| 摘要 |
PURPOSE:To decrease twisting of filament coils by specifying each line diameter of a tungusten heater and a primary mandrel and the winding pitch of a tungusten strand. CONSTITUTION:The ratio D1/d1 of the wire diameter d1 of tungusten heater 1 to that D1 of a primary mandrel 2 which is finally dissolved and removed is assumed to be about 1.0<D1/d1<3.0 and the ratio G1/d1 of the pitch space G1 of a tungusten strand which is spirally wound on the wire 1 and the wire diameter d1 of the wire 1 is assumed to be about 0.5<G1/d1<2.0. This can decrease mutual twisting of filament coils and improve the their production yield. |
