Composite Spool Case Study
CSS was tasked to design and develop a lightweight FRP composite spool for use in a performance sporting goods application. The composite part had to perform like the incumbent machined aluminum spool, mate with existing hardware, and visually communicate a high end product story.
Composite Spool FEA Model
Radical shape changes and high out of plane load conditions made for a challenging composite product development effort. CSS conducted several design and manufacturing trade studies before settling on a viable solution; a pultruded hollow composite core bonded inside a Bladder Inflation Molded composite shell.
Carbon fiber braided biaxial sleeving provided continuous reinforcement from the first wide flange edge, down and through the small diameter hub, and back up to the opposite flange edge. A carbon fiber reinforced sandwich construction on the backside of each flange layup provided the required out of plane stiffness and strength.
Carbon Fiber Composite Spool Assemblies
CSS fabricated custom silicone bladders to bladder mold the carbon fiber shell in clamshell tooling. Shell preforms were laid up over an internal form and infused with epoxy resin during the bladder molding process. The pultruded hollow core was bonded inside the molded shell using a quick set epoxy adhesive.
Several carbon fiber composite spool prototypes were successfully fabricated and tested to demonstrate concept feasibility. CSS' composite spool design was found to be 30-40% lighter than its aluminum counterpart and the outer carbon fiber braid layer delivered the desired visual story.