Air Jet Spinning

A spinning system in which yarn is made by wrapping fibers around a core stream of fibers with compressed air. In this process the fibers are drafted to appropriate sliver size then fed to the air jet chambers where they are twisted first in one direction then in the reverse direction in a second chamber. They are stabilized after each twisting operation.

Air Jet Texturing

See TEXTURING.

Air laying

A method of forming a web or batt of staple fibres in which the fibres are dispersed into an air stream and condensed from the air stream on to a permeable cage or conveyor to form the web or batt.

Air Permeability

The porosity or the ease with which air passes through material. Air permeability determines such factors as the wind resistance of sailcloth the air resistance of parachute cloth and the efficacy of various types of air filters. It also influences the warmth or coolness of a fabric. © 2001 Celanese Acetate LLC

Air permeability test

A measure of the rate of passage of air through unit area of fabric at a specified pressure difference.

Air-,jet spinning

A system of staple-fibre spinning which utilises an air vortex to apply the twisting couple to the yarn during its formation.
Note: The air is blown through one or more nozzles inclined to the axis of the cylindrical yarn passage (see diagram 1). This generates a vortex in the passage which applies a torque to the yarn as it passes through. Two such twisting devices may be used (see diagram 2). The majority of systems using this spinning technique produce a type of fasciated yarn. (See also spinning.)

Air-gap wet spinning

The conversion of a dissolved polymer into filaments by extrusion into a coagulating liquid.
Note.. The extrusion may be directly into the coagulating liquid or through a small air-gap. In the latter case it may be known as 'dry-jet wet spinning' or 'air-gap wet spinning'

Air-jet spinning

A system of staple-fibre spinning which utilises an air vortex to apply the twisting couple to the yarn during its formation.
Note: The air is blown through one or more nozzles inclined to the axis of the cylindrical yarn passage (see diagram 1). This generates a vortex in the passage which applies a torque to the yarn as it passes through. Two such twisting devices may be used (see diagram 2). The majority of systems using this spinning technique produce a type of fasciated yarn. (See also spinning.)

Air-jet textured yarn

A continuous-filament yarn that has been processed to introduce durable crimps, coils, loops or other fine distortions along the length of the filaments.
Note 1: Most, but not all, texturing methods depend upon the thermoplastic properties of suitable manufactured fibres. The principal texturing procedures that are or have been used are:
(i) the yarn is highly twisted, thermally set and untwisted either as a process of three seperate stages (now obsolescent) or as a continuous process (false-twist texturing). In an infrequently used alternative method (sometimes known as 'trapped-twist' texturing), two yarns are continuously folded together (see fold), thermally set, then separated by unfolding;
(ii) the yarn is fed through a nip into a stuffer box The yarn may be pre-heated or the stufferbox may be heated (stiiffer-box texturing):
(iii) the yarn is injected by a plasticising jet of hot fluid (usually hot air, sometimes steam) into a texturing tube or nozzle (hot-find jet texturing);
(iv)the yarn is plasticized by a passage through a jet of hot fluid and is impacted on to a cooling surface (impact texturing);
(v) the heated yarn is passed over a knife-edge (edge crimping);
(vi) the heated yarn is passed between a pair of gear wheels or through some similar device (gear crimping);
(vii) the yarn is knitted into a fabric that is thermally-set and then unravelled (knit-deknit, KDK texturing)
(viii) the yarn is over-fed through the turbulent air stream inside ajet assembly so that entangled loops are formed in the filaments; tllis method may also be applied to non - thermoplastic yarns (air-jet texturing; air-texturing);
(ix) the yarn is composed of bicomponent fibres of asymmetric cross-section and is subjected to a hot and/or wet process whereby differential shrinkage occurs.
Note2.. Procedures (i) and (v) in Note 1 above give yarns of a generally high-stretch character. This is frequently reduced by thermally re-setting the yarn in a state where it is only partly relaxed from the fully extended condition, thus producing a stabilized yarn with the bulkiness little reduced but with a much reduced retractive power.
Note 3: Of the above procedures, only (j), (ii,) and(viii) are currently of major commercials significance; (iv), (v) and (vi) are now rarely, if ever, used.

Air-jet weaving machine

A machine used for producing fabric by weaving

Air-Laid Nonwovens

Fabrics made by an air-forming process (q.v.). The fibers are distributed by air currents to give a random orientation within the web and a fabric with isotropic properties.

Air-Supported Roof

A fabric-based roofing system that is supported and held in place by air pressure.

Air-supported structure (technical textiles)

A structure, for example a fabric roof, supported by internal air pressure.
Note: People and goods may enter and leave the enclosure through air locks. The roof may span considerably more than 200 m. An inflation pressure differential of the order of 1 % atmospheric pressure is used.

Air-textured yarn

A continuous-filament yarn that has been processed to introduce durable crimps, coils, loops or other fine distortions along the length of the filaments.
Note 1: Most, but not all, texturing methods depend upon the thermoplastic properties of suitable manufactured fibres. The principal texturing procedures that are or have been used are:
(i) the yarn is highly twisted, thermally set and untwisted either as a process of three seperate stages (now obsolescent) or as a continuous process (false-twist texturing). In an infrequently used alternative method (sometimes known as 'trapped-twist' texturing), two yarns are continuously folded together (see fold), thermally set, then separated by unfolding;
(ii) the yarn is fed through a nip into a stuffer box The yarn may be pre-heated or the stufferbox may be heated (stiiffer-box texturing):
(iii) the yarn is injected by a plasticising jet of hot fluid (usually hot air, sometimes steam) into a texturing tube or nozzle (hot-find jet texturing);
(iv)the yarn is plasticized by a passage through a jet of hot fluid and is impacted on to a cooling surface (impact texturing);
(v) the heated yarn is passed over a knife-edge (edge crimping);
(vi) the heated yarn is passed between a pair of gear wheels or through some similar device (gear crimping);
(vii) the yarn is knitted into a fabric that is thermally-set and then unravelled (knit-deknit, KDK texturing)
(viii) the yarn is over-fed through the turbulent air stream inside ajet assembly so that entangled loops are formed in the filaments; tllis method may also be applied to non - thermoplastic yarns (air-jet texturing; air-texturing);
(ix) the yarn is composed of bicomponent fibres of asymmetric cross-section and is subjected to a hot and/or wet process whereby differential shrinkage occurs.
Note2.. Procedures (i) and (v) in Note 1 above give yarns of a generally high-stretch character. This is frequently reduced by thermally re-setting the yarn in a state where it is only partly relaxed from the fully extended condition, thus producing a stabilized yarn with the bulkiness little reduced but with a much reduced retractive power.
Note 3: Of the above procedures, only (j), (ii,) and(viii) are currently of major commercials significance; (iv), (v) and (vi) are now rarely, if ever, used.

Airloop fabric, warp-knitted

A warp-knitted fabric with reverse locknit lapping movements, the yams from the back guide bar being overfed to give a short pile on the surface of the fabric.