How to bond carbon fiber
How to bond carbon fiber reinforced polymer (also known as CRP or CFRP)?
This is a composite material with extremely high structural strength making it popular for high impact or highly stressed applications.
It is lightweight, and there is a strong requirement for adhesives
for bonding this material as it cannot be welded and mechanical fasteners
not only add to the component weight, rattling and vibration loosening but can affect the structural integrity of the material if it has to be drilled.
- Aerospace and defense
- Automotive – especially high-end and racing
- Sports equipment – golf clubs, fishing rods
- Medical prosthetics
- Bicycle frames and motorcycle parts
- Wind turbines
Tips for surface preparation:
1. Degrease with Permabond Cleaner A or isopropanol (do not use meths or white spirits as this can leave a residue).
2. Lightly abrade by one of the following methods
-Wet and dry grit paper (carborundum paper) 320 grade recommended.
-Red Scotchbrite pad
3. Degrease again to remove any contamination or loose particles.
It is OK to bond as received but if you wish to have a consistent bonding surface and better mechanical keying of the adhesive then it is recommended to carry out this surface preparation.
What is the best adhesive to bond carbon fiber reinforced polymer?
Several types of adhesives bond well. Understanding the desired cure process as well as what the bond will need to endure will help us choose the best adhesive for each carbon fiber application.
Cyanoacrylate – also known as instant adhesives, super glue, crazy glue, ca glue, etc. For bonding carbon fiber reinforced polymer consider a black, toughened grade such as 735 low viscosity or 737 medium viscosity.
Single component epoxies – Permabond ES5681 has been developed especially for bonding carbon fiber. Offering high strength structural
performance as well as color matched appearance. Permabond also
offers low viscosity clear ES560 which can be used to encapsulate fibers
Two component epoxies – Permabond ET5428, ET5429 and
MT382, MT3281 have been developed specifically for bonding CRP.
Structural acrylics – MMA grades such as TA4246 are very strong carbon fiber bonders.
Polyurethane adhesives – All Permabond polyurethane adhesives offer high strength, high peel strength, and good impact resistance.
With so many choices of adhesives to bond carbon fiber, the desired cure process, the desired environmental resistance, and the desired temperature resistance are key factors in choosing the best adhesive for each application.