How are roll-wrapped carbon fiber tubes made?

A roll-wrapped tube is built from sheets of carbon fiber prepreg. The plies are cut to a pattern, wrapped tightly around a steel mandrel, bound with shrink tape, cured in an oven, and pulled off the mandrel. The tube is then sanded, cut to length and checked. Our carbon fiber tubes are made this way at our own factories in Nanning and Dongguan^[1].

8steps from prepreg to finished tube

2prepreg types: unidirectional plies and a 3K woven ply

6–20 mmstandard outside diameters

Carbon fiber tube workshop with wrapping tables and curing racks — Tube production: wrapping, curing and finishing.

What goes into the tube?

Two prepregs: a unidirectional prepreg, with fibers in one direction, for strength and stiffness, and a 3K woven prepreg for the outer ply, which gives the familiar plain or twill look and holds the tube together across its width. Raw-material test reports for both are kept for our 3K tubes^[2].

The eight steps

Step	What happens	What it decides
1. Cut	prepreg plies are cut to a pattern, at set fiber angles	stiffness, twisting strength
2. Prepare mandrel	a steel mandrel is cleaned and coated with release agent	inside diameter, easy release
3. Wrap	plies are rolled tightly onto the mandrel under pressure: unidirectional plies inside, the woven ply outside	wall thickness, no air between plies
4. Tape	shrink tape is wound over the tube	compaction, outside surface
5. Cure	the tube is cured in an oven	resin properties, strength
6. Extract	the mandrel is pulled out	inside surface
7. Finish	tape is removed, the surface sanded, then clear-coated for gloss or left matte	look: glossy or matte
8. Cut and check	ends cut square; diameter, length, straightness and surface checked	fit and appearance

Typical ply build-up, inside to outside

Unidirectional plies (most of the wall)strength

3K woven outer plyfinish

Clear coat (glossy tubes)gloss

Illustrative proportions. The exact ply schedule is set for each size and load.

Why is the fiber angle important?

Fibers at 0° along the tube give bending stiffness. Fibers at ±45° resist twisting. A woven 0/90° ply resists crushing and splitting. A tube for a drone arm, a telescopic pole and a robot link each need a different mix, so say how your tube is loaded when you ask for a quote.

Finished matte carbon fiber round tubes — Finished tubes, matte surface.

Square carbon fiber tubes — Square tubes are wrapped on square mandrels.

What can be done after curing?

Tubes can be cut, drilled and CNC machined to your drawing, and supplied glossy or matte, plain or twill^[3]. Color, size, length and wall thickness are set per order^[3].

TipAsk a tube factory three questions: which prepreg (fiber grade) is used for the inner plies, what the ply schedule is for your size, and how straightness is checked. Vague answers usually mean the cheapest build.

How does roll-wrapping compare with pultrusion?

Roll-wrapped tubes allow fibers at several angles, a cosmetic woven finish and colors. Pultruded tubes run fibers only along the length and are made continuously, which suits straight, stiff profiles in volume. See how pultrusion works and roll-wrapped vs pultruded sizes.

Send your size and load through the quote form or see the carbon fiber tube page.