Cross-Braid Woven Fiberglass Sleeve — Expandable
A knitted fiberglass sleeve whose diagonal weave expands and contracts: stretch it to pass over a connector, splice or elbow, release it, and the braid closes back to grip the nominal run. One size therefore covers a range of irregular geometries. The fit is set by geometry, not by heat or adhesive. Slip-on installation, no recovery step, natural fiberglass finish. Sized on two diameters: the largest object to pass and the nominal run it must grip.
Specification
| Material | Cross-knit fiberglass |
|---|---|
| Shrink behavior | Expandable slip-on : no heat step |
| Wall type | Open mesh braid |
| Fit principle | Geometry: expand to pass, contract to grip |
Cross-braid geometry: why it expands
In a normal braid the yarns interlace at a fixed angle and the sleeve keeps roughly one diameter. In a cross-knit construction the strands run diagonally in both directions and can slide against each other, so the sleeve moves between two states: compressed along its length it opens wide, stretched along its length it narrows. This is what lets one sleeve size swallow a bulky connector and then sit tight on the cable behind it. Two practical consequences follow:
- Expansion has a limit. Forcing the weave past its designed opening distorts the knit and the sleeve will not return cleanly to shape. The expansion ratio for this grade is on our datasheet request list : send the largest object and we size instead of guessing.
- Grip depends on relaxed diameter. Behind every lump the sleeve returns toward its relaxed ID. If that ID is larger than the run, the sleeve floats and slides; if it is smaller, it grips by weave tension alone : no ties strictly needed on static runs, though ties are still good practice where the run moves.
Passing connectors, splices and elbows
The sleeve is worked onto the run like a sock, not threaded like a tube: gather it, open the mouth over the largest object, and let the lattice do the work. At elbows and formed sections the knit changes angle with the run, which is why this construction suits irregular shapes that fixed tubes cannot follow. Where a route mixes large lumps with long straight sections, position the expansion points where clamps and ties will not fight the changing diameter.
Weave tension and abrasion limits
Glass yarn has good temperature service but limited abrasion resistance in a thin open knit: vibration against a metal edge will eventually cut through the yarns. Route clear of sharp edges, use lined clamps, and where abrasion is the dominant duty consider a coated or heavier braid instead. The exact thermal and abrasion figures for this grade are being collected with the datasheet; we will state them from the datasheet, not from generic fiberglass values.
Common failure modes, and prevention
The sleeve bagged out behind the connector
Cause: Sized only on the largest object, so the relaxed ID exceeds the run diameter and the braid never grips.
Prevention: Give us both diameters, largest object and nominal run. One size is picked to satisfy both; if no single size does, the run needs two sizes joined at the lump.
Yarns pulled loose from the cut end
Cause: The braid was cut unbound and the free yarns unravelled along the knit.
Prevention: Bind before cutting, hot-cut, or order finished ends. Recheck the end after installation: a snag during routing undoes a good cut.
Weave distorted at the mouth
Cause: The opening was forced past the designed expansion to save a size.
Prevention: Respect the expansion ratio; where the lump exceeds it, use the next size and add ties, or split the job into two sleeve sections.
Braid worn through at a bracket edge
Cause: Vibration worked the open knit against a hard edge.
Prevention: Pad or line the contact point, reroute if possible, or move to a heavier construction for that segment. Inspect thin-knit sections during scheduled maintenance.
Frequently asked questions
How does cross-braid geometry expand around a connector?
The yarns run diagonally in both directions, so the braid behaves like a lattice: pull the sleeve lengthwise and the diameter narrows; push the ends toward each other and the same strands fan outward, widening the opening. That is the whole mechanism: no heat, no recovery, purely geometry. In practice you stretch the sleeve to pass it over the largest object on the run, then release; behind the object the lattice relaxes back toward its relaxed diameter and the weave tension holds the sleeve in place on the nominal section.
How should the relaxed ID be selected?
Work from two diameters, not one. The expanded diameter must clear the largest object the sleeve has to pass over: connector, splice or formed part. The relaxed ID should sit at or slightly below the nominal run diameter so the braid grips the cable rather than floating loose behind the object it passed. A sleeve sized only on the largest object stays baggy on the run; one sized only on the cable will not pass the connector. Both numbers together pick one size from the range.
How should cut ends be managed without damaging the braid?
A woven glass braid has no self-edge: once cut, the yarns at the cut line can unravel along the braid. Options, in order of robustness: bind the cut point with tape or a tie before cutting, then cut through the bound section; use a hot-cut method suited to glass yarn so the ends are fixed as they part; or order the sleeve with finished ends from us. Whatever the method, make the cut square and handle the end gently afterwards: pulled yarns travel a surprising distance along a knit braid.
Does the open weave block heat or splash?
The open knit slows direct contact and spreads light abrasion, but it is air-permeable by design: it neither blocks radiant heat the way a foil face does nor sheds molten splash the way a coated heavy-build construction does. Where weld spatter or molten metal is present, step up to a coated high-density construction. Where the duty is conforming over irregular shapes in elevated-temperature surroundings, this weave is the right tool.
Is this sleeve electrical insulation?
No. The open weave leaves the cable's own insulation visible and exposed at the mesh openings; the sleeve is mechanical protection and a thermal-service covering. Voltage isolation has to come from the wire insulation or a dedicated insulating layer. Do not count braid coverage toward a dielectric requirement. We do not publish a dielectric value for this sleeve, and if your spec asks for one we will discuss what test evidence could support it before anyone relies on a number.
Request a quote for Cross-Braid Woven Sleeve
Send the largest object diameter, the nominal run diameter it should grip, route length and quantity. We return the sleeve size, end-treatment options and lead time.