PET Braided Mesh Sleeve
PET Braided Mesh Sleeve is an expandable polyester braid for harness bundling and abrasion protection: a mechanical loom, not an electrical product. The open mesh flares over assembled connectors, springs back onto the bundle, and takes the rub that would otherwise wear wire insulation. Catalogued range is -40 °C to +150 °C, confirmed against your duty at order stage. This page covers the closed expandable construction; the split, self-wrapping variant of the same braid family is listed separately. Send the run OD and the largest end and we return the nominal size.
Specification
| Material | PET (polyester) monofilament braid |
|---|---|
| Operating temperature | -40 °C to +150 °C catalogued; continuous rating confirmed at order stage |
| Shrink ratio | Non-shrink (elastic braid) |
| Wall type | Open expandable mesh |
| Construction on this page | Closed expandable braid (slip-on from harness end); split/self-wrap variant listed separately |
| Electrical function | None : not a dielectric, not EMI shielding |
Cross-Reference & Industry Standard Mapping
Wire harness braided sleeving cross-reference guide for automotive and industrial cable bundling:
| Wellele Series | Sleeve Type | Techflex | Panduit Equivalent | Federal-Mogul (Tenneco) | Reference Standards |
|---|---|---|---|---|---|
| WLL-PET-EXP | Expandable Braided Sleeve | Flexo PET | Braided Expandable | ROUNDIT 2000 | UL 94 V-0 / VW-1, DIN 5510 |
| WLL-PET-SW | Self-Wrap Split Sleeve | F6 Woven | Pan-Wrap | ROUNDIT 2000 NX | ISO 6722, RoHS Compliant |
* Note: All competitor part numbers are registered trademarks of their respective owners and are listed for engineering reference and cross-identification only.
What the expandable mesh actually is
The sleeve is braided from PET monofilament into a deliberately open mesh. Pushed lengthwise, the braid angle flattens and the eye flares to several times its nominal diameter (enough to pass an assembled connector or lug), and released, the monofilament's spring-back closes the mesh onto the bundle. Nothing shrinks and nothing is adhered; the grip is the braid's own elasticity. The open wall moves air, so the harness is not boxed in the way it is inside a closed tube, and the monofilament wall takes the abrasion instead of the wire insulation. Plain PET braid does not provide EMI shielding unless a conductive construction is built into it, and it is not a dielectric: the wires keep their own insulation underneath. What it does is keep a bundle ordered, identifiable and intact against rub-through at branches and clamp lines.
Where PET Braided Mesh Sleeve is used
Primary applications: Harness bundling and abrasion protection. Assemblies that are braided after termination, where the braid must pass connectors and still grip the run.
How to select the right size
Two measurements drive the choice, and they are not the same number:
- Run OD vs largest end. The straight-run bundle OD sets the fit; the largest feature : connector, boot, splice : must clear the expanded eye. Nominal ID, per-size expansion range and harness OD band come from the size table.
- Braid density. A denser mesh covers more and abrades better but ventilates and flexes less; a loose mesh is the opposite. State the abrasion zone and the heat build-up and we pick the density.
- Cut method. Plan for hot-cut finishing at the marked length : see the failure modes below for why a cold shear end causes trouble later.
Common Failure Modes & How to Prevent Them
These are the issues most often seen when installing or specifying PET Braided Mesh Sleeve, with the root cause and the prevention or fix for each.
The braid slid along the harness
Root cause: The nominal size was chosen for connector pass-through rather than run fit, so the mesh sits oversized on the straight run and the elastic grip has nothing to hold.
Fix: Size to the run OD and let the expansion range handle the end, not the other way round. Where the run is far smaller than the end, dress the braid with a clip or tape at the transition.
The end unravelled after a cold cut
Root cause: A shear or scissors cut leaves monofilament tails free to work loose under vibration.
Fix: Hot-cut, PET is a thermoplastic, so the hot knife fuses the ends as it cuts. On a cold cut, tape both sides of the cut line and trim the tails after; never leave a raw sheared end in service.
The mesh wore through at a bracket edge
Root cause: Open mesh concentrates load where a strand crosses a sharp edge, and a single rub line cuts strands one by one.
Fix: Route the braid clear of bracket edges where possible, add an abrasive pad or grommet at fixed rub points, and specify a denser braid where the harness passes a known edge.
It was counted on as insulation or a shield
Root cause: The braid looks like a solid wall and was read as a dielectric or an EMI shield. It is an open polyester mesh with neither function.
Fix: Keep wire insulation as the dielectric and treat the braid as mechanical only. For shielding duty, use a construction with a conductive layer built in, bonded to ground.
The sleeve relaxed near a heat source
Root cause: PET softens toward its range ceiling; a braid run too close to exhaust or engine heat loses its spring-back and slides before it visibly degrades.
Fix: Keep the catalogued -40 to +150 °C as the envelope and confirm the continuous rating for your duty at order stage. Above that envelope, move to a fiberglass or coated construction.
Frequently asked questions
How much may the braid expand over connectors?
The braid flares to several times its nominal ID when pushed lengthwise, which is what lets an assembled connector or lug pass through the eye. The exact expansion multiple per nominal size comes from the size table, which is part of the pending data pack. In practice: size the nominal ID to the straight run and check the largest end against the expansion figure before you commit.
How should the cut end be finished?
PET is a thermoplastic, so a hot knife both cuts and fuses the monofilament ends: the braid cannot unravel past the melted edge. A cold cut frays; if you must cold-cut, tape the braid either side of the cut line first and trim the tails after. For production volumes, hot-cutting at the marked length keeps ends clean without extra finishing.
Is PET braid electrical insulation or EMI shielding?
Neither. It is an open mesh: air and light pass through the wall, and polyester monofilament has no conductive path. Keep the wire's own insulation as the dielectric, and do not count this braid for any shielding duty. Ordinary PET braid does not provide EMI shielding unless a conductive construction (such as a metal-foil or metal-fibre layer) is built into it.
What happens near the 150 °C catalogued limit?
PET softens as it approaches its range ceiling, and an overloaded braid loses its spring-back grip before it visibly fails: the sleeve slides instead of staying put. Near engine or exhaust heat, move to a fiberglass construction rated for the zone. The continuous rating behind the catalogued -40 to +150 °C is confirmed against your duty at order stage.
Closed braid or split sleeve — which variant do I need?
This page is the closed expandable braid: you slide it over the harness end, so it suits new builds or harnesses that can be fed from one end. The same PET braid family also exists as a split, self-wrapping construction that closes over an assembled run mid-length. If you cannot disconnect the harness, that is the variant to ask for.
How is the nominal size matched to the harness OD?
Two measurements decide it: the straight-run bundle OD, which sets the fit, and the largest feature (connector, boot, splice), which must clear the expanded eye. A braid sized to the run but undersized for the end either jams at the connector or is too loose on the line. Send both figures and we return the nominal size; the per-size OD band is part of the pending size table.
Request a quote for PET Braided Mesh Sleeve
Send the run OD, the largest end, duty and colour. We return the nominal size, braid density, the confirmed temperature rating and lead time.
Size range & specification notes
Nominal ID table, per-size expansion range and harness OD band will be published once confirmed. Closed expandable construction on this page; the split self-wrapping variant of the same family is listed separately.