| 摘要 |
<p>An effect yarn is produced by false twist crimping a thermoplastic yarn and varying the degree of heat set twist to give variable bulk along the length of the yarn. Production of variable bulk nylon etc. yarn. In a friction false twisting process in which the twist level is varied in the heating zone, yarn (1) is fed by input feed roller (2) to heater (3) where it is raised to the twist setting temperature. Then the yarn cools to below its second order transition temperature, preferably at least 20 degrees C below, before it encounters a twist snubbing device (4) comprising fixedly located, free running rollers (5,6) and a yarn guide (7) which can be reciprocated. From there, the yarn (1) passes to a friction false twister (8) having a ring-like friction bush (9) rotating on an axis (10), through which the yarn (1) is withdrawn via a guide (11), a wound up at (12). The snubbing yarn guide (7) is reciprocable between the rolling-bearing supported rollers (5,6) in a slot (19) in the base plate (14) and the varying twist level in the heating zone caused by such reciprocations gives rise to a bulk variation lengthwise of the yarn. An alternative twist snubber comprises a rod (24) pivoted at (25) and swingable (arrow 26) to alter the bending angle of the yarn and hence the pressure of the yarn (1) against the end of the rod (24).</p> |
