Most of the Carbon Fiber Tubes are manufactured using Roll wrapped technology, it is formed by rolling carbon fiber fabric pre-impregnated with resin on a mold (usually a metal mandrel), which is then cured into a solid strong tube. Today we’d like to show you how Sinofibre produces carbon fiber tubes.
1. Prepare and Cut the Prepreg
Base on the customer’s thickness and length, we calculate and choose the suitable thickness for each prepreg, then cut them accordingly.
Direction: 90, 0/90, 0/45/90, or other customizable Grade: T300, T700, T800.
Tow: 1K, 3K, 6K, 12K, 24K Weave: Twill, Plain, UD (Unidirectional)
2. Prepare the Mold (Mandrel)
According to the size of the tube, we selected the suitable size of the mandrel, all our mandrels are made of aluminum due to its better contractility, it’s better to remold and control the internal diameter of the tubes.
3. Roll Wrapping
1
Remove the release paper from the prepreg, exposing the sticky surface
2
Iron one end of the cut prepreg onto the mandrel using a small soldering iron
3
Place it on the motor roll shaft, using pressure to roll the tubes properly.
4
Layup and roll the prepreg according to the client’s directional requirements until reaching the desired thickness
4. BOPP Shrink Tape Wrapping
Place the rolled tube on the tape wrapping equipment and twist the BOPP shrink tape on it, to compress the carbon fiber prepreg on the mandrel properly, in this way, the resin will not overflow during the heating process.
5. Heating and Curing
After 4-5 hours of heating in a 140°C oven, the resin in the prepreg is infiltrated and fused, to make the whole structure of the tube more integrated and stable.
6. Demoulding and Removing BOPP Tape
After high-temperature heating, the mandrel contracted, we used a demoulding machine to pull the carbon fiber tube out of the mandrel easily. The prepreg and mandrel are 150mm longer than the tube, so the surface of both ends will not get damaged.
7. Polishing
The mark of BOPP tape is left on the tubes, the surface has to be polished according to the size of customers. Some people like this mark because it has a style with layers, so we just skip this step.
8. Cutting
Cut the tubes according from our CNC cutting machine according to the client‘s requirements.
9. Painting
Apply the Glossy or Matte painting according to the client’s requirement, normally we have 2 steps to keep the painting stable and reliable, one for primer and one for top coating. In this way, the painting is not easy to fade
10. Testing and Packing
Our professional inspection team checks the tubes using specialized tools. Quality-approved tubes are packed in PE bags and carton boxes. For large orders, we use plywood packaging to prevent damage during shipping.
