CORE MATERIAL FOR BASE PART OF SHUTTLECOCK, AND METHOD FOR MANUFACTURING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a core material for a base part of a shuttlecock with improved durability.SOLUTION: A core material for a base part of a shuttlecock includes a foaming agent between cork particles. A difference between a number average diameter in a maximum aspect diameter of the foaming agent in a first region and a number average diameter in a maximum aspect diameter of the foaming agent in a second region outside the first region in the interior of the core material for the base part of the shuttlecock is within 15 microns. The foaming agent preferably includes one that covers hydrocarbon with a thermoplastic resin.