Abstract
The feed tension of the core filament and the drawing tension at the reel are the most important factors on the manufacture of the compound filament. In the first place, the compound filaments were manufactured under the different feed tensions and with the different sizes. The core lengths of them, then, were measured for discussion of the feed tension.
In the next place, the compound filaments and the raw silk were elongated in the drenched state and after drying the strain recovery was measured for discussion of the drawing tension. The following results were obtained:
1) It was made sure that the feed tension of the core filament extends the core of the compound filament in proportion to the feed tension.
2) The upper limit of the drawing tension at the reel was experimentally obtained from the relation between the drawing tension and the recovery of the elongation. In the actual manufacturing, the drawing tension was sufficiently smaller than that.
3) It sometimes happens that the cohesion between the core filament and the cocoon fibers is broken by itself. This can be classified into two cases: the first is the case that the feed tension of the core filament is not suitable, the second is the case that the drawing tension at the reel is too large. Though the external views of the compound filament's in which break down of the cohesion causes are similar, they are not the same.
