Glass wound body and manufacturing method for same, and method for manufacturing composite material

A method for manufacturing a glass wound body formed by a single glass strand being wound up about an axis of rotation, the method comprising the steps of:

• applying a sizing agent to surfaces of a plurality of glass filaments to bundle the plurality of glass filament together and thus form a glass strand;
• winding up the glass strand while traversing the glass strand by moving the glass strand back and forth in a direction of extension of the axis of rotation and thus making a wound package;
• and
• drying the sizing agent to form a film on the surfaces of the glass filaments,
• wherein where, in a range in which glass filaments constituting the glass strand have a diameter of 28 μm or less, a count of the glass strand is represented by X tex and a diameter of the glass filaments is represented by Y μm, X/Y2>8 is satisfied, and
• wherein in the step of making the wound package,
• where, as viewed from the direction of the axis of rotation, an angle formed between a line connecting the axis of rotation and a starting point of winding of the glass strand and a line connecting the axis of rotation and a point where the glass strand is located after start of the winding is represented by θ, where a single travel of the glass strand for a distance of a line connecting both ends of the glass wound body in the direction of the axis of rotation is referred to as a one-way travel, and,
• where, during traveling of the glass strand from the starting point of winding to a first return point at which the angle θ reaches 0°, a number of the one-way travels of the glass strand is represented by T and a number of rotations of the glass strand about the axis of rotation is represented by N,
• the glass strand is wound up to satisfy 2.0≤N/T≤5.5.