RCF Paddle Evolution

RCF (Raw Carbon Fiber) Paddle

The RCF (Raw Carbon Fiber) paddle is known for its exceptional spin and power capabilities. Over time, these paddles have undergone various improvements and technological advancements, making them even more impressive.
One of the standout features of the RCF paddle is its textured surface, which plays a crucial role in its success. This unique texture allows the paddle to generate a significant amount of spin on the ball, revolutionizing the way the game is played.

RCF manufacturing process

The RCF manufacturing process involves the layering of three plies of unidirectional carbon fiber prepregs in a rectangular shape, typically measuring 500 mm by 600 mm. These plies are placed on top of each other in alternating perpendicular directions to ensure optimal strength and stability in the final product.
Prior to the layering process, the carbon fiber prepregs are pre-impregnated with epoxy resin, which enhances their bonding properties and overall durability. This resin acts as a binding agent, ensuring that the carbon fibers remain securely in place during the manufacturing process.
Additionally, a peel ply is placed on the outermost layer of the carbon fiber prepregs. This peel ply serves multiple purposes, including protecting the surface of the composite and facilitating the removal of excess resin during the curing process.
Once the layers of carbon fiber prepregs and peel ply are properly arranged, they are placed into a hot press molding machine. Hydraulic presses apply pressure to the mold, while the entire assembly is subjected to high temperatures for curing. This process allows the epoxy resin to flow and fully impregnate the matrix of carbon fibers, ensuring a strong and cohesive final product.
After the curing cycle is complete, the carbon fiber reinforced composite face sheet is carefully removed from the mold. This face sheet is the outermost layer of the composite and showcases the raw texture of the matrix resin.
It is worth noting that during the curing cycle, the peel ply fabric absorbs some of the epoxy resin from the matrix. As a result, it becomes an integral part of the laminate. When the peel ply is peeled off, it fractures the resin between it and the first layer of carbon fiber reinforcement. This process leaves behind a fresh, clean, and roughened surface of matrix resin, contributing to the unique raw texture of the final product.

FIRST GENERATION RCF PADDLE Cold Mold

The first generation RCF paddle, also known as "cold mold" paddles, gets its name because the manufacturing process does not involve heat, except for the hot press molding of the face sheet. The process starts by precutting polypropylene (PP) honeycomb cores into a panel of specified thickness (14mm, 16mm), measuring around 500 mm x 600 mm. Epoxy glue is then used to attach face sheets on both sides of the PP core, applying pressure to ensure a strong bond. To create the paddle blanks, a computer numerical control (CNC) machine is utilized to cut them out from this three-layer laminated structure. It's important to note that the paddle blanks have exposed PP honeycomb cores along the sides, which necessitates the placement of an edge guard around the paddle.

SECOND GENERATION RCF PADDLE Foamed Edge

The Second-Generation RCF Paddle introduces a significant change with the addition of a foamed edge. This innovative feature involves injecting uncured foam along the edge of the paddle blank, which consists of a three-layer structure with face sheets on either side of the PP honeycomb core. The paddle blank is then placed into a hot press molding machine, where the foam expands and fills the open cells of the PP honeycomb core around the edge. After the thermoforming process, an edge guard is applied to the paddle. However, since the paddle blank is constructed as a Generation 1 paddle, the foamed edge is not connected to the face sheets but only fills the open cells of the core. Consequently, the paddle does not become a fully unibody paddle through this thermoforming process.

The foamed edge of the Second-Generation RCF Paddle offers several benefits, with the primary one being the enlargement of the sweet spot. Even hits that are farther from the center of the paddle feel more stable due to this feature. From a physics perspective, the addition of weight on the edge of the paddle increases its moment of inertia. The further the weight is from the axis of rotation, the more resistance it provides against rotation. As a result, the paddle becomes less prone to rotating on off-center hits, thereby creating a larger sweet spot. It's worth noting that this effect can also be achieved by alternative methods, such as using lead tape around the edge of the paddle to increase its weight.

THIRD GENERATION RCF PADDLE Thermoforming

The Third-Generation RCF paddle is characterized by its extensive utilization of thermoforming. Thermoforming is a process that involves heating up plastic and shaping it into the desired form. In the case of the Third-Generation paddle, the foamed edge, which was previously seen in Second-Generation paddles, is also thermoformed. However, the manufacturing process for the Third-Generation paddle goes beyond just thermoforming. It employs hot press molding, which is used in the fabrication of the face sheet for all RCF paddles. In the case of Third-Generation paddles, hot press molding is utilized throughout the entire manufacturing process, ensuring a high-quality and durable product.
The latest generation of paddles follows a similar design and uses the same materials as the previous ones. However, there is a notable difference in the manufacturing process. Instead of using epoxy glue to join large sheets of material together before cutting them into paddle shapes, the face sheets and PP honeycomb core are now individually cut into paddle shapes. These components are then assembled in a three-layer structure, with a carbon seam foam edge added around the perimeter.
Once the paddle components are assembled, the entire structure is placed into a mold and then into a hot press molding machine. This thermoforming process is crucial as it bonds the layers of the paddle together and gives shape to the Third-Generation paddle. The application of heat and pressure during thermoforming allows the epoxy resin to flow and disperse evenly between all the layers, including the face sheets, PP honeycomb core, and carbon seam foam edge.

