a one-handed crimp on wide straps can leave the bite shallow. With two hands on the lever, the force reaches the mechanical stop without putting excessive strain on the wrist.
Hold the pressure for a moment and release
Hold the crimp closed for two to three seconds to ensure the metal deforms completely. Then open the handles in a controlled motion, without sideways jerking (a sharp twist while removing the sealer can deform the freshly crimped seal or knock it out of line with the strap). Remove the tool cleanly, straight up.
Check the seal and release the tensioner
Inspect the crimped seal: it should show deep, symmetrical marks on both strap layers, with no gaps or sideways deformation, and it should sit flat against the strap. If the seal is good, you can now release the tensioner and trim the excess. PET strap has a higher elastic memory than PP: if the seal gives slightly as you release the tension, that is normal; if it slips or separates from the strap, redo the crimp with a new seal right next to it before letting go of the tensioner.
Complementary products
The sealer is the closing tool in the manual PET strapping system, but it works alongside the strap, the metal seals and the tensioner. If your volume grows, the battery-powered strapping tool integrates every step into a single tool. These are the products in the complete system:
The 16 mm × 1,200 m PET strap is this tool's main consumable. The metal seals for PET (box of 600 units) are the clips the sealer crimps; order seals designed specifically for PET, not for PP, as their thickness and strength are different. The manual PET tensioner applies the tension before crimping. If your daily volume exceeds 100-150 crimps, the battery-powered strapping tool for PP and PET strap integrates tensioning, sealing and cutting into a single operation and considerably reduces physical effort.
Maintenance and care
PET seals are more demanding on the tool than PP ones: the serration and the pivot joint work close to their calibration limit on every crimp. This is the care that keeps the tool in professional operating condition:
- After each workday, clean the jaws with a dry brush to remove strap debris, dust or metal particles; residue built up in the serration distorts the crimp over time, especially with PET seals.
- Every two weeks (intensive use) or every month (regular use), apply a drop of multi-purpose oil to the central pivot; open and close the handles several times without a seal to spread the lubricant through the mechanism.
- Visually inspect the serration at least once a month: if you notice rounded teeth, nicks or uneven wear, the crimps will no longer be symmetrical. The PET sealer works under higher loads than the PP one, and wear appears sooner; replace it when the seals start coming out shallow.
- Store the tool in a dry place. If you work outdoors in humid conditions, dry it before storing to prevent rust in the pivot joint, which is the first point to fail.
Do not use this sealer with metal seals for PP strapping. PP seals are thinner and softer than PET ones; this sealer's deep serration would punch through them without closing them properly, leaving a deformed, unstable seal. To seal PP strap, use the specific manual sealer for polypropylene, whose jaws are sized for that seal.
Frequently asked questions
Does the PET sealer also work for crimping PP strap seals?
We do not recommend it. This sealer's serration is calibrated to penetrate PET's thicker, more rigid seals; if you use it on PP seals, the serration will most likely punch through them without closing them properly, leaving the seal deformed and open. Use the manual sealer for PP strapping when working with polypropylene.
When is it worth switching from the manual sealer to the battery-powered strapping tool?
As an operational reference, above 100-150 crimps per day the battery-powered strapping tool pays for itself through speed and reduced fatigue (tensioning + sealing + cutting in a single motion, with no metal seals). Below that volume, the manual system with a sealer is more economical and sufficient for occasional or low-volume strapping operations.
What if the sealer's lever does not close all the way?
It usually means something is misaligned: the seal may be sitting crooked, the strap may be wider than the tool accepts (over 20 mm), or the jaws may be worn. Stop before forcing the lever, open the sealer, check the seal's position and try again. Forcing the mechanism when something is obstructing it is the most common cause of damage to the pivot joint.