Flying Towards The Hole – Modern Developments In The Materials of a Golf Ball

It is estimated that manufacturers produce 1.2 billion golf balls each year, and polymer scientists have been devoting significant resources to researching materials that can improve the ball’s performance. The contemporary golf ball is a prized accomplishment of modern engineering, and manufacturers are adapting the aerodynamics of the golf ball’s flight by varying the construction of its core layers and dimple covering. Golf balls are primarily composed of polymers and rubber materials, and most professional golfers in recent years have moved from a two-piece golf ball with a thick core to a multi-layer golf ball with a solid rubber center and an outer layer composed of a soft cover.

A three-piece golf ball construction with an inner core, an outer core, and an outermost cover. 

Despite the relative constancy in its overall appearance, modern developments in the inner materials of a golf ball have improved the distance and spin of the object during its flight. The use of synthetic rubbers, such as polybutadienes, has helped with the ball’s elasticity, while the application of a polyurethane cover has aided in the ball’s transfer of energy upon impact. Through innovations in the materials that make up the golf ball, as well as computational simulations that can optimize the ball’s pattern design, polymer scientists have been able to discover new technologies to satisfy the demands of professional golfers.

The materials of a golf ball alter the object’s efficiency and durability, and the newest ball is being infused with the material graphene, an allotrope of carbon, in order to improve the object’s performance. Graphene is not only an ultra-thin sheet of carbon, but it is also the strongest known material on Earth.

The new Callaway Chrome Soft golf ball relies upon graphene as a flexible, yet durable nanomaterial

The thin outer core of the modern golf ball from graphene allows manufacturers to make the inner core of the ball a larger size, which increases the ball’s launch angle and allows for greater distance on longer shots with a reduction in spin. The larger core means that there is a higher level of reactive materials in the golf ball that can maximize its velocity. The added protection from the stronger outer core of the ball also allows the inner core of the ball to have a softer feel. 

Graphene currently being infused in golf balls is an additive mixed with other materials, and manufacturers are tending to combine graphene with a soft urethane cover on the outer layer of the ball. Urethane is able to grip the graphene when the ball is struck by the golf club, which gives it an increased durability and improved scuff resistance. The urethane cover allows the golfer more control due to higher backspin rates on iron and wedge shots around the green, and it does so without losing any distance on the ball.

Urethane covered balls show greater backspin with higher friction values than surlyn covered balls.

Urethane covered multi-piece balls can more effectively reduce the compression of the ball than surlyn-covered balls. These polyurethane covered balls deform more under the large impact of the golf club than ionomer covered balls, and the deformation gradually increases as the cover hardness of the ball is reduced. The deformation of the ball reduces the compression value and allows for a greater area of the ball to come into contact with the face of the club. 
 

The most common three-piece golf balls have a resilient inner core made from synthetic rubbers, which are then mixed with metals like titanium or materials like acrylate. Technological advances in science have allowed polymer researchers to conclude that the most effective golf balls are those with inner cores composed of polybutadiene rubber blends. The application of polybutadienes in the inner core of golf balls has proved to be so valuable because the polymers can blend with other types of rubbers and materials.

Modern golf balls have between 300 and 400 dimples on the outermost cover with an average depth of 0.010 of an inch, and the dimple pattern designs on the ball reduce the drag, and increase the lift, of the object during its flight. 

The dimples minimize the size of the wake region that forms behind the ball, and the pressure pulling back at the ball from behind is reduced because the thin boundary layer diminishes the drag effect. Moreover, dimples on the outermost layer of the modern golf ball promote an asymmetry in the flow of the wake behind the ball, and the downward deflection of the wake, due to the decrease in pressure on the upper surface of the ball, allows the object to lift higher in the air.

With a dimpled golf ball, the streamline flow of air clutches the ball’s surface, which creates a smaller, low-pressure region behind the ball in comparison to a smooth sphere.

Polymer scientists continue to explore small modifications in the depth, surface area, and shape of the dimples on the golf ball because slight changes can modify its performance. Recent research has shown that when modern golf balls have shallower dimples, or when each individual dimple on the ball is enlarged, the ball’s lift coefficient typically increases. 

The flying distance of the ball is inversely proportional to the dimple depth, and shallow dimples are able to generate more spin on the ball than those with deep dimples. Moreover, modern computational science has shown researchers that golf balls with larger surface roughness, due to their large-sized dimples, are able to scoop the turbulent flow around the ball and reduce the drag effect.

There are an endless number of possibilities for the design and construction of the golf ball, and polymer scientists have radically altered the ball’s performance over the last decade through their technological advances. The continual developments in the design of the modern golf ball has improved the dynamics of the ball’s flight, and progress in computer simulations and mathematical research has provided professional golfers with unprecedented control over the height, distance, and shape of their shots on the course. Manufacturers continue to modify the composition of the golf ball’s materials, along with the size and number of dimples on the ball, to adjust its performance. The evolution of the materials that compose the inner and outer core layers of the golf ball, along with the ball’s cover, have fundamentally changed its aerodynamics.

The materials of the golf ball have become so advanced that recently Jack Nicklaus, perhaps somewhat enviously, claimed that the modern golf ball might even fly too far. With the introduction of new technologies, scientists may deserve their own “Green Jacket” for determining future golf tournaments within their laboratories.