Abstract: In a stretch yarn (1) comprising a stretchable core (2) covered by an inelastic fibers sheath (3) the stretchable core (2) comprises first and second fibers (4, 5) that have elastic properties, the first fiber (4) is an elastomer and the second fiber (5) is a polyester based (co)polymer, the amount of the second fiber being in the range of 60-90% (w/w) of the total weight of the fibers of the stretchable core (2); the first and second fibers are connected together at least at a plurality of points (P).

Abstract: A bottom tenser utilized for a drafting means of a spinning frame, especially for fasciated yarn spinning, in which a fiber bundle is attenuated at a high speed exceeding 100 m/min. The bottom tenser as well as a bottom roller corresponding to the tenser is provided with a free end through which an apron is easily removable from and mountable on the tenser and the roller. The tenser may be constituted by a body and at least a guide wall movable relative to the body. The guide wall prevents lateral movement of the apron in its operative position and, in turn, is displaced or removed from the body in its non-operative position so as not to obstruct an apron exchanging operation.