TRPX International
TRPX JAPAN
1.Materials and quality maintenance
・For shaft manufacturing, we use a sheet-like material called carbon prepreg. ‘Pre-Preg’ stands for ‘Pre-Impregnated’ and is a material made of carbon fiber impregnated with resin, which is why carbon appears black. There are dozens of types of prepreg materials used for shafts, each with different elastic modulus and weight, including the strength (modulus of elasticity) of the thread, the weight of the thread, and the content and type of resin. If the carbon sheet is exposed to the outside air for a long time, the resin will volatilize, making it completely unusable. Therefore, at TRPX, we maintain the quality of carbon sheets by storing them in our in-house freezer set at -15℃. The story of TRPX shafts begins with this quality control.
2. Development
TRPX uses a variety of materials in the creation of each shaft. The selection of materials is based on the unique characteristics of prepreg, tailored to the specific goals of the new product. Considerations include the product’s theme, such as movement characteristics, as well as factors like weight and hardness.
Prepeg possesses a fiber direction, or grain, and the orientation in which it is employed is crucial. TRPX predominantly employs the following orientations: 90° = straight layer / 45° = bias layer / 0° = hoop layer. By summarizing these elements, we can determine the elastic modulus, thread weight, resin content and type, fiber direction, and even the inclusion of metal fibers.
3. Carbon Winding
The cut carbon is shaped into the form of the shaft by winding it around an iron rod known as a mandrel. To ensure weight consistency, glass sheets are wrapped around iron shafts, maintaining a constant balance. Subsequently, the carbon is rolled by rotating it and applying pressure with a machine called a rolling machine. This process is meticulously executed to ensure the thorough removal of air during rolling. The starting position of each section is carefully controlled by adjusting the initial position, preventing bias in flex and shape.
4. Heat Treatment
The rolled shafts are baked in a kiln for two and a half hours at 180℃. The hardness of the shaft is significantly influenced by the baking method, with temperature and time playing crucial roles in determining the final finish of the shaft.
5. Polishing work
At TRPX, we pay close attention to the final polishing process. Vibration frequency is measured from 4 directions and 2 locations (butt and tip). It is carefully polished using a modern wrench to ensure that the CPM (Cycles Per Minute) remains consistent from any direction. CPM is a measure obtained by fixing the grip side, vibrating the head, and counting the number of movements in one minute. This value serves as the standard for shaft hardness.
Through many years of experience, TRPX understands precisely which parts of the shaft need polishing to meet standards. Each part is polished in 0.01mm increments. Even a single polishing, depending on the force applied, can alter the properties of the shaft. Therefore, this delicate process cannot be replicated by amateurs.
Since this entire process is done by hand, it becomes a true test of the craftsmen’s skills.