Product Overview

BSTFLEX Unidirectional Glass Fiber Sleeve is a dry tubular reinforcement with its main glass fiber yarns running along the length of the sleeve. Fine supporting yarns hold the longitudinal fibers in a flexible tube, allowing fabricators to place reinforcement around a mandrel or an existing part without cutting and joining a flat sheet. The sleeve is intended for resin-impregnated composite manufacture where reinforcement in the lengthwise direction is part of the laminate design. Diameter, fiber weight, supporting-yarn construction and supply length can be specified for the project.

Fiber Orientation and Construction

In a conventional biaxial braided sleeve, the main yarns cross at an angle. In this unidirectional construction, the principal glass fiber yarns follow the axis of the part. Smaller supporting yarns stabilize the tubular preform during handling and layup. This arrangement is useful when the laminate design calls for a substantial share of fibers in the 0-degree direction.

The installed diameter, coverage and fiber alignment depend on the specified construction and the shape of the part. For a tapered or curved component, trial fitting is the best way to confirm coverage and the required cut length before production.

Typical Applications

• Lengthwise reinforcement of composite tubes, rods and hollow profiles
• Composite layup over tapered shafts and shaped mandrels
• Local axial reinforcement in sporting goods, industrial components and custom assemblies
• Prototype and OEM production where a tubular glass fiber preform simplifies fiber placement

The finished part's strength and service conditions depend on the complete laminate, resin system, cure process and validation tests.

Selecting the Right Sleeve

Start with the part diameter at its smallest and largest points, its overall length and the direction of the loads. Specify the required glass fiber type or yarn if your design controls it. Also provide target fiber weight or areal weight, the allowable supporting-yarn content, and the intended resin and manufacturing process.

Glass fiber sizing must suit the selected resin. Confirm wet-out, drape, compaction and the cured laminate properties with a representative sample. If the design needs balanced fibers around the circumference instead of predominantly axial reinforcement, compare our biaxial braided fiberglass sleeve. For a different reinforcement fiber, see our carbon fiber braided sleeves.

Custom Supply for Composite Manufacturing

BSTFLEX can review a drawing, sample or fiber layup requirement to quote a suitable sleeve construction. Discuss nominal diameter, diameter tolerance, glass yarn, supporting-yarn arrangement, fiber weight, roll or cut length, packaging and forecast volume when requesting an OEM quotation. Production specifications and test data should be agreed for the selected construction before they are added to a project datasheet.

Common Questions

Is this the same as a regular fiberglass braided sleeve?

No. The defining feature here is the lengthwise orientation of the main reinforcing glass fibers. A standard biaxial braid has its main fibers crossing at braid angles. The required orientation depends on the loads in the finished part.

Is the sleeve supplied as a finished composite tube?

No. It is a dry fiber preform for incorporation into a composite layup. Resin selection, impregnation and curing are determined by the customer's manufacturing process.

What information is needed for a quotation?

Send the part drawing or mandrel dimensions, minimum and maximum diameters, length, glass fiber specification if required, target fiber weight, resin system, trial quantity and expected annual usage.