BASE MATERIAL FOR HONEYCOMB CORE AND MANUFACTURE THEREOF

PROBLEM TO BE SOLVED: To provide a base material for a honeycomb core which allows the penetration of an adhesive or a reinforcing resin to be controlled and also can be smoothly spread on a honeycomb structure after lamination and adhesion without the strike- through of an adhesive applied in a strip fashion on one face of the base and further can be used for economically manufacturing a honeycomb core which can be formed into such a state that the resin penetrates into the outer lateral part without the penetration of the resin into the center part by controlling the penetration of the resin into the cell wall of the honeycomb structure so that the resin penetrates into an appropriate depth with advantage such as lightweight, outstanding durability, high water resistance, moisture resistance, corrosion resistance and heat resistance, and provide also a method for manufacturing the base material for the honeycomb core. SOLUTION: This base material for a honeycomb core is made of an unwoven fabric which shows 4.0 km or more average value of tear-breaking length in the longitudinal and the width direction at the time of 5% elongation and 0.05-5.0 cc/cm2. sec. of air permeability. The base material for the honeycomb core is smoothly manufactured by forming an unwoven fabric in which a polyester fiber of 0.170 or more of double refraction (Δn) and 0.10-0.60 g/d of heat contraction stress at 200 deg.C in provided at least partly in the main fiber.