Vinyon Fiber

A manufactured fiber in which the fiber-forming substance is any long chain synthetic polymer composed of at least 85% by weight of vinyl chloride units (FTC definition).

Virgin wool

Fibre from the fleece of a sheep or lamb that has riot previously been spun into yarn or felted, nor previously been incorporated into a finished product.

Virtual mass (technical textiles)

In air-supported and tension-membrane structures, the mass of air which moves with the fabric structure, and which is often much greater than the mass of fabric itself.

Viscometer

A device designed to measure the viscosity (resistance to flow) of the fluid. Many types exist from simple calibrated glass tubes to extensively instrumented on-line shear viscometers.

Viscose

The solution obtained by dissolving sodium cellulose xanthate in a dilute solution of sodium hydroxide.

Viscose (fibre) (generic name)

A manufactured fibre of cellulose obtained by the viscose process (see viscose). (See also Classification Table, p.401.)

Viscose Process

1. One of the methods of producing rayon. (Also see RAYON FIBER). 2 The chemical process used in the manufacture of cellophane. (Also see VISCOSE SOLUTION).

Viscose Rayon

One type of rayon. It is produced in far greater quantity than cuprammonium rayon the other commercial type. (Also see RAYON FIBER.)

Viscose Solution

The solution obtained by dissolving cellulose xanthate in caustic soda from which viscose filaments and cellophane are produced.

Viscosity

The internal resistance to flow of a fluid. (See also ball fall and fluidity.)
note 1: The dimensions of viscosity are ML-IT 1; the usual unit is the pascal second.
note 2: The viscosity of a dilute solution of a polymer is commonly expressed in one of the following ways:
(i) viscosity ratio; relative viscosity: The ratio of the viscosity of a solution of defined polymer concentration to the viscosity of the solvent. This value is diinensionless.
(ii) specific viscosity: The viscosity ratio less unity. This value is dimensionlcss.
(iii) limiting viscosity number; intrinsic viscosity: The value obtained by extrapolating to zero concentration a set of values obtained by dividing the specific viscosity of a solution by the concentration of polymer in the solution for a series of solutions of different low concentrations.
(iv) logarithmic viscosity number; inherent viscosity. The value obtained by dividing the natural logarithm of the viscosity ratio by the concentration for a polymer solution of defined low concentration.

Voile

A light-weight, approximately square-sett, open-textured, plain-weave fabric made from fine yams of sufficient twist to produce a round, compact thread woven one-thread-per-dent unless the number of ends pet- unit length is so high as to render this impossible (see voile yarn). Typical construction:
(i) cotton voile: 23x22; RI 5/2 x RI 5x2tex; 70 g/m2; K=9.2+8.5;
(ii) nylon voile: 40x36; 56x56dtex; 44 g/m2; K=9.5+8.5.

Voile Fabric

A sheer spun cloth that is lightweight and soft. It is usually made with cylindrical combed yarn. Voile is used for blouses children’s wear draperies bedspreads etc.

Voile varn

Single or ply yarn of sufficiently high twist to produce a round, compact, resultant yarn.

Volatile

Readily vaporized at a relatively low temperature.

Volatility

Property of having a low boiling point or temperature of sublimation at normal pressure. Likewise having a high vapor pressure at ambient conditions.