MFC, Cobra International, and Aditya Birla Chemicals present a sustainable solution for closed-loop recycling of watersports fins.


  1. Contributes to circular economy and a sustainable world
  2. Groundbreaking thermoset composite recycling
  3. End of life recycling and recovery of composite components
  4. Closed-loop recycling process enabled
  5. Production tooling recycled in house


MFC HAWAII, working with partners Aditya Birla and COBRA International is taking a massive leap forwards in sustainable development by incorporating recyclable epoxy thermoset systems into production. Using Aditya Birla’s recyclable epoxy systems Epotec YDL5552-THR9351 to infuse watersports fin molds and the recyclable epoxy RTM system Epotec YDL5540-THR9151 to produce components, COBRA and MFC have initiated a sustainable closed-loop recycling process that will significantly reduce composite material waste volumes. Aditya Birla’s novel recyclable epoxy system of Epotec YDL5552 resin and Epotec THR9351 hardener based on proprietary Recyclamine® technology was used to infuse fin tooling, enabling recycling & recovery of the reinforcement and matrix at the end of the tool’s life. 

COBRA CNC machined the fin tooling from infused fiberglass blocks. The mold consisted of 2 x 25mm thick E- glass plates that were infused at 40˚C, then cured at 60˚C for 3 hours before a final post-cure at 80˚C for 8 hours. The laminate stack used 100 plies of 100gsm plain weave glass fabric at the part surface, backed up with 22 layers of 160gsm plain weave fabric, and 16 layers of a 1200gsm stitched triaxial E-glass cloth. COBRA manufacturers MFC fins using this tooling and an RTM process using Aditya Birla’s recyclable RTM system Epotec YDL5540-THR9151.

Typically fins use woven glass and carbon fiber fabric preforms with some parts also using core materials. The novel Aditya Birla resin technology enables the epoxy resin matrix in composite to cleave using a low-temperature recycling process. By conditioning the selected components or molds in an acidic solution at around 80-90˚C for 2 hours, a cleavage mechanism is triggered that breaks the cured thermoset bonds. Reinforcements can be removed when the matrix is dissolved, then the resin solution is filtered and neutralized allowing the re-usable thermoplastic polymer to coagulate and be removed from the solution.