A
bellows tube manufacturing method and a
system for manufacturing
bellows tubes enables composing new mold block trains for molding a
bellows tube of a new pattern and sending the new mold block trains into a molding zone without requiring any preparatory operation and without stopping the bellows tube manufacturing
system, and manufacturing bellows tubes at
high productivity. Elemental mold blocks MBa, MBb, MBc and MBd necessary for composing a first mold block
train 20 and a second mold block
train 22 for forming elemental molds having molding surfaces conforming to the shape of a bellows tube to be manufactured are selected and arranged according to composition data specifying the numbers, types and order of arrangement of the elemental mold blocks MBa, MBb, MBc and MBd to compose the first mold block
train 20 and the second mold block train 22, and the mold block trains 20 and 22 are moved into a molding zone 24. A molten resin is extruded into a space between the mold block trains 20 and 22 moving in the molding zone 24 through an
extrusion die 25 by an extruder 26. The corresponding elemental mold blocks MB of the mold block trains 20 and 22 are clamped to form the elemental molds having cavities as the mold block trains 20 and 22 move in the same direction, and a negative pressure is produced in the cavities to mold a bellows tube. The elemental mold blocks MB of the mold block trains 20 and 22 returned from the molding zone 24 are sorted according to type.