Fallen wool

Wool taken from sheep that have died from natural causes. (See also skin wool.)

Fallen wool

Wool taken from sheep that have died from natural causes. (See also skin wool.)

Fallers

1. Straight, pinned bars employed in the control of fibres between drafting rollers.
2. Curved arms fixed to two shafts on a mule carriage and carrying the faller wires

False reed

Used in addition to an ordinary reed to keep the threads of a fibrous or high-sett warp separated. A false reed is composed of short wires with a loop at the top which are threaded on a band of wire. The wires of the false reed are passed through the warp behind the ordinary reed and divide the warp into groups of three or four threads.

False-twist direction

The direction, S or Z, of twist generated by a false-twisting device upstream of itself.

False-twist level

Real twisting necessarily involves either rotation of a yam end, as in uptwisting or in downtwisting (see ring twisting), or the repeated passage of a thread loop around an end, as in two-for-one-twisting. In false-twisting, a yarn normally runs continuously over or through a false-twisting device which may act at either a constant or varying rate. When the twisting rate is constant and equilibrium has been established, the yam passes through a zone of added twist, then on leaving the twisting device, returns to its original twist level. The added (false) twist level is equal to the ratio of the rotational and axial speeds of the yam.

False-Twist Method

This continuous method for producing textured yarns utilizes simultaneous twisting heat-setting and untwisting. The yarn is taken from the supply package and fed at controlled tension through the heating unit through a false-twist spindle or over a friction surface that is typically a stack of rotating discs called an aggregate through a set of take© 2001 Celanese Acetate LLC up rolls and onto a take-up package. The twist is set into the yarn by the action of the heater tube and subsequently is removed above the spindle or aggregate resulting in a group of filaments with the potential to form helical springs. Much higher processing speeds can be achieved with friction false twisting than with conventional spindle false twisting. Both stretch and bulked yarns can be produced by either process. Examples of false-twist textured yarns are Superloft® Flufflon® and Helanca®. (Also see TEXTURED YARNS Coil Yarn.) 4

False-twist textured yarn

Real twisting necessarily involves either rotation of a yam end, as in uptwisting or in downtwisting (see ring twisting), or the repeated passage of a thread loop around an end, as in two-for-one-twisting. In false-twisting, a yarn normally runs continuously over or through a false-twisting device which may act at either a constant or varying rate. When the twisting rate is constant and equilibrium has been established, the yam passes through a zone of added twist, then on leaving the twisting device, returns to its original twist level. The added (false) twist level is equal to the ratio of the rotational and axial speeds of the yam.

False-twisting

A twisting operation applied at an intermediate position on a yarn or other continuous assemblv of fibres, so that no net twist can be inserted, as distinct from twisting at the end of a yarn where real twist is inserted.
Note 1: Real twisting necessarily involves either rotation of a yam end, as in uptwisting or in downtwisting (see ring twisting), or the repeated passage of a thread loop around an end, as in two-for-one-twisting. In false-twisting, a yarn normally runs continuously over or through a false-twisting device which may act at either a constant or varying rate. When the twisting rate is constant and equilibrium has been established, the yam passes through a zone of added twist, then on leaving the twisting device, returns to its original twist level. The added (false) twist level is equal to the ratio of the rotational and axial speeds of the yam.
Note 2: Equilibrium false twisting is used in one method of yarn texturing where thermal setting is carried out in the zone of temporary twist; it is also used to provide temporary cohesion and thus strength in some staple-fibre processing systems. (See also pin-twisting and frictiontwisting.) The self-twist spinning (e.g., Repco) process is an example of the use of a varying false-twisting rate.
Note 3: Some devices that are usually used for false-twisting have been used to generate real twist in, for example, certain open-end spinning processes (see pin-twisting and frictiontwisting).
Note 4: Static elements such as yarn guides may, in certain circumstances, generate either equilibrium or varying false-twist in running yams.

Fancy

A wire-covered roller used for lifting fibres from the base to the top of the clothing on a swift prior to transfer to the doffer on a roller and clearer card.
Note: The clothing on the swift is usually fillet wire.

Fancy atlas fabric, warp-knitted

A warp-knitted fabric similar in construction to a single or two bar atlas fabric but in which the direction of traverse may change more than once within the repeat and the movement of the threads is not restricted to one wale per course. (See also atlas fabric, single bar and atlas)

Fancy purl

A fabric in which both back and face loops occur in some or all of the wales. The structure may be identified by the particular knitting sequence used, for example,
(i) 1 x 1 purl fabric, in which a single course of back loops alternates with a single course of face loops. 2x2 purl and 3x3 are made in a corresponding way; and
(ii) fancy purl, a general term used to describe patterned purl structures in which a design is formed from back and face loops; also known as 'links-links'

Fancy yarn

A yarn that differs from the normal construction of single and folded yarns by way of deliberately produced irregularities in its construction. These irregularities relate to an increased input of one or more of its components, or to the inclusion of periodic effects, such as knops, loops, curls, slubs, or the like.

Fasciated Yarn

Yarns consisting of a core of discontinuous fibers with little or no twist and surface fibers wrapped around the core bundle. © 2001 Celanese Acetate LLC

Fashioning

The process of shaping a fabric during knitting by increasing or decreasing the number of needles in action. Fashioning is used in manufacturing hosiery underwear and sweaters.