Introduction
The introduction of raw carbon fiber (RCF) paddles has been one of the major innovations in the game of pickleball. These paddles provide greatly improved spin and power generation and have become increasingly popular among pickleball players. Since their introduction, RCF paddles have gone through a series of improvements and technical evolution. In this paper, we will go through the main technological developments of RCF paddles. Note that the following terminology of generations, up to Generation 2, was originally coined by Chris Olson of Pickleball Studio. All release dates are based upon the approval date by the USAP approved paddle list.
Generation 1 RCF
The first model to popularize the use of RCF was the Electrum Model E (approved on June 5, 2021). Since then, countless brands have released their own RCF paddles. In this section, we review the main technology behind Generation 1 RCF.
RCF Facesheet
Anyone who has played with a RCF paddle before will have noticed the textured surface on the paddle. This RCF textured surface is one of the keys behind the paddle’s success. It enables the paddle to generate lots of spin on the ball and has changed the way the game is played.
A typical manufacturing process for a RCF facesheet is described here. Three plies of unidirectional carbon fiber prepregs in the rectangular shape are laid on top of one another in alternating perpendicular directions. A common dimension used in the industry is 500 mm by 600 mm. Carbon fiber prepregs are carbon fiber ply that have been pre-impregnated with epoxy resin. As shown in Figure 1, if we define the direction along the axis of the paddle to be 90 degrees, and the direction perpendicular to that axis to be 0 degrees, then the three unidirectional carbon fiber prepreg plies are placed in a 90-0-90 orientation. Further, a peel ply is placed on the outer most layer. JohnKew Pickleball has a video describing how peel ply works.
Figure 1. Paddle with axes defined.
Three plies of unidirectional carbon fiber prepregs, along with the peel ply, are placed into a hot press molding machine (Figure 2). The upper mold is aligned with the lower mold symmetrically and the mold halves are closed. Pressure is applied using hydraulic presses while the mold is cured at high temperature for a certain amount of time. While curing, the epoxy resin is configured to flow and fully disperse and impregnate the matrix of carbon fibers. After the cooling cycle, the carbon fiber reinforced composite facesheet is removed from the mold.
Figure 2. A hot press molding machine. Molds are placed in between metal trays while heat and pressure are applied.
During the curing cycle of the manufacturing process of the composite, the peel ply fabric absorbs some of the matrix epoxy resin and becomes an integral part of the laminate. When this fabric (peel ply) is peeled off, the resin between it and the first layer of carbon fiber reinforcement is fractured. This leaves a fresh, clean, roughened surface of matrix resin, thus the raw texture. Figure 3 shows how the peel ply can be removed from the facesheet.
Figure 3. Peel ply (semi-opaque top layer) is removed from the underlying carbon fiber facesheet (black).
Paddle Construction
Generation 1 paddles are often called “cold mold” paddles. This is because apart from the facesheet, which is pre-made with hot press molding, the rest of the manufacturing process does not involve heat. Polypropylene (PP) honeycomb cores are precut into a typical 500 mm x 600 mm panel of the specified thickness (e.g., 16mm). Facesheets are attached on either side of the PP core with epoxy glue under pressure. Figure 4 shows the three-layer structure before it is laminated together. A computer numerical control (CNC) machine is then used to cut out paddle blanks from this three-layer laminated structure. Note that these paddle blanks have their PP honeycomb cores exposed along the side, thus requiring an edge guard to be placed around the paddle.
Figure 4. Three layers of the facesheet, PP honeycomb core, and then another facesheet. The top facesheet still has its peel ply on. The bottom facesheet peel ply is face down on the table.
0 Comments
David Block
Clear, concise, very well-written: in other words, unusual these days in someone under the age of 50 - and I'm guessing you are. For old folks (like me; turned 77) communication like this is just what we need to see in order to have confidence in the product. I just took delivery of a Ronbus paddle because I need to soften my game and make it more...mmm...sophisticated. (I.e., I'm too old to power the ball through folks any more). I'm hoping my Ronbus will kind of nudge me in that direction. We'll see. In the meantime, my R1 has a subtle look, which I like, and a very gentle balance. Again, for older folks, paddle balance is crucial since many of us have compromised balance for any of several reasons (e.g., peripheral nerve, spinal stenosis, medication effect, etc.). So whoever designed and engineered the paddle did a very nice job, which attracts old coots of both/all genders. Regards.