Patent ID: 7284902

Claim:
A mixing tube comprising a first mixing passage and a second mixing passage, in each of which a plurality of elements having a sectional shape that changes continuously are connected in series, such that a plurality of types of materials to be mixed pass through the first mixing passage and the second mixing passage, whereby the materials to be mixed are repeatedly divided and aggregated in a passing process; wherein the first mixing passage and the second mixing passage are formed by a first outer frame member, a second outer frame member, and a partition member is interposed between the first outer frame member and the second outer frame member, the three members dividing the mixing tube in a direction toward which the materials to be mixed pass; wherein a plurality of holes, each having the same size as one another, are formed at fixed intervals in the partition member in a direction along which the materials to be mixed are mixed, such that the first mixing passage and the second mixing passage repeatedly divide and aggregate due to the holes, thereby repeatedly dividing and aggregating the materials to be mixed so that the materials to be mixed are divided 2 N times and merged together; and wherein said mixing tube comprises a soft thermoplastic resin which can be squeezed over its entirety with a predetermined force.