Discharge (printing)

To destroy by chemical means a dye or mordant already present on a substrate to leave a white or differently coloured design.

Discharging

The destruction by chemical means of a dye or mordant already present on a material to leave a white or differently coloured pattern.
Note: This term is also used to describe the removal of gum from silk (see degumming).

Discolored Pick

See MIXED END or FILLING.

Dispersant

A dispersing agent often of a surface active chemical that promotes formation of a dispersion or maintains a state of dispersion by preventing settling or aggregation.

Disperse dye

A substantially water-insoluble dye having substantivity for one or more hydrophobic fibres, e.g., cellulose acetate, and usually applied from fine aqueous dispersion.

Dispersion

1. A system consisting of finely divided particles and the medium in which they are distributed. 2. Separation of light into colors by diffraction or refraction. 3. A qualitative © 2001 Celanese Acetate LLC estimation of the separation and uniform distribution of fibers in the liquid during the production of a wet-formed nonwoven fabric.

Dispersion spinning

A process in which polymers that tend to an infusible, insoluble, and generally intractable character (e.g., polytetrafluoroethylene) are dispersed as fine particles in a carrier such as sodium alginate or sodium cellulose xanthate solutions, that permit extrusion into fibres, after which the dispersed polymer is caused to coalesce by a heating process, the carrier being removed either by a heating or by a dissolving process.

Dissolving pulp

A specially purified form of cellulose made from wood tissue.

Distorted thread effect

A mock-leno weave where threads can be displaced from their normal line in either the warp direction (see diagram), or the weft direction.

Distribution Length

In fibers a graphic or tabular presentation of the proportion or percentage (by number or by weight) of fibers having different lengths.

District checks

Bold distinctive woollen cheeks originally made in Scotland, usually in 2x2 twill weave.

Divided harness

A jacquard in which the odd numbered ends in a fabric are controlled by the hooks in the first length-wise or vertical rows in the jacquard, and the even numbered ends are controlled by the other rows.
Note: This type of harness is used when weaving jacquard fabrics having two distinct sets of figuring threads, e.g., double cloths figured by interchange or repps. It makes card cutting easier and simplifies fault tracing.

Divided Threadline Extrusion

Spinning of two separate threadlines from one spinneret.

Dobby

A mechanism for controlling the movement of the heald shaft of a loom. It is required when the number of heald shafts or the number of picks in a repeat of the pattern or both are beyond the capacity of tappet shedding.

Dobby fabric

Any one of a variety of fabrics or a variety of weaves which require a dobby.