Lap waste

A sheet of fibres accidentally wound round rollers or aprons, which may after removal be used as soft waste.

Lapel

The upperpart of the frontedge of a coat, dress, blouse orjacket which folds back on to the main body of the garment, from the neck down to the break.

Lappet

A fabric in which figure is achieved by introducing extra warp threads into a base fabric that is normally plain. The figuring threads are controlled by needle bar(s) between the reed and the fell, with the amount of side-traverse given to the needle bar being controlled by a pattern wheel.

Lappet

A yarn guide that forms the apex of the yarn balloon.

Lapping

A term describing the movement of yarn guides between needles at right angles to the needle bar or laterally in relation to the needle bar or laterally in relation to the needle bar during warp knitting.

Lapping movement (warp knitting)

The compound motion of the guide bars of warp-knitting machines that presents the threads to the needles so that loops can be formed. This compound motion consists in swinging motions of the guides at right angles to the needle bar, and lateral movements parallel to the needle bar.

Lapping notation (warp knitting)

A method of portraying the successive lateral movements of a guide bar or bars. These are generally shown as figures representing the distance guide bars shog sideways parallel with the needle bar as well as figures representing the heights of successive pattern chain links required to bring the guide bars to the appropriate positions. For this purpose, the movements of the bars are normally drawn on point paper as a lapping diagram.

Lase

An acronym for load at specified elongation elongation of a yarn or cord.

Laser

A device for producing an intense beam of coherent light. It is used for cutting spectroscopy photography biomedical investigations etc.

Lash

The selected ends of pile warp yarns for a complete row of carpet pile prior to the insertion of the weft yarn.

Lashed-In Filling

See PULLED-IN FILLING.

Lashed-in weft

A length of weft yarn that has been pulled inadvertently into the shed during weaving. This defect is most likely to occur:
(i) on automatic-bobbin-change looms, as a result of a length of weft yarn extending from the selvedge to the weft-change mechanism after automatic change; and
(ii) on circular-box or drop-box looms, as a result of a length of weft yarn extending from the selvedge to a stationary shuttle.

Lashing-in (defect)

A length of weft yarn that has been pulled inadvertently into the shed during weaving. This defect is most likely to occur:
(i) on automatic-bobbin-change looms, as a result of a length of weft yarn extending from the selvedge to the weft-change mechanism after automatic change; and
(ii) on circular-box or drop-box looms, as a result of a length of weft yarn extending from the selvedge to a stationary shuttle.

Lasting

A very stout, closely woven fabric made from hard-twisted yarns. A worsted lasting, usually a seven-shaft weave, is used for protective clothing in munition works. A 'cotton lasting', which may be of sateen or weft-faced twill weave, is used chiefly for shoe tops and bag linings.

Lastrile (fibre) (generic name U.S.A.)

An alternative name for some types of rubber fibre (see rubber 2). (See also Classification Table, p.401 .)