Raw silk

Continuous filaments or strands containing no twist, drawn off or reeled from silk cocoons.
Note.. The term raw silk is often incorrectly used to describe a silk-noil woven fabric.

Rayon (fibre)

1. (Generic name U.S.A.) A manufactured fibre composed of regenerated cellulose, as well as manufactured fibres composed of regenerated cellulose in which substituents have replaced not more than 15% of the hydrogens of the hydroxyl groups.
Note: The ISO generic names are viscose, modal, and cupro. (See also Classification Table, p.401.)
2. A term used in some manufacturing countries for any manufactured cellulose fibre, including, in some cases, fibres composed of cellulose acetate.

Rayon Fiber

A manufactured fiber composed of regenerated cellulose as well as manufactured fibers composed of regenerated cellulose in which substituents have replaced not more than 15% of the hydrogens of the hydroxyl groups (FTC definition). Rayon fibers include yarns and fibers made by the viscose process the cuprammonium process and the now obsolete nitrocellulose and saponified acetate processes. Generally in the manufacture of rayon cellulose derived from wood pulp cotton linters or other vegetable matter is dissolved into a viscose spinning solution. The solution is extruded into an acid-salt coagulating bath and drawn into continuous filaments. Groups of these filaments may be made in the form of yarns or cut into staple.

Re-breaking

The shortening of fibres in a sliver or top by a process similar in principle to stretch breaking (see Note under converting). Re-breaking may be intended to shorten a limited number of overlength fibres and/or to reduce the average length.

Re-scutched tow

Short flax fibres that are removed during the scutching or hackling processes:
(i) rug tow: short flax fibre removed during scutching and containing extraneous woody material;
(ii) re-scutched tow: short fibre which has been cleaned in a tow-scutching apparatus;
(iii) machine tow: short fibre which has been removed from scutched long flax during the hackling process.

Reach

The distance between the nips of the pairs of rollers in a roller-drafting or stretch-breaking system (see converting).
Note: Another common use of the term 'ratch' is to specify the distance between the front roller nip and the release point of the pins in a pin-drafting system.

Reach

The distance from the back heald to the back rest or back roller of a weaving machine. (See also roller-setting.)

Reaching-in

The operation of selecting individual warp threads and presenting them for drawing-in. This may be done by hand and/or by machine.

Reaction spinning (manufactured fibre production)

A process for fibre production in which polymerization is achieved during the extrusion of one set of reactants into another set of reactants.

Reactive dye

A dye that, under suitable conditions, is capable of reacting chemically with a substrate to form covalent dye-substrate linkage.

Readiness

A noticeable grouping of warp threads due to the reed wires producing warpway cracks. It can be caused by the use of areed unsuited to the fabric construction employed.

Reaming

Further plying of a two-ply yarn with a singles yarn. Reaming is not the same as plying three singles yarns in one operation.

Recommended allowance

The percentage that, in the calculation of commercial mass of textile material and of yarn linear density, is added to the oven-dry mass. The determination of this mass may or may not have been preceded by washing to remove natural or added oils and dressings. The recommended allowance is arbitrarily chosen according to commercial practice and includes the moisture regain. It may also include the normal finish that is added to impart satisfactory textile qualities to the material.

Reconstituted Fibers

Fibers made from recovered waste polymer or blends of virgin polymer and recovered waste polymer.

Recovered wool

Wool rags and manufactured waste, torn up and reprocessed into fibres again, and used for producing shoddy or mungo yarns.