Generation 1.5

The success of the Generation 1 RCF paddles led to new innovations. What has retroactively been called Generation 1.5 was first seen in the JOOLA Ben Johns Hyperion CFS paddle (approved on April 1, 2022). The reason these paddles have been termed Generation 1.5 rather than Generation 2 lies in the fact that they only use thermoforming in a limited context.

Foamed Edge

The main change in the Generation 1.5 paddles is the addition of a foamed edge (Figure 5). Taking a cut out Generation 1 paddle blank (the three-layer structure of a facesheet on either side of the PP honeycomb core), uncured foam is injected along the edge of the paddle. This structure is then placed into a hot press molding machine. During the heating and curing cycle, the foam expands and fills the open PP honeycomb cells around the edge. After this thermoforming process, an edge guard is placed around the paddle. However, because the paddle blank is constructed as a Generation 1 paddle, the epoxy glue is already dispersed and fully attaches the facesheets to the PP honeycomb core. As a result, the foamed edge is not connected to the facesheets and only fills out the open cells of the PP honeycomb core. This thermoforming process thus does not create a fully unibody paddle.

Figure 5. Dissection of a JOOLA Ben Johns Hyperion CFS paddle reveals a foamed edge (yellow). (source)

Benefits of a Foamed Edge

The primary benefit that the foamed edge provides is enlarging the sweet spot of the paddle. Hits that are farther from the center still feel more stable. In terms of physics, by adding weight on the edge of the paddle, the moment of inertia of the paddle increases. The further weight is from the axis of rotation, the more resistance to rotation it provides. This makes the paddle less willing to rotate on off-center hits, thus creating a larger sweet spot. This effect can also be achieved through other methods of increasing the weight on the edge of the paddle, such as adding lead tape around the edge of the paddle.