Rapier Looms

Looms in which either a double or single rapier (thin metallic shaft with a yarn gripping device) carries the filament through the shed. In a single rapier machine the yarn is carried completely across the fabric by the rapier. In the double machine the yarn is passed from one rapier to the other in the middle of the shed. (Also see WEFT INSERTION.)

Raschel lace

Lace fabric produced on a raschel warp-knitting machine.

Raschel warp-knitting machine

A warp-knitting machine with one or two needle bars employing either latch or compound vertically mounted needles (see needle (machine knitting)). The fabric is supported on either one or two trickplates and is withdrawn from the knitting zone in a downward direction. (See also knitting machine.)

Rat-tail cord

A tubular woven cord usually of satin construction.

Ratch

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.

Ratch

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

Ratch

1. See reach and roller-setting.
2. A slight additional drafting of the yarn which takes place towards the end of the mule draw (cotton system).

Rate of dyeing

The rate at which a dye is absorbed by a substrate under specified conditions.te: It may be expressed quantitatively in several ways, such as the weight of dye absorbed in unit time, or the time taken for the substrate to absorb a given fraction of the amount of dye which it will absorb at equilibrium.

Ratine

Originally a thick woollen fabric with a curled nap. This term or ratine, the past participle of the French verb ratiner (meaning to cover with a curled nap), is also applied to a fabric, made from any of a variety of fibres, with a rough surface produced either by using a fancy yarn in a fabric to which a special finishing technique may be applied or by using ordinary yarns in a fabric to which the special finish is applied.

Ratiné

1. A plain-weave loosely constructed fabric having a rough spongy texture which is imparted by the use of nubby plied yarns. It is made from worsted cotton or other yarns. 2. A variant of spiral yarns in which the outer yarn is fed more freely to form loops that kink back on themselves and are held in place by a third binder yarn that is added in a second twisting operation.

Ravel

A type of comb or rail with projecting teeth for separating and guiding warp ends.

Ravel courses

Additional courses used in the manufacture of knitted articles either as protective courses or to facilitate handling in subsequent operations. These courses are afterwards removed.

Raveling

The process of undoing or separating the weave or knit of a fabric. © 2001 Celanese Acetate LLC

Ravensduck

A very heavy linen fabric in 2 x 1 twill weave, such as sailcloth.

Raw Fiber

A textile fiber in its natural state such as silk “in the gum” and cotton as it comes from the bale.