The result of this advanced manufacturing technique is a paddle that boasts a unibody construction, making it significantly stronger than its predecessors. The heat and pressure applied during the thermoforming process ensure that the epoxy resin fully integrates with all the layers, creating a durable and robust paddle that can withstand the rigors of intense use. This innovation in paddle manufacturing has led to a noticeable improvement in performance and durability for the Third-Generation paddles.
The new paddles are made using the same materials and structure as the older ones, but with a different process. Instead of gluing large sheets together and then cutting them into paddle shapes, the face sheets and PP honeycomb core are first cut separately and then attached in a three-layer structure.
A carbon seam foam edge is added around the edge for extra reinforcement before the entire structure is placed into a mold. This mold is then put into a hot press molding machine for the thermoforming process, which bonds all the layers together to create the Third-Generation paddle.
The application of heat and pressure during thermoforming allows the epoxy resin to flow and disperse fully between all the layers of the paddle. This results in a unibody paddle that is much stronger than the previous generation paddles, making it more durable and reliable for players.

Delamination, Disbonding, and Crushed Core

Many players began to notice a strange popping sound and an increase in power when using the Third-Generation paddles a few months after their release. Upon investigation, it was discovered that these paddles had experienced a loss of structural integrity. This problem has been identified as delamination, disbonding, and crushed core.

• Delamination specifically refers to the separation of the carbon fiber plies in the face sheet of the paddles.

• Disbonding, on the other hand, refers to the separation of the face sheet from the PP honeycomb core.

• Lastly, crushed core refers to the issue of the PP honeycomb core being crushed and losing its structural integrity. While these terms are often used interchangeably, it is important to note that delamination itself is quite rare, whereas disbonding and crushed core are more commonly observed issues.

The issue at hand can be traced back to the design and manufacturing process of the Third-Generation paddle. The thermoforming fabrication process used to create the paddle's PP honeycomb core introduces slight variations in thickness at a microscopic level, despite the core appearing flat and smooth to the naked eye.
These variations in thickness result in small gaps between the face sheet and the PP honeycomb core, allowing air to occupy the space in between. Additionally, the carbon seam foamed edge surrounding the paddle forms a completely enclosed unibody structure.
When subjected to high temperatures and pressures, the air trapped within the imperfections of the PP honeycomb core expands, generating significant internal pressure. As a consequence, certain areas of the core may become crushed. Over time, as the paddle is used and the ball repeatedly strikes it, more sections of the core experience compression.
Instead of the ball making direct contact with a solid surface, the crushed areas of the core create a trampoline-like effect. This phenomenon is further amplified by the pockets formed by the crushed core, resulting in a bouncier response when the ball hits the paddle.

FOURTH GENERATION RCF PADDLE Carbon Fiber Grid Foamed Edge

The Fourth-Generation RCF Paddle introduces a new design element by incorporating a carbon fiber grid along with foam on the edge of the paddle. This is a departure from the Third-Generation paddle, where foam was injected along the edge and encased in a fully enclosed carbon seam layer.
In the Fourth Generation paddle, the fully enclosed carbon seam layer is replaced with a carbon fiber grid layer. This grid is permeable, unlike the previous carbon seam layer, which was not. The rest of the paddle's construction and thermoforming process remains the same.
During the curing process, the epoxy resin is carefully configured to flow and disperse fully, ensuring that the carbon fiber grid foamed edge, face sheets, and core are securely fastened together. This innovative design has two main advantages - it addresses structural issues like delamination, disbanding, and crushed core, and it also enhances the overall balance of the paddle, providing both power and control to the player.

The problem of delamination/disbonding/crushed core in the Third-Generation paddles has been successfully addressed. It was discovered that the root cause of this issue was the failure to release internal pressure during the thermoforming process.
The carbon seam layer along the edge was found to be impermeable, leading to the buildup of pressure within the paddle. By introducing a carbon fiber grid that is permeable, the internal pressure can now be effectively released during thermoforming.
This innovative solution has proven to greatly minimize the risk of delamination, disbonding, and crushed core in the paddles, ensuring a higher quality and more durable product for our customers.

Conclusion

In summary, the initial RCF paddles from the first generation excel in producing a high level of spin, enhancing the player's ability to control the game.
Moving on to the second generation RCF paddles, they maintain the spin and power capabilities of the first generation but offer an improved feel due to an enlarged sweet spot, catering to players looking for a more comfortable playing experience.
The third generation RCF paddles take it up a notch by delivering exceptional power, although there is a trade-off with the risk of a crushed core, which players need to be cautious about.
Finally, the fourth generation RCF paddle stands out as the strongest yet, surpassing its predecessors in strength while also significantly reducing the likelihood of a crushed core. This makes it the ideal choice for players seeking the perfect balance between power and control on the court.