Apparatus for interlacing at least one staple fibre yarn with an elastane yarn

摘要

The appts. to combine a staple fiber yarn (F) with an elastane stretch yarn (E), by an air eddy action, has at least three jets (2,2',2) in succession where the yarns (F,E) are continuously eddied by air. The two outer jets (2,2) twist the yarns in one direction, and the center jet (2') twists the yarns in the opposite direction. A unit to block yarn twisting is in front of the first jet (2) and after the final jet (2) in the direction (A) of yarn travel. The yarn twist block is applied by yarn guides (3), offset from the axis of the jets (2,2',2). Each yarn guide (3) works with a yarn deflector (4), offset from the jet axis in the opposite direction to the yarn guide position. The yarn guides (3) and deflectors (4) are rotating rollers. The intervals are equal between the jets (2,2',2), at 30-80 mm and pref. 44 mm. The gaps between the yarn guides (3) and their adjacent jets are equal, but less than the gaps between the jets and pref. one-half the jet interval. The jets (2,2',2) are connected to an air reservoir chamber (1), with two air connections (5) to give an equal air delivery to all the jets (2,2',2). The air delivery to the jets is controlled by a proportional valve to set the air pressure as a function of the yarn travel speed. A controlled yarn brake is at the entry into the assembly (V), with a clamping force which is indirectly proportional to the yarn movement speed. The entry zone into the assembly (V) has a sufficient length to compensate for tension swings in the two yarns (E,F), or the staple fiber yarn (F) and the elastane stretch yarn (E) are fed into the system by separate feeds (6,7).