To obtain a recyclable formed fiber material resistant to permanent set, having improved low resilience and low compression recovery and useful for a cushioning material, a filler, etc., by mixing a specific high-melting fiber with a weldable fiber and thermally welding the mixture.
A fiber block is produced by mixing (A) a high-melting fiber containing a polyester having a crystallinity of 22-30%, a crystal size of 2.5-4.5 nm, 2.5-4.5 nm and 2.0-4.5 nm at plane indices (010), (100) and (1 bar 05), respectively, the crystal size difference between the face indices of ≤1.0 nm, a crystal orientation degree of 50-85% and 30-80% at plane indices (010) and (1 bar 05), respectively, an amorphous part orientation degree of 0.15-0.40, an amorphous part density of 1.31-1.37 g/cm and an amorphous density/amorphous orientation ratio of ≥3.2 with (B) a weldable fiber containing a low melting polymer having a melting point lower than that of the fiber A on at least the outer surface of the weldable fiber, filling the mixture in a mold and welding by heating.
OTA TAKASHI
FUJIMOTO MASUMI
