Jacquard fabric

A fabric in which a large number of warp threads, in excess of the capacity of a dobby, weave differently and therefore require a jacquard mechanism.

Jacquard harness (weaving)

The series of cords and their attachments, from the hooks of a jacquard machine downwards, that control the lifting of the warp threads.
Note: The main parts include neck cords (attached to hooks by connectors and 'V'-links in the case of double-lift jacquard machines), couplings for the main cords that pass through the comber board, wire healds and lingoes. For high speed weaving, lingoes are being replaced by elastics or springs.

Jacquard mechanism (weaving)

A shedding mechanism, attached to a loom, that gives individual control of up to several hundred warp threads and thus enables large figured designs to be produced.

Jacquard repp

A repp structure figured by allowing threads to float as a result of jacquard selection.

Jacquard selection mechanism (knitting)

Any system used to select knitting elements to produce jacquard designs.
Note 1: Originally the term referred only to jacquard punched card and harness mechanisms.
Note 2: In warp knitting the term generally refers to a device for selecting individual guides within a guide bar.

Jacquard tie (lace machines)

The arrangement of the strings used to connect the jacks (see jack (lace machines)) to the jacquard needles on furnishing and string warp machines. Two main systems are employed to obtain the most economic use of the availablejacquard capacity, each having its own particular limitations:
(i) independent or divisional tie: each upright needle controls the corresponding jack in each division across the machine width. The carriage-way pattern repeat is restricted to these divisions or sub-multiples of them;
(ii) universal tie: the majority of the upright needles control two jacks each. Each jack from one end of the machine is thus paired with the corresponding jack at the other end of the machine. A smaller number of jacks (usually one-fifth or one-seventh of the total) in the centre of the machine are controlled by individual upright needles. In making an odd number of divisions, the maximum carriage-way repeat that requires separate jack selection over its entire width is determined by the number of needles controlling individual jacks. This restriction does not apply to an even number of divisions.

Jacquard tie (weaving)

The order in which the harness cords are attached to the neck cords and their arrangement in the comber board (see jacquard harness (weaving)). The tie is known as:
(i) Norwich or London according to the position of the jacquard and harness in relation to the loom. In the Norwich tie, the harness hangs straight and the card cylinder is at right angles to the warp. In the London tie, the jacquard is placed so that the cylinder is parallel to the warp, the harness having a 90' twist. In either case, various arrangements are possible, for example: (a) single tie, in which each jacquard needle controls only one harness cord and only one warp thread, there being only one repeat of the pattern in the cloth width; (b) repeating tie, in which each jacquard needle controls several harness cords and the pattern is repeated several times across the cloth width;
(ii) centre (point) tie, in which each needle controls one warp thread in one half of the pattern repeat and one warp thread in the other, the result being that one half of the pattern is a mirror image of the other;
(iii) border tie, in which some of the jacquard needles and hooks are used to produce a design close to and parallel with the cloth selvedges, the other needles and hooks being used to produce a different design in the rest of the cloth.
Note: Mixed ties (combinations of two or more of the above) are also possible.

Jaffer

A plain-weave cotton fabric with warp and weft in different colours producing a shot effect.

Jappe

A fine plain-weave fabric woven from continuous-filament yarns (originally silk) and of approximately square construction.

Jasp'e

A fabric that has a shaded appearance created by a warp thread colour pattern. It may be woven plain or figured, and is for bedspreads or curtains.

Jasp'e carpet

Carpet having a flame-like regular pattern. It was traditionally produced by using pile yarn dipdyed in hanks to two tones of the same colour or to two different colours, in a fixed proportion of the lengths of the hanks in any one lot.

Jaspd yarn (filament)

A yarn that has the appearance of, but is not, two differently coloured yarns folded together. It is made by texturing together two continuous-filament yarns of different chemical composition, e.g., nylon and polyester, and then dyeing only one of the two components.

Jaspé

1. A fabric used for suiting draperies or upholstery characterized by a series of faint stripes formed by dark medium and light yarns of the same color. 2. A term describing carpets having a faint striped effect.

Jasper

A fabric that has a shaded appearance created by a warp thread colour pattern. It may be woven plain or figured, and is for bedspreads or curtains.

Jaw break

Failure of a specimen, during a tensile test, at the edge of the jaw or within 5mm of its edge.