Characteristics and application history of carbon fiber golf clubs
The biggest advantage of carbon fiber golf clubs is their longer shafts and lower weight, so they can generate higher head speeds and have longer carrying capacity. The golf club must be able to pass the ball with further precision in the intended direction. To increase the "carry", it is most important to keep the club as light as possible to increase head speed and increase the initial speed of the ball.
In order to keep the club light enough, the key challenge is maintaining enough strength to prevent breakage. Toray Corporation of Japan, under the trademark TORAYCA®, has developed a standard elastic high-strength carbon fiber with an elastic modulus of 24 tf/mm2 and a medium-elastic high-strength fiber with an elastic modulus of 30 tf/mm2, which provides good flexural strength.
In addition, in recent years, there has been a demand for lightweight shafts that not only have flexural strength, but also have fracture resistance due to "insufficient torsional strength", Toray has further improved the elongation and strength of the highly elastic material in the bias layer, for higher performance.
As for the other desired properties regarding "directivity", it is important to make the shaft "torsion resistant (increased torsional stiffness)" to prevent the ball's directionality from being reduced due to center twist of the steering wheel. The axis of the shaft does not match the hitting point of the head.
When the layering angle is 0° or 90°, the torsional stiffness is the lowest, and when the angle is ±45°, the torsional stiffness is the highest; A highly elastic yarn with a modulus of 40tf/mm~2 is used as the standard twist-resistant bias material. Currently, torsional properties equivalent to steel shafts are achieved by using carbon fibers with a modulus of elasticity of 46 tf/m2 or higher.
Historically, golf clubs initially used hickory wood (known for their high strength and impact resistance) and other natural materials; thereafter, steel shafts appeared in the 1920s, and carbon fiber golf clubs became the mainstream, and has remained to this day.
Since Shakespeare developed the first carbon fiber golf club in 1972, other manufacturers have followed suit. Carbon fiber golf clubs then became the darling of the Japanese media because American G. Brewer, who won the Pacific Club Masters, used CFRP clubs made by Aldira.
In 1973, the Olympics released a club made in Japan with TORAYCA®/fiberglass fabric, which initially had a specification of 85 g/12° torque, but in the following year a 100% torque specification of 77 appeared. g/6.9° TORAYCA® product and created a large boom called "Black Axis" rotation.
A reel using prepreg is basically composed of a ±45° inner layer (called "corner layer" or "bias layer"), a longitudinal layer at 0° angle (called "straight stock"), and reinforcement/additional layers. Made of thick material. Axle properties such as "flexibility, torque, weight and kick point" are determined by how these layers are combined. Carbon fiber can optimally design these performance characteristics with minimal weight by combining the desired layering angles, thicknesses, etc., which is not possible with traditional metal materials.
In order to adjust the golf club's flexibility, torque, weight, kick point and other elements according to each golfer's physical strength, so as to give the club good portability and excellent directionality, the characteristics of carbon fiber can be used for design optimization, Carbon fiber is used in various types of shafts designed for high-level hitters of senior golf professionals and seniors, as well as female golfers. Today, almost 100% of wood and 65% of iron are made of carbon fiber. There is no doubt that this will continue to be an important material to support the development of golf.