A filamentary core for an elastic composite yarn, particularly for an elastic textile composite yarn, comprising at least two elastic performance filaments, wherein each of the at least two elastic performance filaments is capable of being stretched at least about 2 times its package length and has at least 90% up to 100% elastic recovery after having being released from a stretching 2 times its package length.

A method for making an elasticised yarn includes feeding a roving made of a cotton-based natural fibre at a weight percentage of at least 50% and having a linear mass density between 0.1 Nm and 50 Nm, to a stretching unit, and extracting it from the stretching unit at a speed higher than the unwinding speed. The stretched roving and an elastic fibre are jointly pulled through an overlapping unit, forming a spool of the elasticised yarn. The elastic fibre includes a natural rubber containing more than 80% polyisoprene 1,4-cis. The elastic fibre also includes sulphur as a vulcanization agent; a vulcanization accelerator and a vulcanization activator; an anti-tacking agent; an antioxidant agent; and a stabilisation agent. The elastic fibre is obtained by longitudinally cutting a longitudinally cut flat yarn made of the natural rubber, to attain a linear mass density between 50 dtex and 1000 dtex.

The present invention relates to make stretch yarn by using at least two roving and two elastomeric filaments with variable draft to allow the yarn made in the fabric to get good stretch, good recovery and good shrinkage. The invention is applicable for all types of fibers material and is not limited in the yarn count. The said invention yarn is woven into fabrics exhibiting the excellent stretch characteristics and functional performance for commercial application.

The present disclosure provides a ringspinning system for producing a yarn. It is provided a the ringspinning system comprising a bobbin holder for holding a bobbin from which a first filament is supplied, a drafting stage for drafting the first filament together with a second filament, which is fed to the drafting stage, and a spindle, the ringspinning system further contains at least one sensor for detecting a breakage of the first and/or second filament and/or a roving comprising the first and second filament, which roving comes out of the drafting stage, and a clamp assembly comprising a clamp for fixing the second filament in the case that the sensor detects the breakage, wherein the clamp is provided adjacent the bobbin holder. It is further provided a method for stopping the supply of filaments to a drafting stage of a ring spinning system.

A method for making an elasticised yarn (9) comprises the steps of feeding a roving (1) made of a cotton-based natural fibre at a weight percentage of at least 50% and having a linear mass density set between 0.1 Nm and 50 Nm, preferably between 0.3 Nm and 25 Nm, to a stretching unit (30), and a step of extracting it from the stretching unit (30) at a speed higher than the unwinding speed; jointly pulling the stretched roving (3) and an elastic fibre (2) through an overlapping unit (40) by a ring spinning unit (50), forming a spool (59) of the elasticised yarn, wherein the elastic fibre (2) comprises a natural rubber containing more than 80% polyisoprene 1,4-cis, along with to sulphur as a vulcanisation agent at a concentration set between 0.5% and 3.0% by weight, and along with: a vulcanization accelerator and a vulcanization activator; an anti-tacking agent; an antioxidant agent; a stabilisation agent, the elastic fibre (2) obtained by longitudinally cutting a longitudinally cut flat yarn made of the natural rubber, in such a way to attain a linear mass density between 50 dtex and 1000 dtex, preferably between 100 dtex and 800 dtex, in particular between 150 dtex and 500 dtex. This way, by the above mentioned natural rubber composition, a cotton-based elasticised yarn can be obtained that is not likely to break either when being spun, or when used to make a fabric, in particular a denim fabric. An elasticised yarn obtained this way and a fabric, in particular a denim fabric, manufactured from this yarn.

A method for producing a polyacetal fiber that presents an improved whiteness unevenness is provided. According to one embodiment, there is provided a polyacetal fiber production method that yields a polyacetal fiber using an oxymethylene copolymer having a melt index, at 190° C. under a load of 2.16 kg, of 5-60 g/10 min, wherein the production method includes taking off the polyacetal fiber from the discharge nozzle of a spinning apparatus, and drawing the taken-off polyacetal fiber. The tensile elongation E1 of the polyacetal fiber after the taking off is 20%-500%; the tensile elongation E2 of the polyacetal fiber after the drawing is 10%-100%; E1≥E2; and the single fiber thickness of the polyacetal fiber after the drawing is 0.7-5.0 denier.

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).

The present disclosure provides composite yarn, apparatus and methods preparing thereof. The composite yarn of the present disclosure includes wrapping fibers and a central yarn that is formed by a first body yarn and a second body yarn, wherein a portion of the wrapping fibers are combined with the central yarn in at least one of the following states: a first state, a portion of the wrapping fibers wrap around the first body yarn or the second body yarn; a second state, a portion of the wrapping fibers wrap around the first body yarn and the second body yarn respectively at the same time; a third state, a portion of the wrapping fibers wrap around the central yarn. The composite yarn of the present disclosure has low twist factor and high strength, which solves the problem of severe strength loss associated with low twist factors existing in conventional low-twist techniques.

A filamentary core for an elastic composite yarn, particularly for an elastic textile composite yarn, comprising at least two elastic performance filaments, wherein each of the at least two elastic performance filaments is capable of being stretched at least about 2 times its package length and has at least 90% up to 100% elastic recovery after having being released from a stretching 2 times its package length.

A filamentary core (3) for an elastic composite yarn (1), particularly for an elastic textile composite yarn, comprising at least two elastic performance filaments (11, 13), each of the at least two elastic performance filaments capable of being stretched at least about 2 times its package length and having at least 90% up to 100% elastic recovery after having being released from a stretching 2 times its package length.