Bushing and method for producing glass fiber

A method for producing glass fiber, the method comprising:

• supplying molten glass to a bushing;
• drawing out a plurality of glass filaments from the bushing;
• and then
• gathering the plurality of glass filaments into a strand, wherein
• the bushing includes
• a base plate and
• a nozzle group provided at a bottom surface of the base plate,
• the nozzle group includes
• a first nozzle row in which a plurality of first nozzles are aligned, and
• a second nozzle row in which a plurality of second nozzles are aligned, the second nozzle row being arranged adjacent to the first nozzle row, and
• the foregoing relations (1) to (6) are satisfied:
• y1≤Y≤y2 (1)
• y1=4/3×X+3 (2)
• y2=4/3×X+8 (3)
• X=D14/Lt (4)
• Y=A3−(A1+A2) (5)
• A3=L1×L2 (6)
• where, for each of the plurality of first nozzles and the plurality of second nozzles, D1 is a nozzle hole inner diameter [mm], Lt is a nozzle flow path length [mm], A1 is a nozzle hole cross-sectional area [mm2], and A2 is a nozzle wall cross-sectional area [mm2],
• L1 is an interval [mm] between the centers of adjacent first nozzles in the first nozzle row and an interval [mm] between the centers of adjacent second nozzles in the second nozzle row, and
• L2 is an interval [mm] between the center of the first nozzle row in a row width direction and the center of the second nozzle row in the row width direction.