using traditional spinning or compound spinning methods to produce a yarn whose filament size is below 0 5 denier the traditional spinning method which usually occurs after a false twisting process uses a single polymer under traditional conditions and with traditional equipment to spin out continuous long fiber yarn whose filament size is below 0 5 denier the continuous long fiber yarn is subsequently false twisted and processed into ultra thin fiber textured yarn whose filament size is below 0 5 denier in contrast the compound spinning method which usually occurs after a false twisting process uses two different polymers under traditional conditions and with traditional equipment to spin out continuous long fiber yarn whose filament size is below 0 5 denier the continuous long fiber yarn is subsequently false twisted and processed into ultra thin fiber textured yarn whose filament size is below 0 5 denier the second material used to manufacture the invention of this patent application is thermoplastic fiber with self winding elastic characteristics the thermoplastic fiber is obtained by configuring two thermoplastic polymers of different shrinkages into a fiber cross section by spinning with a compound spinneret having the desired proportionality the different contraction stresses between the interfaces of the two thermoplastic polymers with different shrinkages form spring like screw and generate self winding elasticity see the manufacturing diagram shown in fig2 to form the ultra thin fiber textured yarn with elastic characteristics of this invention thermoplastic.