R&G Technicians Blog
Here we present topics and considerations from the day-to-day work of our technicians in loose order.
Bonding carbon fibre semi-finished products
Customer question:
How do you bond carbon fiber semi-finished products such as sheets or tubes?
R&G technical department, summarized by Thomas Nothdurft:
- Clean the surfaces to be bonded, sand with isopropanol or acetone
- Sand the bonding surfaces, remove sanding dust with 150 - 240 grit
- Optionally remove the remaining dust with the dust binding cloth for mold cleaning under very low pressure.
- Apply a suitable adhesive (e.g. epoxy resin adhesive or laminating resins, filled with thixotropic agent if necessary) and bond the parts.
- Observe the curing times and curing temperatures of the adhesive as well as the joint gaps of the parts to be bonded.
The joint gap dimension is the distance between the surfaces to be bonded. The optimum is 0.1 - 0.2 mm, which provides the highest shear strength, avoids air bubbles and ensures close contact between the adhesive and the component surface.
Gap dimensions of min. 0.05 mm to max. 0.3 mm are tolerable. Larger than 0.3 mm, the gap dimension is too large for structural high strength, but it works with viscous, thixotropic resin.
